This seems to me an incredibly important subject, but there seems to be little or no traffic on DiyAudio about it:
How does one go about sorting out room acoustics (and/or the speaker-to-room interface) in a methodical way, given a moderate amount of test kit (a decent microphone, soundcard + computer + audio analysis software) ?
Given the number of variables involved (position of speakers, furniture, curtains, treatments such as acoustic tiles), trial and error seems a bit time-consuming. I assume recording studio acoustics people have some tips and tricks.
Any ideas?
Cheers
IH
How does one go about sorting out room acoustics (and/or the speaker-to-room interface) in a methodical way, given a moderate amount of test kit (a decent microphone, soundcard + computer + audio analysis software) ?
Given the number of variables involved (position of speakers, furniture, curtains, treatments such as acoustic tiles), trial and error seems a bit time-consuming. I assume recording studio acoustics people have some tips and tricks.
Any ideas?
Cheers
IH
If you are not going to use a wood frame you should consider using fiberglass resin compound to harden the edges. This will help prevent the material from sagging.
You should also try to avoid using fiberglass materials not designed as duct liner. The duct liner material has blunt edges to the fibers that are likely much less distressing to your respiratory system.
Ive been very curious about this software:
http://www.rpginc.com/products/roomoptimizer/index.htm
Ive used a number of other RPG products and have been very pleased. The company’s focus is to work with AIA architects and high-end acousticians. They will of course still talk to us mere acoustical mortals, but I think that they sometimes don’t understand what we don’t understand.
This stuff looks real good also:
http://www.siasoft.com/products/
I have mutual friends with and have had the chance to talk to both authors. Sooner or later Ill have to get around to actually trying this stuff. It just doesn’t fit in with my home life and I haven’t had the cahoonas to get paid to do this stuff for a number of years now.
From my own experience, Ive liked the sound best when I can take the EQ out or the signal chain and adjust the room treatments (carpets absorption and diffusion) until I like the room sound and response.
You should also try to avoid using fiberglass materials not designed as duct liner. The duct liner material has blunt edges to the fibers that are likely much less distressing to your respiratory system.
Ive been very curious about this software:
http://www.rpginc.com/products/roomoptimizer/index.htm
Ive used a number of other RPG products and have been very pleased. The company’s focus is to work with AIA architects and high-end acousticians. They will of course still talk to us mere acoustical mortals, but I think that they sometimes don’t understand what we don’t understand.
This stuff looks real good also:
http://www.siasoft.com/products/
I have mutual friends with and have had the chance to talk to both authors. Sooner or later Ill have to get around to actually trying this stuff. It just doesn’t fit in with my home life and I haven’t had the cahoonas to get paid to do this stuff for a number of years now.
From my own experience, Ive liked the sound best when I can take the EQ out or the signal chain and adjust the room treatments (carpets absorption and diffusion) until I like the room sound and response.
Always been fascinated by this subject, as it always seems to be the no. 1 barrier to good music reproduction... Most rooms sound crap in some way or another, and my current one is dreadful!
Can anyone offer advise for fixing an overly dead room?? The system sounds dull at low volumes, and wrong at high volumes!
I plan to try and remove some crap from the room, but its just finding space elsewhere!
Oh, one more thing... anyone in the UK know where to find a CHEAP (ie. <£40) SPL meter? Preferably just a cheap analogue one..?
-Simon
Can anyone offer advise for fixing an overly dead room?? The system sounds dull at low volumes, and wrong at high volumes!
I plan to try and remove some crap from the room, but its just finding space elsewhere!
Oh, one more thing... anyone in the UK know where to find a CHEAP (ie. <£40) SPL meter? Preferably just a cheap analogue one..?
-Simon
IMHO equalization is not the best route to fixing room problems, although it is sometimes the only practical route since we have to live in these rooms as well as listen to music in them.
