Best setup for speakers and subs

[Anonymous]

Hi all,

Long time since I've posted...sorry if you've missed me   s:wink: :wink: s:wink:  

I bought a speaker board that fits in to the '2 instead of the storage bin lids.  So far I have installed the amp under the passenger side storage bin and connected the 2 8inch subs to it.  My Pioneer HU has sub pre-outs which are going straight to the amp.  But I haven't connected the 2 6x9's yet and was wondering the best way to go about this.

The amp is only 2 channel so if I wanted to connect the 6x9's to it I would have to bridge the connections (apparently that would cross over the balance between right and left?) but on the HU I have set the sub output to only play lower tones i.e. bass.

My HU has another pair of pre-outs so could I use them to go straight to the 6x9's?  (someone told me that they wouldn't be powered as the pre-outs just hold the signal and don't use the HU's 4x50 watt output - is that right)  Or do I need to splice the rear speaker cables from the HU?

Obviously I'm not sure which way to go and either includes cutting some cables so would like to make sure it works before doing so (and I need to buy the cables first!)

Any help would be greatly appreciated!

[markiii]

ok to connect what youi have without buying anything else

use teh headunit speaker outputs to drive teh front speakers (from teh front outputs)

and the 6x9s from the headunit rear speaker outputs.

connect your preouts (sub specific if you have them) other if not, to the amp

set the amp to low pass filter, and connect teh subs to teh amp.

wether ther subs are connected in serial or parrallel depends on teh impedance of your subs and wether the amp is 2ohm stable.

[Anonymous]

Thanks Mark.

My amp is nicely tucked under the storage bin and I set it to Full - not low pass filter...but my head unit has the setting to only allow tones of range below 50 (not sure what measurement that is) to the sub.  Does that achieve the same effect?  Pure guess there but they sound like pretty similar functions.

I'll get some extra speaker cable and connect the 6x9's straight up to the rear speaker leads then.

This sentance has completely thrown me:
wether ther subs are connected in serial or parrallel depends on the impedance of your subs and wether the amp is 2ohm stable.
  s:? :? s:?

[markiii]

ok first question how many pairs of preouts does your head unit have?

ifit only has 2 pairs then these will reflect the same outputs as your front and rear speakers, just at significantly lower voltage levels. In this case you need to connect 1 pair to teh AMP and set the AMP to low pass.

The reason for that is because if you use teh headunit to cut off frequencies it will also cut off the same ranges to the front or rear speaker (depending on if teh preouts are front or rear)

if your head unit is like mine and has 3 pairs of preouts, then front carries teh same signal as teh front speaker outputs, rear as teh rear speaker outputs (though again at much lower levels) and teh 3rd will be sub only.

In this scenario you can connect teh sub preouts to the amp, set the frequency on teh headunit and set the amp to full range of you wish.


with regard to teh subs, your amp only has 2 channels,  and in theory you could use 1 channel for each sub. However when connecting subs you normally run them in mono with both channels on your 2 channel amp bridged create 1 channel with more oomph. I'm assuming your amp can be bridged?

assuming your amp is bridged you now have 1 channel  that is used to run a sub. However as you have 2 subs they must either be connected in parrallel or series.

Series

Amp Positive Terminal - Sub 1 Positive, Sub 1 Negative - Sub 2 Positive, Sub 2 Negative - Amp Negative


or Parrallel

Amp Positive - Sub 1 Positive, Sub 1 Negative - Amp Negative

and also connect

Amp Positive Sub 2 Positive, Sub 2 Negative - Amp negative


what determines which you use depends on what figure your amp is capable of, 2ohm stable? 4 ohm stable?, or 8ohm stable, it will say in teh instructions

and

what ohm your subs are, 4ohm or 8ohm? again it should say in teh manual

lets say your amp is 4 ohm stable (pretty much all of them are) connecting 2 4 ohm subs in series gives total sub impedance of 8 ohms which is not allowed.

if you connect in parallel then 2 4 ohm subs would give you a total impedance of 2 ohms, which again isn't allowed as your amp is 4ohm

take the same scenario again but assume your amp is 2ohm stable and in series it is still a no no but in parrallel both are 2 ohms so you are fine.

if you mismatch the impedances then you will either fry electronics or blow speakers, neither of which is good.

if you can confirm what ohm stable the amp is and what ohm the subs impedances are I can advise you specifically how to connect them.

[Anonymous]

Thanks for your help Mark!

The head unit has 2 pairs of preouts.  1 for sub and 1 for non fading rear speakers.

The amp can be bridged but not sure whether it is serial or parallel.  Also I'm not sure about ohms as I don't have any of the manuals (and the amp isn't a well known make).  I'm thinking I might just be best leaving the subs using a channel each so as not to blow them up!

[markiii]

what make and model are teh amps?

the sub preout, is it 1 phono plug or 2?

[Anonymous]

Ah really can't remember the amp model - I did do a google search on it when I got it but it didn't come up with much.  Think it is an XS something or other.  Could take a look at the weekend if I get round to sorting out the 6x9s.

The sub preout is 2 phono plugs.