Recommended driver for double 15 or 18 sub uk
I'm looking to build a 2 x 15 or ideally 2 x 18 sub. It will be rougly 70/30% movies to music, and would like to go to at least 20hz, maybe touch lower for feel.
The low end is my priority, i appreciate at the expense of efficiency and reduced volume at higher bass frequency's, but its a pretty large sub, so i don't see this as a problem. I also low cut at 60 hz at the moment and will let floor standing hifi speakers take care of anything above.
I initially was going to buy another pa sub, but realised they aren't ideal as don't go low enough, and av subs that are very powerful are very expensive.
Budget around £250 per driver, but could be flexible if going a bit higher gave a significant advantage. I think ported design would be best, and not worried about size.
I'll be using a crest ca9 amp.
Finding the best driver for my needs is the bit im finding the hardest.
I ideally wanted 18's for the extra volume, but the lab15's looks good, and I can't see to find many drivers that are ideal for around 20hz, a couple ive been looking at are
eminense lab15 - Eminence LAB-15 LAB15 Aluminium Basket Subwoofer
BMS 18 S 430 V2 - 18 inch = BMS 18 S 430 V2 - 18" Subwoofer 1200 W 8 Ohms from BMS 272.59
I'm in the UK
Any advice appreciated.
I'm looking to build a 2 x 15 or ideally 2 x 18 sub. It will be rougly 70/30% movies to music, and would like to go to at least 20hz, maybe touch lower for feel.
The low end is my priority, i appreciate at the expense of efficiency and reduced volume at higher bass frequency's, but its a pretty large sub, so i don't see this as a problem. I also low cut at 60 hz at the moment and will let floor standing hifi speakers take care of anything above.
I initially was going to buy another pa sub, but realised they aren't ideal as don't go low enough, and av subs that are very powerful are very expensive.
Budget around £250 per driver, but could be flexible if going a bit higher gave a significant advantage. I think ported design would be best, and not worried about size.
I'll be using a crest ca9 amp.
Finding the best driver for my needs is the bit im finding the hardest.
I ideally wanted 18's for the extra volume, but the lab15's looks good, and I can't see to find many drivers that are ideal for around 20hz, a couple ive been looking at are
eminense lab15 - Eminence LAB-15 LAB15 Aluminium Basket Subwoofer
BMS 18 S 430 V2 - 18 inch = BMS 18 S 430 V2 - 18" Subwoofer 1200 W 8 Ohms from BMS 272.59
I'm in the UK
Any advice appreciated.
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look first at the driver loading:
is it horn loaded or relying on cone/port area, or cone area only (sealed) to produce the bass frequencies?
Assuming it is a standard sealed cabinet, then cone AREA gives the first indication of how low it can go.
there are graphs of SPL vs Cone displacement volume @ a range of frequencies.
Those graphs will confirm what SPL a pair of 15s, or a pair of 18s, can give @ 20Hz.
Here's a calculator that appears to be using the same SPL vs Area data.
Piston Excursion calculator
Then it's a case of building a cabinet that allows those 20Hz frequencies to be reproduced.
I think that a particular driver with it's fixed volume displacement can give when tuned appropriately an extra 6dB at the tuning frequency.
is it horn loaded or relying on cone/port area, or cone area only (sealed) to produce the bass frequencies?
Assuming it is a standard sealed cabinet, then cone AREA gives the first indication of how low it can go.
there are graphs of SPL vs Cone displacement volume @ a range of frequencies.
Those graphs will confirm what SPL a pair of 15s, or a pair of 18s, can give @ 20Hz.
Here's a calculator that appears to be using the same SPL vs Area data.
Piston Excursion calculator
Then it's a case of building a cabinet that allows those 20Hz frequencies to be reproduced.
I think that a particular driver with it's fixed volume displacement can give when tuned appropriately an extra 6dB at the tuning frequency.
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Hi, you need to define how big in Litres each box can go, & how much SPL you'ld like ? Also why choose 15/18" ?
Here's a Reflex sim i did with a Lab 12 that gets down there in a 200L box
A pair here Eminence LAB-12 (LAB 12) 400W 12" Sub-bass Driver 6 Ohms 319.38
Here's a Reflex sim i did with a Lab 12 that gets down there in a 200L box
A pair here Eminence LAB-12 (LAB 12) 400W 12" Sub-bass Driver 6 Ohms 319.38Attachments
that's really interesting
.
I looked and says frequency response from 30hz, although going from the calculator AndrewT posted, it should do it, i assume there's more to it.
I'm flexible on size, but happy with 700-800+ litres
I'm not sure on spl, as ive never tested spl, I'll download an app and have a blast on my subs to get rough idea, but would think 2x18 would be enough.
As for cone size I thought 18's would give more volume than smaller ones, and going bigger, 21" don't seem popular, and ive hear'd mixed things about them, plus there's a lot less choice.
i'll have a look at the sim though, thanks
thats interesting
i check spec and it says from 30hz, but then going from calculator AndrewT posted, its good for it
i'm flexible but I'm happy with around 800 litres.
