as long as the plexi is thick enough not to flex if it's a load bearing surface, then there shouldn't be any effect. particularly not with subs and in a car.
cabinet materials make more of an impact with full range cabinets for home audio, and mainly when dealing with types of wood.
Plexiglass is a terrible source to use as a speaker enclosure for the following reasons:
Plexiglass has high resonance and makes speaker enclosures sound boomy. Therefore it is a terrible source to use for a speaker enclosures, "especially for a subwoofer application.
In a subwoofer enclosure; the cabinet walls get more abuse compared to any other enclosure, because the subwoofer is limited to just bass frequencies (subharmonic = below directional sound).
Subharmonic frequencies are large wavelengths and therefore require that the speaker pump out (like an air compressor)large amounts of air to reproduce low-bass-sound.
When the cabinet resonates, it adds to the original sound, and therefore it becomes untrue.
IMO, I use the highest density materials (or thickest material I can find) to build my enclosures. I aim to build an enclosure that will just house the speaker and have limited added resonance. I want to hear just the speaker itself at its optimum performance.
plexi isn't a great material for boxes, which is pretty commonly acepted.. but for show vehicles, you can get away with using 3/4" or 1" lexan without much resonance or coloration.. granted you're spending $1200/sheet for the stuff. The shitty little boxes you see at best buy with the 1/4" plexi windows usually aren't load bearing panels and they say right on the boxes that they aren't made for high output drivers.. that being said, they sound like a$$ with or without the window.. as most bandpass prefab boxes do anwyay.
point being you can use lexan if its done right, but it's expensive, and for best sonic results, yeah stick to high density wood like MDF, HDF, certain solid woods if you can afford them and feel like working in real woods/cabinetry for construction..
I agree with you mixneffect! But what if there was just a window like oen was originally planning on doing? Would the difference in sound be noticeable?
Bandpass enclosures rattle at high volumes. Even though bass frequencies are non-directional, the sound may be muffled when using the speaker in bandpass/isobaric enclosures. It sounds mechanical. If SQ is not an issue, the sky is the limit.
The design makes the pressure excessive, inside the box. Thats why they sound boomy. The walls resonate and the plexiglass windows usually give, and leak arround the edges.
Just test it for yourself. Go pound someones bandpass/isobaric encoluse with high volumes for a while and see for yourself.
IMO; they are novel ideas that aim to get more for less. You know what we all say? If it sounds too good to be true, it probably is!
Surely walls resonating is a product of poor building not cabinet type? Leaky plexi is another crap build quality issue not box type. Last year I had some Alumapro bandpass boxes on test complete with pointless plexi window, and while I didn't like the sound, there certainly wern't any leaks or plexi giving and they were seriously pounded. What have you got against isobaric loading?
