A frugal recycled sub idea

[Brisso57]

"I have a cunning plan ..." and I'd like comments as to the perceived feasibility.

I have seen a pair of elderly 3-way (sealed/AS) speakers on *B**, and the seller's speil is that they are rated down to 25Hz. 12" woofers.

My idea is to get one of the cabinets, remove the mid and tweeter, and seal over, leaving the woofer. Now get the woofer from the other cab and mount it to the face of the first, making an isobarik setup.

Rewire.

Adjust cabinet volume to suit (approx half the volume would be required).

Perhaps a bit of extra internal bracing. Holey brace?

Voila, el-cheapo isobarik sub. If it panned out to work OK, I'd contemplate doing a bit more carpentry to pretty it up. (WAF)

Comments?

Doug

[Foxx510]

Hate to be a parade rainer onerer, but I think money could be better spent elsewhere. If they are the ones I think they are, the relatively low power rating, and probably lowish cone travel means they won't handle a lot of bottom end. Check out the car stereo store sales, you can get some half decent subs with full T/S specs for reasonable money.

Anyway, I could be totally wrong, just my 2c as they say....

All the best
Adam

[Brisso57]

Originally posted by Foxx510
If they are the ones I think they are, the relatively low power rating, and probably lowish cone travel means they won't handle a lot of bottom end.

Anyway, I could be totally wrong, just my 2c as they say....

All the best
Adam

No model no available, but on the positive side, The room size is small and my general listening levels are only moderate.

Doug

[Original Burnedfingers]

speil is that they are rated down to 25Hz

Unfortunately they are going to be about 20db down at 25hz so why bother?

[dangus]

I thought the normal (but rarely ever written down) rating was 10 dB down. But that's probably in the corner of a small room.

Unless you can pick those speakers up locally, shipping will add considerably to the cost. Try thrift stores, pawn shops, car boot sales, yard sales, etc and you'll likely find some similar old speakers for cheaper.

[Moondog55]

I saw this thread a while ago, and thought I'd add a comment, it can be a way to get a cheap box; the drivers are usually of little value but sometimes a real bargain turns up.
I have a pair of old 10 inch 2-ways here from the 1970's, old SEAS drivers have seen better days but the boxes were well made and with a little 'modding' will do well for a sealed 10" or low VAS 12"

[Brisso57]

Originally posted by Moondog55
I saw this thread a while ago, and thought I'd add a comment, it can be a way to get a cheap box; the drivers are usually of little value but sometimes a real bargain turns up.
I have a pair of old 10 inch 2-ways here from the 1970's, old SEAS drivers have seen better days but the boxes were well made and with a little 'modding' will do well for a sealed 10" or low VAS 12"

Indeed, Moondog55. That was where my whole idea started. I figured that the box size must be pretty right for the woofer that came with it, so if I could find an old 2-way or 3-way that was rated reasonably low, it would save a hell a lot of carpentry!

I really was never floating the idea that it could compete with a "proper" subwoofer. Just that, for a small room and moderate demands for bass in the program material, it may be a satisfactory solution.

Doug

[Moondog55]

I concur, and that was my plan for these boxes, just so much to do and so little spare time.
I am a big fan of electronic cross-oversand PRO amplifiers, and have little difficulty in integrating that sort of cheap option into my listening.
You find some real surprises at garage sales, and usually it is a blown mid or tweeter that has relegated the speaker to the junk pile, some stuff isn't worth repairing but a lot of people don't know that this is even possible

[Moondog55]

OK I am resurrecting this post because I was laid off a while ago ( day before the wedding which was a blow to the finances ) and I now have the time to start a few projects.
I have taken that old chip-board box and resealed all internal edges and added coupling blocks as well.
I picked up a couple of really cheap drivers at the week-end market $25 each 10 inch woofers generic Maylasian manufacture.
I am not going to bother testing them.
Just put them in the box and stuff it with fibreglass and polyfill until it sounds OK, I have some other really cheap drivers that I purchased before I new what I was doing, Jaycar 8inch paper and Dick Smith 4inch poly midrange, using a basic box plot program they will not work in any realistic box so these are going to be open backed, sub crossed first order using 5.5mH laminate core, and the 8's crossed at 500 , have a tweeter here from Jaycar that I can cross at 5 or 6 k.
I'll make them, listen and tweak then give them away to family or a freind, having camera troubles so pictures when I can

[Moondog55]

Ok on closer examination the original chipboard is reaching the end of its life, is there an easy and cheap way to give the board another 3 -5 years of life?? given the original premise of this thread ; emphasis on CHEAP.
I was thinking a wash with waterbased sealant may do the trick but a small 1litre tin of Estapol water based is $36-
Any workable ideas or any trade tricks I can use??
regards Ted