Room correction - what device works best?

"It is well documented that multiple subs can achieve better results than an equivalent single sub in appropriately sized rooms. Typically smoother frequency response from spreading room nodes and higher output/lower distortion from twice the woofer radiating surface."

Onhwy61- I think the key word is CAN. You can definitely get higher output from twice the radiating area (and twice the amplifier power). With careful placement you SHOULD be able to get smoother frequency response. However, it seems to me that it is at least theoretically possible to 1. place the subs so that they reinforce the same room nodes, or 2. create additional nodes. Not likely, but possible. For example, #1 could be achieved by placing both subs in the front corners of the room. If a node were located at the listening position, it would be re-inforced. OTOH, if the subs had a phase switch, setting one to 0 and the other 10 180 might cancel that node. #2 seems least likely but also at least theoretically possible. I'm not an acoustician, so if I am wrong, someone please correct me.

to 180

Al, I agree that the advantages the DEQX bring to the table might (probably) outweigh the down sampling issue, but in that sub $100 DVD players can decode (yes I realize that's all) the native higher sampling rates, it is still somewhat disconcerting that an item that can cost close to $5,000 can't do it all in the native higher sampling rates.
I still wish there were more amps (preferably mono) that could accept direct digital input from devices like the DEQX.

Re: mono subs, I can't help but wonder if a mono sub when being fed summed stereo input might actually find itself competing with channel signals and actually subtracting information in the process. IME, stereo subs have always sounded better than a mono sub when fed stereo signals. But I suppose their could be an exception to my experience that works differently?

05-11-15: Unsound
Al, I agree that the advantages the DEQX bring to the table might (probably) outweigh the down sampling issue, but in that sub $100 DVD players can decode (yes I realize that's all) the native higher sampling rates, it is still somewhat disconcerting that an item that can cost close to $5,000 can't do it all in the native higher sampling rates.

Hi Unsound,

Your reaction is natural and understandable, and as you indicated you recognize that the DEQX processing is much more extensive than what a DVD player has to do. But I think that my use of "much more extensive" understates it considerably. What I envision is that the mathematical computations that are involved in the digital signal processing the DEQX has to perform on the fly, fast enough to keep up with the music data, are HUMONGOUS. My understanding of it is that in real time it has to divide the spectrum into thousands of frequency segments, mathematically determine the contents of each of those segments by converting the series of data samples from the time domain to the frequency domain (that conversion involving a huge amount of mathematics), mathematically adjust the delays and amplitudes of the contents of each of those frequency segments in accordance with the speaker and room calibrations that have been established, as well as in accordance with any additional equalizations that have been programmed, and then put everything back together and convert it back to the time domain (again, a huge amount of mathematics), while digitally adjusting the volume and then converting the data to analog. I think it would not be unfair to characterize the processing a DVD player has to do as not much more than a drop in the ocean compared to that.

I'd imagine that if 24/192 processing could have been implemented in the PreMate which JA measured in a reasonable manner without drastically complicating the design, and/or delaying release of the design considerably (perhaps by lessening the extent to which that design could draw upon their previous design work), and/or making the unit much more expensive, DEQX would have done so.

I don't know, btw, if the design of the more recent HDP-5 which I am getting processes 24/192 as 24/192 or downsamples it similarly. But I'm not concerned either way.

Best regards,
-- Al