Interesting day! (maybe not interesting to read?)

Hello fellows!

An interesting day today. I went on the train down to Kevin’s (Ya-Boo) place along with my trusty DEQ2496 and laptop, measuring gear etc…

Kevin has had a TACT RCS 2.2 for a reasonable while now but has yet to achieve a sound from its correction mode that he was truly happy with. He has spent a fair time trying different target curves and adjusting the a bit but while he got a good improvement in some areas, mainly the bass, the rest of it would still be beaten by using the TACT in bypass thru to his Audio Areo DAC/Pre-amp.

Being a bit more technically minded I said I would give it a shot. To miss out all the boring technical bits I got it to change the sound and while the bass was better, the overall tonality and character of the system always changed. Kevin tried to basically trace the path of how his system currently sounded for the target curve but apparently it still changed the sound a lot for the worse.

After telling the TACT to EQ a completely flat target curve, I think measured it using my laptop to see how well it was actually achieving its target. It didn’t do very well! Completely tilted response, bass light and treble heavy. Not just the sound, but compared to white noise.

We gave up and plumbed in the Behringer DEQ2496 in digital thru mode. I took some white noise measurements of the system using the laptop and then manually altered the DEQ2496’s EQ until we had a pretty flat bass response (I didn’t want to adjust too extremely – 6dB max). I also EQ’d out a few bits in the treble. Nothing too ambitious, just altering the general trend a bit to bring it flatter and less treble heavy.

We now took a listen and immediately the bass was better. More body, better balance and a bit less boom. When A/B’ing the EQ vs. Bypass though Kevin said he liked the bass but the mid and treble was now less lively and ‘real’. I took out all treble EQ and only left in what was below 200Hz. This was the best of both worlds.

We played more music and continued to fine tune it a bit. After a lot of music listening we took the trip back to my place.

Kevin’s Audio Areo DAC/Pre and TACT RCS2.2 came with us for the ride!

I have been wanting to hear my system with a good DAC in it for a while so this was a good opportunity.

We plugged in the Audio Areo, taking its digital feed from the DEQ2496 and then plugged that into my active speakers. (We also tried going in to my pre-amp but the volume levels were way too low)

It sounded pants!

The bass was way to heavy and the treble was quite harsh. The vocals did sound quite good still though. I messed about with EQ and so on for a bit but decided to try the TACT instead, thinking it was probably the tube output stage being too ‘warm’ for its own good.

So while we left the Audio Areo to warm up for a bit, just in case it was that, we plugged in the TACT.

First using it as a DAC only from my DEQ2496 in to my pre-amp. Wow, this sounded a lot better than the Audio Areo! Quite a bit better than the DAC in the DEQ2496 as well. Better imaging and more detail and refinement. Just what I was looking for from a new DAC!

We then tried using the pre-amp in the TACT unit and going directly to my active speakers. Another improvement! Again better imaging, more detail and such a smooth sound! It got even better once warmed up. Sonic Silk ‘twas!

It retained all the tight, tight deep bass and control my system already had, but added a lot more fluidness, openness, detail, refinement and even smoothness while still not being dull and could still rock away to heavy stuff. Brilliant!

The Audio Areo got another go once it was warmed up and sounded a world better than its first attempt, but surprisingly it was a bit more dull than the TACT yet not as smooth. System matching ‘uh?

Oh we also had a Shynyatta (SP?) King Cobra power cord in to the DAC’s. I think it ate my cat though! If only we took a picture…

So the questions that remain in my mind are… with the TACT is there a way to alter what it is actually doing to the signal rather than the target of what you want the signal to look like? (Is this called a core curve rather than the target curve?) Can you tell it not to adjust anything above a certain point? I have signed up to the TACT Yahoo group but am awaiting being accepted in to their little ‘click’.

What DAC/Pre combo’s are there about? It would seem a waste to have a TACT RCS2.2 and yet use the DEQ2496 for room correction (as so far the TACT seems ****e for that!) There is the Benchmark DAC1 (apparently quite harsh, and not quite up there with the quality of the TACT DAC?), some Wadia ones? The Audio Areo (not that good in my system) and the TACT. What others are there with a similar sound to the TACT DAC card in the RCS 2.2?

I’m aware this is a long post and probably a load of boring bollocks but I am tired and quite happy with just how good my system sounded with a top-notch DAC.

Kevin if you would like to add anything then please do! When the power cable sicks up my cat, I want it back, okay?

 

Tenson,

as you may well know I had a full Tact system about three years ago now, and should be able to help.

