car audio advice

[bilbobadbreath]

Hi.

I have an active subwoofer and upgraded door speakers with new head unit in my van. Has been working very well for a few months but now after about 10 mins of use the sound keeps turning off and on, like its got a bad signal. I can disconnect the sub but the door speakers still do the same. After an hour or two it will work properly again for another 10 mins. Is this the head unit overheating? Can I run the door speakers off of the sub? Its driving me mad?

Please advise.

 

[RichardJohnson1]

It sounds to me like you've got a loose connection, have you tried looking at the fixings that cionnect to the back of the stereo

 

[Peter.N.]

.. or it could be a temperature related fault, try running it at low volume and see if it still goes off.

Peter

 

[Mursal]

No I think all those Subs have to work at Max volume, well round here anyway

It may also be over voltage if the van is over charging, but unlikely.
Give the wires a bit of a hard time (wiggle test) to ensure good connections, as above.

This will test the sub for you
http://www.bbc.co.uk/programmes/b01r4yh4

 

[Belle427]

how have you wired the front speakers from the head unit or the sub?

 

[bilbobadbreath]

Hi,

The wiring from head unit to speakers is original, I am guessing this may need upgrading and this is my next step. Would the symptoms fit? The sub is connected to head unit via rca cables (the sub performs as it should). My guess is that the head unit is overheating due to speaker wire not being sufficient gauge. Sound right?

 

[Belle427]

either the speakers are wired incorrectly or the wrong impedance for the head unit, i cant see the wiring causing it.

 

[bilbobadbreath]

why would it work perfectly for 3 months then? seems strange to me

 

[AlanE]

My guess is that the head unit is overheating due to speaker wire not being sufficient gauge. Sound right?

No!

Is the speaker impedance same as required by unit?

why would it work perfectly for 3 months then? seems strange to me

If the speakers were say 4 ohm impedance and unit required 8 then excessive current would flow through output transistors in unit (particularly with high volume levels) causing dry solder joints on PCB.

This could cause exactly symptoms described.

 

[bilbobadbreath]

hmm ok, well this is what I have:

Inphase IPS720i Key Features:

CD / MP3 / WMA / USB
60W x 4 MOSFET power output
Full iPod Control
Dot Matrix Display
1 Preout
Aux-in
Flip Down Front Panel
ID3 Tag
ESP (Electronic Shock Protection)
Blue illumination
Rotary volume encoder
RDS
FM/MW
30 Preset Memories
Random/Repeat Play
Remote Control Included
Security Features: Removable Face

and 2 of these:
In Phase XTC620 6.5 inch 240W 2-way coaxial speakers 16.5 cm

The New XTC series have been redesigned In line with our current philosophy. In Phase have developed the new XTC series to be more aesthetically pleasing moving away from the chrome plated design to a new classic look across the range. Improvements have been made on enhancing the sound reproduction and ease of installation.

Features:

6.5″ (16.5cm) 2-Way Coaxial Car Speaker
High Grade Glass Fibre Cone
High Grade 1″ Kapton Voice Coil
Multi-Directional Neodymium Tweeters
4 Ohm Impedance
Sensitivity: 91dB (1W/1M)
Rubber Magnet Band
Chrome Finished T-Yoke Cover
Including Grills, Speaker Cable And Installation Hardware
Mounting depth 71mm

Seems ok to me, what do you think>?

 

[Mursal]

Duplicate post

 

[bilbobadbreath]

Duplicate post

thanks, that helps.

 

[AlanE]

Something doesn't add up,

You say you have an Inphase IPS720i unit which has outputs for a 4 speaker system with 2 InPhase XTC620.

But in your original post you mention a sub-woofer!

How is it all connected up? Still get the feeling you are either overloading the system in some way causing overheating or the main unit is mounted in such a position that the output transistors are unable to dissipate the generated heat.

Unfortunately the manual for your radio doesn't give any idea of maximum permitted ambient temperature, only that is shouldn't be subject to excessive external temperature.

 

[bilbobadbreath]

Sub woofer is connected via rca cables to pre out on head unit. Speakers are run off wiring harness through upgraded wire. Head unit is situated where it should be in the dash, maybe it can't get enough ventilation there?

 

[Belle427]

ive looked at the info for your unit and it specifies either 4 ohm or 8 ohm speakers can be used so you should be ok. Id double check the security of all your connections first, if that draws a blank then it can only be the head unit at fault.
Do you have the volume at a high level for long periods when this happens?
also if your only using 2 channels of the amp (front spreakers) have you insulated the other wires at the back of the head unit so they cant touch each other?