Room calibration - of some sort
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Liquid Len
- Posts: 652
- Joined: Tue Dec 09, 2003 4:00 pm
- Location: Home By The Sea
Room calibration - of some sort
I am not very happy with my current monitoring system, it's far from flat response, I want to slap an EQ across the mains to try to fix things up a bit. I was wondering if there is any way I can use scope gear to generate pink noise and use a microphone (at my listening position) to create a flatter response. If not, is there any PC software that would do this?
Agreed, fix the room. The problem with calibration using a mic is that every inch you move the mic (and your head) you'll get wildly different results.
The main problem with most rooms is the nodes that result from reflected sound causing peaks & valleys in the low end response. Every position in the room will vary wildly across many frequencies, and the shape of the room will dictate what frequencies are affected the most. So after some moderate (not overdone) treatement to clean up the midrage & high end (auralex foam, hand built sound boxes or w/e) bass trapping is very important. In fact if you were to simply put some foam on the walls to 'dry up' the mids & upper frequencies you'd actually make the low end issues WORSE by comparison, so dealing with everything evenly is most important. It's also important not to totally deaden a room (imo) as it dramatically affects your perception of depth/width and the amount of effects necessary in a mix.
After you invest in room treatment, and then some room construction to float certain surfaces, remove parallel surfaces, add some diffusion etc you might then consider the room to be as good as it's going to get and calibrate the monitoring with eq'ing for a fixed listening position, but keep in mind that's a huge investment in room upgrades first and the 'corrected' listening position will be VERY narrow (not worth it imo).
The main problem with most rooms is the nodes that result from reflected sound causing peaks & valleys in the low end response. Every position in the room will vary wildly across many frequencies, and the shape of the room will dictate what frequencies are affected the most. So after some moderate (not overdone) treatement to clean up the midrage & high end (auralex foam, hand built sound boxes or w/e) bass trapping is very important. In fact if you were to simply put some foam on the walls to 'dry up' the mids & upper frequencies you'd actually make the low end issues WORSE by comparison, so dealing with everything evenly is most important. It's also important not to totally deaden a room (imo) as it dramatically affects your perception of depth/width and the amount of effects necessary in a mix.
After you invest in room treatment, and then some room construction to float certain surfaces, remove parallel surfaces, add some diffusion etc you might then consider the room to be as good as it's going to get and calibrate the monitoring with eq'ing for a fixed listening position, but keep in mind that's a huge investment in room upgrades first and the 'corrected' listening position will be VERY narrow (not worth it imo).
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Liquid Len
- Posts: 652
- Joined: Tue Dec 09, 2003 4:00 pm
- Location: Home By The Sea
well if its just the monitors you want to EQ, you could put a mic pretty close to one, about half way between the drivers and adjust the EQ as best you can. dont try and EQ your room any more than moving speakers further and closer to the walls to change the bass.
you need pink noise, spectrum analyzer, and some EQ. the EQs shouldn't be a problem at least!. you might have to use a software spectrum analyzer, i think theres a winamp plugin which does it.
pink noise can just be a recording of known good pink noise.
you need to use a microphone with a known response curve as well. but most electrts are fairly flat in a wider range than your speakers are anyways.
oh yeah if you have speakers on top of a table or mixing desk get them off. use/make some stands or get some foam and put it under them. hang them if you have to! speakers sitting directly on big reflective/resonant things makes the sound bad.
you need pink noise, spectrum analyzer, and some EQ. the EQs shouldn't be a problem at least!. you might have to use a software spectrum analyzer, i think theres a winamp plugin which does it.
pink noise can just be a recording of known good pink noise.
you need to use a microphone with a known response curve as well. but most electrts are fairly flat in a wider range than your speakers are anyways.
oh yeah if you have speakers on top of a table or mixing desk get them off. use/make some stands or get some foam and put it under them. hang them if you have to! speakers sitting directly on big reflective/resonant things makes the sound bad.
Just like to add .
If you can't invest the money to get a pair of decent monitors for mixing, then invest some money to get good headsets!!!
I think you could get way better results (for your situation) using a good pair of headsets rather than trying to fiddle around with a pair of hifi monitors.
After saying that you could always use both and compare your mix with headset and your monitors.
Basically, the more references you use the more likely you'll get what you're looking for. ( or listening for rather)
Listen to your mix in your car, home stereo, etc...
hope this helps
Yiannis
If you can't invest the money to get a pair of decent monitors for mixing, then invest some money to get good headsets!!!
I think you could get way better results (for your situation) using a good pair of headsets rather than trying to fiddle around with a pair of hifi monitors.
After saying that you could always use both and compare your mix with headset and your monitors.
Basically, the more references you use the more likely you'll get what you're looking for. ( or listening for rather)
Listen to your mix in your car, home stereo, etc...
hope this helps
Yiannis
Headsets aren't a bad suggestion for a second reference as long as you can afford a decent set (avoid the 'boxy' sounding ones from sony). They're certainly an invaluable tool for clinical editing even when you do have decent nearfields.
