5.25" subwoofer

[wall]

5⅛" subwoofer

Hi, I have this Sony 1-825-144-11 subwoofer scavenged from a HT-BE1 home theatre, it's 6Ω, dual voice coil, 13cm cone, 30W.
The original subwoofer (SA-WBE1) was a small bass reflex ported enclosure but it didn't sound good and didn't extend low enough.
What would be the best enclosure type for this small subwoofer?
I know very little about this subject so any help is appreciated.

 

[Sonce]

Transmission line (TL) for the best sound quality.
Vented (bass-reflex) is better for low-end extension, but you already discovered that it does not sound good.
Do not expect much from such a small and cheap "subwoofer".

 

[wall]

And how would I calculate the TL enclosure's dimensions?

 

[pacificblue]

A 5" driver has its limits in any enclosure type.

You need the T/S parameters to determine the best way to use it or whether to use it as subwoofer at all. It is quite likely that the Sony people already did the best they could.

You say, it didn't extend low enough. How low did it go? How low is low enough for you? And at which volume are you listening?

 

[xrk971]

A 5" driver has its limits in any enclosure type.

You need the T/S parameters to determine the best way to use it or whether to use it as subwoofer at all. It is quite likely that the Sony people already did the best they could.

You say, it didn't extend low enough. How low did it go? How low is low enough for you? And at which volume are you listening?

A 5 inch driver with appropriate T/S parameters (moderate Qts) will reach 40 Hz in a mass loaded transmission line. Look in the Full range forum for the Accidental Mass Loaded Transmission Line (AMLTL) technique that lets you design one based on a bass reflex design. If you know nothing of the driver's TS params, use the existing bass reflex volume and vent dimensions and convert to a AMLTL by stretching the box longer with small CSA while maintaining same volume. Stretch out to about 35 to 40 in long to support quarter wave action. Put driver at about 1/3 distance from closed end and on "open" end place same vent size and length. Add stuffing from top of closed end to 2 in below driver. The AMLTL vs bass reflex will improve dynamics, improve cone loading, reduce distortion, and extend bass maybe 5 to 10 Hz - if it works. I have successfully seen this work very well with 5 different drivers usually in Qts range of 0.45 and above. Very low Qts drivers meant for horn loading will it work with technique. But if you already have a BR box, all likelihood is it will work fine. Find some cheap chipboard to test or build out of dollar store foam core. Look in Full range forum for Foam core speaker thread for ideas.

 

[GM]

Greets!

Is the 13 cm cone dimension the distance between the ~center-to-center of the surround [Dd]? If not, what is it?

In a quick Google search I couldn’t find the subwoofer’s frequency response or at least its [Fs] or how low it played before obviously quickly rolling off, so got any idea what it might be even if it’s just based on the music/whatever you use it for?

Anyway, as already noted, we ideally need the driver T/S specs to design any kind of vented cab, though I can come up with a good ‘ballpark’ TL alignment with just this and [Dd]. Worst case is it will be bigger than absolutely necessary.

GM

 

[wall]

The surrounding center-to-center distance is about 105/106mm, if I had to guess I'd say about 80hz with a very steep roll off.
This is the only information about these speakers, page 26:

An externally hosted image should be here but it was not working when we last tested it.

 

[xrk971]

I know you are trying to make something out of this existing driver but unless you measure the TS params (and that might be something too complicated if you are new at this) I suggest buying some inexpensive sub woofer drivers with known TS params to play with and not spend too much effort making something out of this. You are in Portugal so Parts Express may not work for you but try to find something like the Tang Band W5-876SE. It does a fantastic job when used as a pair for 8 ohms as a sub. Only $20 ea Tang Band W5-876SE 5" Shielded Subwoofer Driver 16 Ohms

I built a nice slot loaded bandpass sub with it in this thread http://www.diyaudio.com/forums/subwoofers/258433-light-air-slot-loaded-band-pass-sub.html

It will also work well in a TL or a TH. Reaches 35 Hz and is quite low in distortion and has good efficiency of 95 dB at 2.83V as a paralleled 8 ohm driver.

Good luck.