The No.1 Website for Pro Audio
 All  This Thread  Reviews  Gear Database  Gear for sale     Latest  Trending
Where to put treatment?
Old 8th January 2019
  #1
Gear Nut
 

Where to put treatment?

Hi guys

I (or rather we... or she) have an oddly shaped room in the basement. It’s a rectangle but with a bay window. It’s 3.6 m wide (red), 2 m heigh and apart from the bay window 4 m in length (yellow).

Her hobby is making clothing so as you can see from the picture there a lot of fabric/clothes around.

My hobby is making music and there’s a bit of space for my hobby in the basement as well ;-)

My space is by the green marking in a corner. My head is 1 m from floor/ceiling and 1 m from each of the walls. Speakers are on the walls on each side of the corner with the back of the roughly 0.2 m from the wall.

So... as you can guess that whole setup is a (BIG) compromise.

I tried making some preliminary recordings of noise and played with REW around the listening position. Basically there’s a peak at slightly below 100 Hz. Then serious dips at 112 Hz and 260 Hz. The bottom below 50Hz drops of. But what to expect from 5 inch speakers (Jbl 305)?

I can hear the same if I play the same frequencies on my synth. Heavy resonance around 95 Hz and then the notes at 112 and 260 disappeares.

So... let’s have a few jokes about how my wife should make more room for my hobby and then some serious talk about how to get the most out of the current setup.

So I let the speakers and listening position be where they are (drilling holes in the old walls are not fun and neither is moving everything around again!!!) and put up some treatment where I would benefit the most, remembering that it’s ok not to have perfect conditions - it is just a hobby.

So what should I put up where?

Budget is of course as low as possible and I’m not afraid of DIY ;-)
Attached Thumbnails
Where to put treatment?-1831b961-380e-4fb0-906c-298c5d782458.jpg  
Old 8th January 2019
  #2
Lives for gear
 
Jason Foi's Avatar
 


Well my friend, theres no need for sugar coatings. Its not really worth it given all the constraints you have. You could throw up a few hundred in treatment and have a different bad, but it will still be bad. You could try a demo of dirac live or sonarworks and see if you like that. It should make a noticable difference at the listening position, but i wouldnt go crazy trying to treat the space. Just enjoy the hobby. Good luck!
Old 9th January 2019
  #3
Gear Nut
 

I will upload some measurements tonight, but basically what you’re saying is that I cannot improve it one bit? I checked calculations and the dips n peaks (which as I recall are massive... like 20 dB) matches nicely with the expected modes of the room. So I was thinking bass trap in the corner behind the Mac. Panels of some sort on the ceiling above my chair and on the walls behind each speaker. But if you’re saying it won’t change anything or just create other peaks/dips then yes - I won’t bother.
Old 9th January 2019
  #4
Lives for gear
 

I think Jason is being a little over cautious here. You can definitely make it better with some panels for the first reflections, some bigger bass traps in the corners and something like Sonarworks too. You can probably make some decent improvements just by tweaking the speaker and listener poistions (use speaker stands for easier positioning, and REW to check the results). It won’t be perfect, but it should be a good improvement.
Old 9th January 2019
  #5
Lives for gear
 
Jason Foi's Avatar
 

Quote:
Originally Posted by explorer View Post
I think Jason is being a little over cautious here. You can definitely make it better with some panels for the first reflections, some bigger bass traps in the corners and something like Sonarworks too. You can probably make some decent improvements just by tweaking the speaker and listener poistions (use speaker stands for easier positioning, and REW to check the results). It won’t be perfect, but it should be a good improvement.
Speaker and listening position are in a corner and fixed. The room is shared and there wont be lots of treatment. DSP will provide the biggest return on investment. I suppose treating first reflection points is a good idea, but for a hobby room with a fixed LP, i just dont think throwing up $500 in treatment will make enough of an improvement to justify the cost. If he wants to try and get good results, i agree, moving speaker/listing position and filling corners/treating first reflections will make a huge difference.
Old 9th January 2019
  #6
Gear Nut
 

So putting in a few slabs of high density rock wool on a homemade wooden frame in the corners might help?

These are fairly inexpensive where I live. Should probably be able to treat quite a lot for 100$.

