Digital Room Correction: The Final Frontier?


Like most of you, I've been experimenting with different room treatments, and various other tweaks (footers, power conditioners and cables, interconnects, etc.) for many years trying to optimize my ever changing system.

I've enjoyed my system immensely, but I knew I had some speaker/room problems, and I was growing increasingly tired of listening to an over-ripe lower midrange, a boomy lower bass (even with the speakers 6-7' into the room) and a rolled-off upper-mid/lower treble on my Talon Khorus (and before that similar problems with my Genesis V and ProAC 3.5).

So I attacked my room. I put bass busters in the corners, Roomtunes along the ceiling borders, a thick 12'x15' Oriental carpet, and at one point last year had (count 'em) eight Roomlenses in my room. It all helped.

I tried several different amps, finally settling on a Gamut D200, which helped ameliorate the ripe mids and tightened/lightened the lower bass, aided by a switch to Nordost Quattro-fil ICs and Wireworld Silver Eclipse lll cables (after trying at least 15 cables).

Added an Audiomagic Stealth along with BMI Shark/ EG Fatman PCs. Used Bright Star Gemini sandbox/innertube. Floated the speakers and digital with Aurios. Again, it all helped. Some.

Finally, after hearing one in a friend's system, and being quite impressed, last week I installed a Tact 2.2x in my system. I'll post a review after I've had more time experimenting with it, but I'm flabbergasted.

First, I was both horrified and reassured by the uncorrected room measurements. Horrified to see a 10dB peak at 28Hz, along with a huge rise in the mids and steep drops in the upper-mid/ lower treble. Reassured because that's what I was hearing, and now I could see it on a graph.

Surprised, because I had thought my dedicated room was a reasonable size for audio (16'x24'x10'). Surprised that after such careful speaker placement and measurements, one speaker reached my ears so much before the other.

Surprised to find that all those other tweaks I thought were so helpful, were so minor compared to what the Tact 2.2x can do. I can even-out the frequency response, time align the speakers and clean up the mids and bass with a simple push of a button (well, after some serious mouse work); all with a minimum cost in other areas.

Going back to bypass mode, my speakers now sound like I threw a blanket over them.

More to come....
richards
Rives, from what you are saying, your product would work with DVD-A and SACD formats as well as vinyl (while the TACT would not)--true?
Duddley:
The PARC is designed to do one thing and one thing only--deal with room modes. We wanted to keep everything in the signal path as simple as possible (but not simplier). Thus, we do not address time alignment issues, nor do we operate on the full audio bandwidth--bass only. There are two areas that one might want to apply time alignment to. One is a poorly designed speaker that requires additional processing, and quite honestly most high quality speakers now are designed with cross-over and drivers that do not have this problem. The other occurs from room interactions and is far too great for any device to deal with properly. Even if it could, it could only do it for one very specific spot in the room. TacT will admit that the time alignment issue is not terribly relevant, but since the data is in the digital domain, and they have to do some time alignment to compensate for the digital convolution filters, why not allow the user to adjust it as well.

How do we avoid injecting phase incoherence in analog? Quite simply we don't. It's impossible and is the laws of the type of electrical circuit necessary to do parametric equalization. It's a direct function of the Q (width) and attenuation. There are two types of phase distortion that can be caused. One is cascading and one is indepedent. We use an independent designed filter. The phase shift is maximum at the center pole but is not changed outside of the bandwidth. Initially this was a big concern of mine, but after extensive listening and testing on very high resolution systems we discovered that we could not detect phase shifting with notch filters (attenuation only). We could detect the phase shift when the Q was relatively narrow (greater than 4) and the boost was greater than 6 db. The PARC is to deal with room modes only and thus does not allow for a boost, only attentuation.

Calanctus: That's not quite right. The TacT can work with these formats, but it's going to take their analog outputs (not native digital format), then run them through an A/D, then process the new digital signal, then another D/A. So you can do it, but it's very convoluted and not a very pure way of dealing with these high resolution formats, you will lose much of the detail and ambience of these higher resolution formats with the additional conversion and processing.

In either case--hearing is believing. Please do take time to listen to a unit, whether it's an in home audition (best) or at a dealer or at HE 2003.
With an A-to-D converter option, the TacT units WILL
work with vinyl. I'm using my vinyl system that way.
And, it works beautifully. I've got Magnepan 1.6QR
speakers, and I use Room Lens clones behind them for
greater diffusion, but the TacT RCS 2.0 is an enormous
improvement in the musicality of the system.