BASS TRAP HANGERS -Would be done with ROCKWOOL? YES/NO/MAYBE

Hey Guys, I've collected some pics showing hangers and I've seen bass traps made only using wood and insulation, I think you call it 703. My question is: Would it be done with wood and rockwool glued on, and what the difference between glasswool and rockwool for this specific purpose?

My question is: Would it be done with wood and rockwool glued on, and what the difference between glasswool and rockwool for this specific purpose?

Yes and not much. Have fun! Andre

:) OK! HAS SOMEONE DONE IT?

http://johnlsayers.com/Studio/Pages/Somewhere.htm The inner core is soft fibreboard. The wrapping is dacron wadding - i.e. like they line upholstery with. cheers john

Ok, But the pic shows that those bass traps weren't made up using rockwool on it! :?

I Think that I haven't formulated my question appropriatedly. "LET ME TRY AGAIN": INSTEAD OF GLASSWOOL INSULATION, COULD I USE ROCKWOOL ON THE MDF? IS GLASSWOOL INSULATION BETTER THAN ROCKWOOL :?:

P750souza wrote:

I Think that I haven't formulated my question appropriatedly. "LET ME TRY AGAIN": INSTEAD OF GLASSWOOL INSULATION, COULD I USE ROCKWOOL ON THE MDF? IS GLASSWOOL INSULATION BETTER THAN ROCKWOOL :?:

I gave a clear answer. To repeat more verbosely: Yes you can use rockwool instead of glasswool. One is not better than the other. (New info) The important thing to look at is similar densities. Have fun!

SORRY AVare AND THANKS! I WAS IN DOUBT! REALLY THANKS! :oops: :oops: :oops: :oops: :oops: :oops:

The actual HANGING part of a trap such as this uses a different principle for absorption - it actually relys on the hanging mass to move a little bit, somewhat similar to the "soft" styles of martial arts - in order for the bass sound waves to MOVE the hanging mass, they have to release energy - then that energy is no longer sound, but (slow) movement. Also, some of the energy is converted to HEAT, same as normal absorbent types of traps. The "normal" way of building such a trap is to line it with the denser rockwool type materials, then wrap the actual hanging parts with lighter, fluffier insulation - part of the purpose of the lighter insulation is to keep the individual boards from banging against each other or vibrating; part is to absorb any higher frequencies as well. As far as I know, there is no good reason to use one type of insulation over another, as long as you do NOT use any of the foam type insulations; but any fiberglass or mineral wool insulation should work. The boards themselves can be hung as close to each other as you can get them and still have them hang freely; the more of them in a space (still free) the better the absorption. It's more efficient if the boards are neither parallel or perpendicular to the entering sound waves, but instead hung at an angle. IF that was confusing, let me know and I'll try to post a rough sketch... Steve

IF that was confusing, let me know and I'll try to post a rough sketch... Steve

I understood the principles, and your explanation was actually enlightening, but if you could add some drwaing, I'd appreciate! :idea: Thanks again Steve

It's more efficient if the boards are neither parallel or perpendicular to the entering sound waves, but instead hung at an angle.

This may be nitpicky, but is there a preferred angle? Slight or severe? Interesting...

No preferred angle - a "herringbone" pattern would cause the sound to have to bounce off several (absorbed) surfaces before making its way back OUT of the trap. Part of the answer to this would depend on the available depth of your trap, but typically 30 degrees away from perpendicular to sound travel will work well... Steve

Thanks for the explanation and the drawing. This stuff is sickeningly interesting, like a giant strategic game. Just when you fight your way through one level, you fall through a trap door to face a new set of unknowns. I really shouldn't have slept through science class.

I really shouldn't have slept through science class.

If you can withdraw from your sleep bank now, then several weeks of studying and finally building probably fulfill your needs. :D Andre

:!: :!: :!: Wow :!: :!: :!: :!: :!: CLAPS :!: :!:

Something I forgot to mention - hangers were (IIRC) used when sound levels in studios got 'way too loud, and are intended to provide more absorption of low bass at really loud levels - the "swaying to the beat" syndrome would be unlikely to occur at lower levels, so I'm not sure there would be much difference in performance at LOWER listening levels, with or without the hangers in the above trap. There is already enough absorbent shown to just about eliminate any mid to high frequency sound that strikes that absorber, even WITHOUT the hangers. So, if you're not planning on recording death metal live at concert volume, I'm not sure you'd need the hangers at all... Steve

Finally I can read something that makes me clear the principle of low frequecy control. I want to ask someting: I'm planning to build a rehearsal room for metal bands, so I need to control low frequencies. I plan to build some corner slat resonators, but for the lowests sounds I need something drastic. I know that the depth of the cavity is essential for low freq control. I plan to have a cavity of 600 mm (2' aprox). My question: Wich sizes (lenght, width, high) should the hangers be in order to control frequencies below 150Hz? Thanks. Ed.

Do you have a thread started on this project? There's a LOT more to isolating metal bands than bass traps. In fact, there are situations where bass traps will make the isolation WORSE... Steve

knightfly wrote:

Do you have a thread started on this project? There's a LOT more to isolating metal bands than bass traps. In fact, there are situations where bass traps will make the isolation WORSE... Steve

Thanks for answering Steve. I have a thread in Studio Construction called Isolation Strategies where Avare is helping me to design the inner walls in order to acheive good isolation. I tend to think bass traps as sound treatment for reducing reflections inside the already isolated room. Correct me if I'm wrong. What I intend to do is isolate the room from external noise and reduce the sound leakage from the room to the exterior too; then, after proper isolation is acheived, I'll put some bass hangers to control the low frequecy reflections inside the room, broadband panels for high frequencies and slat resonators for low and mid. So I understand that first you isolate, and then you put absorption inside. If you can give us a hint in the other thread it would be great, here's the link: http://www.johnlsayers.com/phpBB2/viewtopic.php?t=5521

Hi Steve

So, if you're not planning on recording death metal live at concert volume, I'm not sure you'd need the hangers at all

That's not my 1st intention, my concernement comes from the fact that my control room is only 7' X 9' What could you add about treating such a small place :?:

Absorb everywhere(especially corners) you don't need to sit or stand, and get a good digital reverb - that small a space won't work without maximum absorption... Steve