The Quest for Perfection

[jaxvon]

It might be more than just frequency response correction, it might also do phase and time domain correction (though I don't know for sure with the TACT).

 

[Sleestack]

Room correction would be synonymous with EQ right? In other words you're correcting the frequency response for a single position in a room (wherever the calibration microphone is placed). Why would one champion room correction when room treatment benefits the frequency response for the entire room?

First, I don't advocate diregarding room acoustics completely. In fact I use room correction to figure out some of the problems areas in my rooms and make slight adjustments. That being said, I'm not about to make my rooms look like lab.

As for room correction = EQing. No. When was the last time you were able to make millisecond time adjustments with your equalizer?

Straight from TACT's room correction resource page:

"Typical parametric equalization systems hunt for steady state room-modes and have no way of implementing the information gained from a calculation of impulse response. By ignoring the impulse response, parametric equalization systems completely disregard the natural time domain properties of sound.

The human ear relies on the time domain for both the localization of the sound image and the accurate perception of direct sound. In extracting directional information, the brain processes the time-of-arrival differences between the left and right ear, as well as the intensity differences.

When discerning direct sound from reflections, the brain lumps together echoes in the range of 1 to 50 milliseconds. Delays greater than 50 milliseconds are heard as echoes.

A room with a long reverberation decay time could, for example, create wavefronts that effectively mask the direct sound. By measuring the impulse response of an entire system, room correction is able to ensure that the components are working synergistically so that all aspects of a recording can be heard. "

For info on true room correction and the differences v. parametric equalization look here:

http://www.roomcorrection.com/TheProcess/ParEQComparison.html

I didn't believe it until I actually heard it. Don't fight it... your ears will thank you.

 

[Buckle-meister]

That being said, I'm not about to make my rooms look like lab.

What makes you think they have to look like a lab? With a bit of thought, room treatment can be made invisible. And before anyone posts a picture of my own lab-like room, do remember that it's a rented pad, and on that basis, fleeting (especially at this moment in time).

As for room correction = EQing. No. When was the last time you were able to make millisecond time adjustments with your equalizer?

I don't own an equaliser, though I admit that I've been considering purchasing one in order to squash my room's first axial mode because it's at just too low a frequency for my room treatment to touch.

Room correction by electronic means sure sounds like EQing to me, no matter how you want to dress it up.

Straight from TACT's room correction resource page:...

That's great, but it's still only correcting the response at just...one...single...position in the room (unless I'm mistaken) isn't it?

 

[Sleestack]

What makes you think they have to look like a lab? With a bit of thought, room treatment can be made invisible. And before anyone posts a picture of my own lab-like room, do remember that it's a rented pad, and on that basis, fleeting (especially at this moment in time).



I don't own an equaliser, though I admit that I've been considering purchasing one in order to squash my room's first axial mode because it's at just too low a frequency for my room treatment to touch.

Room correction by electronic means sure sounds like EQing to me, no matter how you want to dress it up.



That's great, but it's still only correcting the response at just...one...single...position in the room (unless I'm mistaken) isn't it?

You're correct that it is reading a response at one postion, but what pair of speakers sound the same at every position? Furthermore, it is measuring the effects of the entire room at that listening position. With room treatment, there is still only going to be one ideal sweet spot. With the TACT gear, you could set up mutiple listening positions based on wher you happen to want to sit. If you want the sweet spot to be in the back corner of the room, the TACt gear will allow you to do that.

You read the TACT info. I linked to and you still think it is the same as EQing? In that case I really don't know what to say. The TACT gear has a parametric equalizer, but it is a separate function from the room correction.

The only reason I promote room correction is b/c it was an absolute revelation for me. I have a friend who had Rives come in and design a dedicated theater in his house. He went with their fully customized option and sepnt a ton of money. After hearing what the TACT stuff can do in HT , even he admitted that had he known about it, he would have gone that way.

It is difficult for people to understand what room correction can really do until they hear it, so I certainly don't blame you for your skepticism.

I very much support room treatment as well, but nobody I know has a perfect room.

 

[flyv65]

That's great, but it's still only correcting the response at just...one...single...position in the room (unless I'm mistaken) isn't it?

It was my understanding (at least with the Audyssy gear) that the "correction" is for up to three places in the room, blending the correction to give a more uniform sound throughout.

Bryan...by the way, is your avatar the Macdonald of the Isles tartan?

 

[Buckle-meister]

Bryan...by the way, is your avatar the Macdonald of the Isles tartan?

Bryan? Who's Bryan?

