Adding subs to a PA System

[paulmo101]

Hi

I`m looking for some info on behalf of my son who plays in a group.
They currently have a basic PA setup consisting of a (oldish but reliable) Carlsbro CDX 8+2 powered mixer and a pair of peavey Hisys 2 speakers.
He was looking to add a pair (or one if possible) of subs but we are not sure if this is possible or how to go about it.
His powered mixer is rated at 2 X 300W into 4 Ohms - the hisys 2 speakers are 4 ohms. He was looking to feed the output from the powered mixer into the Subs ( with built in crossovers?) and then feed the signal out of the bass bins into the Hisys 2 speakers for mid and high freqs. Does this seem OK? Also what impedance subs would we need as 4 & 8 Ohm seem to be available in most ranges.
The mixer also has a line out ( Left and Right on 1/4 jacks) would it be better to use these to feed a powered Sub and then leave the Hisys 2`s on the main output?
Any other ideas or suggestions welcome.

Cheers

Paul

[Yorgo]

Any decent subs have passive crossover's built-in to send the sub free signal to the top's once processed by the sub's.

However,

300w a side to power 2 speakers a side ain't that much. Your Hisys 2's have 15" drivers so you'll probably be going for 18" subs, which will probably require around 5002 RMS each to push enough air to have effect.

I would recommend using a passive mixer, getting a decent crossover and 2 decent power amps, but, if this is too much cash, then you're idea of just simply adding subs and using the internal crossover's will work, I just don't see it having much effect.

You could using the line outputs to feed a powered sub but you'd need to clarify that these are unpowered signals before you do so. Remember, realistically, you'd only need 1 sub as you don't get a decen stereo image from signals that low.

Try this;

http://www.andertons.co.uk/JBLEon518...GoogleShopping