The only way to achieve this is to take room measurements then operate the Tact in bypass mode whilst employing the Par Eq facility and setting it up manually. The Room Correction software works with target curves, and without another unit there is no way to verify the results (indeed steady state tones will produce very strange results IME).

An alternative, should you only wish to correct certain aberrations, is to alter the target curve to exactly mirror the existing response. The graph can be enlarged in portions to make this procedure easier but it is still time consuming. Do feel free to PM if you want to know more.

With all respect, if you expected to be able to get decent results with the Tact in an afternoon, you were dreaming! Experience suggests that good results take a lot of time - I felt I had things just about right after 6 months. The main reason people are dissatisfied with RCS is a lack of patience, you need to be fairly dedicated to get the best from it. In addition, it is designed to be used with two subwoofers. In this mode, you are able to get the real benefits that are available.

My system ended up sounding wonderful in hifi terms, with two subwoofers crossing over at 300hz. And yes I have own a Behringer and given time with both, there is no comparison! The Tact is a vastly more sophisticated unit and the properly optimised results are outstanding. I'm not trying to argue or be rude Tenson, merely pointing out that impressions of Tact based on an afternoon of fiddling should be taken with a pinch of salt.

As for the Dac, again my experience was that the Tact dac was most disappointing, indeed I preferred an M Audio Audiophile Dac to the RCS's internal module. I also really admire the AA, although my experience suggests it needs to be used with a preamp for best results.

So I guess from all of the above, we must be listening for different things! Therefore recommendations would be rather pointless, but I will recommend that you look out for a good multibit or hybrid Dac on the used market - I have always found these to be most impressive in the long term.

 

I found this interesting to read.

Particularly where the signal is analogue, do you find that equalization of any kind tends to 'suck the life out of the music' - unless there's a way to use it below, say, 200Hz without affecting the rest?

Also, doesn't equalising above these frequencies alter the balance between direct and reflected sound?

 

Well how many parametric EQ's does the TACT have? It seems really crude and frankly, dumb, not to be able to alter the 'core curve' or whatever it is called.

As i said, Kev has had the unit for .. what about 1 year now? So its not really just an afternoon. I have had the DEQ2496 for about a year and a half as well as being quite used to this sort of thing.

The DEQ2496 produced brilliant results after about 40min of setup.

Except for having a finer resolution (which is limited to not being able to fully control it!), what does the tact do that the DEQ2496 can't then?

I expected the AA to sound better too, but the TACT blew it away. I guess its just system matching. It was smoother, tighter, more detailed and sooo not 'digital' sounding as you might expect.

Steve, I think EQ is alright on analog signals as long as you use top quality A-D and D-A converters. The A-D stages are usually the weak link. If you are only using it on the bass though, i would imagine you can get away with a lesser A-D and D-A.

Why would altering the high frequencies effect the reverberation balance? If you output less treble, you will get a weaker reflection as well! The main thing IME is to not try and EQ any spikes or high Q problems, just use it to alter the general trend. You know, take 0.5dBfrom 2KHz - 6KHz, add 1dB from 8KHz to 10KHz.

 

Tenson, I really don't understand. The Tact has a Para Eq facility that is like the most studio EQ's and is usable in real time, and the Room Correction Eq that is somewhat different. The room Correction works in the time domain, it measures the impulse response and derives the frequency response from that. Whilst the DEQ has an FFT EQ, it's only 61 band I believe. I understand it to be somewhat crude in comparison but Maybe Oedipus could help you out there.

I have never heard of a core curve. I am familiar with target curves which of course you can customise to your heart's content, so what do you mean by " core curve"?

 

Suppose a room has a quirk by which a resonance at, say, 1kHz causes a peak in the frequency response which comprises reverberant sound. If we now equalize so that the overall level is flat, the proportion of reverberant to direct sound has increased due to the resonance.

Or am I wrong here?

 

I'm not against the Ber - I 'll probably get one myself one day, and I already have bass controls but what you describe is exactly what analogue tone controls do, so why bother with digitising it. For PA thats a different matter. I presume it has memory to call up predetermined eq for different venues etc.


'Suppose a room has a quirk by which a resonance at, say, 1kHz causes a peak in the frequency response which comprises reverberant sound. If we now equalize so that the overall level is flat, the proportion of reverberant to direct sound has increased due to the resonance'

I would suggest the proportion is the same. You have screwed the direct response to get the reverberant flat. I dont see how any eq can avoid this - except maybe if you used anti noise speakers at key places but even then you are just narrowing the 'sweet spot' location.

