You are here

Tackling room resonances

For everything after the recording stage: hardware/software and how you use it.

Re: Tackling room resonances

Postby TNGator » Sat Aug 10, 2019 5:40 pm

Well having tried a sweep using make shift DIY traps made from mineral wool (from a roll) I can confirm it is absolutely useless. I did a scan from 40Hz to 500Hz and compared the two graphs. The mineral wool did nothing at all. So rather than buy rock wool and go to all that effort of putting wood etc together.....Im just going to buy a couple of traps from Thomann. Well Im glad i ran the tests though because at least it puts the whole thing to bed. Just for kicks though, Im now going to try the hanging duvet trick and see how that goes.
TNGator
Regular
Posts: 160
Joined: Wed Mar 20, 2019 11:55 pm
Southern kin y'all

Re: Tackling room resonances

Postby Hugh Robjohns » Sat Aug 10, 2019 6:00 pm

TNGator wrote:Well having tried a sweep using make shift DIY traps made from mineral wool (from a roll) I can confirm it is absolutely useless. I did a scan from 40Hz to 500Hz and compared the two graphs. The mineral wool did nothing at all.

I've no idea how many, or how large and deep, your makeshift traps we're, but others have already pointed out that controlling low frequencies with rockwool traps is not easy, and to be effective they need to be REALLY BIG AND DEEP.

So rather than buy rock wool and go to all that effort of putting wood etc together.....Im just going to buy a couple of traps from Thomann.

I dont know the Thomann traps of which you speak, but my advice would be: buy with care! There are an awful lot of companies offering 'bass traps' that perform very poorly. Check the absorption coefficient numbers for frequencies in the range you need to control to ensure the panel will do what you expect...
User avatar
Hugh Robjohns
Moderator
Posts: 24089
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: Tackling room resonances

Postby Sam Spoons » Sat Aug 10, 2019 6:26 pm

If you are testing your 50mm DIY panels you mentioned earlier I refer you back to several references earlier in the thread that say thin lightweight panels will have little or no effect on bass frequencies but, as long as they are not too thin or lightweight they will do useful things in the mid range and above. There is no point in measuring 20-500 Hz to see what difference 50mm thick panels are making 'cos they ain't making any.
User avatar
Sam Spoons
Jedi Poster
Posts: 9908
Joined: Thu Jan 23, 2003 1:00 am
Location: Manchester UK
Finally taking this recording lark seriously (and recording my Gypsy Jazz CD)........

Re: Tackling room resonances

Postby TNGator » Sat Aug 10, 2019 11:52 pm

Hugh Robjohns wrote:
TNGator wrote:Well having tried a sweep using make shift DIY traps made from mineral wool (from a roll) I can confirm it is absolutely useless. I did a scan from 40Hz to 500Hz and compared the two graphs. The mineral wool did nothing at all.

I've no idea how many, or how large and deep, your makeshift traps we're, but others have already pointed out that controlling low frequencies with rockwool traps is not easy, and to be effective they need to be REALLY BIG AND DEEP.

So rather than buy rock wool and go to all that effort of putting wood etc together.....Im just going to buy a couple of traps from Thomann.

I dont know the Thomann traps of which you speak, but my advice would be: buy with care! There are an awful lot of companies offering 'bass traps' that perform very poorly. Check the absorption coefficient numbers for frequencies in the range you need to control to ensure the panel will do what you expect...

What I tried was about 40cm deep by about 30cm wide. I would have thought that size would be effective. Yeah some of the Thomann stuff a coefficient rating but other models dont which is annoying. You would think that all items would carry this rating as standard procedure. The Absorb Coeff is probably the only thing you can really go on.
TNGator
Regular
Posts: 160
Joined: Wed Mar 20, 2019 11:55 pm
Southern kin y'all

Re: Tackling room resonances

Postby TNGator » Sat Aug 10, 2019 11:57 pm

Sam Spoons wrote:If you are testing your 50mm DIY panels you mentioned earlier I refer you back to several references earlier in the thread that say thin lightweight panels will have little or no effect on bass frequencies but, as long as they are not too thin or lightweight they will do useful things in the mid range and above. There is no point in measuring 20-500 Hz to see what difference 50mm thick panels are making 'cos they ain't making any.

