I'm seriously considering going ahead with the build of a small ported 15" Dayton Reference HO for compact PA use.
The model I have going is 2.5 cubes (plus ports, driver) tuned to 37.5 hz with 2x 24"x5" ports, with a bend. Hoping to get into a box around 16x20x20 or so. Has a smooth peak around 45hz. This will be used outdoors as a single sub with a battery powered class-d car amp doing 400 watts into 4 ohms, off large SLA batteries. So the lower end peak seems like a good thing. I get a 95 db/2v/m/2pi peak in hornresp.
One port could be plugged for indoor use providing extension down to 30hz.
I may in the future add a 2nd sub and digital pro audio amp around 800w x 2, for AC use, which would max out the subs.
I have considered horns in detail, but it doesn't seem like they can give the extension in this size package. I've also considered a ported LF pro audio 12", but the HO 15" seems like it has better extension and close enough sensitivity in the same size box, with much more headroom.
I know the driver is very heavy and it will need a solid box, but hopefully I can come up with something that is effective while portable and not overbuilt.
Your thoughts?
The model I have going is 2.5 cubes (plus ports, driver) tuned to 37.5 hz with 2x 24"x5" ports, with a bend. Hoping to get into a box around 16x20x20 or so. Has a smooth peak around 45hz. This will be used outdoors as a single sub with a battery powered class-d car amp doing 400 watts into 4 ohms, off large SLA batteries. So the lower end peak seems like a good thing. I get a 95 db/2v/m/2pi peak in hornresp.
One port could be plugged for indoor use providing extension down to 30hz.
I may in the future add a 2nd sub and digital pro audio amp around 800w x 2, for AC use, which would max out the subs.
I have considered horns in detail, but it doesn't seem like they can give the extension in this size package. I've also considered a ported LF pro audio 12", but the HO 15" seems like it has better extension and close enough sensitivity in the same size box, with much more headroom.
I know the driver is very heavy and it will need a solid box, but hopefully I can come up with something that is effective while portable and not overbuilt.
Your thoughts?
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Outdoors over anything but cement (grass, dirt, sand etc) will be more like 4pi. So don't count on 2pi output just yet....
I have a similar sized cabinet with the same woofer used in my car (but tuned to 30ish Hz). I tested it inside and it had solid output (used a bridged qsc mx1500a...) but I never tried it outdoors so no help there.
I have a similar sized cabinet with the same woofer used in my car (but tuned to 30ish Hz). I tested it inside and it had solid output (used a bridged qsc mx1500a...) but I never tried it outdoors so no help there.
An ss15 isn't that much bigger, but I'm not sure if you want a box that big. If you do sim it in the ss15, see how it works.
When powering off batteries, I'd want the most efficient setup possible, so using that kind of driver as opposed to a 3015lf (similar price, much better efficiency) isn't really the best choice.
When powering off batteries, I'd want the most efficient setup possible, so using that kind of driver as opposed to a 3015lf (similar price, much better efficiency) isn't really the best choice.
Outdoor use would be mainly on paved or packed dirt surfaces.
I have a ported 15" for my SUV in about 4 cubes and it seems to have decent output outside with the hatch open.
I've simmed most of the LF PA drivers - while they claim massive sensitivity, most of them are only marginally more sensitive than the 15" HO below 100hz. The 3015LF was pretty decent, while the Delta-12LFC was a standout for sensitivity with reasonable extension for box size - but only 1-2db above what the 15" HO simmed at the 40-50 hz peak. Unless I'm totally doing it wrong. Simming everything 2pi, 2.83v for 8ohm drivers, 2v for 4 ohm. Amp will max out at 40v.
I found this thread interesting:
BMS 15" in small enclosures - Speakerplans.com Forums
The 15" BMS driver they are discussing has a claimed nominal 98 db sensitivity. But when you look at the spec sheet and do the math, it only really does about 88 db/2.83v/1m anechoic in a sealed box below 100hz. The dayton does pretty much the same as far as I can tell, if not a little better.
I've looked at virtually every type of compact horn available. At this box size I've only found that it's not possible to get better sensitivity and extension than bass reflex - they end up pretty equal when you try to get enough length to the horn for low extension. Then you also have to deal with the group delay of the horn with time correction. An ss15 probably about twice the size and 4-5 db more sensitive (by models).
