hanging bass traps over mix position

beggehorn · Post by **beggehorn** » Fri Jan 30, 2004 5:00 pm

My mix position is under a standard 8' ceiling. I'm looking to hang some sort of panels/traps above the desk which will give me as much trapping as possible without loosing too much headroom. I wouldn't mind angling the surface as it would probably allow for absorbing a lower average freq. yet still not hit me in the head when I stand up. I'm familiar with Ethan's bass trap plans and wonder which version would cover the frequencies to match the height of the room. In his diagram, he shows the traps as being built parallel to the wall. It appears as airtight construction is key. Would I be good to go if I was to build three traps side by side on the ceiling (to cover a 6x4' area over my desk) and make the frames deeper at one end so that they angled behind me? Is there a more efficient solution to what I'm trying to do?

knightfly · Post by **knightfly** » Sat Jan 31, 2004 1:16 pm

Yeah, there is - the center of the room isn't a very efficient place to put bass traps, that will only affect the modes caused by your floor-to-ceiling dimension. It's much more efficient to put bass traps in corners, preferably trihedral (all three walls meeting) corners.

For overhead treatment, you generally want more broadband absorption such as a few inches of rigid fiberglas suspended a few inches away from the ceiling - placing this centered over the mix position helps control early reflections from the ceiling, and kills flutter echo between floor and ceiling.

Aside from the inefficient use of centered panel traps, you would still have the early reflections to control... Steve

beggehorn · Post by **beggehorn** » Sat Jan 31, 2004 4:23 pm

thanks knightfly, I have a bunch of 1" 705 (6lb density) left over from an earlier project and was hoping to use it for the ceiling area. I thought about hangers but figured the panel traps would provide the same effect as well as adding 'some' trapping as well. If I just hang the 705, should I double them up (two one inch sheets)? I guess I'll need to back them for hanging. Will 1/4" plywood do the trick? Also how far down should it hang and how much of an angle will I need to send the reflections behind my head? Thanks again...

knightfly · Post by **knightfly** » Sun Feb 01, 2004 10:07 am

2" of 705 would be a good "cloud" - however, if you back the cloud with anything solid (not porous) you may as well just fasten it straight to the ceiling. The reason for standing off from the surface is to lower the effective frequency that's absorbed, by moving the 1/4 wavelength point lower in frequency. I'm off to work right now, search the site using the words air gap or cloud - otherwise, I'll try to give you a more complete answer (incl. mounting ideas) tonite if possible... Steve

beggehorn · Post by **beggehorn** » Sun Feb 01, 2004 4:27 pm

I've looked around the site a bit and have found some good drawings of the idea. However, almost every suggestion elsewhere says to back it w/ 1/4" ply. I'm assuming you might have thought I was going to hang them parallel to the floor. If I angle them (12 degrees or so- found that on the site too...) won't the ply backing help break up the standing waves and send reflections behind me? My back wall is covered completely with 705 from 32" up from the floor.

beggehorn · Post by **beggehorn** » Tue Feb 03, 2004 7:14 pm

cfuehrer · Post by **cfuehrer** » Tue Feb 03, 2004 8:11 pm

beggehorn wrote:won't the ply backing help break up the standing waves

Most likely it will bounce it right back near where it came from and why not absorb it rather than reflect it to have it reflwct back later?

knightfly · Post by **knightfly** » Tue Feb 03, 2004 9:05 pm

You're right - if you have the available ceiling height, you could do it either way. The angle should be enough to get the reflections that DO make it back through the 705 away from the mix position - although without an elevation drawing it's not a guarantee. Most people don't have the height to pull off angled ceiling hangers, so they just space the absorbent as much as they can to improve lower frequency absorption... Steve