Cheers Timbo. I got it. I'll have a look at it tonight and post the results I find.
Regards,
Paavo.
Har-Bal as room analyser?
Ok Timbo Here goes.
On the face of it you look like you have a pretty reasonable setup though you should really consider investing in some quadratic diffusors place at your primary reflection points as this should vastly improve the imaging you are getting. I know buying them can be pretty expensive but if you are a handy man of sorts you can make good ones at a fraction of the cost. Why I suggest that this is so shall be made clear in the plots.
First up here's your frequency response (frequency domain equivalent of the impulse response).
http://www.taquis.com/harbal/timbo_fr.bmp
Overall it looks pretty balanced though it seems a little weak above 8kHz and a bit thin in the mids around 2 kHz. Probably brighter than I would be comfortable with though as there's quite a strong output around 5kHz. The dip around 200Hz is most likely a floor (or wall immediately behind the speaker) reflection issue. You can't really completely eliminate this low frequency dipping but you may be able to change its magnitude and frequency by altering your speaker placement and their height above the floor.
Next is the overall impulse response.
http://www.taquis.com/harbal/timbo_ir1.bmp
The blank space at the beginning is the time delay of the sound leaving the speaker and reaching the microphone which is about 5ms so I guess the microphone is about 1.7m from the speaker. Then you have the main impulse of the loudspeaker followed by the reverberant tail of the room. The big spike closest to the main one is the one most likely responsible for the dip at 200Hz. This one is not likely to cause major imaging issues. However, there are a number of quite large and isolated peaks, that correspond to primary reflections, that are very likely to be causing imaging ambiguity. This is more clearly seen on a zoomed in view below.
http://www.taquis.com/harbal/timbo_ir2.bmp
What should happen in an ideal listening environment is that the reverberant tail should look like a decaying noise rather than a series of clicks. The reason being that if it is noise like then it doesn't convey an specific directionality but just adds ambience. If it is concentrated in time (as a spike) it means there is a plain reflection arriving at your ears from a direction other than from the speaker and that in turn sets up a ghost image when you listen to it. Then your brain has to try and figure out which image is the correct one: the one you've set up through mixing or the one that is a reflected image. That generally leads to listening fatigue in the long term.
To give you another perspective I've included some results from my setup. Here is the frequency response of my system.
http://www.taquis.com/harbal/my_fr.bmp
Note that the highs are deliberately subdued compared with the mids to give the room warmth. The big peak at 60Hz is the fundametal room mode in my room. It could do with some bass trapping but as of yet there is none. On the whole it isn't a big problem, only on some material.
Next is the room impulse response.
http://www.taquis.com/harbal/my_ir1.bmp
Zoomed in,
http://www.taquis.com/harbal/my_ir2.bmp
What you should note in comparison with yours is that although it isn't perfect, the primary reflections are generally pretty weak in magnitude and there is more energy spread out in the tail throughout the decay time, whereas with yours it is more concentrated at specific times. More interesting to you might be the impulse response without my diffusors (of which I have 4). You should be able to clearly see that without them those primary reflections are significantly stronger.
http://www.taquis.com/harbal/my_ir3.bmp
I can also say without any doubt that the audible effect is abundantly clear. There is no comparison between the two and I'll fight anyone who wants to take my diffusors from me!
Cheers,
Paavo.
On the face of it you look like you have a pretty reasonable setup though you should really consider investing in some quadratic diffusors place at your primary reflection points as this should vastly improve the imaging you are getting. I know buying them can be pretty expensive but if you are a handy man of sorts you can make good ones at a fraction of the cost. Why I suggest that this is so shall be made clear in the plots.
First up here's your frequency response (frequency domain equivalent of the impulse response).
http://www.taquis.com/harbal/timbo_fr.bmp
Overall it looks pretty balanced though it seems a little weak above 8kHz and a bit thin in the mids around 2 kHz. Probably brighter than I would be comfortable with though as there's quite a strong output around 5kHz. The dip around 200Hz is most likely a floor (or wall immediately behind the speaker) reflection issue. You can't really completely eliminate this low frequency dipping but you may be able to change its magnitude and frequency by altering your speaker placement and their height above the floor.