If what comes out of the speaker is is essentially correct and the only problem is that your room bounces things around in an uneven and unpleasant way, why on earth would you want to equalize the source and purposely force incorrect sound from your speakers in order to fix it? The problem is not the system, it's the room; it seems to me that trying to fix room problems at the source is kind of like trying to "correct" a room with walls painted red by putting green-tinted light bulbs in all your lamps and thereby "equalizing" the light frequencies.
A good start is to try and kill first-order reflections from the speakers to the listening area with panels as previously suggested, or furniture if panels are unrealistic. Put them wherever, if a mirror was placed there, you could see the speakers in the mirror. So on the ceiling at the half-way point like Timn8ter has done is the first order of business, since that spot forms a very short and direct reflection path from the speakers to you. In a perfect world you might want to treat the same spot on the floor, but large panels lying about on the floor are oddly inconvenient for most of us. So settle for a rug.
That leaves a spot on each side wall that might benefit from treatment, or at least being something other than a blank wall. (Owners of open-baffle speakers can skip this part ) It's more of an issue in smaller rooms, but if you can manage clever placement of a bookcase or comfy chair or something there might be a benefit. Or place more panels if that works for your spouse.
Bass management is tougher, since there is a lot more variability in rooms and many speakers are designed in anticipation of "room gain" at certain frequencies.
There are several plans for very inexpensive bass traps around the web, you might see if you can make a couple and try them out in your room, moving them around to see what happens.
If what comes out of the speaker is is essentially correct and the only problem is that your room bounces things around in an uneven and unpleasant way, why on earth would you want to equalize the source and purposely force incorrect sound from your speakers in order to fix it? The problem is not the system, it's the room; it seems to me that trying to fix room problems at the source is kind of like trying to "correct" a room with walls painted red by putting green-tinted light bulbs in all your lamps and thereby "equalizing" the light frequencies.
A good start is to try and kill first-order reflections from the speakers to the listening area with panels as previously suggested, or furniture if panels are unrealistic. Put them wherever, if a mirror was placed there, you could see the speakers in the mirror. So on the ceiling at the half-way point like Timn8ter has done is the first order of business, since that spot forms a very short and direct reflection path from the speakers to you. In a perfect world you might want to treat the same spot on the floor, but large panels lying about on the floor are oddly inconvenient for most of us.
So settle for a rug.That leaves a spot on each side wall that might benefit from treatment, or at least being something other than a blank wall. (Owners of open-baffle speakers can skip this part
) It's more of an issue in smaller rooms, but if you can manage clever placement of a bookcase or comfy chair or something there might be a benefit. Or place more panels if that works for your spouse.Bass management is tougher, since there is a lot more variability in rooms and many speakers are designed in anticipation of "room gain" at certain frequencies.
There are several plans for very inexpensive bass traps around the web, you might see if you can make a couple and try them out in your room, moving them around to see what happens.
lol - ask a silly question, get a silly answer, fair enuf!
More seriously though, taking some of the white polyester damping crap out of my speakers and using several progressively shorter layers of rubbery carpet underlay - tried just yesterday - has made them lighter and brighter, this partly helps make up for the dead room effect.
-Simon
I just came on to ask about this very topic.
I was just watching 'Pop Idol' and they were in a studio that had wooden panels on the walls with many holes drilled in. Are these designed to allow the sound wave in but not reflect back out?
Also we are currently looking for a new house and I am hoping to get a good room for my own audio use, hifi, computer, guitars. What should I be considering in terms of flooring (carpet/laminate)?
Matt
I was just watching 'Pop Idol' and they were in a studio that had wooden panels on the walls with many holes drilled in. Are these designed to allow the sound wave in but not reflect back out?
Also we are currently looking for a new house and I am hoping to get a good room for my own audio use, hifi, computer, guitars. What should I be considering in terms of flooring (carpet/laminate)?
Matt
I watched a few minutes of it, but I missed that!!! (clearly the best bit)
Wooden panels with holes drilled in sounds like a panel absorber for soaking up bass. Apparently you can tune these things to very specific frequencies, by the number of holes and size etc.