I have a ported 15" for my SUV in about 4 cubes and it seems to have decent output outside with the hatch open.
I've simmed most of the LF PA drivers - while they claim massive sensitivity, most of them are only marginally more sensitive than the 15" HO below 100hz. The 3015LF was pretty decent, while the Delta-12LFC was a standout for sensitivity with reasonable extension for box size - but only 1-2db above what the 15" HO simmed at the 40-50 hz peak. Unless I'm totally doing it wrong. Simming everything 2pi, 2.83v for 8ohm drivers, 2v for 4 ohm. Amp will max out at 40v.
I found this thread interesting:
BMS 15" in small enclosures - Speakerplans.com Forums
The 15" BMS driver they are discussing has a claimed nominal 98 db sensitivity. But when you look at the spec sheet and do the math, it only really does about 88 db/2.83v/1m anechoic in a sealed box below 100hz. The dayton does pretty much the same as far as I can tell, if not a little better.
I've looked at virtually every type of compact horn available. At this box size I've only found that it's not possible to get better sensitivity and extension than bass reflex - they end up pretty equal when you try to get enough length to the horn for low extension. Then you also have to deal with the group delay of the horn with time correction. An ss15 probably about twice the size and 4-5 db more sensitive (by models).
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Well a 50 lb box that's 4-5db more sensitive could equate to 2x longer battery life. That's a big difference for battery weight, you need to go by Reserve Capacity
Don't forget that having the box in an SUV with the hatch open could be using the cabin as part of the "horn" and adding a huge bump in SPL. You need to test the box outside by itself and see how it sounds! If its enough for you go from there. In my case I needed two ss15's with 600w RMS total and (2) 100 lb deka batteries plus two solar panels in order to rock out on the beach for hours at full tilt with EDM..,
Don't forget that having the box in an SUV with the hatch open could be using the cabin as part of the "horn" and adding a huge bump in SPL. You need to test the box outside by itself and see how it sounds! If its enough for you go from there. In my case I needed two ss15's with 600w RMS total and (2) 100 lb deka batteries plus two solar panels in order to rock out on the beach for hours at full tilt with EDM..,
Well you certainly have a point and something more efficient would be better. But I want to be able to transport this in a sedan with a fold down rear seat, not the old suv which isn't driven much. And I'd prefer solid 40hz extension.
Planning on a pdx 4.150 bridged to provide the 400w / 40v @ 4 ohms to one sub powered by 2x 12v 35ah SLA batteries. 8 ohm PA mains so 75 w each to those. I calculate about 3-4 hours of run time playing music at max volume, but I'm hoping for better than that in practice.
It doesn't have to be insanely loud, it just has to be much, much better than your average portable stereo or factory car stereo.
Honestly, the SS15 is pretty huge. It's small compared to real PA setups, but honestly it's too big for 1 guy to carry around. I'm happy with mine, but for more mobile applications I'm working on a very small 12" TH, about 100 liters internal, and only 15kg total weight, which should give me about 99dB/1W from 50Hz to (hopefully) 200Hz. It's still in the design phase, but top end is a priority for me as I want to use it with 6" tops. So far HR looks quite promising, but it's more of a hard hitter than a deep sub - I'm purposely losing out on the deepest of bass for portability. I gotta go to the pub now to watch football, but when I get around to it I can post up my design (it's still only in my head, needs to be properly sketchupped and hornresped).
Here's another thread I got ideas from, the BMS driver used is actually pretty compareable in sensitivity to the 15" HO dayton in the models, if I recall correctly, however the 12" ho was 2-3 db less sensitive. The slight rise to 40hz is part of the design strategy, to get better output from a small box.
Q12 12" Sub - Speakerplans.com Forums - Page 1
Q12 12" Sub - Speakerplans.com Forums - Page 1
Well I bought the mains for the system, Peavey Impulse 100, at a good price. Decent quality, sound, size, weight, and resale value. 96 db/w/m sensitive on the spec sheet, should get loud enough off 75w battery powered and I have a nice 200w per channel adcom to drive them for AC use.
I calc 117.7 db nominal with 2 speakers @ 1m 75w. The 15" HO sims at 118 db from 400w in winisd, 39hz f3. For AC use the adcom drives the pair of mains to 122db nom, and a pair of subs 800w each with one plugged port (~26.5 hz tune) hits 120 db nom with a 29hz f3 (add room gain as applicable, and ports can be unplugged for more gain as needed). Am I on the right track here?