Assuming you're referring to me, yes, it's Ancient Hunting MacDonald of the Isles; one which I am entitled to wear.

 

[Sleestack]

It was my understanding (at least with the Audyssy gear) that the "correction" is for up to three places in the room, blending the correction to give a more uniform sound throughout.

Bryan...by the way, is your avatar the Macdonald of the Isles tartan?

The Audyssey stuff is a bit different and more basic than the TACT stuff and does in fact do what you say. I found it effective, but imaging was not dead on in any location. With my TACT gear I always introduce people to it by running a 2 channel SACD and telling them it is a 5.1 SACD that just uses the rears for a little expansion of the soundstage. When I have them walk up to the center channel and they realize its not running, I always get something like "WOW, I've never seen such a perfect example of a phantom center channel."

 

[Buckle-meister]

With room treatment, there is still only going to be one ideal sweet spot.

Yes, but room treatment widens the sweet spot. EQing (we'll get to that in a minute ) doesn't.

With the TACT gear, you could set up mutiple listening positions based on where you happen to want to sit. If you want the sweet spot to be in the back corner of the room, the TACt gear will allow you to do that.

Again, if room treatment broadens the sweet spot, then it's still more beneficial than simply moving from one position that's been corrected to another that is then corrected at the expense of losing the previous.

You read the TACT info. I linked to and you still think it is the same as EQing?

Um, no, sorry, I didn't actually read your link. Just speaking from ignorance I guess.

It is difficult for people to understand what room correction can really do until they hear it, so I certainly don't blame you for your skepticism.

Not at all. I'm not skeptical. I'm sure it's a stunning piece of kit. Sorry for coming across so hard on you. I didn't mean to.

I very much support room treatment as well, but nobody I know has a perfect room.

Agreed.

 

[Buckle-meister]

Hello Bryan.

 

[flyv65]

Hello Bryan.

Hello Robbie (or perhaps cousin?) . I see your located in Scotland-do you by chance have Tannoy speakers and Linn electronics scattered about your home?

 

[mtrycrafts]

Bay Area. Any time.

I'll keep it in mind

Once you hear a fully corrected system it's almost impossible to ever go back. Everything just sounds wrong in comparison.

That's the problem if you cannot upgrade to it.

and yes, no magic... just math and science.

LOL. Refreshing.

 

[WmAx]

Straight from TACT's room correction resource page:

"Typical parametric equalization systems hunt for steady state room-modes and have no way of implementing the information gained from a calculation of impulse response. By ignoring the impulse response, parametric equalization systems completely disregard the natural time domain properties of sound.

Sounds like manufacturer double-talk to me....

I like how they specify 'typical parametric equalization'. Of course, the TACT is not typical; it's an automated parameteric equalization system using extremely effective algorythms to determine the filter parameters for a given room/target response. It can not actually correct for room reverb/reflections. However, it can adjust for some of the bass problems, and then it can adjust the overall broad response of the system to correct for speaker distance vs. listening position difference effect upon treble, and for various speaker-based frequency response problems.

-Chris

 

[Sleestack]

Sounds like manufacturer double-talk to me....

I like how they specify 'typical parametric equalization'. Of course, the TACT is not typical; it's an automated parameteric equalization system using extremely effective algorythms to determine the filter parameters for a given room/target response. It can not actually correct for room reverb/reflections. However, it can adjust for some of the bass problems, and then it can adjust the overall broad response of the system to correct for speaker distance vs. listening position difference effect upon treble, and for various speaker-based frequency response problems.

-Chris

I think you are off base here. In fact TACT's resource site talks extensively about the differences between parametric equalization and room correction. Check it out first:

http://www.roomcorrection.com/index.html

 

[WmAx]

I think you are way off base here. In fact TACT's resource site talks extensively about the differences between parametric equalization and room correction. Check it out first:

http://www.roomcorrection.com/index.html

Yes, I see the marketing literature. The system may use a convolver instead of parametric bands to do the same thing as parameteric bands, but with a larger number of corrections possible than individual parameteric bands(every additional parametric band requires more cpu processing, thus you are limited based on this). But I don't see this specified anywhere. Potentially, a convolver can also be used to counter-affect time base effects like reflections, but this is not practically applicable, because this is a process that is so sensitive to movement at higher frequencies, that a couple of centimeters can mean the difference between increasing sound quality and making it vastly worse.

