Equalization, reverberation, and bass modes

Rob Babcock · « **Reply #20 on:** 17 Feb 2005, 07:15 pm »

Patrick is pretty opinionated, and like a lot of engineers he sometimes thinks he's always right (FYI, worked for Harmon International & designed many of Infinity's newer speakers), but he means well. As enamored as some guys are of DSP, even Tom Holman said there's no DSP for a first reflection point. I think room correction will improve in quality and importance as time goes on, but I doubt any amount of processing will ever take the room completely out of the equation. To use an analogy I discussed with Ethan, 'fixing' everything with DSP and ignoring room treatments is sorta like putting on extra deodorant instead of taking a shower.

I realize reviews must be taken for what they are, but nonetheless a hearty congratulations to Ethan on the very favorable review.

ctviggen · « **Reply #21 on:** 17 Feb 2005, 07:26 pm »

That's a long decay time (400 ms). That would definitely interfere with additional notes. Once I get back from AZ, I'll post my results, too.

ctviggen · « **Reply #22 on:** 17 Feb 2005, 07:27 pm »

Oh, and I have quite a few peaks in my room.

Ethan Winer · « **Reply #23 on:** 17 Feb 2005, 08:37 pm »

Rob,

> Patrick is pretty opinionated <

So am I.

> even Tom Holman said there's no DSP for a first reflection point. <

Great point.

--Ethan

8thnerve · « **Reply #24 on:** 20 Feb 2005, 02:46 pm »

I'll throw my hat in the ring here as well and agree with Ethan. There are simply room problems in almost every room which just can't be solved by any level of DSP. Even future DSP developments if two microphones were used in a head dummy where the ears should be, could only solve acoustic problems for that precise location in the room, and that result could only be appreciated if your head were able to be in the EXACT (to the cm) same spot at all times. This is assuming of course that we have improved current DSP by a large margin, and are measuring things that we don't even look for now.

Acoustic products are essential to any listening room where improved sound quality is desired. No product has a similar cost/performance ratio as acoustic products do, no matter what brand you use. (although I do think some are better than others

) When I treat a room, I don't really care where the system is set up. I look at the room itself, and correct for the anomolies of the room. People often comment how different the room sounds, the moment the product is in place, just in terms of speech. Recently, an audio reviewer that I was installing some product for, after placing the product, just sat and talked with me for over 30 minutes before even thinking about listening to music about the dramatic change in our speaking voices.

Although we are most concerned in this forum with the quality of reproduced music, a better acoustic is a profound experience for all parts of life, from conversing with others, to simply being in such a space and hearing the sounds of your environment. We have grown up with distortion being a part of our lives, as we spend most of our time in rooms, most of which are rectangular. This is a terrbile shape for a room from an acoustic standpoint, but really the only viable shape from an economic and construction standpoint.

But I digress. DSP can be very useful for the reduction of peaks due to architecturally based room modes. With proper room acoustics, DSP can be even more effective, and startlingly so. It cannot however, correct for many acoustic problems, that is still the domain of well designed acoustic products.

denverdoc · « **Reply #25 on:** 21 Feb 2005, 10:09 pm »

Funny how this thread has sort of evolved into a pro dsp vs anti dsp debate. No one including myself I hope ever implied that these are mutually exclusive technologies. If I were in Youngho's shoes, I'd map out my room well in advance of buying or building speakers, then try to tame the rooms worse excesses with tuned Helmholtz radiators, pick a location for the mains within a 2 sq yard or so footprint, take care of first reflections with good room treatment products at the likely spots, then get good DSP device to take you to the next level of realism by correcting any nearfield impulse response problems; after that to how much one gilds the lilly by over correcting a particular point in space is at the user's discretion. Certainly, some of the newer methodologies that incorporate neural nets look very interesting indeed. Nuff said,
John