Suzuki SV650 Riders Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
362 Posts
Discussion Starter #1
I have a Kenwood KFCW3514DVC sub, and I have never hooked it up. I need a little help picking out an appropriate amp, as I suck at this stuff.

If someone could give me a short explanation of how power ratings and resistance coincide, that would be awesome.
 

·
Registered
Joined
·
49 Posts
since it's a dual 4 ohm voicecoil sub, you can go a couple different ways. I would go with either a single channel amp and bridge to the two voicecoils on the sub to either 2 or 8 ohms, whatever the amp will handle. Most single channel amps will run 2 ohm which will output more power. You're other (cheaper) option is to go with a 2 channel amp, bridge the voicecoils on the sub to one output and bridge the amp to one output. More than likely this will put you at an 8 ohm which won't be as loud (assumeing the same wattage). Look at these amps...

Keenwood http://www.crutchfield.com/p_113KAC7204/Kenwood-KAC-7204.html?tp=115

Kicker http://www.crutchfield.com/p_2068ZX3001/Kicker-08ZX300-1.html?tp=115

MTX http://www.crutchfield.com/p_236JH300/MTX-JackHammer-JH300.html?tp=115

Bother the Kicker and MTX will run 2 ohm which will allow you to run the most power. Just remember the box you put it in is even more important than the amp or even sub.
 

·
Registered
Joined
·
2,849 Posts
If someone could give me a short explanation of how power ratings and resistance coincide, that would be awesome.
I'll just throw out a general explanation and hope this helps clear it up a little.

Scenario:
Dual Voice Coil Sub (what you just purchased)
1000 watt monobloc amp (1000w x 1 channel)

Most amps are rated at watts per channel given a specific resistance. Say this amp is 1000w x 1 channel at 2 ohms. This means at 4 ohms it will only output ~500 and at 8 ohms somewhere in the range of 250, again the exact output will vary amp to amp. So you have these options:

Wire in series, this will give you a total of 8 ohms, 4 ohms per voice coil (pretty standard) added together. Meaning the sub will get 250 to 300 watts from the 1000w amp.

Wire in parallel, basically wire the positives from each voice coil together then run to the amp, then the negatives and do the same. This will divide the resistance, giving us 2 ohms therefore 1000w from this amp.

Now when it comes to amps and subs there are two wattages you have to pay attention to, peak and RMS (route mean squared). Peak is how much either the amp can output, or the sub can handle for a short time. RMS is the would it puts out or can handle as a standard. When you look at spec sheets it will generally say the power rating and either RMS or Max. So some amps may say 1000w, but that may only be peak. RMS is the more important number, peak is essentially worthless. You want an amp with an RMS output that matches your sub. This will give you (generally, again some amps and subs just suck) the best sound quality and longevity out of both.

Sorry this is just a general run down of how this stuff works.

What kind of music do you listen to? Do you like sound quality or sound pressure?

I personally like Alpine and JL Audio gear. Alpine is a fair amount cheaper though. They both offer reliability and very good sound quality. Check this amp out:
http://www.alpine-usa.com/US-en/products/product.php?model=MRP-M500
It's rated at 500w x 1 at 2 ohms at 14.4v where your sub is rated at 380w RMS. Since no cars actually run a 14.4v electrical system that 500w rating is a bit inflated and this should work just fine. It's just one option though, what kind of price range are you looking at?

For more of an explanation, JL Audio has a good write up on wiring to get a certain resistance: http://mobile.jlaudio.com/support_pages.php?page_id=161

EDIT: D*mn this started as just a short explanation. I realized you're about 3 hours from me. If you plan on putting a whole system in I'd be glad to come down and help out, I've been doing this for a few years now.
 

·
Premium Member
Joined
·
9,691 Posts
No need for a 1000 watt amp. 200-300 watts at 4 or 2 ohms with a 1/2 farad bass cap will be more then enough power to drive that sub and not kill the cars electrical system or battery over time.
 

·
Registered
Joined
·
362 Posts
Discussion Starter #5
Well, I didn't just purchase the sub. I've had it for about 3 years now, and its still just sitting in a box in my closet. Since I have a three year old, I haven't been too inclined to get a system installed in the family car; I didn't think it would be a good idea to deafen my child prematurely. However, I'm sick of not having any bass.

What kind of music do I listen to? Hard to describe, and quite varied, but mostly I'm going to SQL. Good punchy bass, hence why I went with a titanium coated sub in the first place.

I can wire the system up no problem. I just suck at picking out the equipment. Electrical formulas always give me a headache. I guess its a good thing I never went forward with the whole AF/PP mech thing. I never got around to taking electrical classes, though.

Thanks for the help, guys!
 

·
Registered
Joined
·
2,849 Posts
Since you're going more towards SQL, I'd go with the Alpine I linked to or the Kenwood slikirish linked to. Both will give you adequate power and very good sound quality. No need for a 1/2 farad capacitor for this small of a system.
 

·
Registered
Joined
·
49 Posts
caps in general are WWWAAAYYY overrated. I'm running an 800 watt RMS amp with stock battery and alternator, no cap, and no problems. not even headlight dimming at a stop. I've never seen a problem that can't be fixed by upgrading the battery ground instead of installing a cap.
 

·
Registered
Joined
·
5,374 Posts
Big 3 wiring upgrade blows a cap away all day long. Now back to the question at hand.

The amps that have been suggested are good but I want to stress the importance of having the right size box. Have one made to the exact specs of the subs and if you go ported have the port tuned correctly. The best sub won't sound worth crap in the wrong box.

I'd go with a sealed box for your desires of SQL and tight punchy bass. A ported is going to need to be a good bit bigger and it is going to give you deep boomy bass.
 

·
Registered
Joined
·
49 Posts
^^^agreed. I wouldn't buy a pre-built box. I would either have one custom built or build it yourself. It's really not hard to build and seal an enclosure really well. If you need any tips, let me know. You can also try looking at kenwoods website and they should tell you exactly how much air space is needed in the box with and without the sub already installed.
 
1 - 10 of 10 Posts
Top