Hi Sam. No these were different. About 40cm deep. Do you know the funny thing? Just for a laugh. I put a 2 tier stand in the corner put some objects on it to make a make shift diffuser. And the darn thing did a better job than anything else I tried. The graph was really tamed. I couldn't believe the difference. So maybe some diffusion will help just as good as bass traps.
TNGator
Regular
Posts: 160
Joined: Wed Mar 20, 2019 11:55 pm
Southern kin y'all

Re: Tackling room resonances

Postby Wonks » Sun Aug 11, 2019 8:56 am

With that method, you are probably just moving a lot of the problem nodes to another area of the room. But if it gets you the results you want at the listening position, then it's worth experimenting along those lines.

Diffusers stuck against flat walls are unlikely to do much for bass issues; it's the fact that you've effectively changed the shape of the room that you need to work with.
User avatar
Wonks
Jedi Poster
Posts: 8928
Joined: Thu May 29, 2003 12:00 am
Location: Reading, UK
Correcting mistakes on the internet since 1853

Re: Tackling room resonances

Postby Sam Spoons » Sun Aug 11, 2019 10:23 am

TNGator wrote:
Sam Spoons wrote:If you are testing your 50mm DIY panels you mentioned earlier I refer you back to several references earlier in the thread that say thin lightweight panels will have little or no effect on bass frequencies but, as long as they are not too thin or lightweight they will do useful things in the mid range and above. There is no point in measuring 20-500 Hz to see what difference 50mm thick panels are making 'cos they ain't making any.

Hi Sam. No these were different. About 40cm deep. Do you know the funny thing? Just for a laugh. I put a 2 tier stand in the corner put some objects on it to make a make shift diffuser. And the darn thing did a better job than anything else I tried. The graph was really tamed. I couldn't believe the difference. So maybe some diffusion will help just as good as bass traps.

Diffusion is, I believe (no personal experience) good at mid/high frequencies, maybe somebody will be along to say if it works at the low end, my feeling is that it will to a point by blurring the resonances

I suspect that in your room REW is not going to be your friend, you'll never get close to a flat graph and drive yourself mad trying (been there and bought the teeshirt :headbang: ). If you can set the room/monitors/desk up so you can get some absorbers at the mirror points and use headphones to check the bass you should be able to get back to the primary purpose of making/recording music*.

* I'm not suggesting you don't install bass traps just that you accept that they can only have limited effect in rooms like you (and I) have. In my room I have about 3m2 of 250mm deep traps and about 7m2 of 50mm panels, spaced 25-50mm off the wall/ceiling all constructed from RW3 Rockwool. I'd given up on testing by the time I came to install them and installed the full package in one go but, empirically, the room does sound much better.
User avatar
Sam Spoons
Jedi Poster
Posts: 9908
Joined: Thu Jan 23, 2003 1:00 am
Location: Manchester UK
Finally taking this recording lark seriously (and recording my Gypsy Jazz CD)........

Re: Tackling room resonances

Postby TNGator » Sun Aug 11, 2019 10:51 am

Wonks wrote:With that method, you are probably just moving a lot of the problem nodes to another area of the room. But if it gets you the results you want at the listening position, then it's worth experimenting along those lines.

