How many subs on amp?

I'm in the process of upgrading my current sound system. I ordered a Kenwood KAC-8151D mono amp online from the US (I live in South Africa, our prices are a total rip-off!). However, I'm still waiting for my shipment... I intend on powering two 800W 4-ohm subs from this amp, with a 4-channel amp powering front and rears. According to the instruction manual that I downloaded from the Kenwood-site, the mono amp's rated power is 200W×1 channel RMS (the sub's rated input power is also 200W RMS). On the amp, however, there are left and right channel inputs as well as speaker outputs for two channels (two + and two -). Does this mean that I can connect the two subs individually to a channel, or will I have to connect the subs in parallel to a single channel? If connected individually, will the output from the amp be 200W×2 or will it be something else? The amp's output is 400W×1 RMS at 2 ohms. What is the difference in sound quality from a 4-ohm setup versus a 2-ohm parallel setup? I'd like the best SQ, not loudest noise.F R A N S

1985 Mercedes-Benz 230E

320 000 km / 199 000 miles

Full MB Service History

I don't think I supplied enough information on my original post. I purchased two Kenwood KFC-W3009 12" 800W subs, which are rated at 200W RMS at 4 ohms. The amp's specifications are as follows: Max Power Output: 1000 W × 1 Rated Power Output (4 Ω) (20 Hz – 200 Hz, 0.5 % THD): 200 W × 1 (4 Ω) (DIN : 45324 , +B = 4.4V): 200 W × 1 (2 Ω) (100 Hz, 0.5 % THD): 400 W × 1 (1 Ω) (100 Hz, 1.0 % THD): 500 W × 1 Frequency Response (+0, –3 dB): 5 Hz – 200 Hz Sensitivity (rated output) (MAX.): 0.2 V Sensitivity (rated output) (MIN.): 5.0 V Signal to Noise Ratio: 100 dB Input Impedance: 10 kΩ Low Pass Filter Frequency (18 dB/oct.): 50 – 200 Hz (variable) Infrasonic Filter Frequency (18 dB/oct.): OFF / 15 / 25 Hz Bass Boost Circuit (90 Hz): OFF / +6 / +9 / +12 dB With regards to my orginal post: Seeing that the amp has both left and right channel inputs, with two sets of outputs (two +, two -), will the amp deliver 200W to each sub when connected individually, i.e. each sub connected to its own speaker output at 4 ohms? In the instruction manual's wiring diagram, it shows a sub connected to one set of speaker outputs, with another 'ghost' sub (the image of the sub has a dashed outline) connected to the other speaker output, with the text "Subwoofer (L + R)". Is this not then a two-channel setup running at 4 ohms? Why does Kenwood list the amp's specifications at one channel only?F R A N S

1985 Mercedes-Benz 230E

320 000 km / 199 000 miles

Full MB Service History

You may be able to bridge this amp, which would then put out 400x1, if you ran the speakers in parallel, which would put the final impedance load at 2 ohms. IF, the amplifier can go into 2 ohms bridged, which it looks like it can seeing how it says the rating at 1 ohm. If you are not a machine (which i am assuming is true), Or a complete audiophile, I doubt you would be able to hear a difference in sound quality. There is no need to have 2 channels running 2 subs independantly, which is going to have a mono output anyway. Which makes me wonder what wildkartunes is talking about with monoblocks not having good sound quality. how many chanels you have powering your sub, Im pretty sure a blend of the left and right, which will make one channel is what most people do. Having a sub for left, and a sub for right independantly amplified seems rediculous...99 Blazer LT.   Yellow Top. Big 3. Infinity Kappa Speakers All Around. Jensen CD/DVD flip out. 2 Infinity Kappa Perfect 12DVQs powered by a Alpine PDX600.1 (in one custom box, building a FG box)

wow, totally mis-read it, I thought you got a dual chanel amp. yeah , you have two options, run them at 2 or 8 ohms, if you go series or parallel. Go parallel, It will sound great. Mono amps are what subs are supposed to be powered with. You will be pleased.    Odds are the + - + - on the amp, the -s are connected, so are the +s, they just offer 2 to make installations look better, if you have a multimeter, put it on the +> setting, or whatever, or an ohm reading, and see if they are in fact the same (manual would say +'s and -'s are connected parallel internally) In which case just run each sub to the amp, at the 4 ohms each, which means the amp will recognize 2 ohm signal, It will just look neater.99 Blazer LT.   Yellow Top. Big 3. Infinity Kappa Speakers All Around. Jensen CD/DVD flip out. 2 Infinity Kappa Perfect 12DVQs powered by a Alpine PDX600.1 (in one custom box, building a FG box)

I think I found the answer that I was looking for - basically what Kirktcashalini mentioned. I found the following explanantion from Crutchfield.com, which I'm almost 100% sure applies to my setup: Most mono amps have two sets of speaker terminals for convenience of installation: if you are hooking up two subs to the amp and using large-gauge wire, it gives you a place to attach the wires without having to trim them, appearing as if each subwoofer gets its own terminal. But in reality, these terminals are actually tied together inside the amp — both positives are going to the same place inside the amp, as are both negatives. If you are using more than two subs, then you simply use parallel or series wiring (or a combination) to get as close to the minimum impedance of the amp as possible. Kirktcashalini mentioned that I shouldn't notice the difference in sound quality of a 4 ohm setup from a 2 ohm one. Is this the indeed the case? The subs won't play directly into the cabin, rather through it. It probably sounds stupid, but I'm reckoning that because I can't hear the subs actually playing, but rather feeling them, I probably won't notice the difference too much. Does this make sense, or will I indeed notice a difference? What is the actual difference in SQ between a 2 and 4 ohm setup? It's another stupid question, but I'd like an explanation in layman's terms. The reason that I chose two subs, is because my trunk is sealed quite tight. I currently do have a single KFC-W3009 sub in my trunk, but it has to work quite hard to fill the cabin with the necessary low frequencies.F R A N S

1985 Mercedes-Benz 230E

320 000 km / 199 000 miles

Full MB Service History

Hey again. To clarify, the difference between 4 and 2 ohms for sq, may be sliiightly noticable, but you need to understand, you dont even have that option. With 2 single 4 ohm subs, you can either do 2 or 8 ohm final impedance. It should sound good.99 Blazer LT.   Yellow Top. Big 3. Infinity Kappa Speakers All Around. Jensen CD/DVD flip out. 2 Infinity Kappa Perfect 12DVQs powered by a Alpine PDX600.1 (in one custom box, building a FG box)