Suggestions for what to try next for my room?

[reznet]

Hello everyone! I've learned a lot from reading the forum and tried out some things in my room and am interested in what I might try next. I have a small spare bedroom/office, 8.5' x 10.5' x 7.5' where I practice bass guitar, listen to music, and have moved into attempts at mixing an album recorded in my living room. I grew frustrated that I'd get the mix sounding good on my JBL LSR308's, but then have the mixes sound wrong nearly everywhere else. I invested in a calibration mic and REW and began taking measurements, and decided to buy some rockwool and make acoustic panels, and I ended up making enough 6" panels for three corners of the room (the 4th corner is where the door is). After performing before/after measurements, I saw a slight improvement, but not enough to solve my problem. I then learned more about room modes and the difficulty of evening out low frequencies, but also feel a bit burnt out by it. I'm considering putting my room back the way it was and just using headphones, but I thought I'd share my room and measurements and see if you had any advice for me. Budgetwise, I can DIY, but can't afford the more exotic solutions like active absorbers. Would more panels help? Or because of the small room size, am I at the limit of what I can correct passively?

 

[reznet]

here's a picture of my room with the panels installed

 

[bvocal]

Do you have a spare subwoofer? If you do, put it against the back wall, facing the back wall, about 1-1.5 inches out, and delay the signal by the distance to the speaker to the back wall, invert the phase. If you do it right (timing, response curve, volume) you should not be able to hear it, but bass will vanish at the back wall. The goal is to hear the bass from the front speakers once, then have it cancelled out (about 85% +/-) the bass when it gets to the back wall. It's like noise cancelling headphones for your room.
I use 2 subs made from cabinets I had and some pretty cheap drivers and plate amps I had and a mini dsp to handle the delay and eq curve (basically you just want it to be flat, you DO NOT make an eq curve like you would with room correction software, that folly is for subs used as subs, with the sub up against the wall the way I describe you are dealing with the bass at the one location where it is a singularity, the surface of the wall, the fr response curve on the surface of the wall should be the same as what the speaker puts out, as there is no room mode on the surface of the wall.
Cheers
P.S. you can't do it with passive absorption, in my experience, and if you did, it would be so large and expensive it will make my solution quite inexpensive.

 

[DanDan]

Neat looking traps. What problems are you having with Mix translation, or the sound in the room?

Location is an extremely powerful treatment. I suggest you try the speakers all the way to the Front Wall/Window, literally almost touching. Find the new optimum listening position.
The audible benefits of LF absorption many not be that immediately obvious, but Side and Overhead Reflection absorbers will create a Zone Without Early Reflections, a great increase in clarity and great stereo.
Small rooms are difficult and require massive treatment, so bvocal's suggestion is good. I have been musing about doing something similar, using really shallow car woofers to almost eliminate SBIR.
I use and recommend Dirac Live.

 

[kanef]

You do have a problem.
Most important is the massive low frequency issue, but you know that. Rockwool is a poor absorber but you've got it so maybe you can improve it prior to moving up. I'v attached test result I made some time ago as part of my own research, although I took the rock wool research no further. The blue line indicates 300mm rock wool with a 4mm resonator panel in front while the purple indicates replacing the panel with 5mm pegboard . You will notice a substantial improvement in absorption but at the cost of introducing a 125Hz notch. Raw rock wool gave almost no absorption to low frequencies (below the 200Hz 'transition' frequency)
Your panels should be placed along the rear wall, maybe 6" out from the wall. This will give the best 'bag for your buck', as you've got to nail the 1,0,0 modes before going anywhere. A single sub placed mid point between the to speakers will help, in my experience. Though I'm not sure that anti phasing will assist you. The extra sub works well in my experience, in filling out the nulls created by the main speaker nodes and antinodes move the sub around to find the sweet spot for your listening position(s). Suspending the sub halfway from the ceiling to floor may give a result.
I completely understand your frustration. Room treatment has been a new topic for many entering the industry. Sadly there a no short cuts, just incremental improvements.
I'm retired so am happy to help out where I can.

Kind regards and Good Luck
Kanef
Townsville
Queensland Australia

 

[DanDan]

Yes. Welcome kanef.

 

[reznet]

Do you have a spare subwoofer?

Hi bvocal, thanks for the idea! I actually did order a subwoofer but returned it after it didn't help me with the mixing problems and I found some advice that said not to use one unless I was mixing club music . Maybe I'll try again and use your technique, it's certainly interesting.