Next is the overall impulse response.
http://www.taquis.com/harbal/timbo_ir1.bmp
The blank space at the beginning is the time delay of the sound leaving the speaker and reaching the microphone which is about 5ms so I guess the microphone is about 1.7m from the speaker. Then you have the main impulse of the loudspeaker followed by the reverberant tail of the room. The big spike closest to the main one is the one most likely responsible for the dip at 200Hz. This one is not likely to cause major imaging issues. However, there are a number of quite large and isolated peaks, that correspond to primary reflections, that are very likely to be causing imaging ambiguity. This is more clearly seen on a zoomed in view below.
http://www.taquis.com/harbal/timbo_ir2.bmp
What should happen in an ideal listening environment is that the reverberant tail should look like a decaying noise rather than a series of clicks. The reason being that if it is noise like then it doesn't convey an specific directionality but just adds ambience. If it is concentrated in time (as a spike) it means there is a plain reflection arriving at your ears from a direction other than from the speaker and that in turn sets up a ghost image when you listen to it. Then your brain has to try and figure out which image is the correct one: the one you've set up through mixing or the one that is a reflected image. That generally leads to listening fatigue in the long term.
To give you another perspective I've included some results from my setup. Here is the frequency response of my system.
http://www.taquis.com/harbal/my_fr.bmp
Note that the highs are deliberately subdued compared with the mids to give the room warmth. The big peak at 60Hz is the fundametal room mode in my room. It could do with some bass trapping but as of yet there is none. On the whole it isn't a big problem, only on some material.
Next is the room impulse response.
http://www.taquis.com/harbal/my_ir1.bmp
Zoomed in,
http://www.taquis.com/harbal/my_ir2.bmp
What you should note in comparison with yours is that although it isn't perfect, the primary reflections are generally pretty weak in magnitude and there is more energy spread out in the tail throughout the decay time, whereas with yours it is more concentrated at specific times. More interesting to you might be the impulse response without my diffusors (of which I have 4). You should be able to clearly see that without them those primary reflections are significantly stronger.
http://www.taquis.com/harbal/my_ir3.bmp
I can also say without any doubt that the audible effect is abundantly clear. There is no comparison between the two and I'll fight anyone who wants to take my diffusors from me!
Cheers,
Paavo.
hi
Hye Paavo,
Wow, thanks for taking the time on this.
I'm kind of at a loss as to what it all means and what to do about it though.
Some kind of (additional) room treatment is definately in order.
On the magnitude side of your charts it says 10X db. Am I to assume that means that from 0 to 1 is 10 db? That's huge.!
Do you think I could put an eq across my buss to somewhat compensate?
Or, would that not be worth it.
I'll study the charts some more.
BTW, yes, I'm a handyman..
Thanks Paavo..
Tim
Wow, thanks for taking the time on this.
I'm kind of at a loss as to what it all means and what to do about it though.
Some kind of (additional) room treatment is definately in order.
On the magnitude side of your charts it says 10X db. Am I to assume that means that from 0 to 1 is 10 db? That's huge.!
Do you think I could put an eq across my buss to somewhat compensate?
Or, would that not be worth it.
I'll study the charts some more.
BTW, yes, I'm a handyman..
Thanks Paavo..
Tim
Re: hi
No problem, I'd be happy to do this sort of this quite often if it weren't for the fact that I'm on a dialup! Can't get broadband by normal land line as the lines are pair gained. I'd have to go mobile or MDS and I'm not happy with the expense of either at this stage.timbo wrote: Wow, thanks for taking the time on this.
Yes that is correct and though it may sound huge it is "normal" for room responses. A large proportion of the sound we hear in a room is reflected and as a consequence there'll be a lot of narrow peaks & valleys in a measured frequency response within a room. The key to making sense of it is to look at it through blured vision. The average response should be as smooth as possible and nominally sloping downward above 1kHz to give warmth to the reproduced sound. Reasoning for this is twofold: It is generally accepted that short reverb times at HF sounds better for music reproduction so most theatres and auditoriums are designed along these lines and the average listening environment will naturally have a muted HF end owing to the nature of the furnishings (ie. carpet, curtains, apolstered seating in living rooms and cars are little different).timbo wrote: I'm kind of at a loss as to what it all means and what to do about it though.
Some kind of (additional) room treatment is definately in order.
On the magnitude side of your charts it says 10X db. Am I to assume that means that from 0 to 1 is 10 db? That's huge.!
