Cab stuffing/small midrange speakers

[EthanTheHeathen]

I found a couple of crappy old Peavey PA cabs, so I took out the speakers and replaced them with nice Bag End 12s (each cab has 1x12). I'm thinking of cutting bigger holes around where the tweeters were and instead installing a small high/mid speaker. The Bag End 12s are each 8ohms, and I would like each cab to remain an 8ohm cab. Is there a way to add a small speaker and still have the cab be 8ohms? Also, does anyone have some little speakers to recommend?

Also, I'm wondering about whether I should stuff the cabs with that acoustic cotton-type stuff. Just what effect will this have on the cab, and do you think it's necessary? Thanks,

Ethan

 

[AGCurry]

Well, you will want a crossover. A crossover should not affect the impedance. Typically, you'll have an 8-ohm woofer and an 8-ohm tweeter. Crossed over, the impedance of the system will be 8 ohms.

 

[billfitzmaurice]

The Bag End 12s are each 8ohms, and I would like each cab to remain an 8ohm cab. Is there a way to add a small speaker and still have the cab be 8ohms?

Use Eminence LA6 CBMRs or Alpha 8MRs, they have closed backs and don't require separate chambers. Wire them up with Eminence PXB2-1.6 crossovers and you will maintain the 8 ohms impedance.

Also, I'm wondering about whether I should stuff the cabs with that acoustic cotton-type stuff.

Lining them fully with convoluted 'egg crate' foam is better, and far less expensive, you can use a mattress topper.

Just what effect will this have on the cab, and do you think it's necessary?

If internal cabinet surfaces aren't completely lined midrange reflections back to the cone disrupt response above 400 Hz or so. Whether or not the cabinet is properly lined can spell the difference between a nice speaker and a piece of junk.

 

[EthanTheHeathen]

Thanks guys. Just the advice I was looking for. As for the egg crates, wouldn't they be hard to attach without having them rattle around with all the vibration? The mattress foam is a good idea. Also, fabric stores sell bags of cotton for stuffing animals, pillows, etc. It looks similar to the official acoustic stuffing material, so I was thinking that might work well too.

 

[billfitzmaurice]

As for the egg crates, wouldn't they be hard to attach without having them rattle around with all the vibration? .

They would if you used real egg crates. Convoluted foam is called 'egg crate' for its resemblance to them. Stuffing is a bad idea with high power drivers as it might cause them to overheat.

 

[EthanTheHeathen]

Ah, I see. I totally missed the word "foam" after "egg crate." That makes much more sense. Thanks for the tips.