Hu/speaker Question

[Guest justin85]

Just changed my Head Unit from a 10yo Sony with a 10 disc changer in the boot to a Pioneer DEH1430R (built in CD)

 

I took the unplugged the Sony harness from the red Pug one and swapped it for the Pioneer one..

 

Turned it on, and it works, but I only get bass frequencies from the rear speakers (Jensen 6x9's) when I set the fader to full rear and I can get bass from either left or right rear speaker using the balance control. When I set the balance to middle neither speaker gets any bass.

 

Help!

 

Justin.

[Guest simmy]

Speakers are "out of phase"seems a bit strange if they worked fine with the old head unit... unless there's a wiring difference in the adapter plug thing...

 

Basically one of yours speakers is wired positive to positive(red to red), negative to negative (black to black) and the other must be wired positive to negative (red to black) and negative to positive (black to red)

 

This would mean the speakers will be fine when you fade across to one or the other, but when faded to the middle the speaker cones are moving in the opposite direction to each other.... and seeing as bass is pretty much all about cone movement they cancel each other out and there is no virtually no bass...

 

All you gotta do is change over the terminals on one of the speakers, this SHOULD sort it.

 

sorry if you feel i've dumbed it down too much but not being aware of your depth of knowledge i thought it best to keep things simple.

Edited December 21, 2003 by simmy

[Guest d-9]

in a physics lab experiement then i could believe that, however in real life ive never come accross this happening, there is too much stuff in the way to reflect and diffract the sound, etc.

 

I would be more inclined to check there isnt a short somewhere, or a bad earth(do you need to put a seperate earth onto your headunit?), otherwise, check for a shagged headunit.

[Guest justin85]

No - thanks very much for your answer. I did think of that (although couldn't figure why - unless the adaptor is different to the old one) and accordingly played around swapping cables etc. but it doesn't make a difference.

 

The previous setup was installed by the previous owner. He had an in line fuse on the power supply. It also had a black plastic cylinder, approx 10mm long and 25mm in diameter installed with an inline fuse on the yellow cable coming from the Pug connector. Taking the cylinder apart reveals a copper coil wound round a solid core. What's this guys?

 

Justin.

[C_W 3 1 Cars]

in a physics lab experiement then i could believe that, however in real life ive never come accross this happening, there is too much stuff in the way to reflect and diffract the sound, etc.

 

I would be more inclined to check there isnt a short somewhere, or a bad earth(do you need to put a seperate earth onto your headunit?), otherwise, check for a shagged headunit.

It's actually very noticeable when you have one pair of wire swapped around; when you balance to either speaker it has bass but put it in the middle and they don't. Maybe this only happens if they share a common space like 6x9s on a parcel shelf?? As that is when I've noticed it most.

[Guest Theo205]

i'm with simmy....if u only get bass from the rear speakers when you play with balance.. it means that one of your rear speakers is playing on wrong phase...when speakers play in different phases and share the same enclosure, in this case your boot area. one elliminates the otherone)u can cure this by swapping the wiring on ONLY ONE OF the speakers so that it would match the phase of the other...pick a speaker left or right and swap the wires on the +/- terminals...

 

as for that coil thing if its connected on speaker cables it might be a simple DIY passive crossover

[Guest rodneyp]

if that is a passive crossover that could be whats getting rid of the bass. try removing it! also i played a out of phase sample through my subs today (sharing the same enclosure) and there was absolutely nothing! thought id blown em for a sec! ed

[Guest d-9]

oh right, ill have to give it a try and see what difference it makes.

[Guest Theo205]

if that is a passive crossover that could be whats getting rid of the bass. try removing it!

not tryin' to be a wiseguy ere..but just for the record...a coil in a passive crossover usually gets rid of treble whereas bidirectional electrolytic capacitors are used to get rid of low frequencies...

However, justin says he's got bass when balance is moved to either right or left speaker..no bass when both spkrz have the same balance... definately wrong phase on one of the spkrz

[Guest simmy]

at the end of the day how long is it gonna take you to swap over the connectors on ONE of the speakers???

 

If it doesn't have an effect your gonna have lost all of 60 seconds of ur life....

 

to be honest from what you've said its the only logical explanation??

 

 

speakers being out of phase will only really be apparent when sharing the same enclosure as its the speakers trying to move the same air that causes the bass to "disappear". If they're in seperate enclosures it'll have little effect... like having two house speakers in seperate rooms..... will they affect each other?? highly unlikely!!

[Guest d-9]

speakers being out of phase will only really be apparent when sharing the same enclosure as its the speakers trying to move the same air that causes the bass to "disappear". If they're in seperate enclosures it'll have little effect... like having two house speakers in seperate rooms..... will they affect each other?? highly unlikely!!

Which would be why ive never had problems with it before, despite doing it regularly by accident. (never had 6*9s)