[drivinscool]

Hi all, a year or so ago I built a ported subwoofer driven by a BK MF300 amp module. I bought the driver from BK also (the monolith driver) and designed an enclosure of around 90L tuned to 20Hz with the aid of WinISD.

It was all very good fun to build and the sub sounds fantastic.

The problem is I bought a second driver which is still in it's packaging!

What to do with it?

As the first build went so well I was thinking of building another identical cabinet and locating it at the opposite end of the room. Or would I be better off building a second sub tuned to a different (lower) Freq?

Of maybe even a twin driver sub? (although this doesn't seem to offer any benefit according to WinISD)

I'd hate to see it go to waste and I dont really 'need' any more bass volume, but a bit more 15-20Hz wouldn't hurtz

Any suggestions?

The original

[ben.bayliss]

Not what you want to hear, but are those feet from B&Q and intended for kitchen worksurfaces? I swear I've got some of those in black!

[drivinscool]

Originally Posted by ben.bayliss

Not what you want to hear, but are those feet from B&Q and intended for kitchen worksurfaces? I swear I've got some of those in black!

Yep, they work a treat!

Oh, i've removed the 'feet' and put threaded spikes in.

[Laminatedparrot]

Haha, i have about 10 pairs of those feet in various lengths. Combined with a set of gloss white cabinet doors i can make a dozen combinations of shelves and such as i see fit - very useful indeed.

However, as to your actual problem, i have no idea also. It is something i'd be very interested in doing at some point though, as i'm sure my woodwork skills aren't that terrible. If i'm lucky the money i'd save by diy-ing instead of bying retail might actually cover the medical costs of reataching a few of the fingers i'd lose!

[albriscoe]

looking at your woodworking skills from the pic I`d say you`re quite good so I`d have to have a go at a new sub with lower frequency levels just to see if you could hear it

Can I ask you the approx cost of all the materials used inc driver and amp plate

cheers Al

[drivinscool]

Originally Posted by albriscoe

looking at your woodworking skills from the pic I`d say you`re quite good so I`d have to have a go at a new sub with lower frequency levels just to see if you could hear it

Can I ask you the approx cost of all the materials used inc driver and amp plate

cheers Al

The Driver can be found here, for £90 you cannot navigate to this page from the BK website. For some reason BK don't advertise it's availability.

The Amp module I bought second hand, but they are available here for £93

The equiv plate amp is double the price, I found I didn't need any controls as my amp has a nice bass managment system. I just connect the sub-out directly to the MF300.

Wood (25mm MDF), paint, screws and connectors all came to around £40-60.

So all in £250-300(ish)

The saving therefore is not massive as the Monolith itself is such a fantastic price for what you get, and the finishes available. I just enjoy the project.

[albriscoe]

Must admit I like to do it myself but as you say we just can`t seem to get the factory finish that the big boys do.

All in all though a nice project

cheers Al

[micb3rd]

Not sure you would gain much in really tuning any lower, the 90L @ 20hz tune is pretty good. I suppose you could try it.

As Russel tested adding a second identical Monolith will get you more output (quite a bit more) but won't go as low as say SVS subwoofer tuned to 15/10hz.

The only other way would be to build a extra pair of mounting rings (ensure the surrounds don't foul each other) and mount the woofer isobaric, wire it so the system pushes/pulls in unison.

This would give you a little extra bottom end but not really give you any extra db output higher up.

[Russell.Williams]

Given that a second driver is already hanging around, I would probably go the second sub route, but keep them identical.

Two drivers in one cabinet will require a cabinet of twice the volume to maintain the existing tune, never mind a lower one and you'll loose the flexibility of trying out separate or co-located positions that two subs will provide.

Two subs of different tunes will perform differently in more ways than just depth of response; As such, when run together you will tend to get the worst of both subs, rather than the best of each.

Both options will give a boost in SPL of 3-6dB depending on the separation of the subs which if current SPLs are considered adequate give a little extra depth through EQ or just lower distortion.

Personally, I'd be tempted to flog both drivers in order to fund a single better one.

Russell

[deansocial]

im thinking of building 1 myself and would like to know a bit more about the 1 you have already built like what does it sound like etc