Yes I'm checking blue Aran. Sadly they don't seem to sell any of the drivers you mention at 4ohms. Only 8. And I think I'll be lacking power at this impedance.
Maybe I could build a twin 15? My main problem preventing an 18 is the width. Reall want 450mm but could maybe stretch to 500mm (it has to fit under a space designated by the missus as ok for big *** sub and no negotiation is possible 🤣)
So with twin 15 I could use 8ohm drivers, giving me more flexibility for finding drivers to buy. But then maybe the cab would have to grow too much again.
I think 37 would be fine from the roar, but I'd have to shrink the width. How easy would this be, or would it just wreck the whole design?
Loving the feedback rademakers. I feel like I'm edging closer to a solid plan thanks to your input.
Looked at Skar?
https://www.skaraudio.com/products/svr-15-inch-car-subwoofer
https://www.skaraudio.com/products/sk1x15v-single-15-ported-subwoofer-enclosure-box
Or better a complete: https://www.skaraudio.com/products/skar-evl-single-15-inch-loaded-subwoofer-enclosure
You'd just need to rewire it for 4R instead of 1R.
https://www.skaraudio.com/products/svr-15-inch-car-subwoofer
https://www.skaraudio.com/products/sk1x15v-single-15-ported-subwoofer-enclosure-box
Or better a complete: https://www.skaraudio.com/products/skar-evl-single-15-inch-loaded-subwoofer-enclosure
You'd just need to rewire it for 4R instead of 1R.
The thing is you are wanting one subwoofer in a cabinent taht you can use inside and then take outside. But inside is physically tiny with limited room for a nice big bass bin that will work outside. Then the physics of bass inside and outside are totally different. Getting one cabinent to do both is a lose/lose scenario
What you need is clever design. Essentially a configurable system with IB inside that gets flipped to a 1/4 wave horn outside. IB inside will use the subfloor space as a "box". This saves space in the cabin. The baffle inlet could be under a chair of sofa so cost nothing. To covert it to 1/4 wave horn needs a sliding baffle to route the sound out. The horn gives a big dB boost for doofing. The inside infinite bass will give tight pressurised sound. Simple.
What you need is clever design. Essentially a configurable system with IB inside that gets flipped to a 1/4 wave horn outside. IB inside will use the subfloor space as a "box". This saves space in the cabin. The baffle inlet could be under a chair of sofa so cost nothing. To covert it to 1/4 wave horn needs a sliding baffle to route the sound out. The horn gives a big dB boost for doofing. The inside infinite bass will give tight pressurised sound. Simple.
This is an interesting thought kazap. The box will actually be under the bed in the room next to the living room, so I intend to have an opening in the wall so that it's open to the living space. That way I can enjoy it while in bed and also while in the living room
.
This is how I sold it to my lady.
Goes like this:
" I want to make a big sub for use outside for when people come over for BBQs etc"
"Ok... How big are we talking?"
"Erm. Prob about the size of the cooker"
"Right....."
"Also we need a sub for inside 😄)
" Right... And where are we going to keep them?"
"💡! I've got it. I'll build it so it fits onset the bed. That way we only need one! We can use it in bed and I'll have a cut out so it can be used in the living room too. And then when we have a party we will just take it outside.💪💪)
"Mmm. Sure. Ok then. Fine"
"Yes!!! 😊💪💪💪)
Not sure how where to start with your idea tho, or even what it would look like.
Rademakers you are a legend my friend.
What a find. Seems ideal in every way.
Do you think the 600w I will be supplying will be ok? No worries about under driving it?
Guess I can stick a limiter on to avoid clipping.
Will prob order this tomorrow.
Now to pick a box and start building. I think I'll find a copy of horns resp and have a play around now that I know what driver I'm likely to have.
Are those dimensions in W / H / D or other configuration? since a few box designs will want the long dimension in D and others in H, that could be a limiting factor.
My thoughts on this... informed by playing with a few 12V sound systems in the past:
There are so many compromises to balance, you'll probably go in circles a few times trying to determine what will work best for you... keep all options open, be prepared to rework goals as you learn what is a priority. Chasing speaker efficiency alone is just part of the puzzle, and party vibes are made by more than just SPL charts.
Outdoors, it's the thump that carries more than rumble - so IMO upper bass (80Hz) is where you want to be putting your energy. Even a speaker with 60hz high pass will still sound "bassy" in a party context since most tracks have enough harmonics for the bassline to be heard even if the speaker can't go too low.