Edit: Roughly 10$ per m2 for 5 cm thick slabs (sorry for the metrics - I’m strictly an SI unit kind of guy)
Old 9th January 2019
  #7
Gear Nut
 

I’m not much into how the DSP based treatment works. It would be easy to put an EQ on the master channel with narrow bands compensating for the peaks, but I guess there’s more “magic” involved than just that?
Old 9th January 2019
  #8
Lives for gear
 
Jason Foi's Avatar
 

It will help to a certain extent. It takes a lot of tweaking speaker/listening position and then just tons of volume to treat a room. A good starting point in most rooms is putting up a minimum of 16 2'x4x4" panels spaced 4" off the walls. That and some positioning of gear is a good return on investment. Being in that corner is going to really mess with your frequency rrsponse and stereo imaging. Plus your room is almost square and has really low ceilings. Youre going to have strong cancellations kinda low in the spectrum which would need really deep treatment or pressure traps to fix. Try downloading the free demo of dirac and see what you think. "Room correction" typically shines in hard to treat rooms. And yes, its a little more involved than a few parametric eqs on the master bus. Dirac can help with time and phase issues.
Old 9th January 2019
  #9
Gear Nut
 

Here's some actual measurements made in REW. I hope I got the format right.

Again - I'm not expecting any miracles. You can't bend the laws of physics, but perhaps I would be able to do a tad better than a 20 dB drop at 112 and 267.

I would give Dirac a try :-)
Attached Files
File Type: mdat Right speaker.mdat (2.43 MB, 19 views) File Type: mdat Left speaker.mdat (2.43 MB, 25 views)
Old 9th January 2019
  #10
Here for the gear
 

Everywhere

Where should you put treatment? Everywhere you can find a spot. My room has all walls and ceiling treated and I even have the floor in front of the speakers treated. With small rooms such as yours and mine, you can't have TO MUCH.

Thing is, to have any hope of doing anything from 300hz down, you really need to have some depth to it. I have 21" on my front and back walls and about a 1' on the ceiling as well as 8" of rockwool in the 1st's on the walls and even on the floor. I know most won't can't do that, but this is my music man cave and I do as I like. There are other ways to do it with less depth, but those are either harder to construct, esp for the layman, or expensive if you buy them.

I am not by anyone definition knowledgeable in psychoacoustics, so take it with a grain. I do have, * "Two ears and a brain," and I use them.

I think sometimes we get caught up to much in what the numbers mean, or that numbers alone mean a room sounds good or bad. That is not correct to me. I have measured a friends room and the numbers, were less than stellar, but the room was very pleasant an did not fatigue. I have also heard some rooms where the number looked very good, to me anyway, and the sound wasn't nearly enjoyable.

The thing is what I like you may not like, so it might behoove people to listen to as many rooms as they can and find some they like. If they can put their own gear in the room, so much the better, but listen and find out what it is that pleases you and then you can try and get as close to that as your room will permit. I can tell you one thing for sure. There are no perfect rooms and the flattest one I heard, was not my favorite, nor did I want to spend long periods of time in it.

What you choose may not be the best for mixing, but is much better for listening, or visa versa.

Take all I have said with a grain as I am just scratching the surface of acoustics.

JT

*Floyd Toole Quote
Old 9th January 2019
  #11
Gear Nut
 

Quote:
Originally Posted by thompsontechs View Post

I am not by anyone definition knowledgeable in psychoacoustics, so take it with a grain. I do have, * "Two ears and a brain," and I use them.
I think I tend to agree... And I can to a certain extend probably compensate. But if I have a chance with a reasonable effort to reduce the massive dips I would do it. I'm not talking about an ambitious +/-2dB as I saw on another thread. But if I can get within +/-10 dB for the >40 Hz range I would be very happy :-) For the stuff below 40Hz... well. I'm not making dance music so ;-)

I haven't figured out how to use the Dirac thing. I could download a program that seems to want to search for compatible hifi stuff. And they have an App Store app.

I also read mixed reviews and giving it a bit of thought I do not really believe that much in the DSP correction approach. People seem to have some mixed results.

For now I think I'll buy a pack or two of rock wool (that high density terrain stuff) and see how far that will bring me.
Old 9th January 2019
  #12
Gear Nut
 

It's really fun and crazy with these standing waves in the bass range. I do not need my fancy measurement mic and REW to spot the issues. I can just play with the test tone generator in logic. Going from 120 to 115Hz is a huge difference!

