OK so here is the story... sorry, i have been thinking bout it a bit and have come up with a bit so its a bit long

friend of mine drives a CE lancer with all kenwood grear (HU, fronts and rears).

she asked me to help her in selecting an amp and sub to go with the whole set up. so we went down and looked at various options and shopped around. but as with all women she went off without me one day and bought a kenwood amp and sub in box, they were one of the options that we looked at, and she got a good deal so thats ok.

details

Amp: KAC-8103D

http://www.kenwoodusa.com/Car_Entertainment/Amplifiers/KAC-8103D


2 Ohm@14.4V 500 Watts × 1 (100Hz, .8%THD)
4 Ohm@14.4V 300 Watts × 1 (20-200Hz, .5%THD)
Infrasonic Filter 15Hz, 25Hz, -18dB/oct
Low-Pass Filter 50Hz-200Hz (Variable), -24dB/oct
Maximum Output Power Watts
RMS Power Output 300 Watts × 1 (1%THD+N) (4Ω)


Sub: KFC-W3011

http://www.kenwoodusa.com/Car_Entertainment/Subwoofers/Subwoofers/KFC-W3011

Impedance 4 ohms
Peak Input Power 1200 Watts
Rated Input Power 400 Watts
Max Input Power 1 Watts

In its proper sealed box with 8 G wiring kit, amp under the seat. sub, amp, wires and box came to $450 :D

Right, so thats the details


here is the prob, i installed it all last sunday and set it up to how she wanted it. but as with everyone when they get a sub for the first time they overkill the bass and make it way too loud, i set it so that the sub was working very hard but not anywhere near clipping or distorting, i estimate bout 85% of its capabilities (she wanted more but i said no!). now however, she is complaining that the bass beat from the sub is slower that is should be, like the amp is delaying the beat or something. i have not heard it so im not sure but thats what she says. she ic coming up tomoz for to to turn it all down and see what the story is.

has anyone heard of this? the sub and amp are matched, i.e. that amp is designed for that sub so its not under powerded.

the only thing that i can think is that it is cos the sub is under powered, and i think this becasue of the way it is wired in. The amp is a mono bloc so i am used to it have one set of terminals, i.e. one + and one - but this has 2+ and 2- . now looking at the wiring diagrams in the booklet it you are running one sub, you wire it up using the second set only (but its is scetchy diagram at best, not sure if its actually a proper set up or not), but there is no indication on the amp saying use these two only for bridged setup. so im thinking that the sub is only getting half the power from the amp and the second terminals are not in use.

so does this sound right? i have never used kenwood gear so im not sure if you have to bridge the terminals yourself of if the amp does that when only one set of terminals is in use

any would that cause the delay that she is talking about.

that amp should be perfect for that sub
im going to go with the amp not being setup right

*EDIT* reread your post again,
you say it has two sets of terminals on the box?
you wouldnt be able to take the sub out and look how its being wired up?
depending on the wiring you may only have power running to one of the coils, thats if you only put the wire to one terminal

Hmm... some subs can be just slow with faster music, when its near its suspension limits.

Bad phasing can also cause this problem.

Some better/heavier RCA's, and heavier gauge wire to the sub might help too.

Your lowpass is probably set too high drop it to around 80hz. You are trying to play midbass from your sub, this should come from your mids.

so you dont think that the fact that one set of terminals is in use is affecting it????

i havent had a listen to it on dace music so i cant comment on how it sounds yet. i think the cross over is set quite high. i'll drop it as well

Yeah check the xover and the phase. If she still isn't happy then she shouldn't have gone with Kenwood...

that amp should be perfect for that sub
im going to go with the amp not being setup right

*EDIT* reread your post again,
you say it has two sets of terminals on the box?
you wouldnt be able to take the sub out and look how its being wired up?
depending on the wiring you may only have power running to one of the coils, thats if you only put the wire to one terminal


no the sub is a single voice coil and there is only one set of terminals on the sub and on the box (i had to put the sub in the box myself). however, on the amp there are two sets of terminals. i have never come across this on a mono block amp before so i have no idea if i have to bridge them myself of if there is a way to wire them up such that the amp knows its bridges and feeds all power through one set of terminals. there is nothing about it in the booklet that came with it. starting to not like kenwood :(

No you don't, why it has 2 terminals is so you can hook up 2 or more subs straight to the mono and use larger gauge wiring more simply. If you where to add another 4ohm sub, to wire it in parrellel for a 2ohm load, all you would have to do is wire both sides the same. i.e. +ive wire to positive terminal and -ive wire to -ive terminal on both sides ( or vice verse to reverse both subs phase ).

This will mean that the amp will internally present the correct load. :D