Diffusers stuck against flat walls are unlikely to do much for bass issues; it's the fact that you've effectively changed the shape of the room that you need to work with.
Never thought of the fact the problem might be just moving. Ive been testing by running sweeps with REW in blocks. For example 40Hz to 500Hz. Then 500 to say 2K or something and so forth. Because of the point you make, I might do a full sweep in one go and then experiment. I can then compare the two complete graphs. Hugh was warning about buying bass traps as there are companies out selling stuff that simply doesn't work. I've noticed nearly all of the traps on thoman don't have a coefficient rating. I dont fancy handing over money on a gamble. Sending something that size back to germany for a refund would be a nightmare. Yeah I think I'll start from fresh and do a full sweep from 30 or 40 Hz all the way to the high frequencies.
TNGator
Regular
Posts: 160
Joined: Wed Mar 20, 2019 11:55 pm
Southern kin y'all

Re: Tackling room resonances

Postby Wonks » Sun Aug 11, 2019 11:00 am

Don't forget that any low frequency stuff needs to take the LF performance of your monitors and your test mic into consideration. You need to allow for any fall-off in monitor and mic performance when considering the sweep results at low frequencies.
User avatar
Wonks
Jedi Poster
Posts: 8928
Joined: Thu May 29, 2003 12:00 am
Location: Reading, UK
Correcting mistakes on the internet since 1853

Re: Tackling room resonances

Postby TNGator » Sun Aug 11, 2019 11:07 am

Wonks wrote:Don't forget that any low frequency stuff needs to take the LF performance of your monitors and your test mic into consideration. You need to allow for any fall-off in monitor and mic performance when considering the sweep results at low frequencies.
Oh crap. I wouldnt have a clue how to test that or even where to begin. Opening cans of worms can be such fun. What have I done.
TNGator
Regular
Posts: 160
Joined: Wed Mar 20, 2019 11:55 pm
Southern kin y'all

Re: Tackling room resonances

Postby Mike Stranks » Sun Aug 11, 2019 11:28 am

As you know, my room is even smaller than yours - and now I've measured it even smaller than I told you!

I think you've just got to accept that in these small rooms trying to sort the bass issues in the room is always a series of compromises and, IMO, not very successful ones at that.

Treat the mirror-points and get a good subjective sound at the mix position. Don't pump lots of bass into the room with large speakers. Concentrate on the mids and highs and use decent open-back headphones for checking bass.

My room is appalling for bass nodes; I've sorted the mix position and just let the rest of the room look after itself.
Mike Stranks
Jedi Poster
Posts: 6729
Joined: Fri Jan 03, 2003 1:00 am

Re: Tackling room resonances

Postby Sam Spoons » Sun Aug 11, 2019 3:59 pm

This ^ :thumbup: :thumbup: :thumbup:
User avatar
Sam Spoons
Jedi Poster
Posts: 9908
Joined: Thu Jan 23, 2003 1:00 am
Location: Manchester UK
Finally taking this recording lark seriously (and recording my Gypsy Jazz CD)........

Re: Tackling room resonances

Postby TNGator » Mon Aug 12, 2019 9:36 pm

Mike Stranks wrote:As you know, my room is even smaller than yours - and now I've measured it even smaller than I told you!

I think you've just got to accept that in these small rooms trying to sort the bass issues in the room is always a series of compromises and, IMO, not very successful ones at that.

Treat the mirror-points and get a good subjective sound at the mix position. Don't pump lots of bass into the room with large speakers. Concentrate on the mids and highs and use decent open-back headphones for checking bass.

My room is appalling for bass nodes; I've sorted the mix position and just let the rest of the room look after itself.

In the absence of a "mirror buddy" is it possible to just eyeball it? I have one of those laser spirit levels that fires a snipers red dot. I wonder if i shot the laser from each speaker to the wall would it give me an honest reflection point. My hanging duvet which is behind me must easily be covering the correct area due to its width. There are a few articles on this in various issues of the magazine. The speakers on my monitors are only 5 inch diameter so at least they wont be pumping out lots of bass signals. But good point, more bass into the room means more of a headache.
TNGator
Regular
Posts: 160
Joined: Wed Mar 20, 2019 11:55 pm
Southern kin y'all

Re: Tackling room resonances

Postby Hugh Robjohns » Mon Aug 12, 2019 9:41 pm

Yes you can 'eyeball' it -- the mirror point panels should be large enough that the positioning isn't too critical anyway. So you just need to remember that the angle of reflection equals the angle of incidence...
User avatar
Hugh Robjohns
Moderator
Posts: 24089
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: Tackling room resonances

Postby TNGator » Mon Aug 12, 2019 9:47 pm

Mike Stranks wrote:As you know, my room is even smaller than yours - and now I've measured it even smaller than I told you!