Yes - it says nothing about decay time and all that, but it really reveals that I have an issue and I can measure the wavelength for the 115 Hz tone by just moving my head around

Once I get some rock wool up, I will get back with a new measurement... but don't hold your breath waiting. Things are moving slow here.
Old 9th January 2019
  #13
Here for the gear
 

Quote:
Originally Posted by Ninecows View Post
I think I tend to agree... And I can to a certain extend probably compensate. But if I have a chance with a reasonable effort to reduce the massive dips I would do it. I'm not talking about an ambitious +/-2dB as I saw on another thread. But if I can get within +/-10 dB for the >40 Hz range I would be very happy :-) For the stuff below 40Hz... well. I'm not making dance music so ;-)

I haven't figured out how to use the Dirac thing. I could download a program that seems to want to search for compatible hifi stuff. And they have an App Store app.

I also read mixed reviews and giving it a bit of thought I do not really believe that much in the DSP correction approach. People seem to have some mixed results.

For now I think I'll buy a pack or two of rock wool (that high density terrain stuff) and see how far that will bring me.
40hz... Rockwool will work for first reflections on the 8inch range but will not touch 40. You would be much better served by using some cheap pink fluffy and make some corner traps as deep as you can.
If you are going beyond around 8 then you are better served both money and bass to go with cheap fluffy.
Old 9th January 2019
  #14
Gear Nut
 

Quote:
Originally Posted by thompsontechs View Post
40hz... Rockwool will work for first reflections on the 8inch range but will not touch 40. You would be much better served by using some cheap pink fluffy and make some corner traps as deep as you can.
If you are going beyond around 8 then you are better served both money and bass to go with cheap fluffy.
I’m thinking the roll of from 40 and down is just as much caused by the speakers? They’re only 5”, so I guess there’s a limit to how low they can go.
Old 10th January 2019
  #15
Lives for gear
 
Jason Foi's Avatar
 

Please read this and the links it takes you to before you buy anything.

At what depth does fiberglass bat insulation become the better choice over rock wool?
Old 10th January 2019
  #16
Lives for gear
Rockwool works at even 40 Hz, if the right density/GRF is used. But, it needs to be thick...and lot of surface covered.

Another approach to reduce thickness and increase low frequencies absorption are pressure based absorbers.

Read Jens posts here:

Velocity based vs. pressure based absorbers
Old 10th January 2019
  #17
Here for the gear
 

Jason and Jay have some good advice and great links for you. I suggest you read and study before making any moves. When I first started I just threw some **** on the walls and when it didn't work I went to Toole and this forum and figured out why. That's the wrong way round and not cost or time effective. Do the reading first use the porous calculators and every other tool you can find. After you do all that, you still won't know what you are doing, but have a much greater chance of making a productive move instead of just wasting time and money.

The people here can be helpful too. The search function is your friend.

Good luck

JT
Old 7th June 2019
  #18
Gear Nut
 

So finally I got some treatment (or slabs of rock wool). In a wooden frame, nicely covered with a suitable fabric and as far from the walls as possible... which is unfortunately only 2 cm for those behind the speakers :-/ What you cannot see on the picture is that I also have one hanging from the ceiling above the LP.

Anyway. Although it did not do miracles it seems to have improved the acoustics a bit. See the before/after response in the attached measurements.

We're no longer talking about 30 dB drop at 110 Hz, but "only" 10-15 dB. The second dip at 260 Hz is more or less gone.

There seems to be some odd stuff in the upper range, but I think that might be measurement errors. Here I'm even more sensitive to placement of the measurement mic.

So even though there's still plenty of room for improvement I'm pretty satisfied and I'm at least within +/- 10 dB.

Price: 50$ - mainly because I wanted a nice finish and ordered too much of that fabric.

Down-side: Too little space behind the speakers now so I had to change the XLR to an angled jack stick. So for now it's not a balanced and that crappy cable is picking up a lot of noise. But that can be fixed with an angled XLR :-)
Attached Thumbnails
Where to put treatment?-img_9876.jpg   Where to put treatment?-skaermbillede-2019-05-30-kl.-23.08.19.jpg  

Last edited by Ninecows; 7th June 2019 at 08:26 PM.. Reason: Typos
Old 7th June 2019
  #19
Lives for gear
 
Jason Foi's Avatar
 

Nice! Not bad for $50!!
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump