Slot loaded bass reflex designs can be modeled in Hornresp as an OD (offset driver) horn with a ported rear chamber. The horn size can be varied from a small slot to a large horn or anything in between to determine it's contribution to the output and what the resonance of the slot/horn plenum will be.
Hornresp is something I have never got to grips with, working with wood is more my thing. I have built BR speakers using winisd with great results. It seems those that do know how to model ideas in hornresp are reluctant to help us mere mortals with a design.
There are dozens of folks here that regularly help out those that ask questions.
Do you have a design that you want help with?
Do you have a design that you want help with?
I have an outdoor gig coming up in about three weeks. I currently have two 15" slot ported subs tuned to about 35hz. Would it be worth while to attempt to strap them together like this with spacers, what would be the benefits...?
Like what 🙄?
If the cabinets loose frontal area when the cones are pointed at each other the output will be less. Big baffles are good.
I would like very much some plans for something like the OP's idea, maybe not the bass reflex part if that would be a potential problem, but slot loaded so I can mount it above the ceiling in a loft space with a slot in the ceiling, if possible with a horn mouth although not essential but would look good. I have a pair of eminence alpha 15A and Kappa 15 LF, although I'm not sure the kappa's go as low. But I'm open to suggestions on driver selection from 20Hz -50Hz only. I have been thinking infinite baffle but that will mean closing a section of the loft space and insulating it, whereas slot loaded sealed or bass reflex into the slot I would be able to insulate just the box on the outside to stop the cold getting to the drivers. Some help with this general idea would be much appreciated.
Paul,
There are six "general ideas" in your post, and no specific questions.
1) DJK has made plans for PPSL (push pull slot loaded) cabinets. The slot does not change response much from "normal" BR, but does add a slot resonance, usually well above the sub pass band, so can usually be ignored.
2) Slot loading and horn loading are two completely different things, but a long slot and a short narrow horn start to behave similarly.
3) Neither are good choices for bass reflex for 20-50 Hz, in general BR below drivers Fs are not optimal, and neither driver has much linear excursion (Xmax).
4) Driver selection is dependent on enclosure type.
5) Cooling drivers is good, heating them is bad.
6) Search for an appropriate design that fits your application.
Art
There are six "general ideas" in your post, and no specific questions.
1) DJK has made plans for PPSL (push pull slot loaded) cabinets. The slot does not change response much from "normal" BR, but does add a slot resonance, usually well above the sub pass band, so can usually be ignored.
2) Slot loading and horn loading are two completely different things, but a long slot and a short narrow horn start to behave similarly.
3) Neither are good choices for bass reflex for 20-50 Hz, in general BR below drivers Fs are not optimal, and neither driver has much linear excursion (Xmax).
4) Driver selection is dependent on enclosure type.
5) Cooling drivers is good, heating them is bad.
6) Search for an appropriate design that fits your application.
Art
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I have two open backed boxes, open baffle if you like that I used with eminence alpha 15a with 200hz horns and ribbons. I have sold off most of this but may try these boxes facing one another, say 6" apart, with three sides closed to form the slot outlet. I could make this slot adjustable for testing purposes and run them as infinite baffle slot loaded, can use a deqx to set the frequency range and cost me nothing to try. I have sold the 6s33s push pull valve that drove them brilliantly but could use a vintage jap amp before buying another suitable amp.
Larger baffles increase forward directivity, increasing forward output (while reducing rear level), but do not lower extension.
http://www.diyaudio.com/forums/subwoofers/204472-multiple-cabinet-combined-response.html
http://www.diyaudio.com/forums/subwoofers/184986-horn-extender-wave-guide-th.html
Right, but I mean by combining my subs similarly to the first post in this thread...I would think it would lower the extension at the expense of sensitivity.
An externally hosted image should be here but it was not working when we last tested it.
At the risk of further hijacking the O P's thread, I have a 10 x 10 x 8 room so output or sensitivity is not such an issue. Low extension is what I need up to 50hz only.
Yes, if your plan effectively doubles the length of the ports, Fb goes lower, extension at the expense of sensitivity.
Without a picture of your cabinet design in whatever configuration you are thinking of, have no idea what would occur.
It would effectively be the same as the pic above vs. a pair of coventional slot ported subs....
Oh 🙄.
I can visualize six different configurations for "conventional" slot ported subs without closing my eyes, and they can be put face to face four different ways, that would be about 24 different outcomes.
But check my math, been a long day already :^).
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Tip it on it's side, face the pair driver to driver about 4-5" apart, then wood on the gap on 3 sides. Figure it must more or less extend the existing port by about 16", or about 60-70% longer.
And if you put the drivers to the rear, ports at the front, it won't extend them at all.
Tip it on it's side, face the pair driver to driver about 4-5" apart, then wood on the gap on 3 sides. Figure it must more or less extend the existing port by about 16", or about 60-70% longer.
If you want them louder, just stack them and erect some barn doors (pieces of plywood) along each side.
Parking vans or water barrels either side works too.
Trying to go PP with them, not going to help appreciably.
Just curious what my options are. I would think that simming a 60-70% longer port would be about right.
I'm already working on plans for some ghetto barn doors / horn extension. Any comments on aping the funktion-one infrahorn extension, with three panels of plywood?
http://www.funktion-one.com/products/infrahorn/
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