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Old 14th October 2004, 11:37 PM   #1
Triffid is offline Triffid  United States
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Default Best semi-cheap amp for my Kicker

Hello and thank in advance for you help. I currently have a Kicker CVR12, dual 2ohm voice coil in a 1.3 cuft sealed box. You can see the specs here...

http://www.millionbuy.com/kik03cvr122.html

My current amp is a cheapy 2 channel pyramid amp that says it has 400w (200w rms), I know.. ya right.

It sounds awesome up to a certain level and then distorts. I assume I am clipping and need a better amp.

Can anyone recommend a good amp for < $150 (cheaper the better) that will get me some better performance?

Thanks again
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Old 16th October 2004, 01:35 AM   #2
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My go-to amp for great performance and low cost is USAcouctics.
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Old 16th October 2004, 09:47 PM   #3
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Start looking for used stuff, oir visit your local car audio shop, looking for "last year's model" which will usually be on sale at a decent price. Open box/demo units can be obtained for reasonable prices if you haggle with 'em a while.

I'd bet that something with a real 50W X 2 will be putting out lots more power than your crappy Pyramid. Look for good brand names, and look up the specs. Start cruising eBay...

There are new amps that will be in that price range, but I think you're probably better off looking for someone who's just upgraded their decent amp for a bigger one, or, like I said, demo units. New, of course, has the advantage of warranty.
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Old 16th October 2004, 10:34 PM   #4
dangus is offline dangus  Canada
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For giggles, just look at the fuse rating on a Pyramid "amp". I want to know what black magic they use to get 100's of watts out of something with a 5 or 10 amp fuse. Even if Pyramid provides an RMS rating, they could be lying. I've come across two different Pyramid products that flat-out lied about the specs.

If you can't find the specs for some amp, and the price is right, it's worth looking at the fuse(s) to get a rough idea of the power. An amp with 30 to 50 amps worth of fuse should deliver a minimum of 200 real RMS watts, if you get the speaker(s) hooked up optimally.
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Old 18th October 2004, 01:36 PM   #5
Triffid is offline Triffid  United States
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Thanks for the help everyone. I wish there were more options for pawn shops and what not where I live... there is not one in the entire town I look around though.

The pyramid amp does advertise 200 watt rms when bridged.

As far as the fuse goes... it is a 20 amp fuse.

I know it isn't accurate but I did hook up a voltmeter to my speaker in 4 ohm setup and it got as high as 18volt. Can i simply use 18 * 18 / 4 = 81 watts?

Thanks again
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Old 19th October 2004, 04:58 AM   #6
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Heh. I used to joke with friends about Pyramid's power rating scheme. I think we came to the conclusion that the power rating would be the amount of power that the amp could produce with about 24VDC at the power terminals into a dead short for about 1/10 of a second before the power supply melted. My nickname for that was a "lightning strike" rating.

For your math: No. you cannot. For one thing, impedance changes with varying frequency in a speaker. You can get voltage readings which using hte speakers nominal impedance will indicate much higher wattage levels than are actually being produced. There is also the fact that a peak voltage is not an RMS voltage, and therefore does not indicate actual wattage, but the nearly useless "MAX" wattage number. You must take the RMS voltage in order to obtain real wattage. (Hence the name RMS wattage which is, as I've said before, technically incorrect.) If you were feeding yor amplifier a nice sine wave, then you can divide by root 2 (1.414) to get the rms figure. If it was music, then it's more or less anyone's guess. Half is fairly typical of amps that are better than most of Pyramid's lineup.

So, let's assume that your 18V measurement is a peak voltage, giving an RMS value of 12.78V (Hey, give it even more of a benefit of a doubt, and call it 13V.)

Given P=IV and I=V/R that comes up with about 42W -- Remember this is giving the amp a lot of credit, as well as assuming htat hte load is at or near it's nominal value of 4 ohms. (Chances are it is signifigantly higher than that.)

Okay, so let's assume that you really have 42W. We still don't know the THD figure, or S/N ratio of the amplifier at that power level. If these are bad, (And previous experience tells me that they will be) your amp is going to fry speakers with that power output. Not because of "too much power" but because of too much distortion. Call it 30W of "usable" power. (I'd bet on the real figure being closer to 15-20W usable power with the load correctly figured.) This is the amount of power that this amplifier can deliver without soundong bad or destroying itself, save for possible instantaneous peaks.
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Old 19th October 2004, 01:15 PM   #7
Triffid is offline Triffid  United States
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Thanks again for everyones help. So with the current amp i have, i just need to be careful that a clean sound is coming from the sub right?

someone else advised me to purchase this affordable amp... would this fix my problem?...

http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW

Thanks again
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Old 19th October 2004, 03:14 PM   #8
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That amp would be a vast improvement.
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Old 19th October 2004, 04:32 PM   #9
Triffid is offline Triffid  United States
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Thanks man, this is really helpfull. I am going to buy that amp now.

So... would it be a good idea then to hook up my current 2 channel amp (crappy pyramid) to run the front speakers then?

I have these speakers...
http://iweb.alpine-usa.com/pls/admn/...=104&p_main=10


and this head unit is currently running them...
http://www.millionbuy.com/kenkdcmp425.html


I also have some cheapy rear speakers but from what I gather it would be ok to run those from the head unit.

Thanks again
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Old 19th October 2004, 09:10 PM   #10
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My personal opinion: The pyramid amp would be a good thing to use if you need a heat sink for a DIY car audio amplifier. It might even provide a somewhat reasonable transformer for a SMPS for car audio. I would not use it as an amplifier on speakers that I wanted to keep. I lost a couple of good sets of speakers to a Pyramid amplifier.

I'd rate the pyramid amplifier more or less on a par with deck power (Which I also refuse to use.)

If you want to use it for the time being, then go ahead, but turn the gain down.
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