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Documents Folder Title Following special characters are not supported: \ / ? % * : | " < > Privacy Public All Members My Connections Only Me Cancel Create 000386.html 39 KB HTML - Click to view Options Copy Download Link <TITLE> [SC-04-08] Comments and Summary Further Comments on issues raised by Julius Newell by David Murphy </TITLE> pre { white-space: pre-wrap; /* css-2.1, curent FF, Opera, Safari */ } <H1>[SC-04-08] Comments and Summary Further Comments on issues raised by Julius Newell by David Murphy</H1> <B>philip newell</B> <A HREF="mailto:sc-04-08%40standards.aes.org?Subject=Re%3A%20%5BSC-04-08%5D%20Comments%20and%20Summary%20Further%20Comments%20on%20issues%0A%20raised%20by%20Julius%20Newell%20by%20David%20Murphy&In-Reply-To=%3CCAEEhACkMZ%3DvAbCs%2BXHs9LWd4cA%3DAKhrKU1%3DfuQ6p98neM%3DKERA%40mail.gmail.com%3E" TITLE="[SC-04-08] Comments and Summary Further Comments on issues raised by Julius Newell by David Murphy">philiprnewell at gmail.com </A><BR> <I>Thu Jan 19 11:25:27 EST 2017</I> <P><UL> <LI>Previous message: <A HREF="000381.html">[SC-04-08] Comments and Summary Further Comments on issues raised by Julius Newell by David Murphy </A></li> <LI>Next message: <A HREF="000382.html">[SC-04-08] Comments and Summary Further Comments on issues raised by Julius Newell by David Murphy </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#386">[ date ]</a> <a href="thread.html#386">[ thread ]</a> <a href="subject.html#386">[ subject ]</a> <a href="author.html#386">[ author ]</a> </LI> </UL> <HR> <!--beginarticle--> <PRE>And just to remind anybody in this group who is not involved with cinema sound, the unique thing about it (other than the X-curve) is that cinemas are about the only form of mass entertainment via loudspeakers where nobody is controlling either the volume or the equalisation during the entire performance. Whatever film, whatever audience, whatever time of day and whatever weather, the calibration must serve for all. Best wishes, Philip On 19 January 2017 at 09:54, John Woodgate via SC-04-08 < <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08 at standards.aes.org</A>> wrote: ><i> If we accept that we need to measure the direct sound, we can measure </I>><i> that much </I>><i> closer to the loudspeaker with a calibrated directional microphone to </I>><i> reduce </I>><i> reflections. By definition, the room does not affect the direct sound, but </I>><i> of </I>><i> course it is attenuated by distance. </I>><i> </I>><i> Having done that, we can then measure at the 2/3 point to see what </I>><i> changed, and </I>><i> perhaps why. </I>><i> </I>><i> Maybe this is over-simplified, but I'm not sure how. </I>><i> </I>><i> With best wishes DESIGN IT IN! OOO – Own Opinions Only </I>><i> www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England </I>><i> </I>><i> Sylvae in aeternum manent. </I>><i> </I>><i> -----Original Message----- </I>><i> From: SC-04-08 [mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08-bounces at standards.aes.org</A>] On Behalf Of </I>><i> david </I>><i> murphy via SC-04-08 </I>><i> Sent: Thursday, January 19, 2017 12:39 AM </I>><i> To: Brian McCarty <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">bmccarty at coralseastudios.com</A>>; Working group on </I>><i> Measurement </I>><i> and equalization of sound systems in rooms <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08 at standards.aes.org</A>>; </I>><i> Joules </I>><i> Newell <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">joules at newellacousticengineering.com</A>> </I>><i> Cc: Thomas Lagö <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">thomaslagoqirra at gmail.com</A>>; Peter Mapp < </I>><i> <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">peter at petermapp.com</A>>; </I>><i> Robinson, Charles Q <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">cqr at dolby.com</A>>; Floyd Toole <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">soundnwine at sbcglobal.net</A> </I>><i> >; </I>><i> <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">rich at xfrm.com</A> </I>><i> Subject: Re: [SC-04-08] Comments and Summary Further Comments on issues </I>><i> raised </I>><i> by Julius Newell by David Murphy </I>><i> </I>><i> Hi all, </I>><i> SMPTE 2096-1 </I>><i> </I>><i> I note Julius’s comments with interest. Certainly the length and shape of </I>><i> the </I>><i> window applied to the impulse response determines the shape of the low </I>><i> frequency </I>><i> response. To obtain a meaningful low frequency response the time window </I>><i> needs to </I>><i> be at least as long as a full cycle of the frequency concerned [Thomas, be </I>><i> gentle with me :-)] and in many rooms that time length will include </I>><i> reflections. </I>><i> Trying to disentangle the room contribution by spatial averaging is </I>><i> hopeful at </I>><i> best. </I>><i> </I>><i> The real problem is that we are trying to measure the frequency response </I>><i> of a </I>><i> loudspeaker at the other end of the room (2/3 back) and we are on a hiding </I>><i> to </I>><i> nothing. </I>><i> </I>><i> If we accept the proposition that the direct sound from a loudspeaker has </I>><i> the </I>><i> most influence on how it is perceived, ie, the ear-brain can apprise the </I>><i> sound </I>><i> quality by ‘hearing through’ the effects of the room (concrete bunkers </I>><i> excepted) </I>><i> then we need to try to measure the direct sound from the loudspeaker and </I>><i> work to </I>><i> make that as smooth as possible. Certainly the decades of research by Floyd </I>><i> Toole indicates that people can reliably distinguish small variations in </I>><i> the </I>><i> measured characteristics of the loudspeaker independently of the listening </I>><i> room. </I>><i> So, given the geometry of a typical cinema, and a spatial array of </I>><i> microphones </I>><i> around the 2/3 back region, there will be floor and ceiling reflections and </I>><i> early side wall reflections. If we have a window of 20 msecs to measure </I>><i> down to </I>><i> 50Hz, these early reflections will be evident in the tail of the impulse </I>><i> response, and create sum and difference variations in the frequency </I>><i> response. </I>><i> These will still be evident even with a spatial array of microphones </I>><i> because the </I>><i> array would be smaller than the wavelength of the low frequency. Typical </I>><i> numbers </I>><i> would be a 20 msec window to measure down to 50Hz, wavelength of which is </I>><i> ~6.9 </I>><i> metres. A time window from first arrival to 20msecs later will include </I>><i> several </I>><i> reflections, making it very difficult to ‘see’ the actual response at low </I>><i> frequencies. </I>><i> In essence, to measure the frequency response of the loudspeaker you have </I>><i> to be </I>><i> closer to it than the natural boundaries of the