Room correction in high-end system???

OK,lots of praise has been heaped on the Tact and Sigtech RCS systems, including in this months TAS. However, I believe my system is pretty high-end (at least by the "How much does your system retail for?" thread) and do not want to harm the already fine sonic charactersitics. I am generally of the mind that "less is more".

Things that concern me are:
- Putting an A/D and then D/A into my vinyl playback chain.
- Putting a lower quality D/A in place or in addition to my SF Processor 3.
- Replacing my beloved BAT VK-50SE pre with a one box DAC/ADC/RCS/PRE.

If my system were in the sub $40k retail range, I would be running to a room correction system, but am a little sceptical given my current investment. It might even be a little snobbishness. However, if I do like it better with RCS, I'd end up saving a bucket of dough.

Has anyone with a well set-up room and system tried one of these? I'd be expecially curious if Mr. Porter or some of the other vinyl fans have had one of these in their system.

I'm wrestling with the same dilemma, though my system is more modest than yours, metaphysics. You have stated the issues very well: what happens to my analog, is the new DAC as good as the old, and I love my preamp. Dan
Hi Metaphysics
I have a high end system - Spectral, Accuphase, and Avalon
and I have added a DSP - the Accuphase DG-28.
In answer to your first concern - I don't have a vinyl front end, but I don't think you want to convert an analog signal into digital.But as far as running a D to A you don't have to use the DSP as a D to A. It is just connected between your transport and your D to A. The Accuphase works this way and the Tact is available as a DSP only - digital in and digital out, so this way you keep your DAC and preamp in the system. It makes its adjustments entirely in the digital domain, with absolutely no detectable artifacts.The results can be incredible, depending upon how bad your room is. I am in a very small room, with a system that is probably too big for it, yet with the DSP, the boominess in the bass is gone leaving a tight solid bottom, that I could never get from smaller monitors. The midrange opened up, and all of the resolution reappeared.When I press the button on the remote to bypass the DSP, I am amazed at the difference, and find it hard to believe that I ever thought it sounded good without it.
Good Luck
Carl, thanks for the feedback. One more thing that I forgot to mention is that my Sonic Frontiers Transport 3 and Processor 3 work optimally when connected through the IS2E digital interface. I would have to give this up so would probably change to a Levinson digital front end or similar.

As for vinyl, I listen 50/50 vinyl/digital so half of my listening would be done without room correction. Unfortunately, I want it all and if RCS will do more harm than good to my analog front end, I'd prefer to spend the money on room treatments to improve the sound for both sources. The biggest question is:

Will RCS do more good than harm for a great vinyl front end?
Hey Metaphysics
The thing about a vinyl front end is that you have to run it through the units A to D, and that leaves you at the mercy of the quality of their A to D. It also seems sacreligious to convert a beautiful analog signal from a turntable.
I began this process with room treatments. I have ASC cube traps in the front corners, and ASC sound panels on the side and back walls. The cube traps helped but didn't come close to resolving the bass problems. They also put my wife over the edge, given their size.All of this helped a bit but in combination with the Accuphase, it really all came together.
Robert Greene has been writing about these units in Absolute Sound. The new issue compares the Tact, and the Sigtech, and if you go back a ways, the Accuphase is reviewed as well.
Metaphysics, I'm in pretty much the same boat as you. I'm hoping that at some point dCS will put the room correction capability into their Purcell (which I have) so I could see what it does to the digital side of my system without a large cash outlay and another box. However, I don't know how much I really want flat frequency response in my vinyl playback, or any playback, for that matter (I too would not like to bypass my beloved JP80). Green of TAS seems to think that the improvements of flat frequency response far outweigh the additional wire/circuits/digitalization of an analog signal; I'm not so sure. Plus, it could upset the balance of the system which could require new cables, etc., which I have chosen based on how they work in my system and room without the correction. I guess really the only way to find out for sure is to get a dealer to lend you a unit which would be compared on the digital side of the system, that way you could hear for yourself whether you really want the improvements. Given my listening biases, I probably won't want to do it, unless the logical side of my brain takes over.
SACD is also an issue here. You would have to either bypass the DSP or do A-D on the SACD, which I think would reduce its advantages over 16/44.
Rcprince, regarding the balance of the system, my understanding is that you would correct for desired frequency response on the system as a whole, as it is. So you wouldn't need or want to change cables necessarily. Though I suppose how and why we choose the cables we do could be altered dramatically with room correction in the picture.

Also, I'm not sure flat response is the goal here. The folks at TacT seem to feel that a truly flat response would not be enjoyable. The idea is to get rid of the big variations. I have not seen the latest TAS yet, maybe REG has a different perspective.

