Discussion:
Fitting a Sub
(too old to reply)
Chris
2005-07-25 18:40:39 UTC
Permalink
I have a Kenwood KRC-391 Head Unit and have bought a Kenwood KFC-W300S Sub
and a Box.

How do I wire it up to the Head Unit?

What Amp would I need to get that wouldn't break the bank. Currently I have
a 30W X 2 Channel Amp in the car, would this be able to power it? If so how
would I wire it up to it?

Cheers.
Tim..
2005-07-29 17:55:56 UTC
Permalink
Post by Chris
I have a Kenwood KRC-391 Head Unit and have bought a Kenwood KFC-W300S Sub
and a Box.
How do I wire it up to the Head Unit?
What Amp would I need to get that wouldn't break the bank. Currently I have
a 30W X 2 Channel Amp in the car, would this be able to power it? If so how
would I wire it up to it?
I am not familair with the KRC-391, but assume it has some pre-outs on the
back?

In which case you need a 5 meter (or 3 meter if you have a Mini) RCA lead
with Y adapater on the end from front to boot of car, along with some proper
power line, direct from the battery **correctly fused** at the battery, and
grounded locally. tip- get an amp wiring kit.

Your 30wx2 amp is unlikely to be butch enough to power the sub- either get
something bridgeable to 1 channel in the region of 150w+ RMS or a dedicated
class D single channel amp of at least the same power. Whichever you choose
it must have alow pass filter (either fixed or adustable) Around 100-120Hz
is a starting point.

An amp which clips because you're overdriving it *will* damage the speaker.
More power is better than not enough.

Install the amp and use proper speaker wire to link it to the sub. Once
again the power must be hooked up properly. * We dont want any fires.*

Set the EQ on the HU to flat, and the gain on the amp intially at minimum.
Play your fave music at your normal listeing level and slowly turn the gain
on the sub amp up to around 60-80%. Then re-adjust your EQ to taste. Check
the clip / peak LED is only lighting breifly on the bass hits at your
intended full volume.

Thats an abridged set up procedure.

Tim..
Chris
2005-07-29 18:59:29 UTC
Permalink
cheers

this may sound thick but EQ?
Post by Tim..
Post by Chris
I have a Kenwood KRC-391 Head Unit and have bought a Kenwood KFC-W300S Sub
and a Box.
How do I wire it up to the Head Unit?
What Amp would I need to get that wouldn't break the bank. Currently I
have
Post by Chris
a 30W X 2 Channel Amp in the car, would this be able to power it? If so
how
Post by Chris
would I wire it up to it?
I am not familair with the KRC-391, but assume it has some pre-outs on the
back?
In which case you need a 5 meter (or 3 meter if you have a Mini) RCA lead
with Y adapater on the end from front to boot of car, along with some proper
power line, direct from the battery **correctly fused** at the battery, and
grounded locally. tip- get an amp wiring kit.
Your 30wx2 amp is unlikely to be butch enough to power the sub- either get
something bridgeable to 1 channel in the region of 150w+ RMS or a dedicated
class D single channel amp of at least the same power. Whichever you choose
it must have alow pass filter (either fixed or adustable) Around 100-120Hz
is a starting point.
An amp which clips because you're overdriving it *will* damage the speaker.
More power is better than not enough.
Install the amp and use proper speaker wire to link it to the sub. Once
again the power must be hooked up properly. * We dont want any fires.*
Set the EQ on the HU to flat, and the gain on the amp intially at minimum.
Play your fave music at your normal listeing level and slowly turn the gain
on the sub amp up to around 60-80%. Then re-adjust your EQ to taste. Check
the clip / peak LED is only lighting breifly on the bass hits at your
intended full volume.
Thats an abridged set up procedure.
Tim..
Chris
2005-07-30 16:35:23 UTC
Permalink
Cheers Tim

Have seen this http://www.mutant.uk.com/nw480sp.html, would it be ok to
power the sub?

Would I be able to wire the switched power to an ignition live and put a
suitable switch on it, so I can turn the sub off when my young lad is sat in
the back of the car. and keep my existing amp wired up as it is, to the HU
switched power?

Cheers.

