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3 dB per doubling of distance was intended to be used to find how much the rear array should be attenuated. I started out at a calculated value of 8.5 dB, and ended up very close to that with 9 dB.
Huh, that's weird. I was under the impression that in these setups the front and rear arrays should play at (or very near) the same volume, regardless of distance. (In theory there should be minimal losses from a LF plane wave as it travels across the room because it's not expanding at all.) It's hard to argue with the results posted, though! Can you confirm that the rear array is physically playing 9dB quieter than the front?3 dB per doubling of distance was intended to be used to find how much the rear array should be attenuated. I started out at a calculated value of 8.5 dB, and ended up very close to that with 9 dB.
I tried that. Don’t work in my room at all. Maybe it works in a room with no loss, like a concrete bunker? Dunno….Huh, that's weird. I was under the impression that in these setups the front and rear arrays should play at (or very near) the same volume, regardless of distance. (In theory there should be minimal losses from a LF plane wave as it travels across the room because it's not expanding at all.) It's hard to argue with the results posted, though! Can you confirm that the rear array is physically playing 9dB quieter than the front?
Thanks for the confirmation! That’s an interesting data point for sure. 9dB is quite a lot of loss for one traversal of the room. By some rough math (7m / speed of sound) * (60 dB / 9dB) that implies a room RT60 time of 135ms, which would be very low for LF. A bit of a mysteryI tried that. Don’t work in my room at all. Maybe it works in a room with no loss, like a concrete bunker? Dunno….
Can confirm that the rear array is about 9 dB quieter. Will show measurements!
Yep,5db more for 2000as2 and on top of that probably different loads.I got confused by having amps with different gain for front and rear array, as well as different number of speakers on each amp. My math was not correct, obviously…
The idea is to extinguish the wave at the rear wall by adding the exact inverse to it. Since you have losses from front to rear, the rear needs to be attenuated to make that happen. So, this is exactly as expected.Huh, that's weird. I was under the impression that in these setups the front and rear arrays should play at (or very near) the same volume, regardless of distance.
Impressive result, do you have a picture of the arrays?
Couldn't one flush mount all the drivers in a gypsum board wall maybe? (Like cutting 50-50cm from the room in the front and the back)Well, there goes all my hopes of implementing this in a stealthy way for a living room
This will work. I used to have a front array in an infinity baffle. This has all already been discussed in other threads.not sure if/how DBA would work then
It could be much less. In real life, windows and doors can interfere with this dream)). For example, I don’t have a single wall without doors or windows.(Like cutting 50-50cm from the room in the front and the back)
Sure, two blind walls that house the woofers and covering would do. It’s just curious to have two bare walls in your living room…Couldn't one flush mount all the drivers in a gypsum board wall maybe? (Like cutting 50-50cm from the room in the front and the back)
That would make it kind of an infinite baffle I guess.... just an idea, not sure if/how DBA would work then
Or suspend drywall panels fitted with bass shakers instead of woofers. With enough surface area this would probably work…Sure, two blind walls that house the woofers and covering would do. It’s just curious to have two bare walls in your living room…