Hi guys. How to choose right amp? Let's say I have 2x10cm 200W speakers, 2x13cm 220W speakers and 2x12" 1300W subwoofers. When it comes to amp, I have no idea where to start, what to look for, and how many channels I need.

Help?

Thanks.

Well for starters you need to be looking at the RMS power ratings for the speakers and not the max.

For that lot I'd be looking for 2 Amps. A 4 channel amp at around 75w rms per channel for the speakers and something hefty for the sub.

Probably the most important and misunderstood factor is the cabling. To wire that up properly you need a 4agu wiring kit and a splitter for the boot end of that and then short 8agu wiring runs from the splitter to the amps in the boot.

With phono cables and everything else, power etc its probably £100+ of cabling. Don't scrimp on it... £2000 of stereo with £20 of bell wiring will sound like £20 of stereo set up.

All depends on how much money you want to spend but if you can afford it have a look at Audison amps. Just remember an expensive amp that shows lower "true" power ratings will probably give you a better sound than a cheap amp stating thousands of watts output.

If you want any help or advise just ask mate.

As above you need to look at rms rating of the speakers not the max power ratings.

Also those speakers will probably be 4ohm so look at power ratings at 4ohm for the speakers.

What subs are they? I cant give you any info until we know what the spec of the subs is. Again, dual or single voice coil and what ohm each voice coil is.

For what you have you will need 1 4 channel amp and 1 mono amp

That guys for help, totally I started this thread.

So I bought these two sets of speakers;

http://www.caraudiocentre.co.uk/product_m-in-phase-xtc5_p-19737.htm

http://www.caraudiocentre.co.uk/product_m-pioneer-ts-g1021i_p-27574.htm

as sale is now on, I am looking for amp. I was wondering, can you hook up 4 speakers to 2 channel amp? Something like this ;

http://www.caraudiocentre.co.uk/product_m-juice-ja491_p-27698.htm

thats a shame about those inphase speakers mate. Awful isnt the work and I can guarentee they were not £130. That store is known for pulling those stunts along with many others.

As for the amp, you can run 2 sets of speakers off the amp. Reason being its 2ohm stable so when you hook up both sets of 4ohm speakers it will see 2ohm and its stable at 2ohm.

Rated at 375watts x 2 @ 2ohm i'd expect it to be producing something in the region of 50 watts per channel if you're lucky

Edited 1 January, 201313 yr by ryan-re

thats a shame about those inphase speakers mate. Awful isnt the work and I can guarentee they were not £130. That store is known for pulling those stunts along with many others.

As for the amp, you can run 2 sets of speakers off the amp. Reason being its 2ohm stable so when you hook up both sets of 4ohm speakers it will see 2ohm and its stable at 2ohm.

Rated at 375watts x 2 @ 2ohm i'd expect it to be producing something in the region of 50 watts per channel if you're lucky

Thanks mate. I have 1200W sub sitting around, and maybe I should wait and get a nice 1200W 4 channel amp and hook everything up to one amp if possible. What do you reckon?

p.s They are just like sportsdirect. but £20 is still a bargain imo.

Edited 1 January, 201313 yr by hunker7

still a bargin, glad you didnt pay "full price" for it.

What is the sub?

When looking at the ratings you need to take note of the RMS and impedence. The max watts rating is to be ignored as it tells you nothing.

I have this on http://compare.ebay.co.uk/like/350610309517?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar&cbt=y

800W amp was used for this, and it was destroying upholstery

So i thought 4 channel 1200W amp should be ok for whole lot.

if you run both front and rear from just 2 channels you will not be able to use the front / back fader to balance the sound. You should really run 2 amps, one smaller 4 channel one for the front / back speakers and one big single channel or bridged dual channel for the Subwoofers. A 4 channel 1200W amplifier will in reality be 4 x 300W, now keep in mind that the figure is for full blast and as such with that power output will have around 10%THD or more. End result will be distorted sound which will kill your speakers voice coils.

So if I have 2x180W and 2x200W speakers, i would be looking at around 400W 4 channel amp and 600-800W 2 channel (or mono?) for sub?

you are looking at it wrong chap.

Dont look at an X watts amp. You need to look at an amp which does X watts x 4 @ 4ohm (for door speakers) if you are powering four speakers.

The sub you have is 350watts rms meaning you want a mono amp which does 700w rms @ 2ohm (two single 4ohm subs wire to 2 or 8ohm)

The speakers you have bought are rated at 50wrms @ 4ohm (the inphase) and 30wrms @ 4ohm (the pioneer) so these are the numbers you need to look at.

