Can someone please take a look at this amp and tell me if it puts out enough power. It's called the Kenwood KAC-829.
http://cgi.ebay.com/aw-cgi/eBayISAPI...tem=1337317548

I'm planning to power up a single 10 inch Infinity Kappa Perfect subwoofer. Will this amp be good enough? It says 300 x 1 bridged. Does it mean 300 RMS? Thanks!

 

nope, that is at 1 ohm. I'm assuming that your sub is 4 ohm, so you will need to find a mono 4 ohm amp.

 

Hey thanks bro. Now could you explain to me what an ohm is?

 

Could you list some good amps that would go well with my sub. I don't understand this ohm stuff, so i'll probably buy an amp that won't even work.

 

technical definition
Ohm: The unit by which electrical resistance is measured. One ohm is equal to the current of one ampere which will flow when a voltage of one volt is applied

If you look at your woofer, it has an ohm rating....say 4 ohms. In a mono sub install, you match the ohm load with that of the amp. If the amp is a 300x2 @ 4 ohms, you have 2 channels that can each handle a 4 ohm subwoofer at 150 watts each. If you only have 1 sub, you typically bridge the amp into 1 channel which creates a 2 ohm load. Now to match a 4 ohm sub to 2 ohms, you need 2 4 ohm subs wired in parallel, which cuts the load in half and give you a 2 ohm match to the amp.

Series wiring is just the opposite. You can connect several subs of the same ohm level and increase the impedance. Using the same amp from above, you would need 2 1ohm woofers wired in series bridged to the amp to meet the 2 ohm requirement or you could wire 2 sets of 2 2 ohm woofers and run the amp at 300 x 2 at 4 ohms.

It's a bit confusing at first, but eventually you will catch on. In your case, if you have a single 4 ohm woofer, you need a mono 4 ohm amp. Check your woofer to see what ohm load it has and find an amp that matches it.

 

for your application, I would suggest a JL 250/1. This is more then enough power and it is a great clean amp.

 

Thanks for the detailed explanation. I kind of get it now, but still a little bit confused. But anyways, i'll take your word for it on the JL 250/1. So it's 250 x 1 at 4 ohms? Infinity recommends RMS 350 watts, so 250 sounds good enough for me. Do you suggest any other amps over this one? If not, i'm going to get me one tomorrow, so that i can get my ride bumpin. Thanks again for all your help man. You seem like you know what you talking about.

 

there are several mono amps on the market, but I am personally fond of the JL amps. These are not an entry level, nor a top of the line amp, but are far better then any middle of the line products out on the market.

as for my knowledge, I have been an installer/retailer for over 15 years

 

I've got one more question. I'm buying this sub that was used for about a year and half. I don't really know much about subs, so my main concern is if it's going to sound the same as a brand new sub. What i'm really trying to ask is, can the sub lose sound quality from just being used? I'm assuming they will all sound the same as long as they weren't abused. Am i right? Thanks man.

 

it will sound a little different since it will be broken in. just make sure the cone isn't sagging really bad and still has plenty of bounce left in it. Subs will get really loose when they are abused for a long period of time.

 

i hope you check out that used sub well because a lot of people seem to be getting ripped off nowadays.. and since you said you dont know anything about car audio, be very careful... that JL amp should be good... I run a PPI amp and JL subs and an alpine expert amp for my mids n tweets

 

I wish i could take a look at it before i buy it, but the thing is that the seller lives on the other side of the country. Hey i got another question for you guys, how long do subs last? MugenSi00 said something about them getting really loose after time, so how long do they last? And let's just say that they weren't abused.

 

the JBL amps were DESIGNED to push infinity perfects in a sealed box. Usually you run two off a JBL bp1200.1 which is VERY cheap on ebay.

If your running one kappa perfect 10 (rms at 350-400) then a JBL bp.500.1 should make it sing. it's mono-block that when bridiged puts out great power, it's less then $220 on ebay cause the 1200.1's go for about that much I belive. So basically that's my recommendation.

I myself am planning to use a Fosgate BD500.1 to push one infinity perfect dvc 12"

 

KP: well i had my 12" subs (had kicker solobaric.. and then JL 12W6's) for about 4 yrs.. and i pound them pretty hard.. i have a good clean amp (PPI) and i turn it up, but i dont send them into distortion heaven or anything... they still hit very hard as of today.. my friend was very impressed w/ my set up compared to his 2 - 10's.. so i guess even after 4 yrs they dont sound bad... just dont abuse them and dont get a crappy amp which will not send a clean signal to them and u should be fine..

 

Thanks man. Is JBL and JL the same company? Why is the JL more expensive?

 

Just to clear things up a little.
If the amp says 300x2 @ 4ohms then you have an amp that will deliver 300w per channel into a 4 ohm speaker. 150w per channel into an 8ohm speaker and 600w per channel into a 2 ohm speaker.

So you do not neccasarily have to match the impedence levels. Just make sure you have enough power to run the speakers you want to run.

Using you example .

Series wiring is just the opposite. You can connect several subs of the same ohm level and increase the impedance. Using the same amp from above, you would need 2 1ohm woofers wired in series bridged to the amp to meet the 2 ohm requirement or you could wire 2 sets of 2 2 ohm woofers and run the amp at 300 x 2 at 4 ohms.

The two sets of 2ohm speakers would only recieve 150w per speaker.

By the way a 300x2 amp is a very large amp.
Just remember most amp manufactures overstate their power ratings.
If your looking for a good budget amp try looking used.
You can usually get an old Autotek 100 amp for like $100.
Or an old RF punch 150 hd
Or a Rodek 150
I have powered two 12's and two 10's with the Autotek amp before, very good amp.





[Modified by nsxxtreme, 9:18 PM 3/7/2002]

 

Well, first off, no one has asked if this is a single or dual voice coil sub...makes a big difference.

I would say that only cheap amps are overrated....flea market brands or brands like legacy, boss, kenford, rockwood, etc....They can get the job done, but I have seen some advertised at 4000W but only have a 40 amp fuse on them!!!! Waht a joke.

When you start moving up in price range, power supply design has a lot to do with an amp's power output rating. JL amps for example with their RIPS system should be dead on in the power they make. They have a tightly regulated power supply meaning that no matter what input voltage you give them (between 11 and 15V) they will make their rated power. This system ups the ante a bit because they also will make that power at any load between 1.5 and 4 ohms. PPI's older models also had a tightly regulated supply.

Now if you have a Phoenix Gold amp, as the input voltage increases, so does the power output (to an extent) Take the Ti500.4. It's rated at around 12Wx4 @ 12V, but at 75W x 4 @ 13.8V. Big difference. It's power supply isn't as tightly regulated. Soundstream's reference amps were pretty famous for having great power output if you could get a lot of voltage to them (and if they were working at all at the time )


[Modified by rcurley55, 5:44 AM 3/8/2002]

 

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