Members The Snake King Posted March 8, 2010 Members Share Posted March 8, 2010 I've got an 8 ohm head, 4 ohm cab with 2 inputs & 4 8 ohm 10" speakers.Now, I know that running the 8 ohm head into the 4 ohm cab isn't doing damage (other than maybe reducing tube life) but, what it is doing is lowering my output power & making the amp break up way sooner than I want. Anything I can do to make this thing match up to my head? Rewiring?I plan to eventually buy a new cab but I'd really like to have this one around for a little longer until I can get the right one. FWIW, It's a 68 Traynor Bassmaster head going into an 80s Peavey 410FC. Not the greatest cab but it came with the head so, I'm using it.It sounds okay as is but at practice yesterday, it just wasn't able to power over the drums. I know the head isn't under-powered so I figure it's gotta be the 4 ohm cab draining the life out of my sound. Link to comment Share on other sites More sharing options...
Members oinkbanana Posted March 8, 2010 Members Share Posted March 8, 2010 how is your 410FC four 8ohm 10" speakers wired to be a 4 ohm cab? that's like magic my friend. is it a stereo cab? when you use only one input, are all four speakers giving you sound? Link to comment Share on other sites More sharing options...
Members The Snake King Posted March 8, 2010 Author Members Share Posted March 8, 2010 That's only what I can gather from research, when I pull the speakers out, they don't say what they are other than peavey scorpions. When I searched for the scorpions, it says they are 8 ohm.And yes, one input is all I ever use & it does indeed produce sound. Link to comment Share on other sites More sharing options...
Members oinkbanana Posted March 8, 2010 Members Share Posted March 8, 2010 And yes, one input is all I ever use & it does indeed produce sound. from all four speakers? (or just two?) does the cab say it's a 4ohm cab? or is that from research? Link to comment Share on other sites More sharing options...
Members The Snake King Posted March 8, 2010 Author Members Share Posted March 8, 2010 All four. It has 2 inputs, one on top of the other, and the top of the 2 seems to have just a little more output. Wish I had another cab but this is what I'm stuck with at the moment, and it's great for low to mid volume practice & gigs but with a loud drummer it fades, which sucks for my lead parts. Link to comment Share on other sites More sharing options...
Members jhamnett Posted March 8, 2010 Members Share Posted March 8, 2010 Get an Ohm meter and test out the speakers! Anyway, the rule is you NEVER plug into a lower impedance speaker than your amp output, unless you want to really hurt your amp! Also, if you have 4 - 8 Ohm speakers, I'm guessing you have an 8 Ohm cab... Link to comment Share on other sites More sharing options...
Members RoboPimp Posted March 8, 2010 Members Share Posted March 8, 2010 rewired the cab for series/parallel and it will be 8 ohm. double check with a Multi-meter Link to comment Share on other sites More sharing options...
Members oinkbanana Posted March 8, 2010 Members Share Posted March 8, 2010 ^^^ this is most likely unless they're actually 4ohm speakers wired series/parallel , and it is a 4ohm cab. in which case, you will damage your head like jhamnett said.it won't only reduce your tube life, but you're burning out your output transformers (which are $$$ to change) Link to comment Share on other sites More sharing options...
Members Jero Posted March 8, 2010 Members Share Posted March 8, 2010 I've got an 8 ohm head, 4 ohm cab with 2 inputs & 4 8 ohm 10" speakers.Now, I know that running the 8 ohm head into the 4 ohm cab isn't doing damage (other than maybe reducing tube life) but, what it is doing is lowering my output power & making the amp break up way sooner than I want. Why not just plug into the 8ohm jack on the cab? Or do you need both plugged in for that? Also, I thought the ohms thing was the other way around...like 4ohm amp into 8ohm cab ok, but not the other...I must have switched them. Link to comment Share on other sites More sharing options...
Members oinkbanana Posted March 8, 2010 Members Share Posted March 8, 2010 Also, I thought the ohms thing was the other way around...like 4ohm amp into 8ohm cab ok,. but you are correct. Link to comment Share on other sites More sharing options...
Members MakuseruSukotto Posted March 8, 2010 Members Share Posted March 8, 2010 Now, I know that running the 8 ohm head into the 4 ohm cab isn't doing damage Uh-oh. Link to comment Share on other sites More sharing options...
Members The Snake King Posted March 8, 2010 Author Members Share Posted March 8, 2010 yeah I'm a bit dyslexic when it comes to numbers, i've been thinking 4 into 8 the whole time when I've been running 8 into 4. {censored}. Link to comment Share on other sites More sharing options...
Members The Snake King Posted March 8, 2010 Author Members Share Posted March 8, 2010 so would a rewire require a lot of work? would it be as simple as rearranging the connectors attached to the speakers or would i have to rewire at the sockets as well? Link to comment Share on other sites More sharing options...
Members hot_karl Posted March 8, 2010 Members Share Posted March 8, 2010 someone should make like a web calculator for ohms, u put in the amp or cab u have and it tells you potential matches. I always forget. Link to comment Share on other sites More sharing options...
Members wjbratcher Posted March 8, 2010 Members Share Posted March 8, 2010 if you have 4 8-ohm speakers, it is either wired for 2, 8, or 32 ohms. They could be 16 ohm speakers wired for 4 ohms. It's probably worth getting a multi-tester just for this issue. That head is probably excellent-sounding as long as it is in good shape electronically. It would certainly be worth investing in some decent speakers for it. Buy 4 decent 8-ohm speakers and wire it like the above picture. It's not hard to re-wire a cabinet. Or go 2x12! And some of those old vintage amps have decent transformers; they might be able to hold up plugging into half the load it wants to see. I've done that with some old Fender heads and they were none the worse for the wear. Link to comment Share on other sites More sharing options...
Members Liberty Belle Posted March 8, 2010 Members Share Posted March 8, 2010 This is simple, wire two speakers in series(16ohms). then wire the other two in series(16ohms). Then wire them two lots of speakers in parallel=8ohms. Link to comment Share on other sites More sharing options...
Members bisticles Posted March 8, 2010 Members Share Posted March 8, 2010 And some of those old vintage amps have decent transformers; they might be able to hold up plugging into half the load it wants to see. I've done that with some old Fender heads and they were none the worse for the wear. This is *never* a good idea. Link to comment Share on other sites More sharing options...
Members wjbratcher Posted March 8, 2010 Members Share Posted March 8, 2010 This is *never* a good idea. hehe, I agree, and I really don't want to sound like I'm advocating it. I just meant to reassure him that he probably didn't break his amp if the cab ends up being 4-ohms after all. Link to comment Share on other sites More sharing options...
Members The Snake King Posted March 8, 2010 Author Members Share Posted March 8, 2010 I assume maybe these particular speakers manufactured in the 80s may have been different than they are now. It's not my permanent cab for this head but, I traded a combo that I didn't want for the head mainly & he just threw the cab in so I'd have something. He was an amp tech in Nashville so I assumed it matched until I looked a little closer. I plan on getting a 2x12 eventually but at the moment, I may just try to rewire this thing to get me by for a few months. I suppose knowing if they're actually 8 or 16 ohm speakers would help though. There's a label on the back that says the cab is 4 ohms. I can follow a diagram better than just "series" or "parallel" cause honestly, I don't have a clue what either means. Link to comment Share on other sites More sharing options...
Members The Snake King Posted March 8, 2010 Author Members Share Posted March 8, 2010 Looks like they make these speakers in both 4 & 8 ohms upon further research, so I suppose that makes more sense.Now, assuming that these are 4 4 ohm speakers, isn't there a way to wire them for 8 ohms? Or would it be only 16 they could be wired for? If so, 16 would work for running the 8 ohm head correct? Link to comment Share on other sites More sharing options...
Members oinkbanana Posted March 8, 2010 Members Share Posted March 8, 2010 no. you will not be able to make a 8ohm cab with four 4ohm speakers wire them all in series to make a 16ohm cab. your cab is probably currently wired in Series-Parallel Link to comment Share on other sites More sharing options...
Members The Snake King Posted March 8, 2010 Author Members Share Posted March 8, 2010 That's kind of what I thought. I did find some info that states that runner a higher ohm load (16 ohm cab with 8 ohm amp) can cause more damage than the 4 ohm cab with 8 ohm amp due to it causing more flyback voltages to hit the tranny.Anyone have a clue? Link to comment Share on other sites More sharing options...
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