Time to get serious about a sub or two.
I calc 117.7 db nominal with 2 speakers @ 1m 75w. The 15" HO sims at 118 db from 400w in winisd, 39hz f3. For AC use the adcom drives the pair of mains to 122db nom, and a pair of subs 800w each with one plugged port (~26.5 hz tune) hits 120 db nom with a 29hz f3 (add room gain as applicable, and ports can be unplugged for more gain as needed). Am I on the right track here?
Time to get serious about a sub or two.
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Actually, in my horn resp models the bms did about 92 db on 2.83v, and the 15 HO 95 db on 2v, with similar response plots. Even if dayton is fudging the numbers, that's a big margin for error.
Without chuffing / noise?? That's full power into that driver (x-max plus) id be weary of driving it to full power without noise...
well remember that our ears are much less sensitive to LF.... I'm betting those tops will out shine the single sub or two if not horn loaded or in a proper sized box for PA....
I'm pretty sure a 5" round port should be fine. It's under 100 ft/sec in winsid with 800, and under xmax. We're only talking about a ~30hz f3, people get these down to 20hz all the time. The small box is a factor.
Btw if you want to come down one weekend to test the cabinet outdoors that I have built with the Dayton Ref HO 15 feel free...I have plenty of amp power available
this is copied from my install thread on diyma...
I know it would be easier to measure for you, except I have no measurement equip
this is copied from my install thread on diyma...
Got started (and finished actually) on the subwoofer enclosure...turned out to be 2.0 cubic feet internal volume after subtracting the subwoofer displacement and the port duct displacement....tuned to roughly 27hz....
made it from 1/2" Baltic Birch plywood
all buttoned up!
i wasn't going to finish the box, but had some extra neffy wrap lying around and some extra 3M spray 90 so i figured what the heck
I know it would be easier to measure for you, except I have no measurement equip
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Not much I can do about it, these are the biggest boxes I can fit, and they are about as efficient as any other BR box I could come up with.
Btw if you want to come down one weekend to test the cabinet outdoors that I have built with the Dayton Ref HO 15 feel free...I have plenty of amp power available
this is copied from my install thread on diyma...
I know it would be easier to measure for you, except I have no measurement equip
That's a good idea, when I get the mains, I'll rig up an outdoor test with my old ava15 to see if it can keep up, should be fairly compareable. Thanks!
So I've started to flesh out a box design, no plans yet but here's what I'm thinking.
- 22x19x16 inches external.
- Woofer on the 22x16 face
- 16x16 baffle offset to side, recessed 1.5" inwards
- 1/4" wood on baffle out to perimeter of box, 1/2" wood inside that to support grille
- 2 x 5" x 24" ports on same face, outside grille/woofer baffle
- PVC drain pipe ports with long 90 degree
- No port flares, for simplicity
- Thin aluminum strapping to hold ports in place
- Slat bracing as needed on panels
- 1/2" birch plywood
- Internally coated with rubber roofing mastic
- no filling
- thin, large area rubber feet
- pole mount for main speaker on side
- intended to be placed on it's side
- target weight under 60 lb w/driver
Your thoughts?
Also looking at pro sub amps, what do you think about the QSC GX5 at 700w 4 ohms vs. GX7 at 1000w 4ohms? It's nominally a 1.5 db difference for a $200 price jump.......
- 22x19x16 inches external.
- Woofer on the 22x16 face
- 16x16 baffle offset to side, recessed 1.5" inwards
- 1/4" wood on baffle out to perimeter of box, 1/2" wood inside that to support grille
- 2 x 5" x 24" ports on same face, outside grille/woofer baffle
- PVC drain pipe ports with long 90 degree
- No port flares, for simplicity
- Thin aluminum strapping to hold ports in place
- Slat bracing as needed on panels
- 1/2" birch plywood
- Internally coated with rubber roofing mastic
- no filling
- thin, large area rubber feet
- pole mount for main speaker on side
- intended to be placed on it's side
- target weight under 60 lb w/driver
Your thoughts?
Also looking at pro sub amps, what do you think about the QSC GX5 at 700w 4 ohms vs. GX7 at 1000w 4ohms? It's nominally a 1.5 db difference for a $200 price jump.......
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