IMO that depends on the rest of the room. The ideal is to have reverberation times roughly equal across the audible frequency range. This means having materials that will absorb treble, mids and bass in equal measure - so curtains, carpets etc for top-end, and panel absorbers or accidentally appropriate furniture for the lows. I think the reverberation time is a big reason bass normally sounds crap - the time is typically longer than for the upper frequencies. Of course the room modes are what make it really bad. So try for a room with 'golden ratios', to minimise this horrid effect.
Others here are talking about killing early relfections, but when these are all slaughtered, it can sound too dull, in my limited expereince. Using a mirror to find the main side wall reflections is a good trick, then make some foam panels or something. Dont make anything too nice, because you might not like the sound!
The best stuff for the walls is thick lumpy wallpaper, so they say. And if you have a bouncy wooden floor, try to make it solid, this may improve the bass. Use a swept sinewave test tone to find annoying resonances. Play it REALLY feckin' loud
I'lll post some more ideas if you are interested...-Simon
Room Acoustics
Here is a software package I've been looking at for some time. Anyone have any experience with it?
http://www.cara.de/ENU/index.html
Doug
Here is a software package I've been looking at for some time. Anyone have any experience with it?
http://www.cara.de/ENU/index.html
Doug
# The effects of equalization are usually highly exagerated. Something like the Behringer Ultracurve used digitally is the least of your system's worries (generally speaking for the systems I have seen here).
Ever thought about what passive speaker filter components do to the sound and give your amp a headake?
# Low frequencies are a pain in the #$% in almost all rooms (small, medium, big). If you are affraid a digital equalizer will mess up your sound, then only let your bass drivers 'see' it (bi-amp).
# Measuring right and getting the right adjustments with an EQ is very hard
# Small to medium-sized rooms can get good use out of (room-wise) damping mid/high frequencies. Medium to large-sized rooms have mostly the lower frequencies to worry about.
Why do you blame the room? What is the system?
1. Because the big problems cannot be fixed effectively room-wise. If you have measurements about significant effects of basstraps, then I'd be interested to see them. Also: small to medium rooms are ... small to medium-sized, so no room for bass-traps.
2. I only know of one speaker that is 'essentially' correct, and that is Kuei Yang Wang's one-way open-baffle Supravox speaker, which he claims does not need EQ (..and I have to take most of his word for it, because he 'wrote the book' on EQ).
For all >1-way-speakers: by combining drivers, putting a box around it and using a passive filter has nothing to do with being 'correct'; they are all a form of EQ.
All done: 6.00 x 0.60 m rockwool with a nice cloth to cover it up:
Ever thought about what passive speaker filter components do to the sound and give your amp a headake?
# Low frequencies are a pain in the #$% in almost all rooms (small, medium, big). If you are affraid a digital equalizer will mess up your sound, then only let your bass drivers 'see' it (bi-amp).
# Measuring right and getting the right adjustments with an EQ is very hard
# Small to medium-sized rooms can get good use out of (room-wise) damping mid/high frequencies. Medium to large-sized rooms have mostly the lower frequencies to worry about.
Why do you blame the room? What is the system?
1. Because the big problems cannot be fixed effectively room-wise. If you have measurements about significant effects of basstraps, then I'd be interested to see them. Also: small to medium rooms are ... small to medium-sized, so no room for bass-traps.
2. I only know of one speaker that is 'essentially' correct, and that is Kuei Yang Wang's one-way open-baffle Supravox speaker, which he claims does not need EQ (..and I have to take most of his word for it, because he 'wrote the book' on EQ).
For all >1-way-speakers: by combining drivers, putting a box around it and using a passive filter has nothing to do with being 'correct'; they are all a form of EQ.
All done: 6.00 x 0.60 m rockwool with a nice cloth to cover it up:
An externally hosted image should be here but it was not working when we last tested it.