room (floor, ceiling, </I>><i> sidewalls), but far enough away that you comply with requirements for free </I>><i> field </I>><i> conditions. A working approximation is four times the largest dimension of </I>><i> the </I>><i> loudspeaker. Please refer to my earlier upload, showing a diagram of a </I>><i> microphone on a tall stand positioned in front of the screen but several </I>><i> metres </I>><i> back. </I>><i> Anyway, it will be interesting to see if SMPTE takes on board our comments. </I>><i> Regards to all </I>><i> David </I>><i> </I>><i> </I>><i> </I>><i> </I>><i> </I>><i> </I>><i> David Murphy </I>><i> Loudspeaker Design Engineer </I>><i> Commercial Cinema </I>><i> </I>><i> Krix </I>><i> 14 Chapman Road | Hackham SA 5163 | Australia </I>><i> T +618 83843433 | F +618 83843419 </I>><i> Email: <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">dmurphy at krix.com</A> | Web: www.krix.com </I>><i> </I>><i> </I>><i> </I>><i> DISCLAIMER: </I>><i> This email and any files transmitted with it are confidential to the </I>><i> intended </I>><i> recipient and may be privileged. If you are not the intended recipient, </I>><i> please </I>><i> notify Krix immediately. Whilst we have used software to alert us to the </I>><i> presence of computer viruses, we cannot guarantee that this email and any </I>><i> files </I>><i> transmitted with it are free from them. </I>><i> ________________________________________ </I>><i> From: SC-04-08 [<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08-bounces at standards.aes.org</A>] On Behalf Of Brian </I>><i> McCarty </I>><i> via SC-04-08 [<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08 at standards.aes.org</A>] </I>><i> Sent: Tuesday, 17 January 2017 11:11 AM </I>><i> To: Joules Newell; Worki... Expand This file was truncated for preview. Please download to view the full file. 000387.html 34 KB HTML - Click to view Options Copy Download Link <TITLE> [SC-04-08] Comments and Summary Further Comments on issues raised by Julius Newell by David Murphy </TITLE> pre { white-space: pre-wrap; /* css-2.1, curent FF, Opera, Safari */ } <H1>[SC-04-08] Comments and Summary Further Comments on issues raised by Julius Newell by David Murphy</H1> <B>david murphy</B> <A HREF="mailto:sc-04-08%40standards.aes.org?Subject=Re%3A%20%5BSC-04-08%5D%20Comments%20and%20Summary%20Further%20Comments%20on%20issues%0A%20raised%20by%20Julius%20Newell%20by%20David%20Murphy&In-Reply-To=%3CDC98EF6CF2F08F40AA5AA23B3509EDA982B8D68D9A%40KRIX-DC.Krix.local%3E" TITLE="[SC-04-08] Comments and Summary Further Comments on issues raised by Julius Newell by David Murphy">dmurphy at krix.com.au </A><BR> <I>Thu Jan 19 16:23:24 EST 2017</I> <P><UL> <LI>Previous message: <A HREF="000383.html">[SC-04-08] Comments and Summary Further Comments on issues raised by Julius Newell by David Murphy </A></li> <LI>Next message: <A HREF="000385.html">[SC-04-08] Comments and Summary Further Comments on issues raised by Julius Newell by David Murphy </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#387">[ date ]</a> <a href="thread.html#387">[ thread ]</a> <a href="subject.html#387">[ subject ]</a> <a href="author.html#387">[ author ]</a> </LI> </UL> <HR> <!--beginarticle--> <PRE>Hi all, in riposte to John Woodgate, in my experience the sound system calibration is usually done in a mad rush while they are filling the pop corn machines and people are waiting in the foyer of the brand new mullitplex. No pressure - ha! Everything takes longer and costs more - another version of Murphy's Law. So the technicians are usually pushed for time - even setting out as many as 5 microphones takes too long, never mind moving them, etc. Anyway, as Geoff Hill says, we've done our bit - over to SMPTE... Good to read all the opinions Warm regards David David Murphy Loudspeaker Design Engineer Commercial Cinema Krix 14 Chapman Road | Hackham SA 5163 | Australia T +618 83843433 | F +618 83843419 Email: <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">dmurphy at krix.com</A> | Web: www.krix.com DISCLAIMER: This email and any files transmitted with it are confidential to the intended recipient and may be privileged. If you are not the intended recipient, please notify Krix immediately. Whilst we have used software to alert us to the presence of computer viruses, we cannot guarantee that this email and any files transmitted with it are free from them. ________________________________________ From: John Woodgate [<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">jmw1937 at btinternet.com</A>] Sent: Thursday, 19 January 2017 7:24 PM To: david murphy; 'Working group on Measurement and equalization of sound systems in rooms'; 'Brian McCarty'; 'Joules Newell' Cc: 'Thomas Lagö'; 'Peter Mapp'; 'Robinson, Charles Q'; 'Floyd Toole'; <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">rich at xfrm.com</A> Subject: RE: [SC-04-08] Comments and Summary Further Comments on issues raised by Julius Newell by David Murphy If we accept that we need to measure the direct sound, we can measure that much closer to the loudspeaker with a calibrated directional microphone to reduce reflections. By definition, the room does not affect the direct sound, but of course it is attenuated by distance. Having done that, we can then measure at the 2/3 point to see what changed, and perhaps why. Maybe this is over-simplified, but I'm not sure how. With best wishes DESIGN IT IN! OOO – Own Opinions Only www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England Sylvae in aeternum manent. -----Original Message----- From: SC-04-08 [mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08-bounces at standards.aes.org</A>] On Behalf Of david murphy via SC-04-08 Sent: Thursday, January 19, 2017 12:39 AM To: Brian McCarty <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">bmccarty at coralseastudios.com</A>>; Working group on Measurement and equalization of sound systems in rooms <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08 at standards.aes.org</A>>; Joules Newell <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">joules at newellacousticengineering.com</A>> Cc: Thomas Lagö <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">thomaslagoqirra at gmail.com</A>>; Peter Mapp <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">peter at petermapp.com</A>>; Robinson, Charles Q <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">cqr at dolby.com</A>>; Floyd Toole <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">soundnwine at sbcglobal.net</A>>; <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">rich at xfrm.com</A> Subject: Re: [SC-04-08] Comments and Summary Further Comments on issues raised by Julius Newell by David Murphy Hi all, SMPTE 2096-1 I note Julius’s comments with interest. Certainly the length and shape of the window applied to the impulse response determines the shape of the low frequency response. To