And I would actually recommend a pair of 'bookshelf' hi-fi speakers over 3-way hifi jobs that will have an overhyped 80-150hz region and muddled phasey midrange from the crossover & 3-way drivers. Also it's worth noting that due to the way hifi speakers 'project' and hype the sound you're still going to have the same eq issues in relation to the room's low end that I mentioned above. Or as mentioned above, simply go for the option of having several sets of speakers on hand to monitor with can help overcome the deficencies of a single pair, and you'll probably find which ones you prefer for what task rather quickly.
But if you're going to buy a new set of bookshelf speakers consider instead that there are quite a few 'acceptable' nearfield solutions these days that won't break the bank from Yamaha, Mackie (MR8's), KrK and other smaller companies. Avoid the m-audio/behringer/tannoy products in the low end as they each have deficits, and definately avoid anything with a driver smaller than 6" as you'll just be missing too much of the low end picture.
A certain someone who participates in these threads once recommended Yorkville Ysmp1's, and if they're still available that should be a good option as well. They have larger cabinets than is typical in a nearfield, and the balance of sound they put out is impressive considering their very affordable price. I helped a friend get them through this planetz member and was actually rather impressed with how the inexpensive purchase turned out.
Of course if you simply can't afford any other option and happen to already have an eq on-hand, then do what you must within reason. The main reason I'm leery of Hi-fi speakers is because what you work with and use on a daily basis tends to establish a baseline for what you feel is a 'good' or 'balanced' sound, and hifi speakers are definately not this, even with a bit of eq. So avoid overhyping the sound with the eq, as that seems to be what most people do and it will affect your mixes a lot. OH, if you need to go 'buy' an eq then I still recommend either spending that money on some nearfields instead, and definately avoid any 'budget' eq's (under $100) as they're just going to introduce more coloration and phase problems.
And I would actually recommend a pair of 'bookshelf' hi-fi speakers over 3-way hifi jobs that will have an overhyped 80-150hz region and muddled phasey midrange from the crossover & 3-way drivers. Also it's worth noting that due to the way hifi speakers 'project' and hype the sound you're still going to have the same eq issues in relation to the room's low end that I mentioned above. Or as mentioned above, simply go for the option of having several sets of speakers on hand to monitor with can help overcome the deficencies of a single pair, and you'll probably find which ones you prefer for what task rather quickly.
But if you're going to buy a new set of bookshelf speakers consider instead that there are quite a few 'acceptable' nearfield solutions these days that won't break the bank from Yamaha, Mackie (MR8's), KrK and other smaller companies. Avoid the m-audio/behringer/tannoy products in the low end as they each have deficits, and definately avoid anything with a driver smaller than 6" as you'll just be missing too much of the low end picture.
A certain someone who participates in these threads once recommended Yorkville Ysmp1's, and if they're still available that should be a good option as well. They have larger cabinets than is typical in a nearfield, and the balance of sound they put out is impressive considering their very affordable price. I helped a friend get them through this planetz member and was actually rather impressed with how the inexpensive purchase turned out.
Of course if you simply can't afford any other option and happen to already have an eq on-hand, then do what you must within reason. The main reason I'm leery of Hi-fi speakers is because what you work with and use on a daily basis tends to establish a baseline for what you feel is a 'good' or 'balanced' sound, and hifi speakers are definately not this, even with a bit of eq. So avoid overhyping the sound with the eq, as that seems to be what most people do and it will affect your mixes a lot. OH, if you need to go 'buy' an eq then I still recommend either spending that money on some nearfields instead, and definately avoid any 'budget' eq's (under $100) as they're just going to introduce more coloration and phase problems.
http://www.prosoundweb.com/studyhall/lastudyhall/eq.php
Where can i find info about characteristic acoustic absorption of various materials and about bass traps?
@ valis
Why are you not considering software equalization? Any contraindication?
Where can i find info about characteristic acoustic absorption of various materials and about bass traps?
@ valis
Why are you not considering software equalization? Any contraindication?
software equalization is subject to the same limitations of any other eq.
http://www.acoustics101.com/ is from this website:
http://www.auralex.com/ they sell acoutsical materials.
these guys make cool products as well:
http://www.acousticsciences.com/
you can NOT fix the listening environment with eq. you MUST fix the room.
http://www.acoustics101.com/ is from this website:
http://www.auralex.com/ they sell acoutsical materials.
these guys make cool products as well:
http://www.acousticsciences.com/
you can NOT fix the listening environment with eq. you MUST fix the room.
http://www.mhsoft.nl/user/acoustic%20calculator.asp
Room treatments calculation (explore the whole site!)
http://www.youtube.com/watch?v=iyYUpkpL0gw
DiY powerful acoustic panels
Room treatments calculation (explore the whole site!)
http://www.youtube.com/watch?v=iyYUpkpL0gw
DiY powerful acoustic panels
4PC + Scope 5.0 + no more Xite + 2xScope Pro + 6xPulsarII + 2xLunaII + SDK + a lot of devices (Flexor III & Solaris 4.1 etc.) + Plugiator.
