iphone sound output problems

[oliverst14@hotmail.com]

hiya everyone.

This is a bit of a strange one but ill try and explain as best i can. I recently got a new van and the soundsytem was appaling in it. i didnt wanna go down the route of ripping all the speakers aout and upgrading them as its a work vehicle.

I had a 5.1 surround sound pc speaker setup in my bedroom that i didnt use anymore so decided to put it in my van. these speakers used the standard 3.5mm jack inputs now standard pc speakers like this use all 3 of the pcs soundcard outputs (orange,green and black) and as everyone knows an iphone only has 1 output so i decided to get some 2-1 splitters from an audio store so that all 3 went into the 1 iphone socket.

This does work but the sound output is alot lower than when i was running it off my pc. for a while iv thought it was because the iphone didnt output as much as my pc would so thought nothing of it as it is still very loud.

today i was listening to a live album which has been recorded alot lower than my other cds. i decided to try and find out if it was just the iphone or if it was something else. i started unplugging and plugging in the different outputs in different configurations and noticed it sounded different when i was moving them.

i then just plugged one of them in (the front set of speakers) and the output was a hell of alot louder than when all 3 were in. now i know i should be happy with this but im not cause firstly the sound quality was not as good as its not surround. also i want to find a way of getting all the speakers to the same volume as the front ones so its louder as its a waste having 5 speakers if its louder with 2.

has anyone got any advice as to why this is happening, i do have a theory but im not sure and maybe a fix for this.


thankyou verymuch

ps sorry its not laser related but i know you guys will have some advice for me

ps again. the speakers are 240v powered so iv used an inverter in my van to take it from 12v to 240 v with a 4 way attached to the dashboard. this is rated to 600w and the speakers are alot lower than this. cheers

[dream beamz]

Most PC speakers have a DC converter built into them if one is not on the outside already. You should not be upconverting from dc to ac then back to dc with an inverter. Lots of things tend to not work correctly and eventually fry when doing this.

That being said. the problem is caused by splitter. My iphone gets much quieter when I split the signal. Each time you plug up an additional device the output goes down exponentially. This does not occur in bigger devices with a standard headphone jack but does with smaller devices

[T0mmm]

I believe its to do with the impedance of whatever each heaphone socket is attached to; if you're feeding one relatively weak signal into two or more pre-amp circuits then the resistance goes up. Imagine running a big bulb from a small battery.. you add another bulb and they both get dimmer.

How to solve it? you could *try* a ground loop isolator, but i think the signal would be pretty weak to begin with..

[oliverst14@hotmail.com]

thankyou for your help. im not sure what u mean about the dc to ac converting cause these speakers dont have batteries. they run off mains power in my house and im pretty sure dont have any transformer in. all i do is convert the vans power supply to 240 v which is what these speakers run off in the house.

this is what i was thinking. im sure there must be a way of reducing the resistance, if anyone knows a way please let me know. thanks

[dream beamz]

thankyou for your help. im not sure what u mean about the dc to ac converting cause these speakers dont have batteries. they run off mains power in my house and im pretty sure dont have any transformer in. all i do is convert the vans power supply to 240 v which is what these speakers run off in the house.

this is what i was thinking. im sure there must be a way of reducing the resistance, if anyone knows a way please let me know. thanks

Inside one of the speakers, or the sub there is usually a mains to DC converter

[heroic]

There has to be a DC power supply unit either inside one of the speakers or inside a control unit, because amplifiers do not work off AC.