obtain a meaningful low frequency response the time window needs to be at least as long as a full cycle of the frequency concerned [Thomas, be gentle with me :-)] and in many rooms that time length will include reflections. Trying to disentangle the room contribution by spatial averaging is hopeful at best. The real problem is that we are trying to measure the frequency response of a loudspeaker at the other end of the room (2/3 back) and we are on a hiding to nothing. If we accept the proposition that the direct sound from a loudspeaker has the most influence on how it is perceived, ie, the ear-brain can apprise the sound quality by ‘hearing through’ the effects of the room (concrete bunkers excepted) then we need to try to measure the direct sound from the loudspeaker and work to make that as smooth as possible. Certainly the decades of research by Floyd Toole indicates that people can reliably distinguish small variations in the measured characteristics of the loudspeaker independently of the listening room. So, given the geometry of a typical cinema, and a spatial array of microphones around the 2/3 back region, there will be floor and ceiling reflections and early side wall reflections. If we have a window of 20 msecs to measure down to 50Hz, these early reflections will be evident in the tail of the impulse response, and create sum and difference variations in the frequency response. These will still be evident even with a spatial array of microphones because the array would be smaller than the wavelength of the low frequency. Typical numbers would be a 20 msec window to measure down to 50Hz, wavelength of which is ~6.9 metres. A time window from first arrival to 20msecs later will include several reflections, making it very difficult to ‘see’ the actual response at low frequencies. In essence, to measure the frequency response of the loudspeaker you have to be closer to it than the natural boundaries of the room (floor, ceiling, sidewalls), but far enough away that you comply with requirements for free field conditions. A working approximation is four times the largest dimension of the loudspeaker. Please refer to my earlier upload, showing a diagram of a microphone on a tall stand positioned in front of the screen but several metres back. Anyway, it will be interesting to see if SMPTE takes on board our comments. Regards to all David David Murphy Loudspeaker Design Engineer Commercial Cinema Krix 14 Chapman Road | Hackham SA 5163 | Australia T +618 83843433 | F +618 83843419 Email: <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">dmurphy at krix.com</A> | Web: www.krix.com DISCLAIMER: This email and any files transmitted with it are confidential to the intended recipient and may be privileged. If you are not the intended recipient, please notify Krix immediately. Whilst we have used software to alert us to the presence of computer viruses, we cannot guarantee that this email and any files transmitted with it are free from them. ________________________________________ From: SC-04-08 [<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08-bounces at standards.aes.org</A>] On Behalf Of Brian McCarty via SC-04-08 [<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08 at standards.aes.org</A>] Sent: Tuesday, 17 January 2017 11:11 AM To: Joules Newell; Working group on Measurement and equalization of sound systems in rooms Cc: Thomas Lagö; Peter Mapp; Robinson, Charles Q; Floyd Toole; <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">rich at xfrm.com</A> Subject: Re: [SC-04-08] Comments and Summary Joules; SC-04–08: These are very cogent comments, Joules. I would opine that your experience correlating the subjective results of room measurements with the measurements themselves are second to none here. With the deadline for comments back to the SMPTE approaching, I think we’ve ... Expand This file was truncated for preview. Please download to view the full file. 000388.html 4 KB HTML - Click to view Options Copy Download Link <TITLE> [SC-04-08] Comments uploaded by David Murphy </TITLE> pre { white-space: pre-wrap; /* css-2.1, curent FF, Opera, Safari */ } <H1>[SC-04-08] Comments uploaded by David Murphy</H1> <B>Richard Cabot</B> <A HREF="mailto:sc-04-08%40standards.aes.org?Subject=Re%3A%20%5BSC-04-08%5D%20Comments%20uploaded%20by%20David%20Murphy&In-Reply-To=%3C106E01DC1F8C4C8AA091BA58DB84125F%40RCC%3E" TITLE="[SC-04-08] Comments uploaded by David Murphy">rich at xfrm.com </A><BR> <I>Fri Jan 20 04:23:38 EST 2017</I> <P><UL> <LI>Previous message: <A HREF="000384.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI>Next message: <A HREF="000389.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#388">[ date ]</a> <a href="thread.html#388">[ thread ]</a> <a href="subject.html#388">[ subject ]</a> <a href="author.html#388">[ author ]</a> </LI> </UL> <HR> <!--beginarticle--> <PRE>Thomas's document has been uploaded to the document repository as x215-20170119-TLL-AES_FFT_Comments.pdf It can be found at <A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A> Rich Cabot AES Standards Secretary -----Original Message----- From: SC-04-08 [mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08-bounces at standards.aes.org</A>] On Behalf Of Thomas Lago via SC-04-08 Sent: Sunday, January 15, 2017 12:12 AM To: Joules Newell Cc: Peter Mapp; Robinson, Charles Q; Charlie Hughes via SC-04-08 Subject: Re: [SC-04-08] Comments uploaded by David Murphy Dear All, Here comes an attempt to give some more info in regards to FFT, DFT, Gauss etc. I am also covering windows in more detail. In the attached papers, I have references to more info. Feel free to ask questions and I will try to handle this as good as possible. Best regards, Dr. Thomas L. Lagö Chief Scientist & Chairman Cell Sweden: +46 708 357337 Cell USA: +1 479 571 0035 QirraSound Technologies Europe AB Slagetorp 2, 57692 Sävsjö, Sweden Manufacturing unit: QirraSound/VILAX, Tirupsvägen 9, 24593 Staffanstorp, Sweden <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">thomas.lago at qirrasound.com</A> <mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">thomas.lago at qirrasound.com</A>> www.qirrasound.se <<A HREF="http://www.qirrasound.se/">http://www.qirrasound.se/</A>> thomaslago.com <<A HREF="http://thomaslago.com/">http://thomaslago.com/</A>> _______________________________________________ SC-04-08 mailing list <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">SC-04-08 at standards.aes.org</A> <<A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A>> </PRE> <!--endarticle--> <HR> <P><UL> <!--threads--> <LI>Previous message: <A HREF="000384.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI>Next message: <A HREF="000389.