As previously mentioned, treat the room if possible.
Then try some very very clever software: http://drc-fir.sourceforge.net/doc/drc.html
Not as complex as it sounds, but it did take a while to figure out how to do it.
I use FOOBAR 2000 + generated filter to playback FLAC ripped CD's. You will get a slight latency.
I've tried it and the results are good. I could have spent a long time tweaking parameters.... YMMV.
have fun.
Then try some very very clever software: http://drc-fir.sourceforge.net/doc/drc.html
Not as complex as it sounds, but it did take a while to figure out how to do it.
I use FOOBAR 2000 + generated filter to playback FLAC ripped CD's. You will get a slight latency.
I've tried it and the results are good. I could have spent a long time tweaking parameters.... YMMV.
have fun.
Ok, fixing the listening environment by eq, it will work in a narrow area only, due to the phase interaction between sources and reflected sound, and it ain't desirable to work without moving the head.garyb wrote:.........you can NOT fix the listening environment with eq. you MUST fix the room.
Even room main modes have hot and cold spots, but this variations are not so critical (for low frequencies at least), so these resonances can be anyhow compensated by eq afaik.
Definitely I'm taking the OT direction here, but...digital filters usually 'just' emulate analogue, while they might have 'square bells', and very different gain and Q limitations, afaik....garyb wrote:software equalization is subject to the same limitations of any other eq. ............
Last edited by Cochise on Sat Jun 28, 2008 11:24 am, edited 1 time in total.
Try here http://www.johnlsayers.com/phpBB2/index.php (it's an amazing forum & source of information).Cochise wrote:Where can i find info about characteristic acoustic absorption of various materials and about bass traps?
Thx you all for the links
Lot of infos.....I still haven't found tables with the characteristics of reflection/absorption properties of common materials related to freq...
As for the bass traps, I've read somewhere their depth must be 1/4 of the wavelenght of the involved freq, but what about the other dimensions and other building particulars?
Lot of infos.....I still haven't found tables with the characteristics of reflection/absorption properties of common materials related to freq...
As for the bass traps, I've read somewhere their depth must be 1/4 of the wavelenght of the involved freq, but what about the other dimensions and other building particulars?
well,
I'm not building a studio room. Just trying to make my bedroom sound more linear.
I'm moving this way:
Detect the frequencies where the linearity is lost and try to understand the reason.
I'm doing that by ears, using sine sweeps. I calculated room mode freqs and their partials using excell. I should also check the linearity of the speakers before all (open air sweeps?:D )
Fix relevant problems optimizing speakers arrangement, damping loudest reflections by solutions and materials compatible with a bed room, and using eq to compensate mode related boosts in the low range.
I'm not building a studio room. Just trying to make my bedroom sound more linear.
I'm moving this way:
Detect the frequencies where the linearity is lost and try to understand the reason.
I'm doing that by ears, using sine sweeps. I calculated room mode freqs and their partials using excell. I should also check the linearity of the speakers before all (open air sweeps?:D )
Fix relevant problems optimizing speakers arrangement, damping loudest reflections by solutions and materials compatible with a bed room, and using eq to compensate mode related boosts in the low range.
typically, for the room to be useful, all you need to do is:
1. bass absorption(bass traps) which could be as simple as a well placed couch or a closet full of clothing.
2. diffusion. the sound needs to be scattered to avoid what with light would be hard shadows. a couple of walls full of books of varying depths would do that job...
making the room deader will only create other problems.
1. bass absorption(bass traps) which could be as simple as a well placed couch or a closet full of clothing.
2. diffusion. the sound needs to be scattered to avoid what with light would be hard shadows. a couple of walls full of books of varying depths would do that job...
making the room deader will only create other problems.
@ gary
Thx.
Don't reflective/diffusive surfaces have to be far enough from the source?
And what about floor/ceiling solutions?
I've still been thinking it over about properties of materials related to audio frequencies and I might drawn this conclusion: air waves and surfaces containing them could act like a capacitor in AC; if the surface is porous and thick enough to absorb all the air for the half of a whole wavelenght duration ( from the minimum pressure value to the maximum) there will be no reflection..........?
Thx.
Don't reflective/diffusive surfaces have to be far enough from the source?
And what about floor/ceiling solutions?
I've still been thinking it over about properties of materials related to audio frequencies and I might drawn this conclusion: air waves and surfaces containing them could act like a capacitor in AC; if the surface is porous and thick enough to absorb all the air for the half of a whole wavelenght duration ( from the minimum pressure value to the maximum) there will be no reflection..........?
the floor and ceiling are important, but not as important as diffusion on the walls and bass traps. it all depends on how far you want to take it. any effort put into the room is better than just getting out an eq and trying to adjust the response that way. did you read the links i posted? lots of ideas there....