 

Sorry, I didn't explain what I mean very well.

If we equalize a frequency where there is a boost due to resonance, we end up with an overall 'flat' amplitude but with a higher proportion of reverberant to direct sound than in the original recording. This gives an unatural effect.

I'm totally in favour of equalisation for the bass frequencies - although it should be said that we're only equalising for flat response at the listening position. The proportions of reverberant and direct sound are not perceivable at low frequencies.

At mid and high frequencies, there is a psycho-acoustic effect that needs to be accounted for. For example, when we walk around a house talking we tend to be unaware of the significant differences of the reverberations of the different rooms (this doesn't hold for very gross effects such as walking into a tiled bathroom). Our hearing compensates for these differences automatically and it's this that makes the equalisation sound unnatural.

Of course, the other reason that I'm against mid/high equalisation is the veiling effects of placing an extra piece of equipment in the line. If the equalisation was solely in the circuit for the bass sounds, I'd be all for it.

 

Hi Simon,
first RE your Cat.........Im afraid the King Cobra Powersnake made mincemeat of It ...then again as everybody knows powercords have no effect and all sound the same

Having met you a while ago I,ve learnt a very important lesson
Its not what you've got but its what you can do with it.!!

with your Studio knowhow and Tech background along with your radical room conditioning you have managed to fully optimise your components and fine tune to the enth degree.
As I said yesterday dispite the limitations of your small room
your system is IMHO one of the most impressive sounding systems I,ve heard in a long while,imaging pin sharp & tight bass stand out features
Anybody wondering how to improve or optimise there setup would be well advised to have a listen to your system before throwing money at new cables & and mains treatment tweaks Ect
Getting back to the Tact/Behringer debate
I bought the Tact only for room correction I always intended to use my AA Dac IMHO its far superior to the Tact DAC

Yesterday we used the Tacts Auto setup functon
and none of the recomended settings we tried came close to
the performance with the Behringer in its place with Simons
1hour max of measurements and implementation

Yet back to his place The Tact DAC/PRE into his Behringer with his optimised settings did in sound better than the AA thats a fact

my opinion remains unchanged the Tact 2.2X is only for those
who have considerable expertise in the technical side of audio reproduction,for people that can master the software this is probably an awsome bit of kit.I,m going to let Simon Borrow the Tact for a week at some point I,m sure with time he will be able to improve on the Behringer, but hell at £200 that Behringer rocks

Re Stereo Mic

re your reply
Apart from the Bass I'm happy with the sound I,ve only even wanted to correct this issue, I,ll drop you a PM

An alternative, should you only wish to correct certain aberrations, is to alter the target curve to exactly mirror the existing response. The graph can be enlarged in portions to make this procedure easier but it is still time consuming. Do feel free to PM if you want to know more.

 

Okay… Target curve is what you want your systems response to look like after correction. What I mean by core curve is, the EQ the unit is applying to the signal to achieve that corrected frequency response.

It seems like the TACT is working the wrong way round to me. Rather than simply adding or subtracting different frequencies and then seeing the effect this has on your systems frequency response (simple).

…the TACT asks the user what they want their systems frequency response to be, and tries to figure out what EQ is needed to achieve this. But, then you find the TACT isn’t actually very good at working out what EQ needs to be applied. So you then have to adjust the target curve to try and counteract this and it just gets way too tricky and crude. It may not be true, but I recall Kevin saying someone told him a similar thing and it certainly displayed this in our test. The way you can’t tell it not to ‘correct’ certain frequencies without trying to trace the current response to the smallest degree (which is going to take days if you do it accurately – look at the comb filtering effects high frequencies have!) is also just a bit silly.

I may be wrong here as I am a bit unclear on what the TACT's capability is but if I am correct, it does not EQ in the time domain. In fact I believe that is impossible. What it does do is measure the time domain and take that data in to account when calculating its correction curve. The actual EQ it applies is just like any other, albeit very high resolution.

The DEQ2496 may have an FFT analyser built-in but I don't use this. Setting a target curve on the DEQ2496 and then letting the unit measure and adjust EQ until the target is achieved produces just as poor results as the TACT seems to. I personally like to use CoolEdit pro, analysing white noise at a FFT sample size of 32768. Although it is FFT, it is not real-time. It analyses the entire selection as an average.

I have also tried MLS (via ETF) instead of white noise but found the results to be pretty much identical and CoolEdit is more stable and has a better interface.

I think an impulse response based measurement works better for high frequencies, but for bass I actually find in practice that steady-state test tones and MLS work better. When you think about it bass is pretty much a steady tone.

