Sub design recommendations with max 10L enclosure volume

Looking to build a custom "countertop" streaming music system, and want to keep the size reasonable, so I want to keep the sub enclosure to 10L or smaller. I am willing to throw amplifier power at this problem (class D boards are cheap as hell) in order to get bass down to 40hz or lower if possible.

I've been reading about tapped horns and transmission line subs but it doesn't sound like they'll meet my size goals, and as mentioned above, efficiency isn't that high on my list of concerns.

Recommendations for drivers also welcome.
 

mattstat

Member
2009-10-19 7:47 pm
How much max SPL do you want? 90 dB? 100 dB? etc. (at 1 meter measuring distance).

Is smaller more important than louder? (not violating your 10 liter limit though)

Do you want actually flat to 40 Hz, or is that more like a goal for F3 or F10?

If you don't want to involve DSP, I would lean toward a passive radiator design. They tend to be easier to stuff into a small enclosure without being excessively complex. You also don't have to worry about port noise due to the difficulties of cramming adequate port into a small box.

If you're OK with DSP, a sealed enclosure may be a better choice, since you can equalizer the lower frequencies more without excursion getting out of control.
 

trohricht

Member
2018-11-21 8:32 pm
How much max SPL do you want? 90 dB? 100 dB? etc. (at 1 meter measuring distance).

Is smaller more important than louder? (not violating your 10 liter limit though)

Do you want actually flat to 40 Hz, or is that more like a goal for F3 or F10?

If you don't want to involve DSP, I would lean toward a passive radiator design. They tend to be easier to stuff into a small enclosure without being excessively complex. You also don't have to worry about port noise due to the difficulties of cramming adequate port into a small box.

If you're OK with DSP, a sealed enclosure may be a better choice, since you can equalizer the lower frequencies more without excursion getting out of control.
I'll likely be driving this setup with Raspberry Pi, Hifiberry DAC, and piCorePlayer ... so DSP is certainly an option but I'm not looking for something that shakes the whole house. In completely non-technical terms I'm after controlled and natural bass rather than SPL for the sake of it.

I'm more than willing to learn hornresp, and have a decent array of woodworking tools (as well as an almost-as-decent array of woodworking skills) at my disposal.
 

mattstat

Member
2009-10-19 7:47 pm
Since GM took the larger, high output road, I'll take the smaller, low.

Tang Band W3-1876S
https://www.parts-express.com/Tang-Band-W3-1876S-3-Mini-Subwoofer-264-909

In 1.5 liters tuned to 45 Hz, it will give an F3 of about 40 Hz. With 15 watts of input, it'll do around 88 dB (85 dB at 40 Hz). I used them in desk speakers that were a little over half a liter each, and they gave a pleasing performance with passive radiators. That was in a nearfield listening situation, obviously, and I wasn't going for extreme output. I was using one per speaker (left and right).

If you don't have much experience building speakers, you might want to start out with some quick and dirty builds to get a feel for how much output you really need. I'm a fan of prototyping very early and very ugly to get a feel for basic performance. If you're planning on the end unit being highly finished, even more so.
 
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Toaster79

Member
2012-06-10 8:09 pm
IMG_20220806_140739.jpg
 

trohricht

Member
2018-11-21 8:32 pm
I'd use 2.1 d class amp with Tang Band W5-1138SMF as sub in a 7 liter ported box tuned to around 40Hz and 2-4 fullrange drivers 2"-3" in a closed box maybe 0.6-1.2 liter. Maybe something like Mark Audio CHN-50.
This is the kind of approach I was thinking of. Basically the classic "ghetto blaster" format of the 80's, but with a sub cabinet occupying the central area.
 
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trohricht

Member
2018-11-21 8:32 pm
If you don't have much experience building speakers, you might want to start out with some quick and dirty builds to get a feel for how much output you really need. I'm a fan of prototyping very early and very ugly to get a feel for basic performance. If you're planning on the end unit being highly finished, even more so.
How dirty can quick and dirty be while still giving useful outputs? E.g. would a prototype built of 1/2" sheathing plywood (you know, the stuff full of knots and voids) work?
 

mattstat

Member
2009-10-19 7:47 pm
Yes, I think that would be fine. Worst case, you have some resonance in a larger unsupported panel. It won't change the fundamental sound characteristics in most cases. Since you're building relatively small anyway, it's even less likely to be an issue. If you use adequate bracing in the box, even the final build could be 1/2" plywood (regardless of size), though you might want to step up the grade.
 
I built this one to keep me company at work

IMG_20220403_213038.jpg
IMG_20220403_213025.jpg
IMG_20220329_230914.jpg


Altho theres 4x 2" Ayima fullrangers and a 4" down firing GHXAmp "sub" in 8 liter enclosure tuned to about 50Hz. The port is 32/36mm aluminium tube 100mm long. Full rangers have about 0.6 liter compatments per pair and the box is built with 15mm birch ply. The amp is 2x TPA3116 and 76W smps power supply.

I'm building another similar one but with the W5-1138SMF and 2x Peerles 830986 full range drivers
 
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TB W8-740C + SLAPS M8 (150g added mass) in 10 l, will do 99 db @30Hz and 103 db @40hz with 200W (4 ohm)

You should be able to get the TB for around 100€/USD and the M8 for ca 50€/USD
https://www.nonsolospeakers.com/8-20cm/1821-tang-band-w8-740c-8-subwoofer-tb-speaker.html
https://www.earthquakesound.dk/produkt/slaps-m8/

If you could through 400W at it, the UM8-22 would be the better choice (tighter bass sound)

Another option is to use an amp with a build in ADAU1701 DSP, and use Superbass, a psychoacoustic based algorithm to improve the perceived bass response, and used in all small BT speakers and phones.
This will relax the needed output at lower freq.
 
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The Tang Band W5 1138 provides plenty of bass down to 35hz in 9.5 litres, using the SB Acoustics 5 x 8 passive radiator. My 'Tabletop hifi ' has TPA 3116 2.1 Bluetooth amp and 24v lithium battery pack. I used Tang Band coaxials for full range.
 

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trohricht

Member
2018-11-21 8:32 pm
Regarding amps, I have a couple generic TDA7498E boards kicking around, each with peak power of 160W/ch (220W bridged). My understanding is that this chipset gives up quite a bit of power when bridged. Given this, would I be better off:
  • Bridging one of them anyhow to drive something like a Tang Band W8
  • Running unbridged and driving something like two TB W5s
  • Getting hold of a new 2.1 board based on TPA3255 (because more)
 

Toaster79

Member
2012-06-10 8:09 pm
Totally depends on what drivers you're gonna use.

There's been several suggestions and until you decide what exactly you're building it's gonna be hard to suggest what amp/s to use.

How loud should it play?

My disco suitcase posted earlier will fill a 25m2 room without a problem, depending on what music you listen to and where you place it. Play some rap music and the 4" "sub" gonna bottom out pretty soon while playing some '60s or' 70s rock music it'll do just fine. But playing loud also brings some distortions up where you don't want them.

I'd say W5 is the smallest I would go driving it with a bridged tpa3116d2. Anything above that is a bonus.
 

trohricht

Member
2018-11-21 8:32 pm
How would I model the following in hornresp:

A single sub enclosure (eg. 10 liters) housing two sub drivers (eg. Dayton DCS165-4 6-1/2" 4 ohm), each being driven by a separate channel of a TDA7498E amp (160W/ch), plus a passive radiator (or maybe two? One for each sub?)

The multi-driver options in hornresp all seem to relate to series or parallel arrangement on a single amp channel.