The treatment is pretty simple. Get a mirror and run it along the walls to the side and the rear of you to find the points on the wall where you can see your speakers from your listening position. Getting a friend around to help you will save some time in finding those points. When you do mark it out with some masking tape. Each of those points represents an early (primary) reflection which can cause problems to your acoustic imagine. Ideally you should have a diffusor mounted at each of those points. If your budget doesn't allow for this then build as many as you can and experiment to find out which of those points treated has the most radical effect on the sound quality. I'd avoid using "soft diffusion" (ie. z-foam products) as you'll most likely lose some clarity in the acoustic allusion. You might want to consider adding a small amount of z-foam (probably 2") spread evenly around the room to add some warmth (ie. preferentially absorb some HF energy), just don't put it at the early reflection points.
[/quote]
The only thing I'd compensate for with EQ is frequency response deficiency in your loudspeakers. EQ to compensate for room deficiency generally doesn't work. Doing so generally means a loss of clarity and detail. At a guess I'd say your speakers may have a slightly muted top end but it may well be a characteristic of the Mic you used to record the sound.timbo wrote: Do you think I could put an eq across my buss to somewhat compensate?
Or, would that not be worth it.
Well what I'll do is draw up some plans and a description on how to construct the lightweight 1d QRD's that I made to mount on my rear doors in my room. They're pretty quick to make and are relatively cheap on an area basis. They measure 1.5m by 0.42m and I made 2 for a little over $200Aus ($150USD). It'll take couple of weeks to put it together but when it is done I'll post a link on this forum.timbo wrote: BTW, yes, I'm a handyman..
Cheers,
Paavo.
hi
Thanks paavo,
Dialup? Dude...... My condolances.
A big problem is the shape of the room.
here is a rough sketch.
http://www.geocities.com/tim_33431/drawinghole.jpg
that little knook is probably causing all kinds of anomolies.
What do you think?
I'll check out the mirror thing.
I am hearing way too much in the high end. My mixes have been translating pretty well as far as Har-Bal seems to show though.
You know, I've been doing this for like 30 years and have never had a decent sounding room. Amazing. Actually though, I have found that the longer a room the better (like at leats 20 feet).
Thanks for your help.
Tim
Dialup? Dude...... My condolances.
A big problem is the shape of the room.
here is a rough sketch.
http://www.geocities.com/tim_33431/drawinghole.jpg
that little knook is probably causing all kinds of anomolies.
What do you think?
I'll check out the mirror thing.
I am hearing way too much in the high end. My mixes have been translating pretty well as far as Har-Bal seems to show though.
You know, I've been doing this for like 30 years and have never had a decent sounding room. Amazing. Actually though, I have found that the longer a room the better (like at leats 20 feet).
Thanks for your help.
Tim
Do you notice a left right asymetery in the bass at all? That'll be the most likely effect of that knook sticking out. Given the relative size of your room and the near field setup it may not be a big issue though I'd have thought you might get the best bass symmetry with your desk close to the middle of the wall that it sits on.
The other thing I'd be tempted to try is to move the desk out nearer the middle of the room. I'd probably aim to have your listening position 6-8ft from that wall but where the best position is would need to be determined by a bit of trial and error.
Given the frequency response I measured it does surprise me that you think your room is too bright. I'm sure my ears would agree with you. Time to start adding some absorption I'd say. Just make sure your spread it around pretty evenly and don't put too much in. Whether you use hi-tech products or furnishings (like curtains) is up to you. I've read people bad mouthing curtains as a form of acoustic treatment because they aren't very efficient absorbers but that is why I believe they are a good form of treatment. You don't want to absorb everything otherwise the room will sound sterile. Z-foam is so efficient that it is easy to suck the life out of a room. In any case, I've seen many theatres and halls treated with curtains effectively and I don't recall any Z-foam so I don't see any justification for a negative viewpoint on curtains.
By the way, my room is a lot smaller than yours and the absorbing elements are lo-tech curtains and rugs.
Cheers,
Paavo.
The other thing I'd be tempted to try is to move the desk out nearer the middle of the room. I'd probably aim to have your listening position 6-8ft from that wall but where the best position is would need to be determined by a bit of trial and error.
Given the frequency response I measured it does surprise me that you think your room is too bright. I'm sure my ears would agree with you. Time to start adding some absorption I'd say. Just make sure your spread it around pretty evenly and don't put too much in. Whether you use hi-tech products or furnishings (like curtains) is up to you. I've read people bad mouthing curtains as a form of acoustic treatment because they aren't very efficient absorbers but that is why I believe they are a good form of treatment. You don't want to absorb everything otherwise the room will sound sterile. Z-foam is so efficient that it is easy to suck the life out of a room. In any case, I've seen many theatres and halls treated with curtains effectively and I don't recall any Z-foam so I don't see any justification for a negative viewpoint on curtains.