Steve, I'm not sure quite what you mean. If you have your Hi-Fi playing in a room, it all has more reverberation than the original recording.

I think perhaps what you are getting at is that in the higher frequencies ones brain is very time sensitive. If a sound arrives at your ears, it is the first 4-6ms that are most important to our perception of the sound levels. After this the reflections will arrive, and if they arrive within 20ms of the direct sound our mind has a lot of trouble telling them apart.

What this means is that if you EQ high frequencies to be flat, taking the direct and reverberant sound over a longer than 20ms time period as a whole, it won’t actually sound quite flat as your graph indicates. However, giving a .5dB boost or cut in the areas where this additional reverberation is causing quite a deviation form normal, you won’t notice much problems at all. It is also not a problem to EQ the response of your speakers themselves if you think they sound better another way. Basically listen and see what you think, always use very small adjustments in the high frequencies and don’t try to EQ anything smaller than a quarter of an octave from about 1KHz upwards.

This is where impulse response Fourier transform is good because it is supposed to take this time related effect in to account somewhat. I don't know the exact details of this analysing method, but if someone can point me in the direction of a detailed explanation of exactly what methods the TACT uses to analyse its measurements and what it then does to work out its correction curve to achieve the target curve I would be very interested.

The bottom line though, is that you don’t really want to apply any significant amount of EQ to high frequencies. Even the guy who was doing the TACT room at the shows said this. Especially as the response changes so drastically with the listeners location. For bass, you are probably better off with any other measurement technique like MLS or white noise (pink noise is better for real-time FFT).

Anyway, despite all this I don’t see any way my system can really be improved in terms of EQ for the bass; to be honest it is as close to perfect as one is likely to get, both in terms of time domain and frequency response.

I am not bashing the TACT though; it is an absolutely brilliant DAC and pre-amp. I may buy one just for that even if I don’t want the room correction.

 

Anyway, when I get a new DAC/Pre-amp (whatever that may be) I will invite anyone who wants to come down for a listen, to do so. I think the sound we achieved with the TACT doing DAC and pre-amp duty in my system was really something quite special.

 

The dac inside the Tact is not much cop IMO.
As for improving the tact ditch the internal psu completely and construct an off board unit, fully screen the inside (for basically its a PC) this lifts its performance by a serious margin.

 

The Tact doesn't "try" anything Tenson, it does what you tell it. If you don't like the results, it's your fault surely? That is what I meant by it being a time consuming process to fine tune the curve. It's a learning process where you start to understand what frequencies have what effect on your listening perception. It's a different approach.

Which is exactly what the Tact effectively achieves, via it's differing time windows. Tact's philosophy was that narrow band EQ was essential for low frequency EQ, and obviously to achieve that type of resolution, a long measurement window was required resulting in an effective steady state tone. Higher up the frequency range, the measurement windows get progressively shorter.

Tenson, the main limitation with the Tact was knowledge and perseverence. Most people needed to persevere to gain the knowledge neccessary to get the most out of the unit. Auto setup, was fitted by Tact in response to this issue, but was only ever really intended as a solution for the less critical listener.

If you just want to EQ the bottom end in the same way as you do with the Behringer, simply switch the Tact to bypass and use the 16 band para eq from the remote or via the data cable. You then get the smae level of EQ with the Tact digital preamp and DAC facility. Once happy with that, you can experiment with the RCS software and gradually learn how to extract the potential from it. Of course you can use this 16 band Para EQ in real time from the remote in order to understand what it is that you need to include in the RCS to get your desired result. But that's another subject entirely!

 

I can tell you for sure that the TACT did not achieve the target curve. In fact I think it probably digressed further away from it.

You will probably say it wasn't being used right. To me it really seems like the part of the software that works out what EQ is required to achieve the target curve is slightly dodgy. Some target curves would not be too bad, just lacking in treble, where as others, where all that has changed is the roll off and the start frequency for the bass shelving sounded really, really different. Mostly they had absolutely no bass and sounded like a pocket radio. It was no fault of the target curve. The target just was not being achieved. Almost like the software is buggy.

It didn't seem like the measurement windows were very long. Just a few blips and pops, but admittedly done a lot of times. This does not emulate a steady-sate tone though as you have to let the room resonance build up.

Does the TACT have a limit on how extreme the EQ is that it will apply to try and achieve its target? 6dB or something?

If in the software where you set the target, you dont have the target curve right over the top of the displayed measurement, will it adjust the entire volume of the system to match the curves vertical position on the graph, or will it just ignore that?

