[freeflier]

Ps
Before you go there, don't bother with the "a drummer isn't a musician" cheap shot. It's all about time and groove!

 

[ooheadsoo]

Would you care to explain why broadband absorption does not work?

 

[chesebert]

Quote:

Originally Posted by freeflier /img/forum/go_quote.gif You are the one who brought up windows. Now you are just altering the premise to try and deflate my arguement. If you want to talk about close miking and removing the room from the recording then lets talk about that. Would that be practical with an orchestra or even a Jazz quartet. Do you really want to try and create the illusion that a full orchestra is in your living room. I guarantee that would definitely sound like ****. It seems more logical to create the illusion of being at the concert hall. That means capturing the room acoustics and attempting to maintain that integrity at reproduction. I don't know man. How deep did you get into your art? These are not concious decisions. If your ears are open you've got to be hearing yourself as you play (and the other musicians if that applies). If you are not, yes you are right, you probably aren't very good. On the other hand if you hear yourself you hear the room. Sound and tonality are HUGE elements of Jazz (and I would assume Classical as well). Tons of great players are recognized for their sound (Lester Young, Philly Joe Jones, Miles (of course), Wynton Marsallis etc etc) BTW I don't consider myself a great player. I'm a drummer and stopped long ago for reasons I won't go into but... I did study for a number of years with the great Jim Blackley (teacher of many many awesome players like Danny Richmond (Mingus's drummer) and Terry Clark to name a couple). I got exposed to some very deep stuff.

I can't change the tone of my piano.... can you?

and I can't really hear the room interaction very well seeing I sit about 6in away from the sound board

on maintaining the hall acoustic integrity, you are trying to use TACT system to alter that to fit your room. how is that keeping acoustics integrity intact? strange you would be the one bringing up acoustic integrity when you are freely DSPing the incoming signal.

 

[freeflier]

Quote:

Originally Posted by chesebert /img/forum/go_quote.gif I can't change the tone of my piano.... can you? and I can't really hear the room interaction very well seeing I sit about 6in away from the sound board on maintaining the hall acoustic integrity, you are trying to use TACT system to alter that to fit your room. how is that keeping acoustics integrity intact? strange you would be the one bringing up acoustic integrity when you are freely DSPing the incoming signal.

My Tact isn't messing with my head... you are.
1) You don't need to conciously assess the sound of the room. It's part of the sound you are producing. As for getting the sound it's all about "touch".
(BTW a couple of additiions for GREAT tone: Ben Webster, Coleman Hawkins, Pat Metheny).
2) Once again, I'll reiterate. If you want to have a meaningfull discussion about Tact (or related) RCS then you really need to educate yourself. When you artificially reproduce music in any normal sized room you get distortions due to constructive and destructive wave interferance paterns. THAT is what you are trying to remove. Have you ever even seen a sweep of the average room? There is an enormous 8-15 db hump below 200 hz (not mention smaller distortions above). That means bass notes are approximately 6-32 times louder than they should be (6-32 times more power is being generated). THAT'S HUGE!!!!!!!!!!!!!!!!! It's exagerated, muddies the sound, covers a lot of inner detail and messes with the midrange.
And ... it's what most people have been conditioned to think is correct.
BTW the correction filters are generated based on a room sweep. They are not just randomly applied to the "incoming" signal.

 

[freeflier]

Quote:

Originally Posted by ooheadsoo /img/forum/go_quote.gif Would you care to explain why broadband absorption does not work?

Oh man, it's pretty straightforward but I would have a hard time with being able to draw some pictures. Thiink of it this way...a hump due to constructive interfeance looks like a hill and might be 20-50 hz wide. You would need to target the center, know the exact Q factor (width), and also the relative amplitude. These are all unique to each environment. The problem is that there are going to be 2 or 3 or 4 of these major humps (each one unique to your room and speaker system) . Honestly, it was about 10 years ago that I looked into how to make room tuning devices and I forgotten all the details. I ended up concluding that it far too complex a problem to be practical. Like I said before, you could get some results, but they wouldn't even come close to the accuracy possible using custom correction filters applied in the digital domain. Of course it's a different story if you are designing a public venue where months of trial and error would be more cost effective and worthwhile.

