Digital room correction, any recommendations?


Can anyone recommend a correction device that can be inserted between my digital source and DAC, that is relatively easy to use?
psag
I tried a few. I never failed to notice a slight reduction in resolution, despite the improvement in bass response, etc realized via digital correction.

I recommend judicious use of room treatments first, and if that fails, I'd try the digital route.

Just my experience; I'm sure many others will disagree.
I'd highly recommend acquiring software that lets you see the frequency response and reverberation times of your room. Then you can apply room treatments to deal with the areas which can be fixed.

As for digital room correction, I've tried Z Systems and Audyssey and most recently Trinnov. I use a dedicated Trinnov unit that does 4 channels (recently released). I auditioned it for some time in my system before decidig to go ahead with the purchase. It has proven efficacious and worthwhile and I am quite critical of things that alter timbral purity, resolution, etc. One of the nice things about the Trinnov is that it has a highly detailed interface that provides a tremendous amount of information as to the sound in your room and also the means to make fine adjustments over a variety of parameters. The downside is taking the time to understand what you are doing.
Good ideas, Classicjazz.

1. Let me suggest two options for measurement:
RoomEQ Wizard (freeware) but you must add SLM or mic/preamp
XTZ (not free) but includes all necessary hardware/software

2. Good sources for room treatment materials:
www.realtraps.com
www.gikacoustics.com
www.atsacoustics.com
For DIY information:
www.sensiblesoundsolutions.com
http://forum.studiotips.com/

3. Audyssey works well but even with the Pro version, there is limited control. If you are OK with point-and-shoot, Audyssey is the way to go. Also, JBL and KRK have 2 channel devices which, although different, work similarly.
TacT, Trinnov and JBL Synthesis are much more capable and much more complex.
Lyngdorf Room Perfect but it is not cheap ... I think this is similar or same as the technology licensed to the aforementioned KRK.
Lyngdorf is reported to be easy to use. But it requires A/D and then D/A conversion between preamp and amp, and I don't want to do that. I want to do the correction before conversion to the analog signal.
What about the older P1A and P3 processor & DAC from Perpetual Technologies? Would they work in your situation? I see there are a few available now on A'gon.
1. The PT units are simply not supported any more and had limited applications. (I have a pair if anyone wants them.)
2. All the MCH add-ons will require A/D/A conversions as there is no standard consumer MCH digital communications link.
3. The KRK ERGO is, indeed, based on Lyngdorf and it will accept an S/PDIF input.

Kal
Hi Psag

May I suggest reading some of my blog posts on this topic? I have reviewed a number of products from a functional perspective. Disclaimer: I do not sell any of these products.

http://www.acousticfrontiers.com/whats-new/2010/7/1/room-correction-a-primer.html

http://www.acousticfrontiers.com/whats-new/2010/7/18/two-things-a-room-correction-product-must-do.html

http://www.acousticfrontiers.com/whats-new/2010/7/23/room-correction-why-the-needless-analog-to-digital-conversio.html

http://www.acousticfrontiers.com/whats-new/2010/8/1/a-survey-of-room-correction-devices-meridian-tact-lyngdorf.html

There are also a few other relevant posts if you look through the blog archive.

Hope that helps - Nyal :)
Acousticfrontiers, it looks like the Tact 2.2XP meets both of our criteria. Question: Do I lose any of the correction capabilities by using it between my digital source and DAC, rather than as a digital preamplifier?
Psag - if you don't need analog inputs then you can go for the Tact 2.2 mini. The only difference between that and the 2.2XP (as far as I can tell) is that the mini does not have analog inputs. Both units have digital outputs.

Note that using the TacT unit you can set the output bit rate different from the input bit rate i.e. you can use it as an upsampler. Infact it is best to do this since the TacT upsamples everything to 24/96 or so internally to do the room correction and then upsamples or downsamples the output.

