A whole new Cab problem

[thefyst]

Didn't want to get bogged down with several issues in one thread, hope no-one minds.

As im sure I mentioned recently I have 2 2x10s and a 1x15.

The 10" speakers are all 8ohms
the 15" speaker is 16ohms

I am trying to run it all with a hartke ha2500 at either 4ohms or 8 as per the manual.

Can anyone think of a crafty way of doing this?

Im totally happy rewiring things once I know what im doing. I have heard tell of a way of wiring and extension port so the cabs are in parallel but dunno how it would work.

Hope you guys can shed some light on this one

TF

[Dad3353]

Can't be done, lad; sorry. The best I could offer would be to wire the 10" speakers in series (16 Ohms each cab...), daisy-chain this pair of cabs and run the 15" from the other speaker o/p. Total 5.something Ohms (16/3...), so safe for the amp. A tad less power than a 4 Ohm load, but negligibly so, I should think.
Others may be able to improve upon, or disapprove, this option.
Hope this helps.

[Musky]

Douglas' suggestion above is the way to go. You don't have to run the amp at either 4 or 8 ohms, just as long as it's running above it's minimum impedance (which will be 4 ohms) everything will be fine.

[brensabre79]

All above is correct, but I put it to you....
Do you need to run all of the speakers?

It doesn't necessarily follow that it will be louder, or sound better. It's generally not the best thing to mix speaker sizes unless you're bi-amping or have a X-over of course. Because EQ adjustment that works with one speaker may well make the other worse!

Each of your 2x10 cabs will be either 4 ohms or 16 ohms depending on how you wire them.

So if you use both of your 2x10 (without the 15) you can get the total to be 8 ohms, which will work fine. stack them sideways and you'll have a very tall rig which will sound great everywhere in the room!

Or if you really want to use the 15, you could use the 15 and one of the 2x10s for the same effect. But remember that the power will be distributed equally between the speakers, so each of the 10" speakers will be working as hard at producing the same frequencies as the 15"

Quite why you'd need to use all 5 speakers with a 250w amp I don't know. I reckon one of your 2x10s will be plenty, and at 4ohms you'll get the most from your amp.

[BOD2]

What you DON'T want to do is to rewire the actual cabinets. That would devalue them and also cause confusion over what is actually inside - especially at some later date.

It is possible to make a "box" that would connect two cabinets in series. You could then connect the two 2x10s cabs in series to make 16 ohms and then connect that box (16 ohms) to one speaker output on the amp and the 1x15 (16 ohms) to the other speaker output on the amp. The amp would then run at 8 ohms with all that connected.

What would it sound like ? That's anyone's guess ! It might sound good or it might sound no better than running with just two cabinets.

This diagram shows how the "box" would be wired using 1/4 inch jack sockets. The wiring would have to be good speaker quality wire and everything well soldered together.

[attachment=116375:SpeakerBox.jpg]

[thefyst]

Thanks for the advice guys and yeah I kinda do want to run all the cabs...mainly just because I have them and I can... until I find a good deal on something decent anyway. I'm not too worried about devaluing them...ive messed about with em recovering and whatnot so many times

Well I think I'm gonna go with Dads suggestion allthough im not 100% on the maths... I worked it out to be something like 10ohms that way.

just to check 2 16 ohm cabs daisy chained together gives 32 ohms then those in parallel with a 16 ohm cab would give 1/((1/32)+(1/16)) = 10.6 ohm

new to this calculation but i think thats correct

TF

[neepheid]

Have you tried having the two 2x10 cabs stacked vertically? Not only will you get max power out of your amp with the 4 ohm impedance, you'll hear yourself great because you'll have a speaker nearly at head height. It's easy to try - just takes a few mins of your time. If you don't like it, fine, but I'd be keen to know how you get on, as I'm toying with the idea of a vertical 3x10 using my 1x10 combo and an 8 ohm 2x10 vertically oriented.


Regarding the amount of wiring giggery-pokery that you'll have to do to achieve what I fear will be an underwhelming result - your amp gives you 180W into 8ohms, so it'll be even less with a 10-ish ohm load. I hope I'm wrong but I fear you'll be left wondering "is that it?" after all that work.

[brensabre79]

[quote name='neepheid' timestamp='1345737862' post='1781114']
I hope I'm wrong but I fear you'll be left wondering "is that it?" after all that work.
[/quote]

ditto, hence my suggestion of just using two of them! You don't have to use them all just because you have them. And yes, you'll get more volume out of just the 2x10s than you will out of the lot combined in this way. Plus you'll have less to carry - which you'll appreciate at the end of your first gig with that setup!

[Musky]

[quote name='thefyst' timestamp='1345737210' post='1781106']
Thanks for the advice guys and yeah I kinda do want to run all the cabs...mainly just because I have them and I can... until I find a good deal on something decent anyway. I'm not too worried about devaluing them...ive messed about with em recovering and whatnot so many times

Well I think I'm gonna go with Dads suggestion allthough im not 100% on the maths... I worked it out to be something like 10ohms that way.

just to check 2 16 ohm cabs daisy chained together gives 32 ohms then those in parallel with a 16 ohm cab would give 1/((1/32)+(1/16)) = 10.6 ohm

new to this calculation but i think thats correct

TF
[/quote]
It's definitely 5.3 ohms. Daisy chaining the two 210 16 ohm cabs won't give you 32 ohms as the cab sockets will be wired in parallel. So what the amp will 'see' is three 16 ohm cabs.