So look at 50wrms x 4, not 400 watts. I cant stress enough you need to look at the ratings with RMS and at what ohm (the ohm need to correspond with your speakers ohm) written by them ignore anything else

As above but don't worry about having an amp more powerful than the speaker ratings. Best to have a clean signal than a clipped one.

So look at 50wrms x 4, not 400 watts. I cant stress enough you need to look at the ratings with RMS and at what ohm (the ohm need to correspond with your speakers ohm) written by them ignore anything else

On my stereo it says 50w x4, what does that mean?

The sub you have is 350watts rms meaning you want a mono amp which does 700w rms @ 2ohm (two single 4ohm subs wire to 2 or 8ohm)

Can I use 350w @ 4ohm? But it doesn't have to be 700w rms @ 2 ohm, it can be less right?

p.s. please be patient with me, I am good with technical things, electrics takes time.

will do mate, I like helping people with it as I know from when I started out with car audio nearly 10 years ago it took me time to learn it and Im still learning all the time.

That 50w x 4 on your stereo is a max or peak rating. Basicaly its nothing more than a sales thing to make it seem more "impressive" than it really is. In reality you'd be looking at about 10-15wrms x 4.

The same goes for the 200 watt raing on your inphase speakers and 180watt rating on your pioneer speakers. If you look on car audio websites such as http://www.caraudiodirect.com at the very expensive speakers most of them dont have a peak/max power ratings as it might aswell say 1 billion watts for all its worth

Each sub is 4ohm, when you wire them together you will end up with either 2 or 8ohm loads at the amp. Reason is 2 voice coils (the metal coil which uses the magnet to move the speaker/sub up and down) are what determains your speakers ohm (impedence). When you wire multiple coils together the overall impedence changes. In your case it will be 2 or 8ohm depending how its wired.

You can give them less than the 700wrms (combined rms of each sub) but its not recomended. Reason is you are more likely to break a speaker by turning the headunit or gain on the amp up too much due to not enough power than you are if you are giving it too much power. This is where the term "head room" comes from in the car audio world.

Each sub is 4ohm, when you wire them together you will end up with either 2 or 8ohm loads at the amp. Reason is 2 voice coils (the metal coil which uses the magnet to move the speaker/sub up and down) are what determains your speakers ohm (impedence). When you wire multiple coils together the overall impedence changes. In your case it will be 2 or 8ohm depending how its wired.

My sub is single voice coil.

This is the closest i got to 50w rms x 4 @ 4ohm ; http://audiovisualworld.co.uk/shopping/fli-underground-fu720-4-4-3-2-channel-amp-4-x-50-watts-rms.html

But can't seem to find amp for sub.

I thought you had two subs though?

Whats your budget for both amps? I'll have a look for you if you want

I thought you had two subs though?

Whats your budget for both amps? I'll have a look for you if you want

Changed my mind after some thinking, should be enough with 1x12" 1200W sub. Budget; don't want to spend £500 on stereo, but still want a nice setup (as usual). Something decent.

Remember, its not a 1200watt sub

Ill have a look and see whats about

i know. it is 350w rms. You taught me well. And thanks for helping out mate.

Edited 2 January, 201313 yr by hunker7

The inphase components are actually pretty good, i definitely wouldn't amp the pioneers as they are the most basic entry level ones they sell and wouldn't take any sort of power through them.

I take it they are only for rear fill?? if so just run them from the stereo.

Look at a single 4 channel amp 75-100 rms a channel will be fine, run the components on the front 2 and bridge the rears to run the sub, its what i've done in my octavia and works a treat.

amp wise on a budget i'd suggest the jbl gto1004, got that in a customers car running a set of gto comps and a shadow works 12" sub, believe me it rocks.

Edited 2 January, 201313 yr by incarsolutions

pioneers are for front. I have 10cm at front and 13cm at the back. If they will be bad will just get different ones.

what car is it all going into??

definitely wouldn't use the pioneers for front, you want the better spoeakers where you are.

Trouble is good 10cm components are hard to come by and not cheap when you can find a decent set, is there no way of making something to put slightly bigger ones in the front?

Also seems a waste putting components in the rear of a car

Edited 2 January, 201313 yr by incarsolutions

Audi 100 Avant. will have a look, might be possible to fit 16cm , but I doubt.

quick look on ebay found these if not

http://www.ebay.co.uk/itm/INFINITY-REF-4032-4-4-INCH-10CM-105-WATT-CAR-SPEAKERS-SAME-DAY-DESPATCH-/160787987206?pt=UK_In_Car_Technology&hash=item256fb5fb06

should get them speakers tomorrow, so will see how they perform and if bad, will exchange them for something better and maybe bigger. might fit then 13cm at the front, and put 16's at the back.