Building a home theater with a projector and an acoustically transparent screen? These in-wall speakers are designed for use in this scenario. Measurements were taken WITH the screen in place, so it is fairly specific to the material and spacing used;
The screen here is the Seymour AV screen material, available to DIYers or as a pre-built screen. It is very similar to what SMX uses. Top-end attenuation and comb filtering issues are notably less problematic with these materials.
The screen in my case ranges from about 2.25″ to 5″ from the speaker face since I also use an anamorphic lens and have thus curved the screen to keep focus consistent.
Drivers used are: A pair of Dayton RS180-4, a single Dayton RS150-8, and a single Seas 27TDFC per speaker, built WMTW. The RS180-4’s are wired in series. Breakup on the RS150 is -45dB in all cases. Crossover points roughly 350Hz and 1850Hz.
There are three options here. A basic crossover, which leaves in-place the reflection-induced peak (screen distance related.) If you have a receiver with some ability to tweak frequency, you can manually notch out any reflection-based issues your own setup creates. In mine, the center gets this ~5k peak of ~3dB, but the mains have a much more mild peak lower in frequency. These are quite usable with a very low distance like this, and a passive solution is also offered here. This is RED in the response posted, BLACK in the impedance.
There are two notch variations to solve this; In one, the notch is simply added to the same base crossover. Impedance becomes difficult here, but if you’ve the equipment that doesn’t complain, this is simple to experiment with; It’s also a bit easier to tweak to your needs. BLUE in response, RED in impedance.
The second variation includes a bit more work in the crossover and a light bit of BBC dip. BLACK in response, BLUE in impedance. This has the best phase tracking of the three as well.
Inductors used are all 18ga Jantzen.