Is there really no way to verify the results? Can't it take another measurement with its 'Room Correction' in place? This way you could see what is actually going on and continue to fine tune a lot better.

As it happens, I think the PSU in this TACT was actually modded.

Thanks for your info so far Mike

 

I suspect the Aberdeen unit Kev's using However its STILL inside the tact unit.
I laothe tact with a passion, however I have at least 7 clients with the 2.2 units, and whilst its a music killer par excellence' (yes the imaging is stunning and dynamics are very,good, and it has presence, though all of the units are using the dual subs in the corner cross up at around 270hz) set up I've listened too and (measured) on our RTA don't have this issue (In fact the plotted curves where pretty damn close +/-0.6Db max), and certainly the internal tact dac is pretty basicaly grim, and IMO (again I don;t like the AA, should have been at least another league aboue the Tact.
Could there possibly be a fault with the unit?, does it not have self diagnostic and calibration?. maybe a Check up at Tact Uk maybe in order?

 

I'll give it a decent go over the week Kev lends it to me but it definitely wasn't achieving some of those target curves, for whatever the reason may be.

Tony, what DAC/pre combo units would you recommend then? Obviously the AA didn't work well in my system, so if you don’t like it either we might have a similar taste. Something around the £1,000 - £1,500 max mark. Second-hand is no problem. The Cyrus DAC XP springs to mind as well but maybe it isn’t that high-end.

 

Simon,
recommending a dac or anything is tricky unless I'm in the room, so I can get a 'feel' for what you are after.
Have you tried the benchmark?, the MSB Platinum is very good, Wadia 25 and monachy dac 33 these you can safely use their pre sections with recoarse to using a pre, the benchmark really does need a decent pre for sure.
Have heard the Cyrus Dac XP not too bad, but needed mains to really wake it up IMO.
When kev lends it to (also a lot of the Tact guys swear by the Big ben in between it as well), meaure YOUR room first as YOU normally use do 3 consecutive plots thake the mean average. (witrh your PC software)
then drop the tact in Just measure YOUR room agin with the tact in by-pass mode and it all the same, do again 3 Consective plots. then compare.
If still spurious, get out the old trust spl meter and do the hand draulic way!!!
Maybe you need to catch the train up for a listen, then I 'll return the favour with a few dacs if you like. T.

 

Hi Tony,
A music killer.
extended listening to a wide range from "plinky plinky" type music {your term} to hard rock Simons setup with the TacT or
EQ2496 in the chain sounded wonderful even at real mega volumes that I,m not used to.

Re the AA I,ve yet to hear a more enjoyable sounding DAC

maybe its your term "groove" that's confusing, Tenson and I have
differing ideas on what you mean by groove,perhaps you could you expand on your definition of "groove"

Re my 2.2x,I can say it was in the previous owners own interest
to completely optimise this unit and is not faulty

As an experiment Simon is going to Demo at my place in the near
future his latest protoype full room treatment kit,he is confident this will make using RCS redundent in my rig the result will be interesting I'm sure
Tony
I know that you see,listen,own and mod huge amounts of highend kit but I really genuinely think Tenson's rig would suprise you given the modest units used speakers aside.

Its been a long while since I heard your wadia/Belcanto combi
system are you still working from home or do you now have a demo room/workshop to visit, Simon doesnt drive maybe we could pop down for a few hours

 

Kev,
I have a workshop, and demo from home (2 channel) A/V have a seperate demo facillities for those. Though within the next 6 months a custom built demo suites will be available.
If you read my post, I was suggesting a possible reason for the tact not performing, as all the other units I've heard don't seem to suffer from this problem.
If its not a fault, then the results are suggesting the TACT is NOT functioning as is should? therefore is not up to behringer eq, or could there be another Varible at work maybe ;-)?
Also IMO the AA is a far better dac than the Tact unit agreed.
Music killer, its lack of involvement, flow, naturalness and cohesion coupled with its lack of timing abilities.
I use room treatments as well, though I need very few and don't suffer your bass problems.
May I suggest a NOS dac in comparision to the AA Kev, It may surprise you. T.

 

I,ve read loads about the NOS dac but never heard one

I've stuck with AA's for a while now,am quite happy with the performance when used with the TEAC

I suggested the PP3 modright2 dac to Simon as a good unit to buy with a good upgrade path for the future,but he really liked the Tact DAC/Pre so now I'm not so sure it would be his taste
maybe his original thoughts about the Benchmark may be the better option

BTW
the Shunyata CC left him and his cat deeply unimpressed