Oh I see now 🙂 So the size of the 2.5 inch deep MLTL equates to 0.3255 cubic feet, or about 9.217 litres (15" x 15" x 2.5"). Should I make it smaller?
At some point you will bump the rear magnet. But it can be made smaller. Leave room for some melamine foam behind the driver.
That makes sense. Given that the driver's depth is 2.15 inches, anything less than 2.5 inches in terms of the MLTL box depth would be cutting things close.
Unless there's any glaring reason not to, I'll have a go at building the MLTL at the same height and width of 15 inches, and reduce the depth to 2.5 inches. I'll adjust the port length of the schedule 40 PVC pipe to 5.55cm (converting that value to inches resulted in a less memorable number 😉 ). I'll have to stop by a craft shop soon and get some more foam core board!
Unless there's any glaring reason not to, I'll have a go at building the MLTL at the same height and width of 15 inches, and reduce the depth to 2.5 inches. I'll adjust the port length of the schedule 40 PVC pipe to 5.55cm (converting that value to inches resulted in a less memorable number 😉 ). I'll have to stop by a craft shop soon and get some more foam core board!
I've just finished building a pair of these, and I gave them a quick test standing on two window sills. I was impressed by the amount of Bass that appeared!
They're very balanced, and they show off the FaitalPRO drivers very well.
They're very balanced, and they show off the FaitalPRO drivers very well.
Do you have a photo? Glad it worked out. If you feel they are too bright, you can always add a BSC. About 1mH 20ga air core and about 3.3R to 4.7R in parallel should do it. If these sit flat against a wall you probably won’t need BSC.
I'm musing on how to mount them as flush to the wall as i can, but once they're mounted I'll post a picture 🙂
Here they are in place. I used some twine and hung them like pictures...
Nice work. Looks like a simple high payoff project. Cover the foam with some cloth or graphics etc and put a wooden frame around it and it will look right at home. Did you settle on 2.5in thick box? What were your vent dimensions again? It would be good to record the final configuration so others can easily give it a try. Thanks
@xrk971 - of course!
I re-used your instructions from this post: https://www.diyaudio.com/community/threads/full-range-on-wall-for-home-theater.260758/post-4028642
I changed the depth of the box to 2.5 inches, and made the length of the port at the end of the transmission line 5.55cm long.
I re-used your instructions from this post: https://www.diyaudio.com/community/threads/full-range-on-wall-for-home-theater.260758/post-4028642
I changed the depth of the box to 2.5 inches, and made the length of the port at the end of the transmission line 5.55cm long.
I'll have to wait a while before getting another pair of speakers for the Cornu speakers, but in the meantime I was thinking about using the MLTL design for the 6.5 inch polycone woofers, along with an additional tweeter. Not necessarily for the Bass boost, but because the aspect ratio of the enclosure is nice.
The Qts is also pretty high (0.95), so it seems like it might work. The mouting depth of the woofer is 2.875 inches, so I'd guess at least a 3.5 inch deep MLTL box wouold be required.
The Vas is 0.65 cubic feet, and the resonant frequency (Fs) is 52Hz. If we were scaling up the pizza box design, how big would it need to be?
The Qts is also pretty high (0.95), so it seems like it might work. The mouting depth of the woofer is 2.875 inches, so I'd guess at least a 3.5 inch deep MLTL box wouold be required.
The Vas is 0.65 cubic feet, and the resonant frequency (Fs) is 52Hz. If we were scaling up the pizza box design, how big would it need to be?
Assuming we make box about 2x Vas. You could go 25in x 25in x 4in deep. Assuming 0.5in thick plywood then you have 21in of internal width for the channels so you can make the channels 7in wide internally and it would all fit well. Total TL path is 6ft so good for 47Hz Fb on the 1/4wave fundamental frequency. Then use AMLTL method to determine port size for 47Hz. You will need to add a small fullrange or tweeter and crossover as the 6.5in won’t go high enough. One of those small Dayton snap in ND-25 dome tweeters could work.
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Hahah. Yes, foam can work but you will need to double up and reinforce the face with 3/16in subfloor plywood to allow the driver to mount. It’s a bit heavy to hang on on a plain sheet of foam core. You will have to reformat the size since foamcore is only 20in wide. You need 24in at least.
Wait! You already have a design for the PE 6.5" woofer! https://www.diyaudio.com/community/threads/foam-core-board-speaker-enclosures.223313/post-3754821
I'm glad I checked the index! 🙂 I'll read a few times (I have some XPS foam I can butcher), and see if I can slap a tweeter onto this!
I'm glad I checked the index! 🙂 I'll read a few times (I have some XPS foam I can butcher), and see if I can slap a tweeter onto this!
Yes, but it’s huge. I wasn’t very happy with it. I think the 24in x 4in pizza box flat wall MLTL would be better. Have not tried it but seems an easy low hanging fruit build.
Ah, I see - you were going for Bass extension! I suppose the wall loading of the MLTL adds a lot.
I might see if I have some XPS left over that's 24x24 inches. The build did inspire me to consider that material 🙂
I might see if I have some XPS left over that's 24x24 inches. The build did inspire me to consider that material 🙂
Unfortunately the XPS I have left over isn't that size, so I'll have to get some of this fancy plywood you've been talking about 😉
I was wondering about the box volume, and saw that a 24x24x4 inch enclosure is 2304 cubic inches.
This'll fit into a 19.2x30x4 inch format for the same volume. Would the thought end there because of how the 'pipe' would need to be created?
I was wondering about the box volume, and saw that a 24x24x4 inch enclosure is 2304 cubic inches.
This'll fit into a 19.2x30x4 inch format for the same volume. Would the thought end there because of how the 'pipe' would need to be created?