After trying out a couple of projects that involved making MLTL speakers that are wall mounted (like this one ), I started thinking about other potential ideas for our living room.
I was very surprised by the performance of the 6.5" Poly cone woofer and the 1/2" mylar tweeter (that I bought some of from Parts Express a while ago, but they don't stock them any more) in the MLTL enclosure, but unfortunately at 24 inches square they're too large for me to use.
I was wondering if it were possible to build a MLTL enclosure with the intent of wall-mounting it with the exit port of the transmission line firing up to the ceiling (the kids can't leave a mess on the ceiling...so far...), but where the available width of the box would have to be about 8 inches. The height of the enclosure isn't really a concern, so I was hoping if it would be possible to make a narrow, shallow yet tall enclosure.
The provided T/S parameters are as follows:
Here is the mounting information:
Thanks in advance for your help and guidance!
I was very surprised by the performance of the 6.5" Poly cone woofer and the 1/2" mylar tweeter (that I bought some of from Parts Express a while ago, but they don't stock them any more) in the MLTL enclosure, but unfortunately at 24 inches square they're too large for me to use.
I was wondering if it were possible to build a MLTL enclosure with the intent of wall-mounting it with the exit port of the transmission line firing up to the ceiling (the kids can't leave a mess on the ceiling...so far...), but where the available width of the box would have to be about 8 inches. The height of the enclosure isn't really a concern, so I was hoping if it would be possible to make a narrow, shallow yet tall enclosure.
The provided T/S parameters are as follows:
Here is the mounting information:
Mounting Information | |
|---|---|
| Overall Outside Diameter | 6.5" |
| Baffle Cutout Diameter | 5.625" |
| Depth | 2.875" |
| # Mounting Holes | 4 |
Thanks in advance for your help and guidance!
Best to use a TL (basic HR sim is from another 'no-name' 6.5" = ~ 66" L x 6.5" W x 4.5" D (i.d.) with a 23" driver offset stuffed to 'taste' (31.65 L of polyfil) and experiment with port/ceiling spacing for best overall performance (1.0pi), max power = 6-7 W/Xmax
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Thanks @GM! It looks like a pretty simple enclosure to build 🙂
A couple of follow-up questions (mainly to clarify or sanity check):
1. Does the driver need to be offset 23 inches from the closed end of the TL?
2. Does the stuffing need to be added at the closed end of the pipe also?
3. Do you have any recommendations for the distance between the ceiling and the port? Can that be calculated based on wavelength?
I suppose question 2 might be moot, given the amount of stuffing that's been recommended here; I'd imagine that would occupy most of the TL's volume.
EDIT: I did a quick measurement of the walls, and depending on where the woofer should sit vertically, I have somewhere between 11 and 19 inches between the open end of the enclosure and the ceiling.
A couple of follow-up questions (mainly to clarify or sanity check):
1. Does the driver need to be offset 23 inches from the closed end of the TL?
2. Does the stuffing need to be added at the closed end of the pipe also?
3. Do you have any recommendations for the distance between the ceiling and the port? Can that be calculated based on wavelength?
I suppose question 2 might be moot, given the amount of stuffing that's been recommended here; I'd imagine that would occupy most of the TL's volume.
EDIT: I did a quick measurement of the walls, and depending on where the woofer should sit vertically, I have somewhere between 11 and 19 inches between the open end of the enclosure and the ceiling.
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You need a well damped alignment. Scott has a growing Hardwood Series of these. Poplar was first.
dave
dave
@planet10 - pardon my ignorance, but what kind of enclosure have you displayed in the picture? It looks like a bass reflex box to my uneducated eye 🙂
With regard to 'alignment', are you referring to the alignment between the cone surface and the air exiting the port?
@xrk971 - can I use the AMLTL method without the horn being folded?
With regard to 'alignment', are you referring to the alignment between the cone surface and the air exiting the port?
@xrk971 - can I use the AMLTL method without the horn being folded?
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Correct, the sim shows it's uniformly stuffed full length.
Well, basic pipe end correction for a 1.0 pi space is k = 1.728r, so the pipe's acoustical length = build length + its radius ((4.5+6.5)*2)/pi/2 = 3.5"*1.728 = 6", so in theory at < ~6" it will increasingly load its terminus/'vent', ergo to benefit from ceiling load requires a longer TL based on where the driver is located vertically on the wall.
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Ah, I see, so it seems that we'd have some extra theory to account for the distance from the terminus to where the wall and ceiling meet. Knowing what little I know about ports, I'd assume a smaller gap would require a longer port - is that correct?
Then the terminus will need to be > its area to keep tuning within the driver's range making it a crude BL/MLhorn, so 'go for the gusto'? ('70s era Schlitz beer commercial) 😉
😀
"Well, that escalated quickly!"
With regards to wall placement of the MLTL, it seems like I'm going to be physically constrained, and I shouldn't aim to get closer to the ceiling to keep the (additional) length of the TL down.
Would it be safer to consider the speaker as if it were in a 2pi space, rather than one? If it gave a lot of Bass we could just tame it with stuffing.
"Well, that escalated quickly!"
With regards to wall placement of the MLTL, it seems like I'm going to be physically constrained, and I shouldn't aim to get closer to the ceiling to keep the (additional) length of the TL down.
Would it be safer to consider the speaker as if it were in a 2pi space, rather than one? If it gave a lot of Bass we could just tame it with stuffing.
??? Understood; a crude BL/MLhorn can be one where the TL is much longer, allowing a much larger vent area along its length and if to the ceiling it gets a 1pi space loading for a significant gain BW Vs just a pipe vent.
Oh I see! So rather than a vent that looks like a slot, it's a rectangular hole, which would point forward to 'fire the sound' across the ceiling?
The BIB design is pretty cool 🙂 I was using one of the calculators, and it looks like the enclosure's pretty deep because of the horn fold. Unfortunately it won't work for this particular project, but I can think of another where it would 🙂 So many options!