Can i run a 15 inch L7 off this amp?

[MG's VH Wag]

Hi guys, Just got a quick question. I have a kenwood 1000watt monoblock amp and i was wondering is there any chance i could run 1 Kicker 15" L7 off this? I'm pretty sure it wouldn't be good enough but i'd just like to double check before i buy a new amp.

Cheers!

[SPLcamry]

No you carn't, i have that same and it's 500wrms @2ohm, you need a amp 1000wrms 1ohm stable, something like a PDX alpine amp would great.

[MG's VH Wag]

Ok thanks i thought so just wanted to double check. How much would one of those amps set me back?

[SPLcamry]

well the PDX 1000wrms mono blocks are around the $1000 mark, but the Alpine MRD 1000wrms amp goes for arounf $600 brand new. What ever you can afford.

[acarmody]

Why can't he use that amp?? The sub would be way underpowered but it would work.

Is the sub a dual 2 ohm or dual 4 ohm model. And what model exactly is the amp?

[SPLcamry]

well he would under power the sub heaps and the amp will over heat alot, they are crap amp's. Just spend the money on the amp and know that the sub will preform to it's best.

[acarmody]

Yes the sub will be underpowered, but why would the amp overheat. Kenwood may not have the best gear in the world but they aren't all hat crap either. As long as the gain is set properly and the cables are properly set, then the amp should work fine for a long time.

The question was will this amp run that sub, and the answer is yes it will.

[SPLcamry]

It will for a certain time, it will blow.

can i ask why did you buy a 1000wrms sub when you didn't have the power to run it ?

[acarmody]

What will blow, the amp?? Why??

Keep in mind I'm not having a go at you.

[SPLcamry]

Cause the sub requiers 1000wrms to run properly, No matter how low to tune the amp the sub will still want to pull 1000wrms @2ohm. so therfore the amp will melt internaly

[bezz]

You could run it on a 150w rms amp and itd still work fine.

Subs don't 'pull' anything, they simply present a load to the amplifier.

SPLcamry, please do yourself a favour and at least get some knowledge of basic circuit theory.

[holdenboy]

How does a sub "want to pull 1000wrms" ?

I agree with acarmody, that amp will power the sub fine.....you just wont get the full potential from the sub and it'll be easier to clip the amp and feed the sub a distorted signal, harming the sub if anything.

Edit: What Bezz said

[acarmody]

A subs power rating isn't what it requires to run, it is a reading of what it can run. And even that isn't reall accurate as most good subs can handle more than its rating. If you fed 1500wrms into an 15" L7 it would probably happily accept it, assuming you have a properly built sub box and the amp is set up properly.

To the OP, the answer is yes it will run it, BUT, if you are planning on getting a new amp anyway than Alpine PDXs are a good amp like SPLCamry said. But I have found that most 1 ohm stable amp are usually quite expensive. So post up wheather you have a D2 or D4 sub and if your interested we could give you ideas on better amps.

[StoneX]

Hahaha... I give up, everyone take SPLcamry's advice, he's a genius

MG's VH Wag... You need to specify the amp and sub model as that sub comes with different impedence voice coils. All this advice above is useless without knowing if your sub is dual 2 ohm or dual 4 ohm.

[theSeekerr]

Cause the sub requiers 1000wrms to run properly, No matter how low to tune the amp the sub will still want to pull 1000wrms @2ohm. so therfore the amp will melt internaly

I don't think we're allowed to use foul language on this forum, so you should count yourself fortunate that you won't have to endure a torrent of it.

That's garbage. Not just misleading, but completely, totally wrong. An audio amplifier amplifies VOLTAGE. You present a small, say 1 to 2V RMS, signal at the input, it's attenuated by the input pot, and it is amplified it by the amp's gain factor - for a typical 1000W amplifier that might be 30x (also happens to be about 30dB, but that's a coincidental number) or so. So with the volume set at full, your 1V signal is scaled up 30 times, and becomes 30 Volts. Apply that across the terminals of a 1 ohm sub, and you could measure a draw of about 30 amps, or a total power of 900 Watts.

So, let us now repeat the experiment with the volume control set at half way (assuming, for the pedantic electrical engineers, that the pot is a linear type rather than the more typical logarithmic one you'd expect). Your 1V input signal is now a 0.5V input signal. Amplified 30 times, it's applying 15V RMS to the speaker terminals. For a 1 ohm sub, you'll see a current draw of 15 amps, for a total power of 225 Watts.

Now tell me again that subs always draw the same amount of power regardless of the input signal to the amp?

Or would you rather tell me audio trancends "normal" electronics, and that you know better than to believe in simple things like math?

[MG's VH Wag]

Thanks for the response guys. I don't actually have a sub yet for this reason i was just wondering if it could run it or not but now i will save up for a bigger amp before i get the sub.

[theSeekerr]

The datasheet for that sub is a bit odd, it's missing all sorts of parameters, but one that they do specify is efficiency, at 89dB @ 1m @ 1 Watt.

Assuming your amp can really deliver 1000W to this sub, you'd be pumping 119dB, which is obviously really, really loud. Assuming you turned it back down a bit to give yourself headroom to avoid clipping, you could still run it at a continuous 109-113dB, which is still well into hearing-damage territory.

Short version: Unless you need to reach a continuous 119dB, with peaks even louder, your current amplifier is probably fine, provided that it can drive the load. Since there's 2 versions of the sub, at least one of them can be configured to match your amp.

Is your 1000W amp rated at 4ohms or 2ohms? If it's 4 ohms, get the 2ohm DVC and run it in series, if it's 2 ohms, get the 4ohm DVC and run them in parallel. If your amp is a modern Class D design, it may even be rated at 1 ohm, in which case, you'd run the 2 ohm DVC in parallel. Whichever way, you've got a load your amp can drive all the way to 1000W.

A quick poke around the Kenwood website shows that they're a bit sneaky with the marketing, stating "maximum power 12000 W" which turns out to be for 2 amplifiers in bridged configuration. But yeah. Look at the specs of the amplifier, look at the specs of the sub, and do the math. If you don't understand the math, give us the facts, and someone here (myself or StoneX, historically) will give you advice which is based on those facts.

[MG's VH Wag]

Ok here are some specs of my amp that i got off the front off the box.

KAC-8104D Class D Mono Power Amplifier

-Power output
*300watts RMS x 1 (4 Ohms, 20-200Hz, 0.5% THD)
*500watts RMS x 1 (2 Ohms, 100Hz, 0.8% THD)

-Maximum Power Output 1000w x 1
-CEA-2006 Compliant
-2 Ohm load capability

Hope this helps a bit. So do you think i could run one?

[acarmody]

Is your L7 a dual 2-ohm or a dual 4-ohm?

[MG's VH Wag]

I don't have one yet thats why i made this thread to see if i could run one off my current amp lol.

[acarmody]

Oh yeah sorry I forgot you said that. Yeah sure you can run a L7 off that amp. You will need a dual 4-ohm sub, that way you will have 500wrms going into it. Also allows you to upgrade to a bigger amp later. 500wrms isn't exactly window popping power but if you build a proper ported enclosure for it, it will be enough. About 3 cubic feet or thereabouts should do it. I'm not really any good at designing boxes, you will have to wait till one of the audio experts on this forum gives their input. Once you have your box volume, port volume, and port frequency, then actually designing it is quite easy.

[theSeekerr]

OK, so it's good for 500 watts RMS at 2 ohms - that would allow, in an ideal world, a continuous 116dB at 1 metre. Allowing for headroom, you can still manage up to about 110dB, which is more than enough for music purposes, unless you listen absurdly loud or just like to listen with loads more bass than intended.