BTW Don't get me wrong. Digitial RCS can't fix everything and there are 2 areas where mechanical solutions are better. First of all it can't deal with suckouts because that would place outrageous demands on both the amp and speakers (probably blowing both). To address this problem one needs to optimize speaker placement in order to minimize the Allison suckout. Secondly the Tact RCS can't really address the phase distortions caused by early reflections of higher frequencies or the reverb of the room. For these, reflection damping panels are probably the way to go (or a much bigger room). As far as I'm concerned RCS fixes the most pernicious problem, the HUGE bass hump inherent to virtually all rooms. For the secondary stuff you need to combine solutions.

 

[chesebert]

Quote:

Originally Posted by freeflier /img/forum/go_quote.gif My Tact isn't messing with my head... you are. 1) You don't need to conciously assess the sound of the room. It's part of the sound you are producing. As for getting the sound it's all about "touch". (BTW a couple of additiions for GREAT tone: Ben Webster, Coleman Hawkins, Pat Metheny). 2) Once again, I'll reiterate. If you want to have a meaningfull discussion about Tact (or related) RCS then you really need to educate yourself. When you artificially reproduce music in any normal sized room you get distortions due to constructive and destructive wave interferance paterns. THAT is what you are trying to remove. Have you ever even seen a sweep of the average room? There is an enormous 8-15 db hump below 200 hz (not mention smaller distortions above). That means bass notes are approximately 6-32 times louder than they should be (6-32 times more power is being generated). THAT'S HUGE!!!!!!!!!!!!!!!!! It's exagerated, muddies the sound, covers a lot of inner detail and messes with the midrange. And ... it's what most people have been conditioned to think is correct. BTW the correction filters are generated based on a room sweep. They are not just randomly applied to the "incoming" signal.

so how does your room change when you load the room up with real instrument? like I said do I need to TACT my instrument?

uh..actually having designed a sound card via TI DSP I think I know at least how DSP works on a fundamental level. room correction is no more than digitally equalizing your signal via filter constructed with impulse responses generated.

I prefer my speaker to load the room similar to a real instrument where I don't need any TACT to 'correct' anything. If the speaker sounds like POS, then I get another one that don't. why is the concept of changing speaker so hard? If you want to experience full symphony, then it won't happen in your 10x10 room no matter how much DSPing you put on the signal, the trick .....is to get a larger room with larger speakers.

It's ok if TACT is your thing. I just know that I don't want another EE to tell me how to listen to my music in my room.

 

[ooheadsoo]

Quote:

Originally Posted by freeflier /img/forum/go_quote.gif Oh man, it's pretty straightforward but I would have a hard time with being able to draw some pictures. Thiink of it this way...a hump due to constructive interfeance looks like a hill and might be 20-50 hz wide. You would need to target the center, know the exact Q factor (width), and also the relative amplitude. These are all unique to each environment. The problem is that there are going to be 2 or 3 or 4 of these major humps (each one unique to your room and speaker system) . Honestly, it was about 10 years ago that I looked into how to make room tuning devices and I forgotten all the details. I ended up concluding that it far too complex a problem to be practical. Like I said before, you could get some results, but they wouldn't even come close to the accuracy possible using custom correction filters applied in the digital domain. Of course it's a different story if you are designing a public venue where months of trial and error would be more cost effective and worthwhile. BTW Don't get me wrong. Digitial RCS can't fix everything and there are 2 areas where mechanical solutions are better. First of all it can't deal with suckouts because that would place outrageous demands on both the amp and speakers (probably blowing both). To address this problem one needs to optimize speaker placement in order to minimize the Allison suckout. Secondly the Tact RCS can't really address the phase distortions caused by early reflections of higher frequencies or the reverb of the room. For these, reflection damping panels are probably the way to go (or a much bigger room). As far as I'm concerned RCS fixes the most pernicious problem, the HUGE bass hump inherent to virtually all rooms. For the secondary stuff you need to combine solutions.