-Chris

 

[Sleestack]

Yes, I see the marketing literature. The system may use a convolver instead of parametric bands to do the same thing as parameteric bands, but with a larger number of corrections possible than individual parameteric bands(every additional parametric band requires more cpu processing, thus you are limited based on this). But I don't see this specified anywhere. Potentially, a convolver can also be used to counter-affect time base effects like reflections, but this is not practically applicable, because this is a process that is so sensitive to movement at higher frequencies, that a couple of centimeters can mean the difference between increasing sound quality and making it vastly worse.

-Chris

Sounds like you just want to be a skeptic without really even knowing exactly what is involved in the technology or ever actually exposing yourself to it. If that's the case so be it, but it seems rather closed minded on your part.

One thing I do know, the TACT systems can take room with many acoustic problems and make it sound closer to perfection than anything I've heard, and I've heard plenty of great systems in great acoustic environments. I also know that I've never used a parametric eq that makes time ajdustments for each speaker relative to the rest of the system using pulse signals to measure a room's impulse response.

 

[WmAx]

Sounds like you just want to be a skeptic without really even knowing exactly what is involved in the technology or ever actually exposing yourself to it. If that's the case so be it, but it seems rather closed minded on your part.

One thing I do know, the TACT systems can take room with many acoustic problems and make it sound closer to perfection than anything I've heard, and I've heard plenty of great systems in great acoustic environments. I also know that I've never used a parametric eq that makes time ajdustments for each speaker relative to the rest of the system using pulse signals to measure a room's impulse response.

I am familar with the available tehchnologies, and the physical/practical limitations of such technologies. Of course you must record an impulse(or derive the impulse from MLS signal) to derive a convolver filter; so it sounds as if this may be what the TACT is doing.

What is it that I seem skeptical about? The only thing I am skeptical about is claims that electronic system can correct for room reflection(s)/reverb(s), since I am not aware of any such proven system for hi-fidelity use(non hi-fidelity applications are a different matter). A convolver has very limited ability in that realm, in real application. However, a convolver does make for an excellent frequency response correction filter.

-Chris

 

[Sleestack]

I am familar with the available tehchnologies, and the physical/practical limitations of such technologies. Of course you must record an impulse(or derive the impulse from MLS signal) to derive a convolver filter; so it sounds as if this may be what the TACT is doing.

What is it that I seem skeptical about?

-Chris

You don't know for sure what TACT is using, their technology is proprietarry and has developed for 10 years by Boz, yet you know all about its limitations? Plus you have no experience with the TACT gear first hand?

Perhaps you weren't being a skeptic, but your first post started out "sounds llike manufacturer double talk to me," so I mistakenly assumed you were doubting my assertions regarding the "perfection" achievable with the TACT systems. If so, my fault.

 

[WmAx]

You don't know for sure what TACT is using, their technology is proprietarry and has developed for 10 years by Boz, yet you know all about its limitations?

I highly doubt that TACT has developed any unique digital technology. The unique thing about them is moving a convolver to hardware component(as where you normally have to use a computer), and then providing an excellent automatic set up system/algorythm. I can only presume the 'propreitary' part is the algorythm they are using to determine the correction(s).

Perhaps you weren't being a skeptic, but your first post started out "sounds llike manufacturer double talk to me," so I mistakenly assumed you were doubting my assertions regarding the "perfection" achievable with the TACT systems. If so, my fault.

I never said anything to the effect of the TACT not improving the sound of your system. I have no doubt that it improved the response greatly, compared to the uncorrected response.

-Chris

 

[Sleestack]

I highly doubt that TACT has developed any unique digital technology. The unique thing about them is moving a convolver to hardware component(as where you normally have to use a computer), and then providing an excellent automatic set up system/algorythm. I can only presume the 'propreitary' part is the algorythm they are using to determine the correction(s).

You may be right, but highly doubting is very different from knowing.

I never said anything to the effect of the TACT not improving the sound of your system. I have no doubt that it improved the response greatly, compared to the uncorrected response.

As I said, my fault.

 

[mtrycrafts]

Sorry. I only work in metric.

The yardstick is different for each of us, and there are multiple yardsticks per person (I suspect this is not an answer you'll like ). You maybe content with your boom-boxes where I would not be. But then, both of us would be content with boom-boxes as opposed to not having the means to play music at all.



I believe that obtaining perfection is similar to knowing you're rich; in both cases money is irrelevant.

Oh, I should have said the meter stick
Yes, yes, but I think this was about perfection, not being content. I would never call my booboxes-2, being perfect
I was just wondering about perfection. It is elusive and a singular reality then with no consensus of any kind possible. Boy, ...