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#388">[ date ]</a> <a href="thread.html#388">[ thread ]</a> <a href="subject.html#388">[ subject ]</a> <a href="author.html#388">[ author ]</a> </LI> </UL> <hr> <a href="https://secure.aes.org/mailman/listinfo/sc-04-08">More information about the SC-04-08 mailing list</a><br> Expand 000389.html 6 KB HTML - Click to view Options Copy Download Link <TITLE> [SC-04-08] Comments uploaded by David Murphy </TITLE> pre { white-space: pre-wrap; /* css-2.1, curent FF, Opera, Safari */ } <H1>[SC-04-08] Comments uploaded by David Murphy</H1> <B>Thomas Lagö</B> <A HREF="mailto:sc-04-08%40standards.aes.org?Subject=Re%3A%20%5BSC-04-08%5D%20Comments%20uploaded%20by%20David%20Murphy&In-Reply-To=%3C01B1DDCA-FE48-493C-BF69-DD76F7565F5D%40msn.com%3E" TITLE="[SC-04-08] Comments uploaded by David Murphy">thomaslagoqirra at gmail.com </A><BR> <I>Fri Jan 20 04:28:05 EST 2017</I> <P><UL> <LI>Previous message: <A HREF="000388.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI>Next message: <A HREF="000390.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#389">[ date ]</a> <a href="thread.html#389">[ thread ]</a> <a href="subject.html#389">[ subject ]</a> <a href="author.html#389">[ author ]</a> </LI> </UL> <HR> <!--beginarticle--> <PRE>Thanks! I will send another document this weekend in regards to proper FRF measurements in rooms using FFT analysis. ><i> On 20 Jan 2017, at 10:23, Richard Cabot via SC-04-08 <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08 at standards.aes.org</A>> wrote: </I>><i> </I>><i> Thomas's document has been uploaded to the document repository as </I>><i> x215-20170119-TLL-AES_FFT_Comments.pdf </I>><i> </I>><i> It can be found at <A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A> <<A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A>> </I>><i> </I>><i> Rich Cabot </I>><i> AES Standards Secretary </I>><i> </I>><i> </I>><i> -----Original Message----- </I>><i> From: SC-04-08 [mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08-bounces at standards.aes.org</A> <mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08-bounces at standards.aes.org</A>>] On Behalf Of </I>><i> Thomas Lago via SC-04-08 </I>><i> Sent: Sunday, January 15, 2017 12:12 AM </I>><i> To: Joules Newell </I>><i> Cc: Peter Mapp; Robinson, Charles Q; Charlie Hughes via SC-04-08 </I>><i> Subject: Re: [SC-04-08] Comments uploaded by David Murphy </I>><i> </I>><i> Dear All, </I>><i> </I>><i> Here comes an attempt to give some more info in regards to FFT, DFT, Gauss </I>><i> etc. I am also covering windows in more detail. In the attached papers, I </I>><i> have references to more info. Feel free to ask questions and I will try to </I>><i> handle this as good as possible. </I>><i> </I>><i> Best regards, </I>><i> Dr. Thomas L. Lagö </I>><i> Chief Scientist & Chairman </I>><i> Cell Sweden: +46 708 357337 </I>><i> Cell USA: +1 479 571 0035 </I>><i> </I>><i> QirraSound Technologies Europe AB </I>><i> Slagetorp 2, 57692 Sävsjö, Sweden </I>><i> Manufacturing unit: QirraSound/VILAX, Tirupsvägen 9, 24593 Staffanstorp, </I>><i> Sweden </I>><i> <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">thomas.lago at qirrasound.com</A> <mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">thomas.lago at qirrasound.com</A>> <mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">thomas.lago at qirrasound.com</A> <mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">thomas.lago at qirrasound.com</A>>> </I>><i> www.qirrasound.se <<A HREF="http://www.qirrasound.se/">http://www.qirrasound.se/</A>> <<A HREF="http://www.qirrasound.se/">http://www.qirrasound.se/</A> <<A HREF="http://www.qirrasound.se/">http://www.qirrasound.se/</A>>> </I>><i> thomaslago.com <<A HREF="http://thomaslago.com/">http://thomaslago.com/</A>> <<A HREF="http://thomaslago.com/">http://thomaslago.com/</A> <<A HREF="http://thomaslago.com/">http://thomaslago.com/</A>>> </I>><i> </I>><i> _______________________________________________ </I>><i> SC-04-08 mailing list </I>><i> <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">SC-04-08 at standards.aes.org</A> <mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">SC-04-08 at standards.aes.org</A>> </I>><i> <<A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A> <<A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A>>> </I>><i> </I>><i> _______________________________________________ </I>><i> SC-04-08 mailing list </I>><i> <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">SC-04-08 at standards.aes.org</A> <mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">SC-04-08 at standards.aes.org</A>> </I>><i> <<A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A> <<A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A>>> </I> </PRE> <!--endarticle--> <HR> <P><UL> <!--threads--> <LI>Previous message: <A HREF="000388.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI>Next message: <A HREF="000390.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#389">[ date ]</a> <a href="thread.html#389">[ thread ]</a> <a href="subject.html#389">[ subject ]</a> <a href="author.html#389">[ author ]</a> </LI> </UL> <hr> <a href="https://secure.aes.org/mailman/listinfo/sc-04-08">More information about the SC-04-08 mailing list</a><br> Expand 000390.html 5 KB HTML - Click to view Options Copy Download Link <TITLE> [SC-04-08] Comments uploaded by David Murphy </TITLE> pre { white-space: pre-wrap; /* css-2.1, curent FF, Opera, Safari */ } <H1>[SC-04-08] Comments uploaded by David Murphy</H1> <B>John Woodgate</B> <A HREF="mailto:sc-04-08%40standards.aes.org?Subject=Re%3A%20%5BSC-04-08%5D%20Comments%20uploaded%20by%20David%20Murphy&In-Reply-To=%3C042e01d27301%241b76fcb0%245264f610%24%40btinternet.com%3E" TITLE="[SC-04-08] Comments uploaded by David Murphy">jmw1937 at btinternet.com </A><BR> <I>Fri Jan 20 04:39:33 EST 2017</I> <P><UL> <LI>Previous message: <A HREF="000389.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI>Next message: <A HREF="000391.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#390">[ date ]</a> <a href="thread.html#390">[ thread ]</a> <a href="subject.html#390">[ subject ]</a> <a href="author.html#390">[ author ]</a> </LI> </UL> <HR> <!