Anechoic Speaker Testing Room


Thread Starter
May 11, 2022
My AV System  
Preamp, Processor or Receiver
Yamaha MGP16X, DBX Driverack Venue 360
Main Amp
Seismic Magnitude Series
Hi, Vic here... so i want to be able to setup an anechoic testing room going here in my front office in brampton for being able to create proper FRD files. These files are for my crossover guy to help me design a crossover for a tall and esoteric-shaped 6-way speaker set idea for a special listening room powered by rack amps in a hybrid active/passive setup. Going tri-amped + sometimes a 4th amp for ultra lows below 50hz when a person wants to add the mono center into the experience. Otherwise just two channel tri-amped to the passive network. (in 2 channel mode without the sub low, will amp the bass woofers with the highest powered amp, the midbass and mids with a second amp, and the high mids, highs, and ultra highs with the lowest power rack amp. Feeding amps from a pretty decent DSP crossover and processor. Otherwise can also go single two channel amp to the fully jumped passive network.

So for the testing, I can put the room into anechoic mode, at least i hope i can with these stacks for foam strips i can pile into tall towers... basically all these extremely firm 6 X 24 inch polyester foam offcuts - the results of the stacks being about 6 inches thick and can pile all the way up.. i can do this all around the room and only lose about 9 inches of the footprint if i do a basic wall treatment behind these on the wall first, pile those strips in front, and then with some large 8 foot tall acoustic panels leaning on them on the front side to keep them in place from tipping over into the room. Will also bass trap two corners with a full triangle fill behind corner fabric panel covers.

But i was wondering if this treatment is enough going all the way around to be able to make everything extremely flat in a dead way for the room response to be used as a valid anechoic testing room? the room has large storefront windows and hollow drywall, each of which will be covered with that first inch or more layer of paneling of extreme firm foam first, and am hoping that the windows and hollow drywall to each 'helmholtz out' some different bass frequencies depending on their resonances, hopefully with some good luck to cancel stuff out, but I am not counting on it hence the very thick treatment regardless. Ceiling is ceiling tiles drop ceiling but with tons of foam up there on top of them creating some low frequency trapping. Modally this room does not sound bad at all there doesnt appear to be any major audible buildup other than basic reflection issues untreated.

room is 107 tall (but about double if the ceiling tiles don't really 'count'. above the ceiling tiles is a bunch of the same foam.
the length is 172 and width is 124 and there is an angled notch in the corner with the 90 degree sides being about 55 x 55 removed out of the room with that angle.

My question is is it possible to do accurate FRD files in such a room for both the close and 1M measurements? I'll certainly run some sweeps through the room to see what the plots look like. but will go all out like this only if you guys think its worth to even set this thing up to begin with.

And as i was saying, im trying to create some very uniquely shaped speakers for this room when the room is converted to being used for the sound listening (and healing) experience. i guess when i remove the stacks.

The rest of the room would be the bean bags for the 3 sitting positions with only the center beanbag getting the most optimized stereo listening experience. The stacks of 6 x 24 x 1,5 extreme density foam strips I have no shortage of for piling everywhere as I get them every month and I sell them. I have huge piles of this stuff so I may as well use them for something when I am not selling them.

Do any of you think its possible to get a proper testing room before I go for all this? Because its hard to get FRD files for alot of speaker brands. And even then i wouldn't trust them as I would want to make my own because with some of these brands you simply never know how well they were tested and where.
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