Strange query

[sankeerthreddy]

hi guys , i was thinking whether if i cud get a HU with 2 pre outs ,a nd install a 800w woofer without any amplifier and all the stock speakers in my OHC , would it be better? or is it a must to get an amplifier with every subwoofer.

[blueraven316]

you need an amp for a woofer, otherwise buying a woofer is a waste of money.

[akshay1234]

unless its an active sub.. active subs arent too good anyway.

[speedzak]

Hello!! Whether it is a 2 pre out or 10 pre outs, you can't do that!!
Never ever a SUB can be powered by the pre-am outputs from a HU unless there's some amplifying between.

[jkdas]

zak! some pio HU's can but only 8inch subs or smaller... read a post by an audio guru here

[blueraven316]

Originally Posted by jkdas

zak! some pio HU's can but only 8inch subs or smaller... read a post by an audio guru here

A good pair of 6X9s will produce better bass connected directly to the head rather than preouts to however small sub it is.

[sankeerthreddy]

thanks guys, u made it clear to me.i learnt a very good lesson tht no sub can ever be powered by the HU , without an Amp.

[Rehaan]

Originally Posted by sankeerthreddy

thanks guys, u made it clear to me.i learnt a very good lesson tht no sub can ever be powered by the HU , without an Amp.

For purely academic purposes -

I remember a discussion in the ICE section where there was a mention of a HU which had an inbuilt amp specifically for the subwoofers as well. A class D amp if i am not mistaken.... i tried looking buy could not find the link....maybe some regular ICErs can help you. I know Navin was part of that discussion.

cya
R

[speedzak]

Originally Posted by jkdas

zak! some pio HU's can but only 8inch subs or smaller... read a post by an audio guru here

NO!!! pre-outs cannot power a SUB.
Yes, speaker outputs from the HU may power an 8incher or a 6"!!

[sankeerthreddy]

rehaan and speedzak , can u guys tell me the HU with a built in Amp.

[hydrashok]

Originally Posted by speedzak

NO!!! pre-outs cannot power a SUB.

Exactly. They are Pre-Amplifier outs, so the output would be unamplified, even by the HU's internal amp.

I do remember a discussion about a Pio HU (6850? 6750?) that can power a very small sub from the rear channels of the HU. But I guess all that is just marketing stuff. No sub can be powered even close to "well enough" by a regular HU's internal amp.

[Technocrat]

Well even My HU(Pio 5750) has the option where in the rear two channels can be used to power a small sub. Even otherwise it has options which can convert the existing 6X9s into subs as in its gives only low frequencies through the rear & they do give a pretty decent bass

[navin]

Originally Posted by Rehaan

... I know Navin was part of that discussion.

I remember this the HU was a Panasonic that claimed to put out 60W rms/ch but I have no idea where to find it. I have not heard this HU but someone else had put up a link to the advert that made that claim. I dont think this HU is available in India and that might be the reason why the thread died an un-eventful death.

[Sam Kapasi]

No, Rehaan is correct. I clearly remember a Pioneer HU that could be used to drive a small subwoofer.
It was a useless proposition and AFAIK pioneer does not make this anymore.

[Bass&Trouble]

Sankeerthareddy, you cannot drive four speakers AND a sub from a head unit. But you can do two speakers plus a sub. The sub will get low power, so no point using a 800W sub etc. Even this is not run off the pre-outs. The pre-outs cannot drive a speaker also, let alone a sub. The sub has to be driven off select leads of the rear speaker connection wires.

Here is the thread that I think people are referring. The relevant discussion starts at the bottom of the page and continues to the next one.