You might be able to fit 2x 15" drivers in a reflex box and have some decent output at the cost of efficiency. This could be a path to take if you're confident in the power available in your boat.
Otherwise a tapped horn or Roar-style tapped pipe with resonator would be what to look at for higher output.
A factor that really dictates what to choose is amp output, since you won't have as high a voltage swing (which determines driver excursion thus output) to play with, having one efficient box might not have the same outright output as two boxes running in parallel - at the cost of power draw of course.
I've had a bit of a realisation around this whilst planning my next bicycle sound system, that for the same total volume and amplifier voltage a single driver in a tapped horn box won't have as much total output as two drivers in reflex boxes.
That isn't a revelation in itself, but surprisingly the Hornresp "amplifier power" chart reveals an unexpected detail around this, I'll need to document and share it in a thread of my own to be discussed and picked apart.
So I'd be looking at more weight and maybe less run time (to be discussed) with two reflex instead of one horn, but more total output for the power source and amps I have... but since a battery is smaller than a speaker box, and I'm limited by total volume I can carry, it's a compromise I'd make.
If you have enough grunt in your battery bank, topped up by solar, perhaps brute force of multiple driver bass reflex is an approach to take.
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Are you out east london way? We're up the river these days, all solar electric boat 🙂 Have you considered a couple of THAM 12? 30x50x55cm, response to 50Hz outdoors (in a narrowboat cabin will gain a lot at the bottom 😉) and 100dB/W/m sensitivity. A couple outside will be enough for the towpath most places 😀
In my experience I used a stereo dual 8 inch box and a bridged 300WRMS amp and it was like a PA system, very loud. For you, I would go with a smaller driver like two 8 or 10 inch to play deeper in a smaller box, and use woofers instead of subs to get more efficiency. Since you are probably using a car audio amp for 12V batteries and solar, a 300W-1000W car amplifier would be reasonable for power requirements. If you need more power, you could use a power inverter and a house amp like a 100w/channel receiver and two speakers.
Which woofers instead of a sub would you suggest . I need a PA party speaker for my picnics with family. Our Marshall and Bose S1Pro is not exciting
Any pair of large 8 or 10 inch home stereo woofers, however, I did find a GRS 10SW-4 10inch subwoofer at parts express that may suffice at 88db rating, and it's cheap. I would use at least two or three speakers or more for loudness, instead of one big Speaker. Large magnets and stiffer suspension will play louder. PA woofers will be louder, but not as low. Use a good mid or fullrange and tweeter for highs. Another option, is to add a few 6x9 car speakers, as they take up little space and are plentiful and full range
It might be possible to squeeze a Tham 15 in - if 500 wide is acceptable.
https://www.martinsson.cc/blog/index.php?entry=high-end-low-end---diy-notes
But this gives fairly high efficiency - 100 db/w but might be concidered to be lacking in low end.
I would not bother with domestic speakers as very inefficient - With the cubic volume you have available - and the maximun sizes it would be easy enough to build a double 15" reflex cabinet & tune to suit - Maybe 40hz or lower so more hi-fi than PA but more usable in the domestic setting - 450 X 1000 X 800 is 360 litres external after all.
Which 2 of the dimensions are the front of the speaker, as this would effect how practical a double 15 would be.
https://www.martinsson.cc/blog/index.php?entry=high-end-low-end---diy-notes
But this gives fairly high efficiency - 100 db/w but might be concidered to be lacking in low end.
I would not bother with domestic speakers as very inefficient - With the cubic volume you have available - and the maximun sizes it would be easy enough to build a double 15" reflex cabinet & tune to suit - Maybe 40hz or lower so more hi-fi than PA but more usable in the domestic setting - 450 X 1000 X 800 is 360 litres external after all.
Which 2 of the dimensions are the front of the speaker, as this would effect how practical a double 15 would be.
We were east London way. Just spent a couple of weeks moving round to the grand Union, hence the lack of responses. Sorry about that.
So hopefully going to start construction of the sub some point this weekend. Using a modified cubo sub 15 design. Cubo was gracious enough to help with the designs. Am going to be using a b&c 15nw100. 4 ohm. And will be powering it with a 600w RMS (into 4 ohm) JBL amplifier.
Sorry for the lack of response. Lots going on here and have also been moving the boats to another canal, which is looong.
I know I'm a little bit late but I have a couple of observations and suggestions:-
Getting sub-bass in the open air is a task and a half - probably not worth pursuing. 40hz is easily doable. I've no idea how old your are but the DJ at your school disco was probably filling the gym using 200w!
