What 2-channel amp?

Karl_CLCoupe · Post by **Karl_CLCoupe** » Fri Dec 10, 2004 3:22 pm

Currently I have a Sony MD headunit, running 6 speakers, which is over-loading it. I am running 2 3.5" Infinity Kappas upfront, with 2 6.5" Pioneer speakers in the parcel shelf and 2 6" x 4" Pioneers beside them. I have been told the best route to go is a 2 channel amp so I can power one pair of those speakers (I'm thinking the 6.5", as they can handle the most power), and add a sub later.

The 6.5" speakers can handle 220watts max, so what sort of power amp should I go for so I can get decent bass over a sub too?

Finally, I'm not too sure about all the jargon that is supplied, so can anyone explain why the figures are quoted at 2 ohms and 4 ohms?

Thanks in advance.

Karl.

david burton · Post by **david burton** » Fri Dec 10, 2004 4:14 pm

Lots of options

You need a 4 channel amp if you want to add a sub. A 2 channel amp will only power one set of speakers (2 channels is one stereo output - left and right).

Definitely get a 4 channel amp. Worth it in the end.

Be vary wary of ratings. If you get a sony rating, you can usually halve it to compare it to a rockford fosgate rating and so on - it's extremely variable and some manufacturers quote rubbish.

A typical stereo speaker is 4 ohms, so the power going to it is half compared to a 2 ohm speaker (Power = volts squared / resistance). Look at the 4 ohm speaker rating for a good guide. If you wire more than one set of speakers up into 2 channels you can fiddle this so the amp "sees" 2 ohms. Some subs are 2ohm rating too. Manufacturers usually quote 2ohm ratings so the amps look more powerful.

For a good middle ground amp - go for an Alpine / RF/ Phoenix Gold / JL Audio or similar quality.

220W will be a peak power for the infinities - half this for an RMS rating. 110W or so. you will find that a 2 x 60W RMS at 4 ohm (good quality) amp will probably be fine for this.

If you get a sub, you will probably want at least 100W RMS at 4 ohms going into it (you could get a 2 ohm sub and this would then see 200W).

I would look for a 4 channel amp which (on ebay) will probably cost about 150 quid for a 4x50W rms (same as a 2x50W + 1x100W rms bridged).

http://www.caraudiodirect.co.uk/product ... cts_id=959
http://www.caraudiodirect.co.uk/product ... ts_id=2028
http://www.caraudiodirect.co.uk/product ... ts_id=2398

is a good guide. HTH.

Karl_CLCoupe · Post by **Karl_CLCoupe** » Fri Dec 10, 2004 4:56 pm

Ahhh, I must have misunderstood that guy at 'frauds then! Right, so thats set me on the right track.

Thanks.

Karl.

david burton · Post by **david burton** » Fri Dec 10, 2004 5:01 pm

There are some good phoenix gold "buy it now"'s on ebay at the moment mate - worth a look

Karl_CLCoupe · Post by **Karl_CLCoupe** » Fri Dec 10, 2004 6:31 pm

Would these be suitable for the application I'm after?

Sub:
http://caraudiosecurity.com/catalog/pro ... ts_id+1005

Amp:
http://caraudiosecurity.com/catalog/pro ... ts_id+2859

Karl.

david burton · Post by **david burton** » Fri Dec 10, 2004 10:38 pm

they look good to me - the reference series is well respected, I might be tempted to upgrade another 30 quid on the sub if you can afford it - it'll probably be worth it