I think you've just got to accept that in these small rooms trying to sort the bass issues in the room is always a series of compromises and, IMO, not very successful ones at that.

Treat the mirror-points and get a good subjective sound at the mix position. Don't pump lots of bass into the room with large speakers. Concentrate on the mids and highs and use decent open-back headphones for checking bass.

My room is appalling for bass nodes; I've sorted the mix position and just let the rest of the room look after itself.

PS...forgot to mention Mike...I was avoiding using headphones to mix but then I noticed you mentioned "open cans" not closed ones. Im guessing the open cans let in a little of the room?
TNGator
Regular
Posts: 160
Joined: Wed Mar 20, 2019 11:55 pm
Southern kin y'all

Re: Tackling room resonances

Postby TNGator » Mon Aug 12, 2019 9:48 pm

Hugh Robjohns wrote:Yes you can 'eyeball' it -- the mirror point panels should be large enough that the positioning isn't too critical anyway. So you just need to remember that the angle of reflection equals the angle of incidence...
Thanks Hugh :)
TNGator
Regular
Posts: 160
Joined: Wed Mar 20, 2019 11:55 pm
Southern kin y'all

Re: Tackling room resonances

Postby Sam Spoons » Mon Aug 12, 2019 10:15 pm

TNGator wrote:PS...forgot to mention Mike...I was avoiding using headphones to mix but then I noticed you mentioned "open cans" not closed ones. Im guessing the open cans let in a little of the room?

Open cans don't really let any room in because you are not exciting the room but they do sound more natural.
User avatar
Sam Spoons
Jedi Poster
Posts: 9908
Joined: Thu Jan 23, 2003 1:00 am
Location: Manchester UK
Finally taking this recording lark seriously (and recording my Gypsy Jazz CD)........

Re: Tackling room resonances

Postby TNGator » Mon Aug 12, 2019 10:17 pm

Sam Spoons wrote:
TNGator wrote:PS...forgot to mention Mike...I was avoiding using headphones to mix but then I noticed you mentioned "open cans" not closed ones. Im guessing the open cans let in a little of the room?

Open cans don't really let any room in because you are not exciting the room but they do sound more natural.
Ah. Yeah I dont mind cans when recording or lets say listening to educational vids when trying to hear the effect of an EQ or compressor. But i couldnt mix with them. Id feel closed in and claustrophobic.
TNGator
Regular
Posts: 160
Joined: Wed Mar 20, 2019 11:55 pm
Southern kin y'all

Re: Tackling room resonances

Postby Mike Stranks » Mon Aug 12, 2019 10:48 pm

Have you ever tried good open-back headphones? All headphones are not the same... :lol:
Mike Stranks
Jedi Poster
Posts: 6729
Joined: Fri Jan 03, 2003 1:00 am

Re: Tackling room resonances

Postby TNGator » Mon Aug 12, 2019 10:51 pm

Mike Stranks wrote:Have you ever tried good open-back headphones? All headphones are not the same... :lol:
No Mike, I only have a pair of closed ones. They are great for recording but Ive never tried open ones. Might be worth investing. Like closed ones, are these designed for studio use as opposed to everyday hi fi headphones?
TNGator
Regular
Posts: 160
Joined: Wed Mar 20, 2019 11:55 pm
Southern kin y'all

PreviousNext

Who is online

Users browsing this forum: Sam Spoons