Just to clarify, I agree to a degree with this assessment (where I said "although it is sometimes the only practical route") but perhaps didn't emphasize it enough. I stand by my opinion that room problems are best solved by room treatment, when possible and practical.Nielsio said:
I don't have any numbers of any kind relating to bass traps, but I'm just generally curious: are you suggesting that bass traps have no effects and wish me to prove otherwise by producing numbers? I hope you will explain further if I have been laboring under such a huge misconception all this time; my main goal on these forums is to learn.
Well, your exception aside, then you'd be correcting the speaker with EQ, not the room, so we are again in agreement.
By the way, if you are aware of the One True Speaker and all others are inferior, then why are we all wasting our time here?
Re: Room Acoustics
There are a couple of shortcomings, the major one of which will be solved in the next version, but not enough to put you off buying it.
Mick
Doug I have Cara and I highly recommend it. Particularly for the price. Its a very sophisticated tool and I've found that the predictions match reality well.Doug said:
There are a couple of shortcomings, the major one of which will be solved in the next version, but not enough to put you off buying it.
Mick
SimontY said:
It was when they were showing the clips of the rehearsals with the orchestra.
The main reason they stood out is because it would give your room a real studio look. Obviously they would have to be tuned to give improved audio, not just improved aesthetics!! Thanks for confirming what I thought they were for and I will look into it more.
Matt
HeatMiser and others, please see (especially the first part):
http://www.prijsindex.net/tmp/room acoustics and eq.html
..by Kuei Yang Wang
In my toplist there is the BD-Design Oris Reference Ultra Extreme, but it's _way_ expensive. In terms of room acoustics it's reverbrant range matches Kuei's theories perfectly.
Also, Kuei's Supravox system is room-wise very good, but that doesn't mean it's perfect (power handling, cone break-up, height of sound-source, to name a few).
Also, the document describes suggested speaker design
http://www.prijsindex.net/tmp/room acoustics and eq.html
..by Kuei Yang Wang
In my toplist there is the BD-Design Oris Reference Ultra Extreme, but it's _way_ expensive. In terms of room acoustics it's reverbrant range matches Kuei's theories perfectly.
Also, Kuei's Supravox system is room-wise very good, but that doesn't mean it's perfect (power handling, cone break-up, height of sound-source, to name a few).
Also, the document describes suggested speaker design
Easy - I've heard it in two rooms, my previous one was much larger. I had bass problems in that one too - height and width were nearly identical
This most annoying bump was around 55hz, not really where one wants it... The other dimension caused a peak at 30-40hz, which is not a big problem, and actually good for home cinema In the old larger room, the sound was more spacious and lively, sort of more open, more realistic in many ways. This one sounds closed-in, and the bass is unimpressive, and lumpy. The dimensions are small enough to cause problems right through the crucial (for me) mid-bass and upper bass, but at least that leaves good low-bass, and reasonable integration between sub and speakers @ 50hz. One thing I hate is that some notes are virtually inaudible, and some are quite strong. This is a room problem, as is most colouration in my system. The room is as important as the speakers, in a good, 'full range' system.
Btw, I would never like to EQ anything but the bass, in a tri-amped system, but I can't afford that kind of setup! And my speakers are 2-way!! Putting a box inbetween amps must really kill detail etc. But I don't want to debate it, and I don't mean to annoy, I am fully aware that its a tradeoff, which some like and others hate.
The system I have is kind of irrelevant I think, just normal dynamic speakers (d'apollito) run from an integrated amp. Because of the crap bass in my room, I have the ports loosely stuffed with wadding, total stuffing is crap, and leaving them open the bass dominates, destroying ALL music!
I think I need a SPL meter, then I can see where my problems lie, instead of guessing!
-Simon
Room Acoustics
Here is a good link for building your own bass traps.
http://ic.net/~jtgale/diy2.htm
I've often wondered though, how do bass traps absorb bass frequencies as the wavelengths are longer than the size of the traps
Hope that not a stupid question
Doug
Here is a good link for building your own bass traps.
http://ic.net/~jtgale/diy2.htm
I've often wondered though, how do bass traps absorb bass frequencies as the wavelengths are longer than the size of the traps
Hope that not a stupid question
Doug
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