--beginarticle--> <PRE>I'm locked out. My password was rejected, so I went through the process of setting a new one. That is rejected as well. This changeover has been very badly managed indeed. Why were we not forewarned? Why aren't we give the option of seeing our password entry in clear instead of those damned dots? Most sensible web sites allow this. With best wishes DESIGN IT IN! OOO – Own Opinions Only www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England Sylvae in aeternum manent. -----Original Message----- From: SC-04-08 [mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08-bounces at standards.aes.org</A>] On Behalf Of Richard Cabot via SC-04-08 Sent: Friday, January 20, 2017 9:24 AM To: 'Working group on Measurement and equalization of sound systems inrooms' <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08 at standards.aes.org</A>> Subject: Re: [SC-04-08] Comments uploaded by David Murphy Thomas's document has been uploaded to the document repository as x215-20170119-TLL-AES_FFT_Comments.pdf It can be found at <A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A> Rich Cabot AES Standards Secretary -----Original Message----- From: SC-04-08 [mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08-bounces at standards.aes.org</A>] On Behalf Of Thomas Lago via SC-04-08 Sent: Sunday, January 15, 2017 12:12 AM To: Joules Newell Cc: Peter Mapp; Robinson, Charles Q; Charlie Hughes via SC-04-08 Subject: Re: [SC-04-08] Comments uploaded by David Murphy Dear All, Here comes an attempt to give some more info in regards to FFT, DFT, Gauss etc. I am also covering windows in more detail. In the attached papers, I have references to more info. Feel free to ask questions and I will try to handle this as good as possible. Best regards, Dr. Thomas L. Lagö Chief Scientist & Chairman Cell Sweden: +46 708 357337 Cell USA: +1 479 571 0035 QirraSound Technologies Europe AB Slagetorp 2, 57692 Sävsjö, Sweden Manufacturing unit: QirraSound/VILAX, Tirupsvägen 9, 24593 Staffanstorp, Sweden <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">thomas.lago at qirrasound.com</A> <mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">thomas.lago at qirrasound.com</A>> www.qirrasound.se <<A HREF="http://www.qirrasound.se/">http://www.qirrasound.se/</A>> thomaslago.com <<A HREF="http://thomaslago.com/">http://thomaslago.com/</A>> _______________________________________________ SC-04-08 mailing list <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">SC-04-08 at standards.aes.org</A> <<A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A>> _______________________________________________ SC-04-08 mailing list <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">SC-04-08 at standards.aes.org</A> <<A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A>> </PRE> <!--endarticle--> <HR> <P><UL> <!--threads--> <LI>Previous message: <A HREF="000389.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI>Next message: <A HREF="000391.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#390">[ date ]</a> <a href="thread.html#390">[ thread ]</a> <a href="subject.html#390">[ subject ]</a> <a href="author.html#390">[ author ]</a> </LI> </UL> <hr> <a href="https://secure.aes.org/mailman/listinfo/sc-04-08">More information about the SC-04-08 mailing list</a><br> Expand 000391.html 7 KB HTML - Click to view Options Copy Download Link <TITLE> [SC-04-08] Comments uploaded by David Murphy </TITLE> pre { white-space: pre-wrap; /* css-2.1, curent FF, Opera, Safari */ } <H1>[SC-04-08] Comments uploaded by David Murphy</H1> <B>philip newell</B> <A HREF="mailto:sc-04-08%40standards.aes.org?Subject=Re%3A%20%5BSC-04-08%5D%20Comments%20uploaded%20by%20David%20Murphy&In-Reply-To=%3CCAEEhACnuJEn_ivn3Jq8qHhbkFy_FJx_yY3rozsGsUtJU_eqmUA%40mail.gmail.com%3E" TITLE="[SC-04-08] Comments uploaded by David Murphy">philiprnewell at gmail.com </A><BR> <I>Fri Jan 20 05:09:33 EST 2017</I> <P><UL> <LI>Previous message: <A HREF="000390.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI>Next message: <A HREF="000393.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#391">[ date ]</a> <a href="thread.html#391">[ thread ]</a> <a href="subject.html#391">[ subject ]</a> <a href="author.html#391">[ author ]</a> </LI> </UL> <HR> <!--beginarticle--> <PRE>As I mentioned last week, I have also been locked out for a couple of weeks. I wrote to the Webmaster but he can't help. Some people have suggested that perhaps I don't have a new-enough version of Windows for the new website (which they are up-dating). Philip On 20 January 2017 at 10:39, John Woodgate via SC-04-08 < <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08 at standards.aes.org</A>> wrote: ><i> I'm locked out. My password was rejected, so I went through the process of </I>><i> setting a new one. That is rejected as well. </I>><i> </I>><i> This changeover has been very badly managed indeed. Why were we not </I>><i> forewarned? </I>><i> Why aren't we give the option of seeing our password entry in clear </I>><i> instead of </I>><i> those damned dots? Most sensible web sites allow this. </I>><i> </I>><i> With best wishes DESIGN IT IN! OOO – Own Opinions Only </I>><i> www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England </I>><i> </I>><i> Sylvae in aeternum manent. </I>><i> </I>><i> </I>><i> -----Original Message----- </I>><i> From: SC-04-08 [mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08-bounces at standards.aes.org</A>] On Behalf Of </I>><i> Richard </I>><i> Cabot via SC-04-08 </I>><i> Sent: Friday, January 20, 2017 9:24 AM </I>><i> To: 'Working group on Measurement and equalization of sound systems </I>><i> inrooms' </I>><i> <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08 at standards.aes.org</A>> </I>><i> Subject: Re: [SC-04-08] Comments uploaded by David Murphy </I>><i> </I>><i> Thomas's document has been uploaded to the document repository as </I>><i> x215-20170119-TLL-AES_FFT_Comments.pdf </I>><i> </I>><i> It can be found at <A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A> </I>><i> </I>><i> Rich Cabot </I>><i> AES Standards Secretary </I>><i> </I>><i> </I>><i> -----Original Message----- </I>><i> From: SC-04-08 [mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08-bounces at standards.aes.org</A>] On Behalf Of </I>><i> Thomas Lago via SC-04-08 </I>><i> Sent: Sunday, January 15, 2017 12:12 AM </I>><i> To: Joules Newell </I>><i> Cc: Peter Mapp; Robinson, Charles Q; Charlie Hughes via SC-04-08 </I>><i> Subject: Re: [SC-04-08] Comments uploaded by David Murphy </I>><i> </I>><i> Dear All, </I>><i> </I>><i> Here comes an attempt to give some more info in regards to FFT, DFT, Gauss </I>><i> etc. I am also covering windows in more detail. In the attached papers, I </I>><i> have references to more info. Feel free to ask questions and I will try to </I>><i> handle this as good as possible. </I>><i> </I>><i> Best regards, </I>><i> Dr. Thomas L. Lagö </I>><i> Chief Scientist & Chairman </I>><i> Cell Sweden: +46 708 357337 </I>><i> Cell USA: +1 479 571 0035 </I>><i> </I>><i> QirraSound Technologies Europe AB </I>><i> Slagetorp 2, 57692 Sävsjö, Sweden </I>><i> Manufacturing unit: QirraSound/VILAX, Tirupsvägen 9, 24593 Staffanstorp, </I>><i> Sweden </I>><i> <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">thomas.lago at qirrasound.com</A> <mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">thomas.lago at qirrasound.com</A>> </I>><i> www.qirrasound.se <<A HREF="http://www.qirrasound.se/">http://www.qirrasound.se/</A>> </I>><i> thomaslago.com <<A HREF="http://thomaslago.com/">http://thomaslago.com/</A>> </I>><i> </I>><i> _______________________________________________ </I>><i> SC-04-08 mailing list </I>><i> <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">SC-04-08 at standards.aes.org</A> </I>><i> <<A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A>> </I>><i> </I>><i> _______________________________________________ </I>><i> SC-04-08 mailing list </I>><i> <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">SC-04-08 at standards.aes.org</A> </I>><i> <<A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A>> </I>><i> </I>><i> _______________________________________________ </I>><i> SC-04-08 mailing list </I>><i> <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">SC-04-08 at standards.aes.org</A> </I>><i> <<A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A>> </I>><i> </I></PRE> <!