By the way, my room is a lot smaller than yours and the absorbing elements are lo-tech curtains and rugs.
Cheers,
Paavo.
Paavo,
I thought your spectrum analysis showed my room as being bright?
Big spike around 5K. Yes?
My consol is in the middle of that wall. The picture may be off. To move it anywhere is not really possble. I can barely even walk into the room now there is s much junk. I mean tables and tape decks and instruments and monitors and computers and and and:)
I think curtains and the like are just fine (at least for a home studio). You do what you gotta do. I track my acoustic in an adjacent bedroom with beds and curtains etc. The sound difference is incredible. Actually I think a lot of my reflective issues are due to the reflective surfaces of the stuff in the studio that is necessary to make the music. Ironic. The desk is a big reflector
I made a few gobos out of 1" styrofoam. Do you think they would be good for anything?
Hard to believe your room is smaller..
thanks
Tim
I thought your spectrum analysis showed my room as being bright?
Big spike around 5K. Yes?
My consol is in the middle of that wall. The picture may be off. To move it anywhere is not really possble. I can barely even walk into the room now there is s much junk. I mean tables and tape decks and instruments and monitors and computers and and and:)
I think curtains and the like are just fine (at least for a home studio). You do what you gotta do. I track my acoustic in an adjacent bedroom with beds and curtains etc. The sound difference is incredible. Actually I think a lot of my reflective issues are due to the reflective surfaces of the stuff in the studio that is necessary to make the music. Ironic. The desk is a big reflector
I made a few gobos out of 1" styrofoam. Do you think they would be good for anything?
Hard to believe your room is smaller..
thanks
Tim
Yeah, my spectral analysis did show it to be bright in the upper mids and low highs. As you said 5kHz. Looks similar to what my room balance was untreated.
I didn't realise your room was full of gear! That would make things awkward but I guess it doesn't discount the possibility of re-arranging things. You just need to find some temporary space to move things about, though you'd want to have alot of free time cos it would involve a lot of stuffing 'round. I guess having all those bits 'n pieces will help diffuse the sound though, so it isn't all bad. Might lack stereo symetry though.
If you want to use 1" styrofoam that should be ok. Just make sure you spread it around the room fairly evenly. For instance, you could use strips about 6 inches wide and hang 'em floor to ceiling every 2 feet or so. If it still sounds too bright bring 'em closer together (say 1ft apart). If it sounds too dead space them out a bit more and maybe even make them narrower and more plentiful. It's just trial and error really.
Yep, my room is smaller than yours though it is relatively free of gear. When I get the diffuser plans done I'll post some picks of my room along with it and you'll get the idea. The funny thing is, before we built this house I was somewhat resigned to the fact that I'd have to have a small room that would probably be acoustically dissappointing. After the fact I'm actually very happy that it is small because the effective proportion of diffusion I can include for a given budget in this room is much bigger than If I had a bigger one, so it is a bit of a blessing in disguise. I'm quite pleased with it now.
Cheers,
Paavo.
I didn't realise your room was full of gear! That would make things awkward but I guess it doesn't discount the possibility of re-arranging things. You just need to find some temporary space to move things about, though you'd want to have alot of free time cos it would involve a lot of stuffing 'round. I guess having all those bits 'n pieces will help diffuse the sound though, so it isn't all bad. Might lack stereo symetry though.
If you want to use 1" styrofoam that should be ok. Just make sure you spread it around the room fairly evenly. For instance, you could use strips about 6 inches wide and hang 'em floor to ceiling every 2 feet or so. If it still sounds too bright bring 'em closer together (say 1ft apart). If it sounds too dead space them out a bit more and maybe even make them narrower and more plentiful. It's just trial and error really.
Yep, my room is smaller than yours though it is relatively free of gear. When I get the diffuser plans done I'll post some picks of my room along with it and you'll get the idea. The funny thing is, before we built this house I was somewhat resigned to the fact that I'd have to have a small room that would probably be acoustically dissappointing. After the fact I'm actually very happy that it is small because the effective proportion of diffusion I can include for a given budget in this room is much bigger than If I had a bigger one, so it is a bit of a blessing in disguise. I'm quite pleased with it now.
Cheers,
Paavo.