Chris
Post by Tim..
Post by Chris
I have a Kenwood KRC-391 Head Unit and have bought a Kenwood KFC-W300S Sub
and a Box.
How do I wire it up to the Head Unit?
What Amp would I need to get that wouldn't break the bank. Currently I
have
Post by Chris
a 30W X 2 Channel Amp in the car, would this be able to power it? If so
how
Post by Chris
would I wire it up to it?
I am not familair with the KRC-391, but assume it has some pre-outs on the
back?
In which case you need a 5 meter (or 3 meter if you have a Mini) RCA lead
with Y adapater on the end from front to boot of car, along with some proper
power line, direct from the battery **correctly fused** at the battery, and
grounded locally. tip- get an amp wiring kit.
Your 30wx2 amp is unlikely to be butch enough to power the sub- either get
something bridgeable to 1 channel in the region of 150w+ RMS or a dedicated
class D single channel amp of at least the same power. Whichever you choose
it must have alow pass filter (either fixed or adustable) Around 100-120Hz
is a starting point.
An amp which clips because you're overdriving it *will* damage the speaker.
More power is better than not enough.
Install the amp and use proper speaker wire to link it to the sub. Once
again the power must be hooked up properly. * We dont want any fires.*
Set the EQ on the HU to flat, and the gain on the amp intially at minimum.
Play your fave music at your normal listeing level and slowly turn the gain
on the sub amp up to around 60-80%. Then re-adjust your EQ to taste. Check
the clip / peak LED is only lighting breifly on the bass hits at your
intended full volume.
Thats an abridged set up procedure.
Tim..
Tim..
2005-08-01 19:13:31 UTC
Permalink
Post by Chris
Cheers Tim
Have seen this http://www.mutant.uk.com/nw480sp.html, would it be ok to
power the sub?
No, it doesnt appear to be bridgeable to me. Though I might be wrong.

Why do you want a 4 channel amp? Are you planning to use the spare two
channels to power your front speakers or???

A bridgeable 2 channel-er or a D class single channel or, even simpler an
active sub (i.e. amp built in) is what you want.
Post by Chris
Would I be able to wire the switched power to an ignition live and put a
suitable switch on it, so I can turn the sub off when my young lad is sat in
the back of the car. and keep my existing amp wired up as it is, to the HU
switched power?
No. Definately not. Do not switch the power feed to the amp. There is a
simpler solution. ( A reasonably powered amp (say 200w RMS) will pull
25-30amps under full load. You'll end up setting fire to something. )

The Amp is switched by a remote lead which runs from the HU to it. This
comes to +12v as soon as your power up the HU and carries only afew mA. Put
a switch in this if you want to disable the sub.

EQ - equalisation - tone controls.

Tim..
Chris
2005-08-04 18:28:05 UTC
Permalink
OOPS, Should have been the NW240SP 2 channel amp :-(

The HU power feed to the amp was the one I meant, to put a on/off switch.

would I be able to power both amps from the HU on/off wire?

Cheers
Post by Tim..
Post by Chris
Cheers Tim
Have seen this http://www.mutant.uk.com/nw480sp.html, would it be ok to
power the sub?
No, it doesnt appear to be bridgeable to me. Though I might be wrong.
Why do you want a 4 channel amp? Are you planning to use the spare two
channels to power your front speakers or???
A bridgeable 2 channel-er or a D class single channel or, even simpler an
active sub (i.e. amp built in) is what you want.
Post by Chris
Would I be able to wire the switched power to an ignition live and put a
suitable switch on it, so I can turn the sub off when my young lad is sat
in
Post by Chris
the back of the car. and keep my existing amp wired up as it is, to the HU
switched power?
No. Definately not. Do not switch the power feed to the amp. There is a
simpler solution. ( A reasonably powered amp (say 200w RMS) will pull
25-30amps under full load. You'll end up setting fire to something. )
The Amp is switched by a remote lead which runs from the HU to it. This
comes to +12v as soon as your power up the HU and carries only afew mA. Put
a switch in this if you want to disable the sub.
EQ - equalisation - tone controls.
Tim..
Tim..
2005-08-05 08:04:51 UTC
Permalink
Post by Chris
OOPS, Should have been the NW240SP 2 channel amp :-(
The HU power feed to the amp was the one I meant, to put a on/off switch.
would I be able to power both amps from the HU on/off wire?
Yes.

Don't top post.

Tim..

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