Hey guys,

Question... Is it best to match RMS watts on amps with speakers?
or best to go lower or higher than the speaker RMS?

Also, what causes distortion? not enough watts running to speakers? does that cause clipping?

Really just want to try match up amps with speakers and what i should be looking for.

My godfather is into electronics and used to make his own car amps in the 80's, he told me it would be better to go lower than the speaker needs?
That way there would be no way of harming the speaker?
so if the speaker requires 80RMS (just example) i would go for an amp the puts out 4 x 60RMS or so?

Also is it always best to look at the power an amp puts out at 4ohms?
That way the amp isnt working as hard to put out the power and helps with the clarity of the music?

It is nice to provide more headroom to speakers so that you can turn gains down and ultimately lower the noise floor.

Most 2 way speakers / components will handle 50 RMS, so it would be good to give them 50 RMS or more...as for clipping - many things can cause it...lack of power, poor installation, filters and gains set a little too liberally etc.

Your uncle's advice sounds like it is more relating to non-loudspeaker setups. Most car sound is based around loud-speaker applications, so power handling is more critical.

Just be weary - speakers cop the most wear and tear so the more power you pump through them, the lower the life expectancy you get (typically, as a general rule).

Thanks for the quick reply dcstraight

So best to go for something a bit more and turn the gain down?

Anyway i dont want something very loud, though if i turn it up i want more clarity than just an increase in sound level

at the moment i have a 75RMS amp and that would be good for speakers that are 50RMS?

RMS watts are the ones that count. When comparing amplifiers for power output it is important that you note the load impedance and the supply voltage.

For example - A typical (say brand A amp) will deliver 40W RMS into 4 Ohms with a 12 V supply. It will deliver 60W RMS into 4 with 14.4V (the nominal supply voltage in a car) so this rating is valid also. Finally it will deliver twice these powers ie 80W and 120W into a 2 Ohm load. Quality amps shouldl deliver equally with all channels driven.

The causes of distortion are many, clipping is only one type and typically happens when there is insufficient power available (either supply volts, or amplifier watts) or when inputs are over driven. The harmonics generated by clipping can be very hard on HF speakers. I recommend using amps with more headroom ( higher power ratings). This will give a cleaner sound even at lower levels before the clipping becomes noticeable. The down side is when you turn up the volume it can be tough on the lower frequency drivers where most of the power is normally directed. You can hear these being over driven more easily and there is more forgiveness in larger drivers.

Finally you need to consider the speakers efficiencies. Remebering that powers, volume and hearing are exponential with all else being equal you will need 10 times the power to perceive double the volume. Bear in mind also that a speaker that is 3dB more efficient will only need half the amplifier power to achieve the same volume.

You get what you pay for in most cases.

Cheers,
C

Well to narrow everything down.

Im looking at going all Alpine because i get a handsome discount from them...

so i currently have a ALPINE MRV-F545 4ch Amp
(which i am selling on here but im thinking of keeping)
* 75 watts RMS x 4 at 4 ohms (@ 14.4v)

The speakers i was looking at are the Alpine DDLinear 6-1/2" Flagship Component 2-Way Speaker Set
* RMS Power 50 Watts

I want to go with dual 10" subs again because i liked my previous rockford fosgate dual 10's
The Type-X 10" subwoofers Power Range (RMS): 500W-1000W

Will the PDX-1.1000 (Per channel into 4 ohms : 1000W x 1 ) be enough to power both subs?
or would i need 2 amps to be on the safe side?

If you are directing that question to me I would suggest you have adequate power in your amplifiers and seemingly appropriate speakers.
To fully apreciate all that your equipment can deliver you will need a well thought out install and appropriate cabling etc.
I tend to go more for the sound quality at realistic volumes (plus a bit) rather than just huge volume at average quality. It is hard to get good quality sound in a house let alone a car so if one has to be compromised its the SPL's.
You have the makings of a good system.

Cheers,
C

for the record alpine do make a type x amp

Also i thought the type x subs were 1000RMS and 1500Watt peak

Type X amp?
No they have never named their amps like that
That amp i mentioned above is the top of their range

The Type X sub specs i got straight from the australian alpine website.

Thanks for your help Commando

Yes type x were correct its just the max rms to run sub min is 500 i didn't understand the 500 to 1000 range stuff.

and yes sorry the amp wasn't made but then again your isn't even listed heres the current best amp

http://www.alpine.com.au/products/produ ... odelID=262

better yet but this one from america

http://www.alpine-usa.com/US-en/product ... g=en&tab=F

It was their best just before these ones.
They havent been on sale that long
and i dont really need anything more powerful really

Just have to look around for a sub amp because i would prefer to have 1 than 2
might go for that one from the US if i can get it with the discount

you can run two subs off any amp in parallell

Yes i know, my last set up had 1 amp with 2 subs
but at the same time i want to have enough power for my subs
I think previously my subs were under powered because i bought the setup with the car and 1 of the subs tore off the metal frame