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[minister]

So when I asked,

minister wrote on Fri, 12 February 2010 22:15

Andrew Hamilton wrote on Fri, 12 February 2010 21:32 [...electrically, rather than one which is mixed only acoustically (in the air).  The two domains are identical in many respects.  Two identically amplified, correlated signals sum to just over +6.02 dBSPL, for example (not +3). How do two correlated signals acoustically sum to such a uniformity in any thing but maybe an anechoic chamber?

You said :

Geoff Emerick de Fake wrote on Sat, 13 February 2010 05:54

Although I don't agree at all with andrew about the audibility of temporal displacement, I agree with the fact that two acoustic signals may combine at +6.02dB, even in a non-anechoic environment, provided the acoustic paths are strictly identical.

But now when somebody sites a room where it happened:

minister wrote on Fri, 19 February 2010 09:24

Greg Reierson wrote on Tue, 16 February 2010 19:52 minister wrote on Tue, 16 February 2010 19:36 In theory, I can understand the idea.  In practice, is there such a room? Glenn Meadows said mono would sum +6dB in his Hidley room, and he's not one to joke about that sort of thing, but it always sounded like a stretch. Anything less and it ain't gonna happen. GR That's pretty good.  Must be very hard to achieve!

You said:

Geoff Emerick de Fake wrote on Fri, 19 February 2010 16:17

Although perfect +6.02dB acoustic summing is inachievable in the real world, it doesn't take much to achieve 5dB+. Just good symmetry.

Which is it?

Again, I don't fully understand these things, but I have a vague grasp.  I suspected that it was only theoretically possible for perfect summing which is why I asked the question and why I question the correlation of acoustic to electrical summing.  It is easy to see how hard it would be to achieve a perfect sum.

As to the other stuff, I have no idea what Andrew is talking about.  Then again, there are many things I don't understand.

[Laarsø]

DC,  Thanks for your longsufferink patience with this thread, and my Eastern Europe spellinks of English, which is obviously second language to me.  (My first language is actually "body English," but that's for another thread)...  It obviously takes a lot more than this to get you "offset,"  DC...

dcollins wrote on Fri, 19 February 2010 17:43

Laars Space Camp Mastering laarsoglethorpe@gmail.com "Lack of DSD post filtering fried a lot of expansive twitters." (D. L.) Geoff Emerick de Fake Sr. Member Offline Posts: 348 Re: NSEQ-f curves? minister, What I meant is that near-perfect acoustic summing can be achieved even in a very reverberant space. The important element in acoustic power summing is identical (perfectly symmetrical) acoustic paths. Reflections and reverb have almost nothing to do with power summing. In fact, the more reverberant a space is, the more power combines "perfectly". Just like perfect electrical summing does not exist in the real world (only in theory), I make a distinction betwen perfect and near-perfect. In reality, if you have a reasonably symmetrical room, with reasonably symmetrical loudspeakers, and you place a measurement mic in the median plane, you can easily find a locus where SPL combines at +6. dcollins Hero Member Offline Posts: 2815 Re: NSEQ-f curves? Geoff Emerick de Fake wrote on Sat, 20 February 2010 00:34   In reality, if you have a reasonably symmetrical room, with reasonably symmetrical loudspeakers, and you place a measurement mic in the median plane, you can easily find a locus where SPL combines at +6. So it doesn't seem like the 6dB summation is much of a figure of merit at all? DC Dave Collins Mastering Pulse Techniques LLC Geoff Emerick de Fake Sr. Member Offline Posts: 348 Re: NSEQ-f curves? dcollins wrote on Sat, 20 February 2010 15:02 Geoff Emerick de Fake wrote on Sat, 20 February 2010 00:34   In reality, if you have a reasonably symmetrical room, with reasonably symmetrical loudspeakers, and you place a measurement mic in the median plane, you can easily find a locus where SPL combines at +6. So it doesn't seem like the 6dB summation is much of a figure of merit at all? DC You're correct. The real figure of merit is how smooth and continuous is the area where proper power summing is verified. Print Pages: 1 ... 3 4 [5]   Go Up « previous next » R/E/P Community > R/E/P > R/E/P Archives > Brad Blackwood > NSEQ-f curves?   SMF 2.0.19 | SMF © 2021, Simple Machines | Terms and Policies XHTML RSS WAP2 Site Hosted By Ashdown Technologies, Inc. Page created in 0.049 seconds with 21 queries.

[Geoff Emerick de Fake]

minister,
What I meant is that near-perfect acoustic summing can be achieved even in a very reverberant space. The important element in acoustic power summing is identical (perfectly symmetrical) acoustic paths. Reflections and reverb have almost nothing to do with power summing. In fact, the more reverberant a space is, the more power combines "perfectly".
Just like perfect electrical summing does not exist in the real world (only in theory), I make a distinction betwen perfect and near-perfect.
In reality, if you have a reasonably symmetrical room, with reasonably symmetrical loudspeakers, and you place a measurement mic in the median plane, you can easily find a locus where SPL combines at +6.

[dcollins]

Geoff Emerick de Fake wrote on Sat, 20 February 2010 00:34

In reality, if you have a reasonably symmetrical room, with reasonably symmetrical loudspeakers, and you place a measurement mic in the median plane, you can easily find a locus where SPL combines at +6.

So it doesn't seem like the 6dB summation is much of a figure of merit at all?


DC

[Geoff Emerick de Fake]

dcollins wrote on Sat, 20 February 2010 15:02

Geoff Emerick de Fake wrote on Sat, 20 February 2010 00:34   In reality, if you have a reasonably symmetrical room, with reasonably symmetrical loudspeakers, and you place a measurement mic in the median plane, you can easily find a locus where SPL combines at +6. So it doesn't seem like the 6dB summation is much of a figure of merit at all? DC

You're correct. The real figure of merit is how smooth and continuous is the area where proper power summing is verified.