Tyke

iTrader: (1)

Hello all...How many watts does the Nackamichi amp of the GS400 push to the 10" speaker? I tried searching, couldnt find the specs...Anyone know where to look??? Thanks!

Robert_J

You can find that out with a DMM. First find the resistance of the sub. Then play a 50hz sine wave through the system at full blast and measure the voltage. Convert the voltage to watts. It won't be exact due to a sub's natural impedance rise but it will be close.

WARNING - playing sine waves at high volumes will burn up subs and overheat amps. Your test tones should be short burst of about 5 seconds with at least 30 seconds between them so things can cool down.

-Robert

kramer5150

For my ES300 / Pioneer OEM.... If I had to venture a guess its no more than ~15-20 RMS. They are low-pass crossed over somewhat high too, some where around 120Hz. I would guess its not a very steep crossover slope too.

These are just my impressions listening to music, with the car moving.

kramer5150

Shouldn't the tones be played just to the point of audible clipping... and then back down the volume a hair? Won't that give you more of an RMS measurement?

If you turn it up full-tilt... isn't that the same as a MAX wattage output spec?

Thanks Robert... I always learn a lot from your posts.

Robert_J

RMS is sustained output while peak is just that. A short burst of power. Backing down a little won't give you the full output. A big question that wasn't asked is "what's the output before clipping or distortion?". That's going to be much lower and require more tools to perform the test. There are no standards in the car audio world for testing amps. That's why companies like Pyramid and Audiobahn exist. Enormous power output at pawn shop prices. If they had to state their real power, they would even sell at their current price. One reason I've got a nice collection of PPI M and AM series amps from 1990 and 91. My big one does 150x2 at .01% distortion.

-Robert

DrexLex

Playing the signal into hard clipping will give a rather uncertain power measurement, let alone unimportant. Voltmeters that read RMS voltage seldom use true RMS conversion, as it's expensive. Usually they use either half wave or full wave rectification average responding readings that are calibrated to show the RMS value. That means as long as the signal being measured is a sine wave, the meter is giving an accurate RMS voltage reading. As the signal becomes more distorted, like the almost square wave one gets in hard clipping, the average responding meter will diverge from the true RMS value. And who cares how much heating value an amplifier has, of no one listens to it in those conditions?

Plus, once the non-clipped (1% or less THD) power output is know, that is easily compared to other amplifiers.

Per CEA specs, rated power is measured after no less than 5 minutes of sustained output at the clipping point, and dynamic power is measured with 20 ms bursts at the clipping point. RMS measurements apply to both. The CEA standard can be bought at http://www.ce.org/Standards/3108.asp. Notice the list of well known car equipment companies that adhere to the standards.

strongsail

I recently had the Nak power amp out of my 99 SC4, and it had a label on the bottom that said 40w x 4, 100w x 1. I don't know if that's RMS, but I would hope so; and if it is RMS, it's probably into 4 Ohms. Whatever the rating, the sub portion of the amp just ain't strong enough! I replaced it with a 200W RMS mono sub amp and a new sub. I've got it tuned and I'm happy

And RMS power ratings are the only ones worth noticing. All the "max" and "peak" ratings are BS.

Tyke

iTrader: (1)

Thanks exactly what I needed!

and thankx to the other guys too, its jsut that I didtn have any equipment to measure anything