--endarticle--> <HR> <P><UL> <!--threads--> <LI>Previous message: <A HREF="000390.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI>Next message: <A HREF="000393.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#391">[ date ]</a> <a href="thread.html#391">[ thread ]</a> <a href="subject.html#391">[ subject ]</a> <a href="author.html#391">[ author ]</a> </LI> </UL> <hr> <a href="https://secure.aes.org/mailman/listinfo/sc-04-08">More information about the SC-04-08 mailing list</a><br> Expand 000392.html 3 KB HTML - Click to view Options Copy Download Link <TITLE> [SC-04-08] Moving mic again </TITLE> pre { white-space: pre-wrap; /* css-2.1, curent FF, Opera, Safari */ } <H1>[SC-04-08] Moving mic again</H1> <B>Jean-Luc Ohl</B> <A HREF="mailto:sc-04-08%40standards.aes.org?Subject=Re%3A%20%5BSC-04-08%5D%20Moving%20mic%20again&In-Reply-To=%3C0820b7d5-9c15-675a-2a27-aa524aa7ce6d%40ohl.to%3E" TITLE="[SC-04-08] Moving mic again">jl at ohl.to </A><BR> <I>Fri Jan 20 05:19:44 EST 2017</I> <P><UL> <LI>Previous message: <A HREF="000405.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI>Next message: <A HREF="000394.html">[SC-04-08] Moving mic again </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#392">[ date ]</a> <a href="thread.html#392">[ thread ]</a> <a href="subject.html#392">[ subject ]</a> <a href="author.html#392">[ author ]</a> </LI> </UL> <HR> <!--beginarticle--> <PRE>Dear all, "in my experience the sound system calibration is usually done in a mad rush" I already proposed last year to check the manual scaning method (moving microphone) and I insist because : - it takes less time - it will be adopted by some acoustics standards (ISO,...) because of accuracy and reliability - it costs less : only one mic and preamp, and only one calibration to pay every year Please read the papers I just <A HREF="//secure.aes.org/standards/documents/?ID=91&file=%2Fmoving%2Dmic%2Ezip&filesize=14880118">uploadedhttps://secure.aes.org/standards/documents/?ID=91&file=%2Fmoving%2Dmic%2Ezip&filesize=14880118</A> It is not a power response measurement, the obtained curves are near Predicted In Room (see Olive and Toole). It does not give IR nor phase but the amplitude curve is the most important one especially if you are in a rush ! There is no commercial software optimised yet for this method, but it is very easy to use : record the 20 or 30 seconds of pink noise played while you move the mic and use an averaging analyser Cheers Jean-Luc </PRE> <!--endarticle--> <HR> <P><UL> <!--threads--> <LI>Previous message: <A HREF="000405.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI>Next message: <A HREF="000394.html">[SC-04-08] Moving mic again </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#392">[ date ]</a> <a href="thread.html#392">[ thread ]</a> <a href="subject.html#392">[ subject ]</a> <a href="author.html#392">[ author ]</a> </LI> </UL> <hr> <a href="https://secure.aes.org/mailman/listinfo/sc-04-08">More information about the SC-04-08 mailing list</a><br> Expand 000393.html 5 KB HTML - Click to view Options Copy Download Link <TITLE> [SC-04-08] Comments uploaded by David Murphy </TITLE> pre { white-space: pre-wrap; /* css-2.1, curent FF, Opera, Safari */ } <H1>[SC-04-08] Comments uploaded by David Murphy</H1> <B>John Woodgate</B> <A HREF="mailto:sc-04-08%40standards.aes.org?Subject=Re%3A%20%5BSC-04-08%5D%20Comments%20uploaded%20by%20David%20Murphy&In-Reply-To=%3C045f01d27309%24fbe933f0%24f3bb9bd0%24%40btinternet.com%3E" TITLE="[SC-04-08] Comments uploaded by David Murphy">jmw1937 at btinternet.com </A><BR> <I>Fri Jan 20 05:43:06 EST 2017</I> <P><UL> <LI>Previous message: <A HREF="000391.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI>Next message: <A HREF="000403.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#393">[ date ]</a> <a href="thread.html#393">[ thread ]</a> <a href="subject.html#393">[ subject ]</a> <a href="author.html#393">[ author ]</a> </LI> </UL> <HR> <!--beginarticle--> <PRE>I now can log in. The new system allocated me a different email address from the one I used to log in previously. I am puzzled by this sentence in Prof. Lagõ's document: The block length must be 2^N and that is not the case for the FFT. Should that last be 'DFT'? With best wishes DESIGN IT IN! OOO – Own Opinions Only www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England Sylvae in aeternum manent. -----Original Message----- From: SC-04-08 [mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08-bounces at standards.aes.org</A>] On Behalf Of Richard Cabot via SC-04-08 Sent: Friday, January 20, 2017 9:24 AM To: 'Working group on Measurement and equalization of sound systems inrooms' <<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08 at standards.aes.org</A>> Subject: Re: [SC-04-08] Comments uploaded by David Murphy Thomas's document has been uploaded to the document repository as x215-20170119-TLL-AES_FFT_Comments.pdf It can be found at <A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A> Rich Cabot AES Standards Secretary -----Original Message----- From: SC-04-08 [mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08-bounces at standards.aes.org</A>] On Behalf Of Thomas Lago via SC-04-08 Sent: Sunday, January 15, 2017 12:12 AM To: Joules Newell Cc: Peter Mapp; Robinson, Charles Q; Charlie Hughes via SC-04-08 Subject: Re: [SC-04-08] Comments uploaded by David Murphy Dear All, Here comes an attempt to give some more info in regards to FFT, DFT, Gauss etc. I am also covering windows in more detail. In the attached papers, I have references to more info. Feel free to ask questions and I will try to handle this as good as possible. Best regards, Dr. Thomas L. Lagö Chief Scientist & Chairman Cell Sweden: +46 708 357337 Cell USA: +1 479 571 0035 QirraSound Technologies Europe AB Slagetorp 2, 57692 Sävsjö, Sweden Manufacturing unit: QirraSound/VILAX, Tirupsvägen 9, 24593 Staffanstorp, Sweden <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">thomas.lago at qirrasound.com</A> <mailto:<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">thomas.lago at qirrasound.com</A>> www.qirrasound.se <<A HREF="http://www.qirrasound.se/">http://www.qirrasound.se/</A>> thomaslago.com <<A HREF="http://thomaslago.com/">http://thomaslago.com/</A>> _______________________________________________ SC-04-08 mailing list <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">SC-04-08 at standards.aes.org</A> <<A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A>> _______________________________________________ SC-04-08 mailing list <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">SC-04-08 at standards.aes.org</A> <<A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A>> </PRE> <!