To clarify:

Are you referring to helmholtz resonators, which are the old way of attacking the problem? Today, people are increasingly tending to use broadband absorption, i.e. absorption that covers 40hz-7khz or other various ranges, which absorbs all of those frequencies, thus reducing in amplitude the reflections that are causing the constructive and destructive interference, as you put it. This also deals with the timing issue that the strong and early reflections create, confusing our ears with the direct sound. The idea is to target all bass reflections (and other reflections if desired) instead of using helmholtz resonators to target just the peaks, which, as you have mentioned, is way too complex to handle efficiently. In other words, instead of targetting the constructive interference and leaving the destructive interference alone, as the tact would likely do, they target all interference equally. Remove (or at least reduce) the reflection and the problem is diminshed. It even helps with the Allison suckout. I think it used to be such that old absorption products did not absorb bass frequencies very efficiently and were thus only suitable for early reflection affecting imaging from the midrange on up, but that is no longer the case.

Tube traps typically refer to a tube of fiberglass, either filled or hollow, and are one form of these broadband absorbers. Other trap types are panels or tricorners made of fiberglass or other materials. AFAIK, helmholtz resonators are not called tube traps.

Problems with this approach?

Btw, I have a couple measurement mics that cost me a couple hundred and have played with using my computer for room correction. It's fun, but you know as well as I do that it doesn't solve everything.

 

[freeflier]

Quote:

Originally Posted by chesebert /img/forum/go_quote.gif so how does your room change when you load the room up with real instrument? like I said do I need to TACT my instrument? uh..actually having designed a sound card via TI DSP I think I know at least how DSP works on a fundamental level. room correction is no more than digitally equalizing your signal via filter constructed with impulse responses generated. I prefer my speaker to load the room similar to a real instrument where I don't need any TACT to 'correct' anything. If the speaker sounds like POS, then I get another one that don't. why is the concept of changing speaker so hard? If you want to experience full symphony, then it won't happen in your 10x10 room no matter how much DSPing you put on the signal, the trick .....is to get a larger room with larger speakers. It's ok if TACT is your thing. I just know that I don't want another EE to tell me how to listen to my music in my room.

Fallacy #1: A speaker isn't an instrument. It is a transducer. A saxophone is an instrument. Just because they both make a sound doesn't make them the same anymore than the image of flower pictured on your TV needs water the way the real thing does.

Fallacy #2: People don't cram and orchestra or a quartet (or even a steinway) into the average sized living room. Have you ever heard how a sax sounds in a small room? That's not the environment it was designed for. That's why people go to listen in a full sized (often dedicated) venue. It is in this setting that an instrument(s) can properly "load" the room. If you then want to the load another room with a recording of a loaded room, be my guest (I won't cram this down your throat. To each his own). But... don't muddy the water by claiming that this is some kind of realistic or natural phenomenon. BTW the Tact equipment goes well beyond simple amplitude correction. It is also making phase and time corrections and tinkering around with some simple DSPs doesn't mean you know what this technology is all about. If simple DSPs did the job properly Tact would be out of business (you can get this basic stuff free on the web). There are certainly limitations to what can be done but you clearly don't understand them. Why don't you just do a little research so that you know what you are talking about. Better yet, go and listen to proper setup. It won't sound quite right at first because of the compensations your brain has made for the distortions you are accustomed to (This is similar to the way your brain needs a day to adjust to a new eyeglass prescription). Listen with an open mind and give it a couple of days and THEN make up your mind...instead of shooting your mouth off in a nonsensical abstract debate.

Once again I will reiterate that the Tact can't do everything. The biggest issue IMO that it can't address is the smearing in the time domain as a result of boundry effects in the lower frequencies. That is the problem I alluded to when I made my initial post about placing low frequecy drivers in the corners (where they work best) and then digitally crossing/aligning them with mid/high satelites. I think I've said all I intend to here. This is a waste of time.

BTW Nearfield miking does nothing to mitigate the effects of standing waves.

 

[ooheadsoo]

Oh.

 

[chesebert]

Quote:

Originally Posted by freeflier /img/forum/go_quote.gif Get your parameters straight. People don't cram and orchestra or a quartet (or even a steinway) into the average sized living room. They go and listen in a dedicated venue that has been designed to maximize the listening experience (or is at the very least much larger than your room). In this setting the instruments "load" the room. If you want to the load another room with a recording of a loaded room, fine. But don't muddy the water by saying that this is some kind of natural phenomenon. BTW the Tact equipment goes beyond simple amplitude correction. It is also making phase and time corrections and tinkering around with some simple DSPs doesn't mean you know what this technology is all about. If simple DSPs did the job properly Tact would be out of business. There are certainly limitations but you clearly don't understand them. Why don't you just do a little research so that you know what you are talking about. Better yet, listen to proper setup. It won't sound right at first because of the adjustments your brain has made for the distortions you are used to (This is similar to the way your brain needs a day to adjust to a new eyeglass prescription). Listen with an open mind and give it a couple of days before shooting your mouth of about a bunch of theoretical nonsense. Once again I will reiterate that the Tact can't do everything. The biggest issue IMO that it can't address is the smearing in the time domain as a result of boundry effects in the lower frequencies. That is the problem I alluded to when I made my initial post placing low frequecy drivers in the corners (where they work best) and the digitally crossing/aligning them with mid/high satelites. I think I've said all I intend to here. This is a waste of time.

actually you are the one with the closed mind, and furthermore you refuse to acknowledge TACT is nothing more than a DSP unit that sells for $3,000.

If you ever programed a DSP chip you will know how simple it is, relatively compared to designing an amp (bipolar/FET stuff, opamp based stuff don't count

that is, not saying designing and programming a DSP is an easy thing.

However to categorically denied basic DSP theories as 'nonsense' you have self-invalidated all your arguments wrt DSP and TACT. I say you pick up a DSP book and get yourself some education in that.

 

[Wodgy]

Quote:

Originally Posted by freeflier /img/forum/go_quote.gif BTW the Tact equipment goes beyond simple amplitude correction. It is also making phase and time corrections and tinkering around with some simple DSPs doesn't mean you know what this technology is all about.

I find it hard not to laugh when I read this kind of thing. TACT owners often seem very eager to repeat the marketing claims that company makes, but usually have no real understanding of signal processing. Any correction of the impulse response corrects both amplitude and phase.

TACT makes decent gear, don't get me wrong. But it does nothing that a software based convolver doesn't do, and it doesn't replace the need for decent room treatment.

 

[freeflier]

Quote:

Originally Posted by ooheadsoo /img/forum/go_quote.gif Oh.

ooheadsoo,
Personally, if I was dead set against digital room correction, I would try to minimize the whole issue with a very high quality monitor that has well controled and rolled off bass. With the right choice you could probably find something that rolls off just as room gain starts to kick in and try and balance them.
Be advized though, that accurate bass is going to sound a little light at first but... if it's done right you soon realize that a lot of music is hiding behind the exagerated bass bloat that most poeple seem to covet.

 

[freeflier]

edited

 

[freeflier]

Quote:

Originally Posted by Wodgy /img/forum/go_quote.gif I find it hard not to laugh when I read this kind of thing. TACT owners often seem very eager to repeat the marketing claims that company makes, but usually have no real understanding of signal processing. Any correction of the impulse response corrects both amplitude and phase. TACT makes decent gear, don't get me wrong. But it does nothing that a software based convolver doesn't do, and it doesn't replace the need for decent room treatment.

Did I say different? As far as I know not all DSP "equilizers" use an impulse response to generate
their filter. I've also commented repeatedly that in order to use this stuff right you need to understand the limitations. That is not the point. These comments come up in response to people who dismiss the potential because of some kind of philosophical aversion to "processing". In fact as far as I'm concerned the REAL potential is not in the room correction aspect but rather in digital crossover technology.

 

[freeflier]

Quote:

Originally Posted by chesebert /img/forum/go_quote.gif actually you are the one with the closed mind, and furthermore you refuse to acknowledge TACT is nothing more than a DSP unit that sells for $3,000. If you ever programed a DSP chip you will know how simple it is, relatively compared to designing an amp (bipolar/FET stuff, opamp based stuff don't count that is, not saying designing and programming a DSP is an easy thing. However to categorically denied basic DSP theories as 'nonsense' you have self-invalidated all your arguments wrt DSP and TACT. I say you pick up a DSP book and get yourself some education in that.

Are you just going to keep twisting my words untill you confuse the issue to the point where the whole discussion is so incoherant you can claim some kind of victory?
Of course it's a DSP. I never said it wasn't. I was dismissing simple free DSP technology. It's like claiming that software you get supplied with your camera is just as good as the software in a dedicated Photoshop package just because they are both Software. What kind of nonsense are you going to hit me with next?
How do you know what the Tact does? Have you read the white paper? Have you ever heard one? Who are you trying to kid. Get off your lazy ass.