 

[reznet]

Neat looking traps. What problems are you having with Mix translation, or the sound in the room?

Mainly that the lows (bass guitar) are way too quiet when I listen to my mix in my car (a Subaru Outback with a sub) or my home office (Logitech speakers also with a sub). Doesn't make sense, does it? What I think it actually is is not the lows (i.e. under 100hz) but the low mids - what makes a bass guitar sound like a bass guitar. It doesn't help that the bass was recorded with flats and doesn't have a lot of high frequencies, but what are there get completely lost when I add in the other instruments. I'm trying to mix an album of keys, bass, and drums playing a kind of jazzy fusion and it seems that I can't hear the definition of the bass guitar when I'm not listening in my mixing room or on my senheiser 500's (I think they're 500's - they're very old).

Location is an extremely powerful treatment. I suggest you try the speakers all the way to the Front Wall/Window, literally almost touching. Find the new optimum listening position.
The audible benefits of LF absorption many not be that immediately obvious, but Side and Overhead Reflection absorbers will create a Zone Without Early Reflections, a great increase in clarity and great stereo.
Small rooms are difficult and require massive treatment, so bvocal's suggestion is good. I have been musing about doing something similar, using really shallow car woofers to almost eliminate SBIR.

I'll try moving the speakers closer to the front wall. thanks for the suggestion!

I use and recommend Dirac Live.

I run from my PreSonus FireStudio out to my JBL monitors - would I need to get some kind of pass thru device that I would then use Dirac with?

 

[reznet]

You do have a problem.
Most important is the massive low frequency issue, but you know that. Rockwool is a poor absorber but you've got it so maybe you can improve it prior to moving up. I'v attached test result I made some time ago as part of my own research, although I took the rock wool research no further. The blue line indicates 300mm rock wool with a 4mm resonator panel in front while the purple indicates replacing the panel with 5mm pegboard . You will notice a substantial improvement in absorption but at the cost of introducing a 125Hz notch. Raw rock wool gave almost no absorption to low frequencies (below the 200Hz 'transition' frequency)
Your panels should be placed along the rear wall, maybe 6" out from the wall. This will give the best 'bag for your buck', as you've got to nail the 1,0,0 modes before going anywhere. A single sub placed mid point between the to speakers will help, in my experience. Though I'm not sure that anti phasing will assist you. The extra sub works well in my experience, in filling out the nulls created by the main speaker nodes and antinodes move the sub around to find the sweet spot for your listening position(s). Suspending the sub halfway from the ceiling to floor may give a result.
I completely understand your frustration. Room treatment has been a new topic for many entering the industry. Sadly there a no short cuts, just incremental improvements.
I'm retired so am happy to help out where I can.

Kind regards and Good Luck
Kanef
Townsville
Queensland Australia

Thanks for your suggestion, kanef. I'll try putting the panels behind me, 6" off the wall instead of in the corners and see if that helps. Thanks!

 

[kanef]

Thanks for your suggestion, kanef. I'll try putting the panels behind me, 6" off the wall instead of in the corners and see if that helps. Thanks!

Absorption will improve markedly with the pegboard. Remember to have the board on the room side. It seems counterintuitive but the board will really move with the bass. And trap some of the return energy giving you bonus Absorption. And it’s a cheap modification. If you make a frame of 1/2 inch square mdf and mount it inside the carcasses so the pegboard is a little below flush you can glue the pegboards to the frame. This helps keep the resonance modes aligned. We want phase coherence at this point at all costs.
cheers
Kanef

 

[DanDan]

Bass trapping works much better in a corner. This is the converse of placing a speaker in a corner where the bass output is massively increase.
Your translation problem is kinda the opposite to what one might assume. I guess you are hearing too much bass, so turning it down while mixing. Your speakers are very close to the side walls, so this is probably causing excess LF. Oddly perhaps placing the speakers at the window may tighten things up. Windows absorb LF.

 

[Bpape]

You will have issues in the height dimension. 2 4" thick panels spaced down 4" from the ceiling over your head and at the ceiling reflections will help. Try some also centered on the wall behind your seat.

I would agree you are hearing too much bass so mixing it down.

Also, I don't see reflection zone panels on the side walls where you are definitely getting some SBIR issues shown in the graphs - again, big peaks so you are mixing down in level.