#1
Hi guys, I have a pair of OHM P.A speakers from the early 80's that were gifted to me by a friend who knows no more than me about amplification. Each speaker has a 15 inch speaker and one horn and they run at 150 watts at 8 ohm. The problem I have is that I am using a useless 30 watt bass combo to power it, by using the external speaker output and a series connection. I literally have no clue of what to do if I wanted to utilise the full 300 watt potential of these speakers. What kind of amp head would I be looking at and what kind of connection would be needed (parallel or series?). I know that this is a bit of an essay but my set up right now is too crap to live with.
Thanks guys
#2
Quote by J3G2
Hi guys, I have a pair of OHM P.A speakers from the early 80's that were gifted to me by a friend who knows no more than me about amplification. Each speaker has a 15 inch speaker and one horn and they run at 150 watts at 8 ohm. The problem I have is that I am using a useless 30 watt bass combo to power it, by using the external speaker output and a series connection. I literally have no clue of what to do if I wanted to utilise the full 300 watt potential of these speakers. What kind of amp head would I be looking at and what kind of connection would be needed (parallel or series?). I know that this is a bit of an essay but my set up right now is too crap to live with.
Thanks guys


The speakers don't have a 300 watt potential; they have a 150 watt potential.

What you'd be looking for to utilise their full power would be an amp that gives out 150 watts to a 4 ohm load.
#3
Ahh...crap
I was hoping for something a little more explosive to be honest, but oh well.
So I need a head with 150 watts at 4ohms? Would I be able to use both speakers and if so, how would I hook them up? Sorry for all the questions, but I'm a no0b when it comes to this stuff. Thanks for the help so far dude
#4
Quote by J3G2
Ahh...crap
I was hoping for something a little more explosive to be honest, but oh well.
So I need a head with 150 watts at 4ohms? Would I be able to use both speakers and if so, how would I hook them up? Sorry for all the questions, but I'm a no0b when it comes to this stuff. Thanks for the help so far dude


With decent speakers 150 watts is more than adequate for most situations. I play in a 4 piece (guitar, bass, drums, vox) and I have two 150 watt speakers and a head that runs 150 watt into 4 ohm or 75 watt into 8 ohm. When we practice I only use one of my cabs, so I'm only running at 75 watts, and I have no problem being heard over drums/guitar. When we play a show and I use both cabs I have loads of headroom. In the bigger venues I run through the PA too so it's never a problem.

And yes, a 150 watt 4 ohm head is what you want. The head should have two speaker out connections, you just need a couple of speaker cables. The speaker cables run out of the head and into the speakers. Though speaker cables look the same as guitar cables, they're different; don't try and use standard guitar cables. You can pick a pair of decent speaker cables up pretty cheap though.
#5
Ah right sweet mate I appreciate all that advice. You've just saved my speakers and wallet. Thanks for everything!
#6
Quote by Ziphoblat
The speakers don't have a 300 watt potential; they have a 150 watt potential.

What you'd be looking for to utilise their full power would be an amp that gives out 150 watts to a 4 ohm load.


Actually it's 150 watts at 8 ohms. Since he have two 150 watts speakers, he would need an amp at 300 watts or higher at 4 ohms to utilize the full power of both speakers.
#7
.....and now i'm confused again! Think I might just make the noises with my mouth and set fire to the cabs