Head and Cab Compatability

[Youngatheart]

Hi All,

I realise that there are already some excellent posts on the subject of impedence etc but I'm really struggling to get my head around a rig I'm trying to put together so any input would be gratefully received.

I've just brought an Ashdown ABM 500 EVO II head the specs which show it has an RMS of 575 watts which I assume is at 4ohms although I can't see that stated any where.

Right, now the cabs I'm looking at are as follows. One is a 2x10 rated at 200w @ 8 ohms and the other is a 1x15 rated at 300w @ 8 ohms.

Will this set up work? if so will I have to run the cabs in series or parallel?

I know I should be able to work this out from the information available but I want to get it right as I need to order the cabs soon.

Thanks for all your anticipated assistance

[paul, the]

It's been so long since I did all this. This Wiki link should help:

[url="http://wiki.basschat.co.uk/info:amps:impedance_and_wattage"]http://wiki.basschat.co.uk/info:amps:impedance_and_wattage[/url]

You're certainly not being thick, all of us didn't know at some point.

[Musky]

When you run your cabs together with the Ashdown they will usually be wired in parallel - whether you run a lead from the amp to each cab or daisy chain the cabs. So you'll be getting the full 575w from the amp into a 4 ohm load.

The power will be split equally between the cabs, so each will be getting a tad over 285w each. Obviously the 15 inch will be fine, but the 2x10 could be overloaded. You can still use it, but you'll have to use your ears for when it starts to complain and back off the volume. Otherwise you could be looking at a pricey repair job.

[Youngatheart]

Thanks,

That all makes good sense. What do you need to be doing to make an amp work to it's full capacity? in all honesty I can't imagine me ever really cranking the head up as it's mainly for on stage sound as I run through a PA.

[bass_ferret]

If you hear the cabs distorting turn it down. Can be hard to notice in a maelstrom of guitars and drums so listen carefully and you should be OK.

[King Tut]

I don't think you'll have to worry about overloading the 2 x 10. With the amount of volume you'll have available with that rig - you'd have to be pretty extreme to drive it into clipping. Go for it mate!

[rodl2005]

I reckon you'll be fine. Sounds like a great rig! congratulations! Outta the Ashdown amp-w/ a spkr lead- into the 2x10"- then "daisy-chain" (run a lead from) the 2x10" cab to the 1x15" Of course U can also just run the 1x15" by itself or the 2x10 at smaller gigs/reheasals etc.... Great way to go!

[Youngatheart]

[quote name='rodl2005' post='216581' date='Jun 11 2008, 08:07 AM']I reckon you'll be fine. Sounds like a great rig! congratulations! Outta the Ashdown amp-w/ a spkr lead- into the 2x10"- then "daisy-chain" (run a lead from) the 2x10" cab to the 1x15" Of course U can also just run the 1x15" by itself or the 2x10 at smaller gigs/reheasals etc.... Great way to go![/quote]

Thanks I'll try and get a photo on here as and when I get everything together.