Considering you're desire to hold parties outside, stereo will provide better quality than mono - consider a 2.1 system. e.g. a stack with a 15" bass driver, topped with two (detachable) 2 x 8" + bullet or compression tweeter. Cross at about 150hz. When hosting a party, detach the mid / treble units and place at either end of the boat, using top hats and stands if required.
From memory BOSE 302s provided a awesome kick in the open air. Although the system only used 2 x 12" drivers, if you have the woodworking skills perhaps you could 'scale up' the design to accommodate 2 x 15".
I know what a narrowboat is - I thought everybody did.
https://www.hifiengine.com/manual_library/bose/302.shtml
Getting sub-bass in the open air is a task and a half - probably not worth pursuing. 40hz is easily doable. I've no idea how old your are but the DJ at your school disco was probably filling the gym using 200w!
Considering you're desire to hold parties outside, stereo will provide better quality than mono - consider a 2.1 system. e.g. a stack with a 15" bass driver, topped with two (detachable) 2 x 8" + bullet or compression tweeter. Cross at about 150hz. When hosting a party, detach the mid / treble units and place at either end of the boat, using top hats and stands if required.
From memory BOSE 302s provided a awesome kick in the open air. Although the system only used 2 x 12" drivers, if you have the woodworking skills perhaps you could 'scale up' the design to accommodate 2 x 15".
I know what a narrowboat is - I thought everybody did.
https://www.hifiengine.com/manual_library/bose/302.shtml
I think many here mis the point of the OP. He wants to make a minisound like used a lot these days in the reggae/dub scene as 12V soundsystems. Those are mono and mostly 3 way and should go to 32Hz to play the music right.
The llimitations he has are space, and most use bigger cabinets than he can accomedate. I see a lot of Tham15 and Cubo 15 cabinets used as sub. Kick is often a reflex with a midbass driver, top is mostly a compression driver in horn.
These don't get to 30Hz, but that is the max they can get from a 12v sound system running on car batteries. And I agree that that is also the max you will get with the limited space (Hoffman Iron Law). If you really want it lower, you will loose volume in that limited space.
You can go lower, but that takes space. A friend of me (Stakx Sound Solutions) is selling minisounds (including amps and dsp) like that as his bussiness (next to building full scale dub soundsystems) but he is using miniscoops with 8" subwoofers, and running 2 of those miniscoops per stack.
They won't fit your space altough, as they are bigger (see picture). These are designed by experienced engineer altough, and go to the lower 30's at decent volume (enough for garden parties). I played on one of those for about 150ppl, running it from a 8A 220v socket.
The llimitations he has are space, and most use bigger cabinets than he can accomedate. I see a lot of Tham15 and Cubo 15 cabinets used as sub. Kick is often a reflex with a midbass driver, top is mostly a compression driver in horn.
These don't get to 30Hz, but that is the max they can get from a 12v sound system running on car batteries. And I agree that that is also the max you will get with the limited space (Hoffman Iron Law). If you really want it lower, you will loose volume in that limited space.
You can go lower, but that takes space. A friend of me (Stakx Sound Solutions) is selling minisounds (including amps and dsp) like that as his bussiness (next to building full scale dub soundsystems) but he is using miniscoops with 8" subwoofers, and running 2 of those miniscoops per stack.
They won't fit your space altough, as they are bigger (see picture). These are designed by experienced engineer altough, and go to the lower 30's at decent volume (enough for garden parties). I played on one of those for about 150ppl, running it from a 8A 220v socket.
Grew up near the Grand Union Canal in Croxley Green so I know well what a narrowboat is. 😉
A single 15" horn might not be the best option for playing very low and loud so perhaps consider ported, when 360l becomes quite a large enclosure, possibly for a pair of 18s bridged to give you 4 ohms. I feel there is often no replacement for displacement! As many have suggested, you will have to compromise between low and loud!
I have used these guys almost exclusively for many years. Very keen prices!
Blue Arran
A single 15" horn might not be the best option for playing very low and loud so perhaps consider ported, when 360l becomes quite a large enclosure, possibly for a pair of 18s bridged to give you 4 ohms. I feel there is often no replacement for displacement! As many have suggested, you will have to compromise between low and loud!
I have used these guys almost exclusively for many years. Very keen prices!
Blue Arran
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I'd be looking at the X1 sub on speakerplans.com for inspiration. Apparently 131Db continuous with a 31Hz f3. 6th order BP box, think the original driver is unavailable but search the forums for alternatives.