--endarticle--> <HR> <P><UL> <!--threads--> <LI>Previous message: <A HREF="000391.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI>Next message: <A HREF="000403.html">[SC-04-08] Comments uploaded by David Murphy </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#393">[ date ]</a> <a href="thread.html#393">[ thread ]</a> <a href="subject.html#393">[ subject ]</a> <a href="author.html#393">[ author ]</a> </LI> </UL> <hr> <a href="https://secure.aes.org/mailman/listinfo/sc-04-08">More information about the SC-04-08 mailing list</a><br> Expand 000394.html 6 KB HTML - Click to view Options Copy Download Link <TITLE> [SC-04-08] Moving mic again </TITLE> pre { white-space: pre-wrap; /* css-2.1, curent FF, Opera, Safari */ } <H1>[SC-04-08] Moving mic again</H1> <B>david murphy</B> <A HREF="mailto:sc-04-08%40standards.aes.org?Subject=Re%3A%20%5BSC-04-08%5D%20Moving%20mic%20again&In-Reply-To=%3CDC98EF6CF2F08F40AA5AA23B3509EDA982B8D68D9B%40KRIX-DC.Krix.local%3E" TITLE="[SC-04-08] Moving mic again">dmurphy at krix.com.au </A><BR> <I>Fri Jan 20 06:49:03 EST 2017</I> <P><UL> <LI>Previous message: <A HREF="000392.html">[SC-04-08] Moving mic again </A></li> <LI>Next message: <A HREF="000395.html">[SC-04-08] Moving mic again </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#394">[ date ]</a> <a href="thread.html#394">[ thread ]</a> <a href="subject.html#394">[ subject ]</a> <a href="author.html#394">[ author ]</a> </LI> </UL> <HR> <!--beginarticle--> <PRE>HI all, I can see a bit of confusion here! When John Woodgate said moving microphone I took that to mean that the microphone was placed in a position near the source (screen) and measurements taken at that position in space. Then it was moved to the 2/3 back position (time consuming) and other measurements were taken at that position ie, microphone also didn't 'move'. I didn't intend using a continuous signal and moving while measuring, with the test system presumably making repeated measurements ie periodically sampling the frequency response. I have encountered the technique before, and I s'pose it could give reasonably consistent results. I speed read one of the papers in the zipped upload, in which there was some diagrams showing a humanoid waving the microphone at arms length, and also waving it around on a short stick. An interesting concept for cinemas. I wonder how big a stick you would need in order to get consistent results for the LFE, especially in the 30Hz region, wavelength ~11.5 metres, ~37.5 feet. To avoid a null I would think you would have to move over a range of at least 1/2 wavelength. Anyway, the deadline time is fast approaching. I hope Mark and Richard can suitably condense our AES comments and send them to SMPTE before their deadline. It seems to me there are two issues: 1) what technology /techniques you need in order to adjust to a consistent frequency response across a wide range of cinema (room) sizes and shapes and 'reverberation' times. 2) what is the desired target frequency response - the X Curve, a modification thereof, a simple 'flat' response, or a gradually shelving response from lower frequencies to higher frequencies, as suggested by Floyd Toole. regards and thanks David David Murphy Loudspeaker Design Engineer Commercial Cinema Krix 14 Chapman Road | Hackham SA 5163 | Australia T +618 83843433 | F +618 83843419 Email: <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">dmurphy at krix.com</A> | Web: www.krix.com DISCLAIMER: This email and any files transmitted with it are confidential to the intended recipient and may be privileged. If you are not the intended recipient, please notify Krix immediately. Whilst we have used software to alert us to the presence of computer viruses, we cannot guarantee that this email and any files transmitted with it are free from them. ________________________________________ From: SC-04-08 [<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08-bounces at standards.aes.org</A>] On Behalf Of Jean-Luc Ohl via SC-04-08 [<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08 at standards.aes.org</A>] Sent: Friday, 20 January 2017 8:49 PM To: Working group on Measurement and equalization of sound systems in rooms Subject: [SC-04-08] Moving mic again Dear all, "in my experience the sound system calibration is usually done in a mad rush" I already proposed last year to check the manual scaning method (moving microphone) and I insist because : - it takes less time - it will be adopted by some acoustics standards (ISO,...) because of accuracy and reliability - it costs less : only one mic and preamp, and only one calibration to pay every year Please read the papers I just <A HREF="//secure.aes.org/standards/documents/?ID=91&file=%2Fmoving%2Dmic%2Ezip&filesize=14880118">uploadedhttps://secure.aes.org/standards/documents/?ID=91&file=%2Fmoving%2Dmic%2Ezip&filesize=14880118</A> It is not a power response measurement, the obtained curves are near Predicted In Room (see Olive and Toole). It does not give IR nor phase but the amplitude curve is the most important one especially if you are in a rush ! There is no commercial software optimised yet for this method, but it is very easy to use : record the 20 or 30 seconds of pink noise played while you move the mic and use an averaging analyser Cheers Jean-Luc _______________________________________________ SC-04-08 mailing list <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">SC-04-08 at standards.aes.org</A> <<A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A>> </PRE> <!--endarticle--> <HR> <P><UL> <!--threads--> <LI>Previous message: <A HREF="000392.html">[SC-04-08] Moving mic again </A></li> <LI>Next message: <A HREF="000395.html">[SC-04-08] Moving mic again </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#394">[ date ]</a> <a href="thread.html#394">[ thread ]</a> <a href="subject.html#394">[ subject ]</a> <a href="author.html#394">[ author ]</a> </LI> </UL> <hr> <a href="https://secure.aes.org/mailman/listinfo/sc-04-08">More information about the SC-04-08 mailing list</a><br> Expand 000395.html 8 KB HTML - Click to view Options Copy Download Link <TITLE> [SC-04-08] Moving mic again </TITLE> pre { white-space: pre-wrap; /* css-2.1, curent FF, Opera, Safari */ } <H1>[SC-04-08] Moving mic again</H1> <B>Ram@rns.co.in</B> <A HREF="mailto:sc-04-08%40standards.aes.org?Subject=Re%3A%20%5BSC-04-08%5D%20Moving%20mic%20again&In-Reply-To=%3C9DC2CC354954453DA4771D8A50B661A6%40DESKTOPB7GPSS4%3E" TITLE="[SC-04-08] Moving mic again">ram at rns.co.in </A><BR> <I>Fri Jan 20 08:31:21 EST 2017</I> <P><UL> <LI>Previous message: <A HREF="000394.html">[SC-04-08] Moving mic again </A></li> <LI>Next message: <A HREF="000396.html">[SC-04-08] Moving mic again </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#395">[ date ]</a> <a href="thread.html#395">[ thread ]</a> <a href="subject.html#395">[ subject ]</a> <a href="author.html#395">[ author ]</a> </LI> </UL> <HR> <!