Ohmage help please cab building

[rennie234]

Hey all.

I'm planning on building a couple of 1x15 cabs or a single 2x15 cab.

The speakers I've got are rated at 250w@8ohm each.

The amp I'm planning on using is rated at 300w@4ohm or 450@2ohm

Is it possible for me to do this without blowing the speakers or overloading the amp?

If so how?

Parallel or Series? etc.?

All help is greatfully recieved.

Cheers
Chris

[LawrenceH]

[quote name='rennie234' timestamp='1319736187' post='1417993']
Hey all.

I'm planning on building a couple of 1x15 cabs or a single 2x15 cab.

The speakers I've got are rated at 250w@8ohm each.

The amp I'm planning on using is rated at 300w@4ohm or 450@2ohm

Is it possible for me to do this without blowing the speakers or overloading the amp?

If so how?

Parallel or Series? etc.?

All help is greatfully recieved.

Cheers
Chris
[/quote]

If the speakers are wired parallel (the standard way) then used together they will present a load of 4 ohms in total. Your amp will be happy with either 4 or 8 ohms total load, assuming it's not got a valve power stage in which case you have to select the appropriate ohm rating on the amp with a switch. A lot of amps claim to operate at 2 ohms but aren't too happy about it...4 is good and safe.

[Mr. Foxen]

Might be goo to understand a bit more about how 'wattage' and speaker and amps and volume interact before trying to make cabs.

[icastle]

Wire the two cabs (or two speakers) in parallel.
That'll give you a 4Ω impedance.

Your amp is capable of supplying 300W into a 4Ω load.
That means that each driver will need to be able to cope with 150W - you've got plenty of headroom there as you're using 250W speakers.