I own a Sigtech and currently use it with dCS Elgar and 972 units direct into customized Melos 400watt monoblocks driving Dunlavy SC-Vs. If you are addicted to a pure analog vinyl sound you should not use the current generation of DSP. ASC room treatment is the only really high end alternative. Neither TACT or Sigtech will have units that have sample rates of 96 or 192 in the forseeable future. So using the new dCS A to D will not work since you won't be able to use the higher sample rates. If you are primarily digital, the Sigtech is an excellent addition no matter what the cost of your system in and has no audible negative artifacts.

Very few people spend enough time or effort on good room layout and treatment (physical or DSP). If your system is north of $40K you sure aren't hearing your money's worth without it.
drubin: if you use the accuphase dg-28, together with their 2-box sacd combo (dp-100/dc-101), you don't bypass the system bus in the dac and, thus, get "true" sacd playback. or so i'm told. this is a waay expensive trio of electronics, tho.

i've experience analogue playback for some time through a digital pre/dac (accuphase dc-330) that takes a signal from a>d, d>a. on the whole it sounds quite good, tho i still prefer a "straight" phono stage for the last extraction of ambiance and air.

i'm also dubious of digital correction devices. the only one of spent any time with is the accuphase. while it does, indeed, offer readily apparent corrections to the output curve in a less-than-perfect audio environment (and what space isn't thus?), it always has a sort of "too perfect" quality about it. kinda like surgically-enhanced female breasts; they may look enticing but virtually never appear "real."

Kelly, can you say more about that "too perfect" quality?

The DG-28 is a digital graphical equalizer, which corrects in the frequency domain only with 64 linked filters. This is like the Z-Systems RDP-1 but with more filters. The Sigtech and Tact units correct in the time domain, that is the arrival times of the sounds that are "distorted" due to room reflections and speaker phase anomalies. The approach and results of these two signal processing technologies is worlds apart. Frequency domain correction only will not give satisfactory correction.

Frequency domain correction only will not give satisfactory correction for these room interactions. Adjusting the frequency response without correcting time anomalies results in a processed sound that degrades well produced recordings.

Forgive me for reposting some previous material, but it addresses questions raised in this thread. The reason DSP doesn't degrade the signal is that the Sigtech algorithms have a bit precision that is greater and calculation rates that are faster than the Redbook CD standard. Sigtech’s internal bit precision is 56 bits compared to the CD’s 16 bits and can calculate a full bandwidth 2544 tap filter at the Redbook 44.1 kHz sampling rate. The particular filter implementation is software determined based on the actual time domain measurements of your room and speaker.

The sound at your ear should be both and simultaneously phase accurate and with a flat frequency response relative to that encoded in the original bit stream. The speaker and the room interaction “degrades” that sound through standing waves, first refection bounce, etc. are the primary targets for the Sigtech algorithms. Once these are addressed the unit can shape the overall frequency response if desired but if your speakers are flat to begin with most of the frequency correction happens as a result of the time correction.

With good room treatment (Physical or DSP) the goal should be to smooth the frequency response while damping the first and most of the second reflections while leaving the direct sound and later reflections to provide air. Sound travels at about 1 foot per millisecond. Reflections under 5-7 ms are perceived as colorations. Over 30 ms the perception is of ambiance, reverberation or echo. The best DSP units use algorithms that are designed with the psychoacoustics in mind as well as with variable amounts correction with respect to frequency so as to not over correct a speakers inherent response. If your speakers are already impulse coherent to begin with, like the Dunlavys, all of the DSP power can be applied to room correction. The Sigtech can correct up to the first 50 milliseconds.

