[bfreedma]

but then what it the objective? to remove the room(by compensating for all the reflexions changing FR and phase) or mimicking some ideal room?

IMO, it's to reduce the most objectionable room issues. That's about the best you can hope for with most of the common REQ solutions.

I'd love to try the full version of Dirac one day, but at over $10k, that's not happening. The reduced capability versions available from some companies (Emotiva for one) don't interest me and have some implementation flaws.

 

[RRod]

So do people call phase issues a "time domain" problem?

 

[bfreedma]

  So do people call phase issues a "time domain" problem?

 
They can be interrelated but I wouldn't say it that directly.
 
For anyone who didn't major in acoustics looking for a good book that covers much of what we've been discussing, I recommend:
http://www.amazon.com/gp/product/0240520092/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
 
Toole is pretty straight forward (as much as the content can be) and sticks to the science of sound reproduction without getting into unicorn dust theories.

 

[RRod]

   
They can be interrelated but I wouldn't say it that directly.

 
I wouldn't either, but such a confounding would explain why they always seem to come up in the same breath (on this forum at least).

 

[bfreedma]

   
I wouldn't either, but such a confounding would explain why they always seem to come up in the same breath (on this forum at least).

 
Well, it wouldn't be the first time in Head-Fi history people incorrectly used nomenclature.  It happens all the time at AVS too. Getting everyone using terminology correctly would probably cut out half the arguments and a good chunk of the posts.
 
Correct use of audio terminology on this site or world peace - which is the more achievable goal?

 

[castleofargh]

 

   
I wouldn't either, but such a confounding would explain why they always seem to come up in the same breath (on this forum at least).

 
Well, it wouldn't be the first time in Head-Fi history people incorrectly used nomenclature.  It happens all the time at AVS too. Getting everyone using terminology correctly would probably cut out half the arguments and a good chunk of the posts.
 
Correct use of audio terminology on this site or world peace - which is the more achievable goal?

coming from different countries doesn't help for sure. I learned the little I know in audio reading it in english on the web. so if you guys give me a misuse of word enough times, I will learn it and misuse it like a boss.
the first one I got, I guess was "microphonics" to talk about mechanical cable noises ^_^. that one even crossed the continents and we vastly misuse it in french too.

 

[analogsurviver]

I am firmly convinced that time/phase errors are more detrimental than amplitude errors. Audibly so.
 
It is perfectly possible to equalize say headphones to have a next to identical frequency response between the left and right channel - WELL within 1 dB. If  the EQ employed results in any phase delay between the two, it will sound a lot worse than if it is EQed for zero phase difference while still being not too far off in amplitude - say 1 dB. 
With parametric EQ, it usually is possible to get both right - but it is a time consuming process.
 
Definitely it can be done.

 

[bigshot]

  Thanks - As I stated I am not against DSP but as far as room set-up I was goin gto suggest trying the AVR calibration vs by ear and see what you think if you had it. 

 
I started using the built in auto EQ in my Yamaha. It dialed my sub down to zero, put a huge dip in the response at 100Hz and made my rears much too loud. I used that as the jumping off place to refine my response, and then when I was happy with it, I brought in a friend who is a professional sound mixer to run a tone sweep to double check my results. That was my process. It took longer than just "set it and forget it" but the results are as good as I can get with my equipment, and it sounds phenomenal to human ears.

 

[bigshot]

 
What are these many problems in the time domain?

 
Phase cancellation is the biggest one. Reducing primary reflections is the best way to reduce that to acceptable levels.
 
P.S. Time is the cause, cancellation is the effect, if that helps make the terms more understandable.

 

[bigshot]

   
what are these time domain problems that need time-domain DSP algorithms to correct, and why would you worry about these fixes more than achieving a flat frequency response with frequency-domain DSP?

 
Generally a 5.1 system will have a setting to set the distance each speaker is from the main listening position. That is is the main DSP that corrects for time problems. Time isn't a huge problem in normal sized rooms. The response of your speakers and the response of your room is much more important generally. Unless you have a very large room to fill.

 

[bigshot]

  As I am happy with my multi point Mcacc room calibration which addresses Speaker Adjustment, Equalizer, Phase Control,Speaker Polarity Check, Standing Wave Control, Subwoofer Equalizer, Independent Dual Subwoofer Output, Full Band Phase Control. I have then checked the SPL level at various points in my room and am satisifed with both what I hear and measure. I am certain I can't achieve that by ear alone.

 
Your ears probably can't hear half of the corrections anyway, so it really doesn't matter. The only problems are the problems that are problems within your range of hearing.

 

[StanD]

 
coming from different countries doesn't help for sure. I learned the little I know in audio reading it in english on the web. so if you guys give me a misuse of word enough times, I will learn it and misuse it like a boss.
the first one I got, I guess was "microphonics" to talk about mechanical cable noises ^_^. that one even crossed the continents and we vastly misuse it in french too.

Misuse it like a champ. 

 

 

[bigshot]

  but then what it the objective? to remove the room(by compensating for all the reflexions changing FR and phase) or mimicking some ideal room?

The theory among a lot of folks is to remove all of the sound of the room to make "pure" sound. But one thing I learned from my acoustic Victrola is that the room can add a very important factor to the sound. We accustom ourselves to the sound of a room as we speak in it. If suddenly the sound of music doesn't have the same acoustic as our voices, it can make the music sound false. There are good effects and bad effects of room acoustics. Obviously frequency response imbalances and phase cancellation are bad effects. Those are best to deal with. But a little bit of resonance or "live" sound isn't necessarily a bad thing. You can synthesize those things with DSPs and a sometimes they are built into the mix, but a familiar sound is a good thing.
 
Like I say, hardcore purists will disagree, but I have found this to be true for me. The thing about early Caruso acoustic records is that they were recorded very dry. No room acoustic at all. Victrola dealers told customers to place their Victrolas in the opposite corner of the room to use the walls and floor as extensions to the horn, and to add room acoustics that were perfectly natural because they were created by a real room... yours. Accurately reproducing music is easy. Accurately reproducing space gets more tricky. If you have a little non-destructive REAL space to work with, it can add some nice depth cues to your sound system. You just don't want too much so it gets all mushy and mixed up.

 

[StanD]

 
The theory among a lot of folks is to remove all of the sound of the room to make "pure" sound. But one thing I learned from my acoustic Victrola is that the room can add a very important factor to the sound. We accustom ourselves to the sound of a room as we speak in it. If suddenly the sound of music doesn't have the same acoustic as our voices, it can make the music sound false. There are good effects and bad effects of room acoustics. Obviously frequency response imbalances and phase cancellation are bad effects. Those are best to deal with. But a little bit of resonance or "live" sound isn't necessarily a bad thing. You can synthesize those things with DSPs and a sometimes they are built into the mix, but a familiar sound is a good thing.
 
Like I say, hardcore purists will disagree, but I have found this to be true for me.

If one sits too close to their rear speakers, they could get delay lines.

 

[Don Hills]

   
I agree it isn't either-or; the language of the blurb makes it seem like the author thinks that time-domain issues are the greater concern, that's all.

 
When you are selling hammers, you describe all problems as nails.