Long question: wiring, amp, wattage question

[Okapi]

I am aware they are old

Kenwood KFC-W3009

# 12" 4-ohm subwoofer

# pearl mica injection-molded polypropylene woofer cone with urethane foam surround

# overlapping ribs on cone surface for improved rigidity and dampened resonance

# extended pole piece and bumped back plate for increased cone excursion

# power range: 35-400 watts RMS (800 watts peak power)

# frequency response: 25-800 Hz

So My amp went out, and well I've been thinking if there was a better way of hooking these things up

Audiobahn A8002t

# 200 watts RMS x 2 at 4 ohms

# 400 watts RMS x 2 at 2 ohms

# 800 watts RMS x 1 at 4 ohms

# stereo or bridged mono output

# Tri-way capable (Tri-Way crossover required)

# MOSFET power supply

# 4-gauge power and ground leads recommended — wiring and hardware not included with amplifier

# high gloss chrome plate finish with blue illumination

# variable crossovers (50-750 Hz, 18 dB/octave high-pass, and 50-120 Hz, 18 dB/octave low-pass)

# subsonic filter (20-50 Hz)

# 18 dB bass boost (switchable on/off)

# preamp outputs

# preamp- and speaker-level inputs

# cooling fan

I'm considering purchasing this amp:

Kenwood X1200M

RATED OUTPUT POWER (14.4V):

• 800W RMS x 1 @ 4Ω

• (20Hz-200Hz @ 1%THD)

• 1200W RMS x 1 @ 2Ω

• (100Hz @ 1% THD)

RMS POWER OUTPUT (CEA-2006)

• 800W RMS x 1

• (RMS @ 4Ω, 1% THD+N)

• 75dBa Signal-To-Noise Ratio

BUILT-IN CROSSOVER CONTROL:

• Variable Low-Pass Filter: 50Hz-200Hz (-24dB/oct)

• Variable Infrasonic Filter: 15Hz-40Hz (-24dB/oct)

TERMINALS:

• Battery: Hex Type (4 AWG)

• Ground: Hex Type (4 AWG)

• Speaker: Hex Type (8 AWG)

• Operating Voltage: 14.4V

• Current Consumption: 90A

• S/N Ratio: 105dB

• Frequency Response: 20Hz-200Hz

• Input Sensitivity: 0.2V ~ 5.0V

I've been looking at wiring diagrams at Crutchfield.com

Since the subs work (hooked up an old amp to test), I didn't really feel the need to replace them, they sounded great so, I figured no need to change anything. But, I always felt the subs should have hit much better, so I just always figured it was the amp, but after looking at a few wiring diagrams on crutchfield.com I found maybe it is better to use a single channel with a daisy chan setup at 2 ohms. (I was probably running them at 200 RMS, instead of the 400 RMS at 4 Ohms). I am a beginner with this kind of stuff, but I don't mind reading, and I don't see how my system can be that complicated to warrant a pro setting it up. I have been check out parallel diagrams, and series diagrams, and it seems the best setup would be to run a parallel setup at 4 ohms running 800 watts RMS with a single channel? Not sure if that would damage my speakers though.

I am also looking at the head unit (as I guess that went out too lol), Alpine iDA-X305 since I have the iPhone 3gs, but I've seen good and bad reviews will be checking it out in person before buying from store/off web.

Some input would be great, thanks in advance.

Also hola, as this is my first post.

(I've read the big 3 and I will probably do that a bit later as I wan some sound more than a perfect audio system right now)

Click to read more...

 

[jeeper07 5,000+ posts]

If the subs are a SVC 4 ohm sub you can either wire them to a 2 or 8 ohm load. So you need 800 watt rms (400 watt rms per) at 2 ohms, or 400 rms for each at 4 ohms.

 

[Okapi]

Right, but the amp I am looking at is capable of doing that? Also, if I ran

more rms then what is listed, does this shorten the life or can just damage them prematurely?

I am looking at the watts listed for the kenwood amp I am purchasing and it is 4 ohms at 800 rms, but I'd I use a 2 channels , would that give me 400 rms each?

Just checked and I have an svc, there is only one negative and positive per subwoofer. • 800W RMS x 1 @ 4Ω with a parallel hook up?

http://a248.e.akamai.net/pix.crutchfield.com/ca/learningcenter/car/subwoofer_wiring/2SVC_4-ohm_mono.jpg

with this type of wiring?

Btw:

I have a 4 guage positive to the battery and a 4 guage negative directly connected to the chassis, if this isn't a good setup your input would be great.

 

[ahole-ic]

Right, but the amp I am looking at is capable of doing that? Also, if I ranmore rms then what is listed, does this shorten the life or can just damage them prematurely?

I am looking at the watts listed for the kenwood amp I am purchasing and it is 4 ohms at 800 rms, but I'd I use a 2 channels , would that give me 400 rms each?

Just checked and I have an svc, there is only one negative and positive per subwoofer. • 800W RMS x 1 @ 4Ω with a parallel hook up?

http://a248.e.akamai.net/pix.crutchfield.com/ca/learningcenter/car/subwoofer_wiring/2SVC_4-ohm_mono.jpg

with this type of wiring?

There is no difference in that and just running the other sub to the other set of terminals on the amp. The amp has 2 + and 2 - if it is a mono amp. They are internally connected which effectively wires them in parallel. "Daisy chaining" like you said is not going to help. That's just another way to wire in parallel. Just leave it wired the way you have it. If you want it louder, get a better box built

 

[Okapi]

I am not suggesting you are wrong, because I have a lot to learn. But based on series wiring the ohms double, and with parallel wiring the ohms can stay at 4, if this is wrong why do all the sites point out a difference between series and parallel. Also when I think of daisy chaining I consider if series. I wouldnt be surprised if I was wrong though.