See the manual esp pages 12/13

http://www.tactlab.com/Resources/Downloads/22MINI/22MINIManual.pdf?bcsi_scan_B318185731EFFDE3=0&bcsi_scan_filename=22MINIManual.pdf

Nyal
Hi Psag,

Before making a final determination, I'd read up on the different technological approach that Trinnov use.

http://trinnov-audio.com/en/optimization/features/overview

They employ some very sophisticated modeling and mathematics to analyze the sound. Also, read up wherever you can on the Tact and Lyngdorf approaches and see what you find from other users and ex-users (of any of this gear).

I agree with Kal's comment above regarding the steps. I have the XTZ software and then tried Audyssey (as built into my Denon AVP-A1hdci) and auditioned a Multichannel version of the Trinnov Pro unit. Both units took a digital in; the Denon output an analog signal while the Trinnov passed the digital signal to my DAC (Boulder).
I know some people who have experimented with the Behringer Ultracurve. But I believe that problems with room acoustics should not be solved using those machines. A sound engibeer nce explained it to me, but I'm not a sound engineer. But it has to do with trying to fix a time problem in the frequency domain.
Classicjazz,

I should look into Trinnov. Unfortunately their marketing material is not very in depth about what their unit does!

Where did you get your demo unit from?

Thanks!
Mordante... I have heard all the theoretical reasons why the $300 Behringer DEQ2496 won't fix room acoustic anomalies. But, mine do an excellent job. Don't you know that bumblebees can't fly.
10-12-10: Psag
Acousticfrontiers, it looks like the Tact 2.2XP meets both of our criteria. Question: Do I lose any of the correction capabilities by using it between my digital source and DAC, rather than as a digital preamplifier?
Psag

I believe the 2.2XP outputs 2 stereo channels and 2 subwoofer channels, but I guess if you connect it between source and DAC you would loose the 2 subwoofer channels. Maybe you can get an earlier version that didn't account for the .2 and avoid paying for a feature you won't use.
However I have not used one of these, so you might want to double check if my conclusion is correct.
Hi,
I happen to be local to the US Trinnov rep (and partner in the company) and borrowed a unit from him. Curt is very helpful and knowledgeable. I picked up my ST2 Pro today and will run it through its paces this weekend and take notes. Seeing as no one has reviewed the Trinnov in depth I may write something up. What I like is that the unit shows both the frequency and time domain response and corrects for each separately (or you can make the corrections by creating your own target curves).

The Trinnov ST2 Pro (there will be a consumer version with RCA SPDIF and Toslink digital I/O and RCA analog I/O) can process 4 channels although there are 8 channels' worth of inputs, 4 XLR RCA and 4 AEX/EBU channels. I believe you can mix and match - I will be testing this with my Oppo player to see if I can get the LPCM left right stereo in via digital and the center and subwoofer in via analog (using XLR adapters since the Oppo outputs are RCA).

You can also biamp and use the output (4 channels) with the software based crossover.

Feel free to ask me more pointed questions. I almost went for the Accuphase DG38 earlier this year but feel that the Trinnov approach seem quite solid and innovative. For one, the Trinnov people seem to have made significant inroads in professional cinemas and on the professional level, which lends some credibility to their approach. The well known US home theater component company ADA also will be releasing their version of a RC unit based on Trinnov technology.
I corresponded with the DEQX people, and I'm impressed with the attention they gave to my questions. They even researched my speakers, to determine whether the active crossover feature might be of benefit. I was surprised to learn that the external active crossover feature can be implemented without bypassing the internal passive crossover- they can be made to work together in the interest of reducing driver distortion. Also, their unit has digital ins and outs, so it meets Acousticfrontier's criteria listed earlier in this thread.
I realize this is a really old thread, but Psag's post above using an active crossover to pass through a passive crossover would take away the advantages of going active in the first place?
I've had the DEQX in my system now for several years. We decided not to implement the active crossover feature, which would have required opening the speaker and disconnecting the passive crossover.