Which 18" sub-woofer cones

[RomfordNavy]

May I ask for suggestions for which 18" sub-woofer cones to use. These are to go into a pair of sealed triangluar 30mm ply boxes; I know triangular is not good but is all I can do in the space available.

 

[sigbergaudio]

May I ask for suggestions for which 18" sub-woofer cones to use. These are to go into a pair of sealed triangluar 30mm ply boxes; I know triangular is not good but is all I can do in the space available.

Nothing wrong with triangular?

Here is a quite extensive database of drivers:

Loudspeaker Database

 

[voodooless]

What are the goals here? How much volume do you have to play with? How low do you want those things to go? How much power is available? How loud should they go?

 

[jhaider]

How much volume in those enclosures?

 

[RomfordNavy]

What are the goals here? How much volume do you have to play with? How low do you want those things to go? How much power is available? How loud should they go?

As low as possible, mid to upper bass is handled by the existing floor-standers which will sit on top of these, pic of them attached.

Buying a suityable amp will be the next project once these are built so no specification for the power yet. To be used for music/tv listening in a domestic environment so exceptional loudness is not necessary.

 

[RomfordNavy]

How much volume in those enclosures?

Haven't calculated that as a bit difficult with the triangular shape having flat side panels towards the front and didn't bother as I can't change the volume anyway within the space available. But obviously going to be quite small; triangle is approximately 20"x20"x20"x22".

 

[voodooless]

Haven't calculated that as a bit difficult with the triangular shape having flat side panels towards the front and didn't bother as I can't change the volume anyway within the space available. But obviously going to be quite small' triangle is approximately 20"x20"x20"x22".

Ballpark is good enough for a closed box. How about a trapezium size? That might squeeze out a bit more volume.

As low as possible

How loud? Small box and loud means more expensive woofer and high power need. Hoffmans iron law applies

 

[RomfordNavy]

Ballpark is good enough for a closed box. How about a trapezium size? That might squeeze out a bit more volume.

Approx 42,000 cm3. Trapezium won't help in this case; triangle is bigger as goes back into the corner of the room. could loose the small 10cm flats on the front corners and go with full triangle out the sides but increase in volume would be insignificant.

 

[DVDdoug]

Plug the potential woofer's Thiele Small parameters and cabinet volume into speaker design software (WinISD is free). That will help you to choose a woofer and determine if a sealed or ported box is better.

Sealed is usually better in a small box, and you might find that a smaller woofer performs better.

With a small sealed box you'll probably need EQ to extend the bass. If you are building your own amp, the EQ can be built-in.

And yeah... The shape of the box isn't important because bass has long wavelengths.

 

[voodooless]

Haven't calculated that as a bit difficult with the triangular shape having flat side panels towards the front and didn't bother as I can't change the volume anyway within the space available. But obviously going to be quite small' triangle is approximately 20"x20"x20"x22".

Ballpark is good enough for a closed box.

As low as possible

How loud? Small box and loud means more expensive woofer and high power need. Hoffmans iron law applies!

As for woofers that would work, some of these may:

Loudspeaker Database

Dayton also has a follow up series for their Ultimax. Try to simulate a few of them, see what works in the enclosure.

 

[melomane13]

B&C Speaker 15TBW100 - 15″ Subwoofer 4Ω

Technical parameters and comparison of the B&C Speaker 15TBW100 15″ Subwoofer 4Ω · Resonance frequency 39Hz · Power handling 3000W · Sensitivity 93dB · Xmax 12mm · Magnet: Ferrite

loudspeakerdatabase.com

B&C Speaker 15TBW100

15″ / 380 mm fr 39 Hz Q factor 0.31 Sensitivity 93.6 dB Linear excursion ± 12 mm Program power 3000 W

in 24 liters closed box, we get 100 db spl at 20hz 116 db 50 hz and 126db 100hz ...
in 40 liter bass reflex, +8 db after 35 hz but 8 db lost at 20hz.

i think is enough the closed box...

 

[voodooless]

B&C Speaker 15TBW100 - 15″ Subwoofer 4Ω

Technical parameters and comparison of the B&C Speaker 15TBW100 15″ Subwoofer 4Ω · Resonance frequency 39Hz · Power handling 3000W · Sensitivity 93dB · Xmax 12mm · Magnet: Ferrite

loudspeakerdatabase.com

B&C Speaker 15TBW100

15″ / 380 mm fr 39 Hz Q factor 0.31 Sensitivity 93.6 dB Linear excursion ± 12 mm Program power 3000 W

in 24 liters closed box, we get 100 db spl at 20hz 116 db 50 hz and 126db 100hz ...
in 40 liter bass reflex, +8 db after 35 hz but 8 db lost at 20hz.

i think is enough the closed box...

View attachment 515271

That’s not super ideal. Low-ish Xmax, low Qts, high-ish fs. VAS is a bit high, but to be expected. These PA subs aren’t really made to play so low. I’m sure this will need a lot of power to reach those high SPLs

But putting 15” woofers in the mix opens up many more possibilities for sure, so that is a good idea.