two 8"s in a box...

[chris661]

It's an idea, but I've seen the size of subs which use horns....

maybe when I get my own house...

And I've never really done speaker building on this scale before, so I think a simple, sealed box would be better, as there's less to go wrong...

101Litres for the box vs the 42L box I'm going to use....

In a small room.

Not really what I'm looking for, but a good idea nonetheless.

Thanks for the input, and for looking

 

[chris661]

Ok - subwoofer all built - even mum is pleased

I decided on a cube shape

drivers in push/push configuration, with one driver facing into the cabinet, and one facing out

This removed second harmonic distortion.

Then I built the thing

I was forced to use chipboard, because we have loads of it, and it matches the furnature in my room...

made 2 black covers (MDF + speaker cloth)

stuck those on with sticky pads

I have only braced it vertically so far

Plan to make some horizontal braces, weather permitting...

I also "borrowed" dad's 17 year old PA amp - I know it's not ideal, but it was that or a 7W/channel amp I took out of some rubbish 2.0 speakers.

Pictures attatched...

 

[chris661]

The review

and with the covers on, in my room

Well, it's not the loudest I've heard, but it's (easily) the lowest (not including cinemas)

The bass is fast, low, and generally chunky sounding - which is good

The thing is that i spent £32 on drivers

£5 on LT circuit components

£5 on MDF + speaker cloth

The rest I already had (eg amp)

so - my £42 project, which created "the best-sounding reasonable-sized sub I've ever heard" - according to dad, who is (past 40) positively ancient, and must have heard some systems in "his time".

I will draw up the design, and post that, with pics of bracing etc, when I find the time...

 

[richie00boy]

Glad it worked out How are you doing the crossover and what speakers are you mating it up with?

 

[chris661]

Made a XO using a stereo volume control (there's 2 resistors which determine the XO point, so I thought it would be better to make it variable, to find the best sounding XO frequency, then make a permanent version

Using it with this: http://www.amazon.co.uk/Sony-CMT-HX5BT-CMT-HX5BT-CMTHX5BT-CEL/dp/B000OVTUKQ

dual 4" drivers - reasonable volume levels, but amp not up to the 2x75W output it claims

but I listened before i bought etc, and the sound (despite what they say) is pretty good...

so - XO around 60Hz (speakers start falling off around there), and all is well

*gets calculator* so... my system's total price is

£162 - because i got the stereo for £120.

 

[chris661]

checked - 2nd order active crossover (variable, ofc)

more pics (and better quality) attached

Added CD to give a sense of scale...

 

[chris661]

Picture of the bottom.

Only used screws for this as I plan to add more bracing, sealed with foam gasket.