amp info

FTOGPXJAZZA · Post by **FTOGPXJAZZA** » Wed Jun 17, 2009 10:17 pm

i just brought some new subs and got a good deal and want to know will this amp power my 3 kenwood 12 inch subs kfc-w3011 1200w,

subs info
http://www.caraudiocentre.co.uk/product ... -22616.htm

this is the amp
http://cgi.ebay.com.au/New-5000-Watt-2- ... 7C294%3A50

pete_gpx · Post by **pete_gpx** » Thu Jun 18, 2009 12:03 am

I 100% guarantee you those amplifiers will not make anything over 360W RMS per channel, and I can say that they will not even reach that during standard use.

How can I tell? Look at the fuses pictured on the end of the amplifier. They're only 25A. Here's an exert from an article on car audio amplifiers that I think explains it better then I could;

Here's where you will be able to tell a decent manufacturer from the crap. Let's say you are looking at a 250 watt (RMS) amplifier. The first physical thing I look at, is how big of a fuse do they recommend (or what size fuse is in the end of the amp)? I know right now that 250 watts OUT will demand (and I use 50% efficiency to keep it simple) 500 watts in. 500 watts in, divided by the (car running) battery voltage (14.4v) is about 35A. If I look at the end of the amp, and see a 20A fuse, I'm walking away, as there is no way that amp can make 250 REAL watts, continuously. 14.4v times 20A, equals 280 watts in. 250 watts out, divided by 280 watts in, translates to an 89% efficiency. In a class A/B amp, this is an impossible number, and it even stretches the imagination for digital amps, as well. The theoretical MAXIMUM efficiency for class A/B is 66%, (95% for digital) so someone is lying.

The idea is, that amp can not possibly produce the power they have it rated at, simply due to the fact that the fuses they obviously recommend for it are incapable of handling that amount of power, without blowing. Definitely an indicator of the company trying to pull the wool over your eyes in regards to the amplifiers true power.

Aside from its power output, its damping factor is most likely terribly low, as it generally is with cheaper units. This means your subwoofers will produce sloppy, horrible sounding bass.

Honestly, get something decent. The overall quality of the system at the end of the road will be a reflection of the amount of effort and money you have spent during your time building it.

On a side not, those Kenwood subwoofers are OK units, although definitely not anything competition topping. They are only single voice coil units, capable of handling a rated 400W RMS.

With a decent amplifier, not even something monstrously expensive, three of them should give you a nice kick and bring out a few rattles you didn't know about before.

FTOGPXJAZZA · Post by **FTOGPXJAZZA** » Thu Jun 18, 2009 12:23 am

thanks heaps mate verry helpfull ill be getting an amp from a the dealer i got the subs from and try and get them to chuck another sub in for a good price. ill let u guys know what i ended up getting and ill post up pics of my custom install,

pete_gpx · Post by **pete_gpx** » Thu Jun 18, 2009 1:12 am

How much are you paying for each sub?

FTOGPXJAZZA · Post by **FTOGPXJAZZA** » Thu Jun 18, 2009 1:51 am

there 100each but got a deal for 4 at $75 each brand new just subs no boxes

pete_gpx · Post by **pete_gpx** » Thu Jun 18, 2009 3:22 am

That's not a bad price. We had them at WOW for $84.

96_FTO · Post by **96_FTO** » Thu Jun 18, 2009 12:56 pm

lulz @ 5000w. They get more and more exaggerated every year... Get a good second hand amp instead imo