aaron7

iTrader: (7)

I have Pioneer 6x9" speakers... 220w max. Ya, right.
I have a Urban Audio 200w x4 amp, uh huh, I believe that.

Is there a way to find out what speakers can really handle?

Or what amps really do put out?

I don't care about the UA amp... but I am curious as to what it puts out!

RaMaiRGoD69

for true power pay attention to RMS ratings then for subs look at sensitivity and amps look at Total Harmonic Distortion

Slick86

its usually half of max.

blyth18md

check this thread, i wrote a long drawn out post on calculating amp out put

Boomin Boy

http://www.eatel.net/~amptech/elecdisc/measpwr.htm

if you really want to test the actual output you can go there

but when you buy a lot of amps brand new they will come with a birthsheet that says what the particular amp was tested at

junkyarddog

Now that was actually a good link, very informative. They even pointed out that the inductive reactance of the speaker coil will show exagerated readings.

RMS is .707 MAX, but the exagerated figures in amps tend to set the 50% trend. That test mentioned above won't lie, I like it!

But then again, who cares about power, it's only a number. Doesn't it just have to sound right? Although it is interesting being able to catch a manufactrurer in a lie.

junkyarddog

That amp repair tutorial CD looks like fun! $69 isn't so bad if it really gets into all of that stuff. Thanks for sharing that link!

A friend of mine is into amp kits, building amps with anything form OP-AMPs to tubes, it's alot of fun. I want to create a car amp from FETs, just because I have a few lying around. building my own seems the only way to get an amp to sound the way I want it to these days.

Jim85IROC

iTrader: (2)

The short answer... you don't.

The long answer.
power ratings are way too subjective to ever believe 100%. To just say that a speaker can "handle" 100 watts doesn't actually tell you a damned thing. 100 watts of what? I can pump a 100 watt, 2khz tone into a speaker all day long, but if I pump a 100 watt, 2hz tone into the same speaker, it'll kill it.

100 watts in a sealed enclosure, or free air? If in an enclosure, what size? It matters you know. Stick a Brahma in a 20 cubic foot box and you can destroy it with a few hundred watts. Put it in .5 cubic feet, and it'll take over 2,000 watts.

What about in a ported box? You better run a subsonic filter or you could kill that sub with a lot less power than you think. Below the tuning frequency, that box wont' damp the natural motion of the driver.

What about tweeters? You really think a typical car audio tweeter can handle the power it's rated at? Hell no. Most high frequency drivers are rated approximately 10x higher than they can actually physically handle, because most people are too stupid to realize that a tweeter only sees approximately 10% of the power that a sub sees, so they rate a "full range equivalent".

I don't feel like getting into amp power ratings, but suffice to say that very, very companies provide accurate numbers for their amps.

aaron7

iTrader: (7)

The only amps I have seen with a birth cert. were Rockford Fosgate amps. What others do that?

I asked this because I want to know if I should amplify my interior speakers, or leave them hooked to my head unit. The problem is, like I said above, 220w max 6x9, and I think the fronts are 75w max. My radio says it puts out 45w max a channel, but once again, I don't know what it really puts out.


The only way I can see to match components would be to get the same brand, because then you know that the wattage rating uses the same scale!

(I know what you mean about tweeters... how could a 1" speaker use 1000 watts max, when my subs take the same amount ? )

Jim85IROC

iTrader: (2)

A lot of good quality amps come with birth certificates.

Anyway... amping your speakers is always a good idea. Head unit power specs are grossly overrated, so even a small 4 channel amp will make a big difference. Just make sure you run a high-pass filter on the front speakers, and run a high pass on the rears too if you have a sub. As long as you run a high pass, it's unlikely that you'll push enough power into them to cause damage.

aaron7

iTrader: (7)

Sounds like a plan. Any 4 channel recommendations? I do have the Urban Audio 200x4

The way I have it now, I have the bass at -4 (range is -6 to 6) and the gain on the amp turned up, so my subs do all the bass and the interiors don't get maxxed out.

Also, what about amps with the high pass filter on them? Will that work, or are those not as good quality as an external crossover?

Jim85IROC

iTrader: (2)

the way you've got htings set up with your bass boost is rudamentary at best. When you get an external amp you'll be able to filter your signals properly and your sound quality will improve a ton.

Anyway, the high-pass filters in 4 channel amps are sufficient. Virtually all decent quality amps use a 12db/octave filter just like you'd find in an external filter.

As long as you stick with a brand name, you'll be golden. Unless you've got a mega-high powered sub system, any 30x4 or higher amp from somebody like Pioneer, Kenwood, Alpine, Rockford, etc will be sufficient.

aaron7

iTrader: (7)

A 30x4 will be good? Ok, well, what ohmmage should I be looking for? I know some amps say 400x4 and such, but when you break it down to the ohm rating that you actually use, it's way less.

I'm so bad at the electronics part of sound systems!

Jim85IROC

iTrader: (2)

If you stick to a name brand amp, they will publish the RMS power ratings. You want 30x4 RMS or more. Even brands like Pioneer and Kenwood that call their amp a "240 watt amp" still publish their RMS per-channel numbers.

Boomin Boy

my HU is rated at 60X4 which in reality is something like 23X4 rms...after switching to a POS kenwood 25X4 amp i can notice a huge difference in output and sound quality.

amplifying speakers isnt about giving them more wattage, its about giving them cleaner wattage that they can actually use.

Jim85IROC

iTrader: (2)

No, it's about more wattage. Head units don't make the power they say they do.