Genius!

[Iyse]

I was in halfords today looking for a job (might as well), and I got to talking to this guy that works there who I always see when I go in for a look around. He asked me about my system, how it was going etc. and I said it was great and asked about his.

Now, this may seem obvious to many of you, but I thought I'd share the genius idea he put into my head. I went off buying a 4 way amp because I thought I'd have to buy another 2 way amp to power:

a) 2 fronts
b) 2 backs
c) A sub

This guy told me his plan to get a 4 way amp, bridge 2 channels for the sub (obvious), and use the other two channels for the fronts. I asked him about the backs, and his proceeded to inform me that he'd just run the backs off the head unit. !! What a great idea. It's not like the backs are as important as the fronts anyway, and if worst comes to worst, the doors could always be modified to take 4 speakers in the back, all run off the head unit, which would give the same amount of volume as two amped speakers in the front. I'm still in shock that I never realised this could be done.

 

[Howard]

I have my four way amp bridged for a sub on two channels , and the other two channels running the rear speakers, with the head unit powering the fronts.

The fronts are just used for infill anyway, thats why as a rule the front speakers are always smaller than the rears. You won't get any real bass out of the fronts, they are just there to fill in the soundstage.

Amping up the fronts will probably just make them distort at a lower level than the rears. Amp the rears and sub , power the fronts off the head unit and slightly bias your fader towards the rears, like if the scale is 0 (fully front) to 10 (fully rear) set it on a 6 or 7 and see how that sounds.

Give it a go, you might like how it sounds.

H

 

[guydewdney]

i use this setup - i run a two channel amp to run the fronts, running off the front pre-outs, the rear speakers are run from the HU (the front speaker cables..), the sub is run from the rear pre-outs - this allows an alteration of front & rear to sub ratio to be altered very easily using the fader function on the HU.

to alter front to rear is harder as it means the gain on the amp has to be altered. but i dont sit in the back of my car so i dont care.


seemed obvious to me...

 

[Howard]

Hmmmmmmm
fair enough

 

[Thmsshaun]

I have my four way amp bridged for a sub on two channels , and the other two channels running the rear speakers, with the head unit powering the fronts.

H

Agree with that one.
At the moment headunit is running rear and front. but rear will be amped with some replacement components for the front infill sound.

 

[se97mlm]

I shall be powering the fronts and rear shelfs (upgraded) in parallel on a 2ch amp, which worked great in my previous car. I will then have a separate mono amp for my sub and power the rear door speakers off the head unit.

Just waiting on a cd changer switch box and a stealthboxz enclosure before i can begin in earnest; only want to pull the interior out once!!

 

[se97mlm]

Well it's all in and it's absolutely bl**dy marvellous!

To save space though I think i may opt for a mega 4 channel amp, bridge two channels for the sub, and run the fronts and rears in parallel from the other two.

In my personal experience, it is worth amping the front speakers and ensuring they are a little louder than the rears, but making sure that they cut off at about 80-100Hz. In a standard ported or sealed sub box (ie not isobaric) the bass is not directional, so you get the impression that all the sound comes from the front. I think it is important not to ignore the rears, as the shitty acoustics in a car necessitate some sort of in-fill, but don't let them dominate... however...

In response to only amping the rears, I think this sounds awful; i mean, how many times do you go to a concert, then deliberately turn your back away from the stage so the sound is behind you ?!? wtf?!

Each to their own I suppose...

 

[Alps]

depends what sort of power you want and the clarity you are going for!

you will find the fronts will distort as the sub hunts for power from your 4 ch amp.

best to go either for 2 amps, or top end from high power head unit and a good sub amp.