--beginarticle--> <PRE>Hi All, When the microphone is moved from front to back we normally encounter anomalies in the LF region caused by floor dips and boundary encounters. In the Mid and High frequency crossover region, in most cases there will be dips caused by displaced drivers. IMHO non of this can be solved by averaging. As far as Mid and High frequencies are concerned, say from 1kHz to 20kHz it may be preferable to measure the direct arrival in the prime position usually 2/3 and equalize and correct signal arrival times for the best results. On the left and right sides(off axis) of the cinema the frequency response anomalies in the Mid-High section arises due to directivity problems. This again may not be made better by averaging and equalization. Precise loudspeaker polar data helps. LF sections are mostly flat from 30Hz to 125Hz when close miked. All the problems start with the room interaction. Here averaging and equalizing and balancing with Mid-High section has been a exercise in trial and error in most cases. Experience counts. I would look forward to experts comments on the above. Thanks and regards, Ram -----Original Message----- From: david murphy via SC-04-08 Sent: Friday, January 20, 2017 5:19 PM To: Jean-Luc Ohl ; Working group on Measurement and equalization ofsound systems in rooms Subject: Re: [SC-04-08] Moving mic again HI all, I can see a bit of confusion here! When John Woodgate said moving microphone I took that to mean that the microphone was placed in a position near the source (screen) and measurements taken at that position in space. Then it was moved to the 2/3 back position (time consuming) and other measurements were taken at that position ie, microphone also didn't 'move'. I didn't intend using a continuous signal and moving while measuring, with the test system presumably making repeated measurements ie periodically sampling the frequency response. I have encountered the technique before, and I s'pose it could give reasonably consistent results. I speed read one of the papers in the zipped upload, in which there was some diagrams showing a humanoid waving the microphone at arms length, and also waving it around on a short stick. An interesting concept for cinemas. I wonder how big a stick you would need in order to get consistent results for the LFE, especially in the 30Hz region, wavelength ~11.5 metres, ~37.5 feet. To avoid a null I would think you would have to move over a range of at least 1/2 wavelength. Anyway, the deadline time is fast approaching. I hope Mark and Richard can suitably condense our AES comments and send them to SMPTE before their deadline. It seems to me there are two issues: 1) what technology /techniques you need in order to adjust to a consistent frequency response across a wide range of cinema (room) sizes and shapes and 'reverberation' times. 2) what is the desired target frequency response - the X Curve, a modification thereof, a simple 'flat' response, or a gradually shelving response from lower frequencies to higher frequencies, as suggested by Floyd Toole. regards and thanks David David Murphy Loudspeaker Design Engineer Commercial Cinema Krix 14 Chapman Road | Hackham SA 5163 | Australia T +618 83843433 | F +618 83843419 Email: <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">dmurphy at krix.com</A> | Web: www.krix.com DISCLAIMER: This email and any files transmitted with it are confidential to the intended recipient and may be privileged. If you are not the intended recipient, please notify Krix immediately. Whilst we have used software to alert us to the presence of computer viruses, we cannot guarantee that this email and any files transmitted with it are free from them. ________________________________________ From: SC-04-08 [<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08-bounces at standards.aes.org</A>] On Behalf Of Jean-Luc Ohl via SC-04-08 [<A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">sc-04-08 at standards.aes.org</A>] Sent: Friday, 20 January 2017 8:49 PM To: Working group on Measurement and equalization of sound systems in rooms Subject: [SC-04-08] Moving mic again Dear all, "in my experience the sound system calibration is usually done in a mad rush" I already proposed last year to check the manual scaning method (moving microphone) and I insist because : - it takes less time - it will be adopted by some acoustics standards (ISO,...) because of accuracy and reliability - it costs less : only one mic and preamp, and only one calibration to pay every year Please read the papers I just <A HREF="//secure.aes.org/standards/documents/?ID=91&file=%2Fmoving%2Dmic%2Ezip&filesize=14880118">uploadedhttps://secure.aes.org/standards/documents/?ID=91&file=%2Fmoving%2Dmic%2Ezip&filesize=14880118</A> It is not a power response measurement, the obtained curves are near Predicted In Room (see Olive and Toole). It does not give IR nor phase but the amplitude curve is the most important one especially if you are in a rush ! There is no commercial software optimised yet for this method, but it is very easy to use : record the 20 or 30 seconds of pink noise played while you move the mic and use an averaging analyser Cheers Jean-Luc _______________________________________________ SC-04-08 mailing list <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">SC-04-08 at standards.aes.org</A> <<A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A>> _______________________________________________ SC-04-08 mailing list <A HREF="https://secure.aes.org/mailman/listinfo/sc-04-08">SC-04-08 at standards.aes.org</A> <<A HREF="http://standards.aes.org/sc.cfm?ID=91">http://standards.aes.org/sc.cfm?ID=91</A>> --- This email has been checked for viruses by Avast antivirus software. <A HREF="https://www.avast.com/antivirus">https://www.avast.com/antivirus</A> </PRE> <!--endarticle--> <HR> <P><UL> <!--threads--> <LI>Previous message: <A HREF="000394.html">[SC-04-08] Moving mic again </A></li> <LI>Next message: <A HREF="000396.html">[SC-04-08] Moving mic again </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#395">[ date ]</a> <a href="thread.html#395">[ thread ]</a> <a href="subject.html#395">[ subject ]</a> <a href="author.html#395">[ author ]</a> </LI> </UL> <hr> <a href="https://secure.aes.org/mailman/listinfo/sc-04-08">More information about the SC-04-08 mailing list</a><br> Expand 0 Comments Public All Members My Connections Only Me PublicAll MembersMy ConnectionsOnly Me Public All Members My Connections Only Me