If your primary source is Analog, I highly recommend the ASC products. By absorbing and diffusing reflections they do reduce time domain distortions. I use them along with the Sigtech, as I listen to a mix of analog and digital.
My system is similarly high end...spectral/theta/eidolon.
I would not mind trying a tact or a sigtech. I can tell you that I listened to a high end (wilson/krell) system both with and without the sigtech. The difference was not at all minor and this was in a room with some room correction (tube traps) already installed. My own conclusion was that if the sigtech did despoil the true also had very significant advantages and it was definitely in the strongly positive column.
Still, I am not using it....Why? This seems a bit strange but it just seems to be "cheating". I enjoy my music very much and I enjoy my hobby very much. Maybe it is a matter of fickleness or gear obsessiveness but I like the tinkering and having a sigtech might end all that for me....Hey, I like the music but I like the tinkering.
After all the good reviews of these items I wonder if there is any oteh rnuts out there that feel the same way.
I know exactly what you are saying. Room correction is such a radical departure from the way I have approached building my system that I'm not sure I can handle the change. It feels like my options will be somehow more limited, I'll have fewer places to tweak and fewer areas to "blame" for the source of my dissatisfaction.
Interesting post. Because I went through the SAME dilemna not long ago.
First of all, my system consists of
Sony SCD-1
Linn CD-12
ML 360s
ML 33H
SF Amati
A 'high end' system by most standards I assume.
But was I happy? no... my room/speakers combination was a huge problem, no matter where I put the Amati. So I tried the TACT RCS 2.0. No harm. and honestly, not that expensive a toy to try if it does what it says on paper.
MAGIC. You should not underestimate how much your room is harming the sound quality/balance of your system. The TACT is a DD device. This is how my front ends are connected for the time being (work in progress as usual)
CD12 to ART II directly (analog)
CD12 Digital Out to TACT to ML 360s to ART II
There is little doubt that the CD12 DAC is far superior then that of the 360s, but I CONSISTENTLY prefer the sound using the TACT then the CD12 direct to CJ ART.
The effect/correction is STUNNING.
Even if you have doubt about this 'non purist' approach, at least have your room measured before you decide.
To address your question regarding LP or SACD, consider the upcoming dCS Greig ADC/Upsampler. the TACT cannot deal with 192Khz yet, but they can handle 96kHz just fine.
So before you get so stubborn and reject this approach, just go measure your room professionally and then you will find out whether these room correction devices are useful for you. my guess is, 95% of us will benefit. The improvements outweighs the sonic degradion by far.
The only answer is to try it. The room is the
most important/expensive component in yr system and unless
you are very lucky it needs dealing with. Every day I hit
the bypass button to remind myself what I used to
listen to and congratulate myself about!! The Tact
RCS does offer sampling at 96/24 in their ADC, by the
way. There is no record that is not hugely better in my

There are no simple ways to use the Tact as in 'plug and
play'. You just got to mostly be able to extrapolate from
your initial messing about. I took it on faith. In
Indonesia that was the only option. Its taken me
6 months now and every week I learn a way to use it
better. My opinion how did/does anyone ever live
without it?

Rest of my set up Sota/SME V/Pass aleph 3/AvantGarde

I have SigTechs and a Tact and I listen to analog and CD. I bought an external A to D going to the SigTech or Tact for converting my analog. I also upsample to 192 coming out of the SigTech (dCS) and use the dCS D to A (Purcell and Delius). While it (A to D conversion) may have some negative sonic footprint, I would sure hate to try to hear it in a blind test.

And whatever the negative consequences of that conversion, I can assure you that it pales in comparison to the huge improvement brought about by the SigTech.

And for using the SigTech in the digital mode (digital in and out), I would challenge anyone to hear it when it is in the circuit in what SigTech calls "AllPass".

Best improvement I have ever invested in. And while the SigTech is not inexpensive, the benefits it provides are worth twice the price.

The Tact is better than not having any room correction (and a lot less expensive than the SigTech) but also nowhere near as good/accurate---and that is easily demonstratable.
Audioguy123,What external ADC are you using? I had a Wadia 160 for a while, but sold it along with my Wadia 27ix.
There are enough positive testimonials here that I am close to taking the plunge. I plan on keeping my current SF Transport 3 and Processor 3. However, I will be upgrading to 96/24 upsampling when the Processor 3 upgrade comes out next month. Does anyone know if this will be worth it with the Tact 2.0? Does the Tact or SigTech put out 96/24?

The Tact puts out 24-44/48/96 (whatever it is fed -- not doing upsampling)and the SigTech puts out 24-44/48. Since virtually zip is offered on 24/96 input (especially if SACD wins), the 96 sampling rate is not that critical at the moment.

And for what it is worth, I have done numerous comparisons of CD and their LP counterparts (digitized) and the LP STILL sound better. I have also demonstated to numerous analog folks and did not tell them I was digitizing and NOT ONE could tell.
Audioguy, are you saying that the digitized LP sounds better than a digitized CD or are you saying that a digitized signal from a turntable front end sounds better than that of a non-digitized LP? -- i.e. can we expect better performance from a Tact or Sig on an analog front end?
I am saying several things: (1) the digitized LP sound better than the CD of the same recording (ignoring the room correction), but(2) even if the digitized LP is not a good as the non-digitized LP, the room correction advantages far outweigh any degradation you might get from the digitization process.
which ones is better imean sonically no significant
accuphase dg 28 or tact?