TACT RCS 2.0 Users Group

I am a big believer in DSP correction. I had the Tact unit in my system for a week comparing it to the Sigtech. I believe that one of the greatest short comings of the Tact unit is insufficient instrumentation power built into the unit to effectively set it up without hours of trial and error. To start with, several of the Tact correction curves have ridiculous bass boosts below 30HZ. But more importantly when I measured the in room response with independent professional real time analysis equipment, what the Tact displayed as the correction curve did not track the measured frequency response. The Sigtech did. By fiddling around and iteratively using the real time equipment to take frequent measurements, I did get a decent correction curve from the Tact although I strongly prefer the Sigtech. However, set up for the Sigtech was accomplished in 2 hours using the supplied Sigtech instrumentation. I’m afraid that most Tact users will not be able to get the optimum performance out of their units due to the challenges of set-up. I believe that Tact should offer additional set-up processing power or a service as does Sigtech. The speakers I use are Dunlavy SC-V’s

To tao. With the Tact alone you are not in control because the curves that you see do not track the actual in room measurements as measured by a professional impulse based instrument with full MLSSA capabilities. With the SigTech you do. If you want to use the SigTech instrumentation but not their D to A the total cost is about $7500. You can have 4 curves in memory. The Tact was in my system 1 year ago. There was a noticable digital glare when I added it into the system, even in bypass mode. I can't detect any with the Sigtech. I was using a Theta ProGen Va. I currently have the MSB Platinum and the dCS Elgar/972 combo. From looking at the chip sets in both the Sigtech and the Tact there are multiples of raw computing power in the Sigtech. When I finally got it set up, the Tact was a decent DSP but what bothered me is that do DID NOT give the correction that you thought you were getting. If you are as perfectionistic as you say you should really buy a real time analyzer. They aren't that much compared to a lot of high end gear.

The Sigtech unit does not yet support 24/96. I just spoke to Sigtech and they are waiting for the dust to settle on the format wars. The do have a 24/96 design. What I do is take to output of the Sigtech and run it into my dCS 972 upsampler and then into the Elgar DAC. My transport and DMX Satellite outputs go to the Sigtech. They recommend that you use outboard A to D and D to A units

Over the last year the topic of Tact vs. Sigtech has come up several times. In looking back at my posts on this thread I see that I didn't post here that my experience with the Tact was one year ago which I believe was one major software release ago. From my discussions with others, the glare seems to have been removed and I will certainly eliminate that comment since I have no further first hand info. However, I understand that the setup software is the same so I believe that the problems with correction curves are probably still there.

Short answer,many "poor" recordings aren't that bad. They just have significant musical info in frequency bands that are distorted by room interactions. It is EXACTLY like removing distortion. As I have said in previous posts, most audiophiles will never really hear the caopabilities of their systems without digital room correction systems.

I don't know the recordings you refer to and I can't hear your room but there are several things that COULD be going on. I say could because it would take careful measurement and listening to determine it. The most general reason is that those recordings with the most improvement have sensitive musical info at the frequencies that your room and/or speakers are most "off" combined with placement of those instruments on the left to right soundstage so that the effect of the room interactions are most noticeable. Also, the musical info is not buried in the mix. I will use an example from my situation with a Sigtech and Dunlavy V's. I have asymmetric bass response in several narrow bands starting at 80 and ending around 200hz due to a large Middle Eastern style arched door in the plaster wall. If I listen to a well-recorded string quartet with the cello in its normal position on the right of the sound stage the cello sounds thin and hazy. Reverse the channels and the quartet sound fine. Kick in the Sigtech and it sounds fine. Play a quartet recording with an extra wide soundstage or a tight soundstage and the effect almost goes away. Second possibility, you may have a general rise in response from the lower midrange (room or speaker). Recordings mixed with a similar rise in response (not uncommon with pop and rock) will sound bad. Recordings without the rise will sound OK. Both will sound better with the DSP turned on and correcting for that rise. These are the real effects I've heard and measured. Of course this may have nothing to do with your specific situation. and correcting for that rise.
One simple test is to play the recordings in question in mono or on headphones and note the difference.

For any DSP room correction system:

For 5: Remeasure only when things that impact the time behavior or gross frequency behaviours of your system change. That includes new speakers, new pieces of furniture, moving your speakers, moving your furniture, or moving your listening position.

For 4: the answer should be to take a true time domain measurement after each curve fit to see that you actually achieved your desired response but that is the limitation discussed above.

One additional suggestion which is a substitute for indpendent measurement. Get a good Mercury Living Presence CD that was recorded in Mono. A stereo recording played in mono won't work because you do't know the actual left right time response. I recommend the Dorati recording of Tchaikovsky's Swan Lake with the Minneapolis Symphony. It doesn't matter if you don't like classical this is a test record. Listen to the last 15 minutes with your eyes closed. If your curves succesfully correct for the room and speaker anomolies, the image should be rock solid between the speakers. If the instruments wander depending on what is playing or how many other instruments are playing, you should check your speaker placement and remeasure. This should work with just about any reasonable target frequency response curve.

I assume from your question that you would be using the Tact as a DAC also. The DAC portions of the Tact or the Sigtech are not as good as the best DAC's out there. The combination of a DSP and an MSB Platinum DAC (which I used for the last year) will give you a better sound. Th choice of volume control could be in the preamp or a Z-Systems (which is also an excellent unit).

As per above, I compared the Tact to outboard DAC's and it isn't as good. The digital volume control is best over a limited range. I use a shunt to ground volume control in my monoblocks to allow for setting the output from the digital volume control in the Z-Systems (which has a better digital volume control than the Tact) to its best range.