Never tested spl, so nothing to gauge it by, but i'll download an spl app, and have a blast.
I thought 18's cos of then extra volume, and going bigger, 21" would reduce choice and they're not very popular, but not against it if there a good ones for sensible money.
but thanks for sim, i'll have a look.
When you said double 15 or 18 sub 2 x 15 or ideally 2 x 18 sub, i thought you meant 2 seperate boxes. It now sounds like you mean 1 box ? If so 700-800+ litres is going to be one hellava BIG & Heavy box ! Not a problem though, if that's what you want.
As it's for roughly 70/30% movies to music, it sounded as if it were for home use. But based on the above size, it appears it might not be. Unless you built it indoors, or have have an extremely large window/door opening, how would you get it in ? Where is this going to live ?
It doesn't work like that. Output SPL is based on a combination of things, effeciency/specs of the driver/s - size/type/tuning of box - box placement - power capabilities. So a smaller driver "can" give more SPL than a larger one, it all depends on the aforemementioned !
As it's for roughly 70/30% movies to music, it sounded as if it were for home use. But based on the above size, it appears it might not be. Unless you built it indoors, or have have an extremely large window/door opening, how would you get it in ? Where is this going to live ?
It doesn't work like that. Output SPL is based on a combination of things, effeciency/specs of the driver/s - size/type/tuning of box - box placement - power capabilities. So a smaller driver "can" give more SPL than a larger one, it all depends on the aforemementioned !
yeah I've poorly explained it, doing one box with 2 subs in.
Its for home use, I think quite a large cab is needed to get decent volume at 20hz, Ive just sold some horn speakers around that size, originally for live use, but tried them inside, and I moved them about without too much difficulty, they weighed about 103kg, although they had wheels. I put my tv on top of the sub and have the speakers either side, so it's basically a big tv stand, I don't think this horn work that well inside, no surprise, wasn't what it was designed for.
Crossover was set from 27Hz, what they recommended, but you got such a volume drop as freqency go down, I know thats normal, but Is another reason I would like a subs thats optimised for such low freqency, in that hoping that won't happen so much.
At the moment using a smallish 2x15 front mounted sub that goes to 31hz, and does 135spl, but just not low enough.
Its for home use, I think quite a large cab is needed to get decent volume at 20hz, Ive just sold some horn speakers around that size, originally for live use, but tried them inside, and I moved them about without too much difficulty, they weighed about 103kg, although they had wheels. I put my tv on top of the sub and have the speakers either side, so it's basically a big tv stand, I don't think this horn work that well inside, no surprise, wasn't what it was designed for.
Crossover was set from 27Hz, what they recommended, but you got such a volume drop as freqency go down, I know thats normal, but Is another reason I would like a subs thats optimised for such low freqency, in that hoping that won't happen so much.
At the moment using a smallish 2x15 front mounted sub that goes to 31hz, and does 135spl, but just not low enough.
I resimmed & realised that i had over estimated the Actual power that the L12 could take that low down without exceeding Xmax. It would still get down there in that box, but you would need to limit the power to around 170W. This is due to a dip around 28Hz. In this instance the LAB15 would give you a few more dB. But again has that dip, so is limited to around 450W. This is in the same 200L box tuned to 20Hz with a 4th order HPF @ 14Hz. So building 4 or 2 x 2 would get you around 120dB @ 20Hz. In reality, depending on the size of the room & placement, it could be more. Unless you live in a house far away from other properties, i think that would be more than you need, or would be allowed, without a knock on the door very soon from the authorities ! So the L12's would still be fine.
Use that calaculator.
It is not about power input.
To get the SPL you need cone area.
one 18" with 12mm of Xmax gets you 110dB @ 1m from a sealed cabinet.
You may find that a 6mm Xmax 18" driver can get around the same 110dB @ 1m
Can anyone confirm the typical ratios of Xmax requirements for sealed vs vented?
It is not about power input.
To get the SPL you need cone area.
one 18" with 12mm of Xmax gets you 110dB @ 1m from a sealed cabinet.
You may find that a 6mm Xmax 18" driver can get around the same 110dB @ 1m
Can anyone confirm the typical ratios of Xmax requirements for sealed vs vented?
Yeah i also don't quite follow how to work out vented on that.
So far I think the lab12 maybe better for 20hz, lower fs, 22hz for lab12 and 28hz for lab15, and I can get them alot cheaper than lab15, so 4x12 not that much more than 2x15, they do have little more xmas as well, which I guess also helps a little redeem there smaller size, if only by 1mm.
But I will keep looking for 18's
So far I think the lab12 maybe better for 20hz, lower fs, 22hz for lab12 and 28hz for lab15, and I can get them alot cheaper than lab15, so 4x12 not that much more than 2x15, they do have little more xmas as well, which I guess also helps a little redeem there smaller size, if only by 1mm.
But I will keep looking for 18's
I omitted "vented cabinet" from the above.
It should read:You may find that a 6mm Xmax 18" driver can get around the same 110dB @ 1m in a vented cabinet.
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