So I'm designing a very small WMTW speaker with 2 passive radiators behind the 2 woofers, and I face a problem:
Because I want to keep the cabinet small, I can only use 1/4'' BB walls, but 1/2'' for the front baffle. The combination of very high excursion drivers in a tiny thin wall cabinet will result in quite severe cabinet rocking from the high excursion capabilities of the W4-1720 as well as the 2 non dual opposed passive radiators behind the woofers. Using thicker walls is *not* an option. Now I'm willing to live with that compromise to keep the speaker absolutely small, but I thought of a different arrangement.
What if I dual opposed both woofers and passive radiators in this fashion?
W P
WTMP
This way all the vibrations will be cancelled out, leaving me with an inert cabinet. However, there is going to be one woofer firing backwards. The crossover will be set at 300Hz, LR4. I'm not quite sure what the effect on sound quality will be if one woofer is firing backwards, even if the bandwidth is limited to just ~350Hz and below.
So given these two options, which one would you pick for better overall sound quality? Cabinet vibration or rear firing woofer?
Because I want to keep the cabinet small, I can only use 1/4'' BB walls, but 1/2'' for the front baffle. The combination of very high excursion drivers in a tiny thin wall cabinet will result in quite severe cabinet rocking from the high excursion capabilities of the W4-1720 as well as the 2 non dual opposed passive radiators behind the woofers. Using thicker walls is *not* an option. Now I'm willing to live with that compromise to keep the speaker absolutely small, but I thought of a different arrangement.
What if I dual opposed both woofers and passive radiators in this fashion?
W P
WTMP
This way all the vibrations will be cancelled out, leaving me with an inert cabinet. However, there is going to be one woofer firing backwards. The crossover will be set at 300Hz, LR4. I'm not quite sure what the effect on sound quality will be if one woofer is firing backwards, even if the bandwidth is limited to just ~350Hz and below.
So given these two options, which one would you pick for better overall sound quality? Cabinet vibration or rear firing woofer?
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The gain primarily lies in opposed mounting of the passive radiators, as they have the largest mass and largest excursion. Below 300 Hz the woofers will be close to omnidirectional in a small cabinet so mounting position does not matter too much.
I don't think the cabinet vibration itself will be a problem. The cabinet acts like a dipole woofer so it will not be effective in transferring those vibrations to the air. It can however be a problem if the vibrations enter the desk the speaker is standing on, a vibrating desk is audible.
I don't think the cabinet vibration itself will be a problem. The cabinet acts like a dipole woofer so it will not be effective in transferring those vibrations to the air. It can however be a problem if the vibrations enter the desk the speaker is standing on, a vibrating desk is audible.
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Why do you think cabinet vibration won't be a problem? Wouldn't that color the sound?
Hi,
I don't know how you think you'll end up with an inert
resonant free cabinet, you simply won't, in any sense.
Quite franky it sounds like your ambition exceeds your
knowledge / experience by a rather large degree, and
your looking at things the way you see them, not the
way they actually are.
If you want very small dump the PR's and build a
sealed 3.5 way of half the current internal volume.
rgds, sreten.
I don't know how you think you'll end up with an inert
resonant free cabinet, you simply won't, in any sense.
Quite franky it sounds like your ambition exceeds your
knowledge / experience by a rather large degree, and
your looking at things the way you see them, not the
way they actually are.
If you want very small dump the PR's and build a
sealed 3.5 way of half the current internal volume.
rgds, sreten.
With vibration I meant only the part of the vibrations that goes away with opposed woofer mounting: the cabinet shaking as a whole. The amplitude of that motion is negligible compared to the motion of the woofers, because the cabinet is way heavier than the woofer cones.
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