Kenwood amps

[shawnwilliams]

I just bought a new kenwood amp yesterday(KAC-9152D)
it took a huge chunk out of my wallet (500) but i'm hopin its worth it.
I'm powering 2 MTX 6000 15's I obviously have the power to due this but i just want to know how good these amps are and if there anything i whould watch out for this.

[sr20de4evr]

are you sure that model number is right?

[PaulD]

I absolutely LOVE these posts ....... don't you think you should ask about whether something is any good or not BEFORE you buy it ?

[Diceman83]

heh... I know I should have. Of course, my entire collection of sound upgrade stuff didn't even cost as much as that amp.

[shawnwilliams]

the reason is b/c i got the amp, but i haven't been using mono amps before and for some reason i cant get it to turn on. I dont know if you have to change the wiring or it has to be running at 2ohms to work.

[ponchonutty]

Originally Posted by shawnwilliams

the reason is b/c i got the amp, but i haven't been using mono amps before and for some reason i cant get it to turn on. I dont know if you have to change the wiring or it has to be running at 2ohms to work.

Nope, they're no different than any other amp really. Take a look at the speaker terminals to make sure that they are actually what you think they are. Sometimes they are setup a little different than regular amps. Also, make sure you have the proper power, ground, and turn on.

[shawnwilliams]

i took it to a pro at A&B sound (were i got it) and found out it was just a faulty amp, after I hooked up the new one, my 15's are pounding like crazy. The amp just came out in stores this week, it says 900rms at 2ohms on it but i did a power check on it and it puts out 590rms@2ohms which is great b/c my 2 subs r 300rms@4ohms.

FOR THE NEWBIES
Anyone who wants to know how to do an actual power check or the most your amp actually puts out (you can also do this at the store to see how badly you r actually geting ripped) take the total of your fuses EX. 60 and times it by 14.4 to get the MAX watts then times that number and times it by .7 to get the rms. That number will be around the actual rms due to you dont always get 14.4V of POWER.

[sr20de4evr]

Originally Posted by shawnwilliams

i took it to a pro at A&B sound (were i got it) and found out it was just a faulty amp, after I hooked up the new one, my 15's are pounding like crazy. The amp just came out in stores this week, it says 900rms at 2ohms on it but i did a power check on it and it puts out 590rms@2ohms which is great b/c my 2 subs r 300rms@4ohms.

FOR THE NEWBIES
Anyone who wants to know how to do an actual power check or the most your amp actually puts out (you can also do this at the store to see how badly you r actually geting ripped) take the total of your fuses EX. 60 and times it by 14.4 to get the MAX watts then times that number and times it by .7 to get the rms. That number will be around the actual rms due to you dont always get 14.4V of POWER.

That will get you within maybe +/- 50% of the actual power output, that's about it. And you don't need to multiply by .7, that's to convert an AC voltage/current in the form of a sine wave into an rms voltage/current, the power coming from your battery isn't AC and it's not in the form of a sine wave. It's DC, so technically it's already "rms".

[notladstyle@yahoo.]

Originally Posted by sr20de4evr

That will get you within maybe +/- 50% of the actual power output, that's about it. And you don't need to multiply by .7, that's to convert an AC voltage/current in the form of a sine wave into an rms voltage/current, the power coming from your battery isn't AC and it's not in the form of a sine wave. It's DC, so technically it's already "rms".

you cant measure RMS without knowing the true draw from your amps, your fuses are ridiculous benchmarks as they are only there to prevent fire. You also cannot measure against 14.4 volts because when any substantial load is placed on the electrical system most regulators will drop to and maintain 12.5 to minimize stress on the alternator.

To get a decently accurate measurement without any measuring equipment, take an ohms/ampre meter and measure the current draw while running a test tone(below 100hz for subs) and use 12.5 volts. If you have yellow/redtop or a real cap (1f @ 20v +/-10%) then you might get away with 13-14v then take 60-70% of that value to compensate for innefficiency.

You can easily find a subwoofer test tone on any p2p

*** CHEAP OHMS METERS WILL ONLY MEASURE 10-15 AMPS BEFORE CATCHING ON FIRE ***

... so ensure your ohms meter can channel the current. or get an amp meter

() I claim no responsibility for your death

[sr20de4evr]

Or just measure the voltage and current leaving the amp and don't worry about efficiency....and you think a capacitor would do anything for you on a test tone? haha, on a test tone it'd be even worse than not having one at all.

[notladstyle@yahoo.]

Originally Posted by sr20de4evr

Or just measure the voltage and current leaving the amp and don't worry about efficiency....and you think a capacitor would do anything for you on a test tone? haha, on a test tone it'd be even worse than not having one at all.

The current leaving the amp requires a real meter... I was giving a method using only an amp meter. and no a cap wouldnt help with a test tone but it might help with scaling...

[shawnwilliams]

They way I was taught is what they teach you in an audio school in alberta, if you want to work in any high electronics store, or big in the industy in canada you have to go there. (simply the best).
Any you have to take you voltage in and your fuses to measure the output b/c your amp may say 1000rms but you fuses only with allow 500rms. That's why the pro's look at the fuses output first.

[sr20de4evr]

Originally Posted by notladstyle@yahoo.

The current leaving the amp requires a real meter... I was giving a method using only an amp meter. and no a cap wouldnt help with a test tone but it might help with scaling...

a real meter like what?

My cheap little DMM can read up to 10 amps rms of AC current, with a 4ohm sub that's enough to measure 400rms of power, provided you had another one or a scope to measure the voltage across the terminals. More than 10 amps and you would need a clamp-type ammeter, but the same goes for measuring the power going into the amp, except if you're measuring the input side you would need a clamp-type ammeter for any more than ~80rms instead of 400rms.

[sr20de4evr]

Originally Posted by shawnwilliams

They way I was taught is what they teach you in an audio school in alberta, if you want to work in any high electronics store, or big in the industy in canada you have to go there. (simply the best).
Any you have to take you voltage in and your fuses to measure the output b/c your amp may say 1000rms but you fuses only with allow 500rms. That's why the pro's look at the fuses output first.

The problem is, those fuses are slow blow. You can draw double their rating for quite some time before they'll let go, they're only there to cut the power in case of a huge surge. If you go by the fuse rating you're only going to get somewhere in the neighborhood of the right answer. Not every amp has a fuse anyway, out of the 3 amps in my car right now only one of them has a built in fuse, and it happens to be the smallest and cheapest of the 3.

[ponchonutty]

Fuses=RMS that's gotta be one of the funniest things I have heard. As anyone knows, the RMS output is totally dependent on the power input just like stated above.

Back in the early days we use to use a stepup voltage regulator like what's used on Nascar. Well, you could set them up so they'd regulate a true 14v or even 15.5v. It's how pros would cheat in competitions. Most amps were rated at 12volts so you could easily double many amps' outputs by going to 15v..