Speaker Cabs Help

Kenny_D

Got hold of two speaker cabs for free but dont know what I need to use them. They have to be powered as I opened up the back and there is two 65W 16ohm speakers in each and nothing else except some foamy stuff. Anyway I've got a roland chorus ac60 and I've got my Peavey classic 50 coming in soon. Is there anyway I can play my guitar through the cabs without buying a power amp? I saw on the back of the peavey that there is a connection for 16ohm and 8ohm speakers depending if someone changes the speakers. If I just put a 1/4" lead from the cab into the peavey 16ohm connector will it work. Just afraid I might damage something. The connection at the back of the cabs is a single 1/4" lead. I'll post up a pic later. Would be great if I could try them out just to see what kind of sound I'd get. They've been lying around here for months without use and I dont want to let them go before I even hear them

Thanks

feylya

If they're normal guitar cabs, they don't need extra power. Use a speaker cable (not an instrument cable) to connect the combo or head to the cab, making sure to match impedance. It is possible to use different impedences but I can never remember which way it works so to be on the safe side, use 16 ohm-16 ohm or 8ohm - 8 ohm.

Eoin Madsen

With two 16ohm speakers in each it's likely that the speakers are wired in parallel to give an impedance of 8 ohms per cab. If you connect both cabs up to one amp, you'll need to use a 4 ohm output, or set whatever method of switching impedance your amp uses to 4 ohms.

It's safe to use a cab with greater impedance than the amp, but not the reverse - so in this case I wouldn't recommend using both unless your amp has a 4 ohm setting or output.

As Feylya said, make sure you use speaker cable. A guitar lead has too low a gauge of wire!

Kenny_D

OK so if I just connect one cab to the peavey 8ohm connection would that work too. So all I need is a speaker cable. I take it i'll get it in musician inc

Eoin Madsen

Yes. If you can show pictures of the insides of the cabs we can confirm that they're wired in parallel - just on the off chance. But it seems unlikely that they'd be wired any other way.

If you really want to use both cabs at once you could rewire them yourself in series - you'd get 32 ohms per cab, and 16 ohms when using both. It'd mean you'd really have to use both all the time though - a 32 ohm cab isn't much use on it's own really.

I imagine Musician should have some speaker cable, but I don't know for sure, tbh.

Kenny_D

I'll try it with one cab and see how loud it is. One cab should give me 130watts while the amp itself is only 2 x 25watt speakers. I'll have a look for the camera in a while and get up some pics

Would maplin have the cables? I know they sell speakers and stuff

feylya

How do you figure a cab will give you more wattage?

Kenny_D

Dunno. If the amp is rated at 50 watts and the cabs are 130 watts. 130 > 50

Doctor J

It won't give you more wattage but it does have an effect on how many watts your amp can send to it. For example, the Peavey Firebass head is rated at

700 W RMS into 2 ohms
475 W RMS into 4 ohms
275 W RMS into 8 ohms

Ohms are resistance, so the great the ohm value, the harder it is for your amp to deliver the goods. If your amp isn't rated to handle low ohmage, it will moree than likely overheat swiftly and cook itself. Which is bad.

Kenny_D

Lol 3 years of doin physics and I only copped that now. Man I hate physics. Anyway... I'll see what happens

Just read this on Harmony central bout the classic 50

"2/12 COMBO two channel amp made in 1977 - 50 LOUD Watts RMS - 4 ohm output, 2 jacks, one plugs into the combo's 2 blue marvel (square magnet) speakers, a second jack is there for an additional cabinet (something MUST be plugged into the first jack for the second jack to work, according to the manual)"

Anyway the only connectors I saw where an 8 and 16 ohm. Maybe it was his older model. I'll head to the peavey site now and check out the manual and connections on it

Amp is in Ireland now anyway. If GLS act as fast in the morning as they did with my last order from komplett then it could arrive tomorrow with my guitar. Fingers crossed

Eoin Madsen

GStormcrow wrote:

Would maplin have the cables? I know they sell speakers and stuff

I buy my cable from Maplin but I solder my own jacks. They do sell some pre-made leads but I don't know if they do jack-jack speaker cable. It'd be worth a try anyway.

Quattroste

They have jack-jack speaker cable in Blanchardstown.

Eoin Madsen

Someone in town definitely does it. Musician Inc, Musicmaker, Perfect Pitch Instrumental, or Maplin.