preblems with subwoofer

[dogy49]

Hi guys!

Realy sorry for my bad english, but i hope you will understand me.

Asked all my friends, who know something about electricity, but nobody gave me a normal answer to my problem, so here i am, asking you guys!

So, i am using now Kenwood KDC-316UR radio in my car and basicly a week ago i added to it pioneer ts-wx206a subwoofer. (i will post the specs on both of them above)

The sub is active and radio has a RCA output for sub, so basicly i dont think i'm such a looser, to manage to do the wiring wrong. The prblem is that yesterday Sub stopped working. But not in an ordinary way - basicly it works(the red indicator is on), but no signal is going to it. i tried to put in RCA a standart AUX wire and plugged in my phone with a quiet music, but no soud apeared. So i opened it up and realised that there is a burned place on microsheme.

I am not a first time user so my Sub's Gain was constantly 3/4 of maximum. The other thing is that radio was turned on when this happened, but it was not loud, (basicly i could talk with passengers).

I just cant understand why it burned. ofcourse i will fix it, but i don't want it to happen again, so maybe you have some answers, why or what to do, to get thru with this?

Oh yeah, one friend said, that it could be becouse of voltage, that comes from radio is 2,5V, but Sub has a 2V input, but do that could realy matter so much, that it burns down a michrosheme??

really hope for some advise!

Specs for Sub:

Bandpass Amplified Subwoofer

Built-in MOSFET 150 W power amplifier

Large dual port bandpass design

RCA/speaker level inputs

Input level control/phase switch

Built-in variable LPF (50 - 125 Hz, -12 dB/Oct)

Aluminium die-cast heat sink

Nominal output power: 60 W

Frequency response: 35 - 200 Hz

Sensitivity: 107 dB (in-car), max SPL 128 dB (in-car)

Enclosure Volume 18 litres

Dimensions (W x H x D) 274x316x412 mm

Powerful Bass Sound

And the radio:

Maximum Output Power 50W x 4

MOSFET Power IC

Auxiliary input

Auxiliary Type Mini-jack

Pre-out 1 RCA

Pre-out Output Level 2.5V

Preout Rear / Subwoofer Switchable

Subwoofer Reference Level Adj.

Source Tone Control & Memory Bass / Mid / Treble

Balance/Fader/Loudness Control

Preset EQ

Bass Boost Circuit

Low-pass Filter

Click to read more...

 

[fly_marlin]

So is the sub blow or is the amp?

 

[dogy49]

Tehnicly i guess that amp's signāla input. If you can tell me how to test what is blown, i can try and tell you more precisely.

 

[fly_marlin]

You can take out the sub and test the resistance of the coil(s). If it's fine, should read pretty close to the resistance stated in the spec.

 

[Boomin_tahoe 5,000+ posts]

107dB sensitivity?

Why do I find that hard to believe?!

 

[dogy49]

Managed to open up the sub and take a pic. it seems that i misunderstood what burned. By looking at it, it seems that the burned place is Grounding. there is a pic of burned place and what goes in to it on the other side...

now why woud the ground burn up on aplifier?

and i still can't understand why did the fuse on my power cable didn't work..

Could it happen if the ground cable maybe has a bad connection somewhere?

 

[fly_marlin]

Managed to open up the sub and take a pic. it seems that i misunderstood what burned. By looking at it, it seems that the burned place is Grounding. there is a pic of burned place and what goes in to it on the other side...
now why woud the ground burn up on aplifier?

and i still can't understand why did the fuse on my power cable didn't work..

Could it happen if the ground cable maybe has a bad connection somewhere?

The fuse on the power cable is for the wire only. I'm not sure if that amp has protection circuitry in place. I've had a burnt ground once - it happened because the cable got loose and was connecting/disconnecting. The whole terminal melted, however, the amp continued to function fine. You may've had a bad ground. Where are you grounding the amp? Picture?

From the 2 pictures above, and I'm no engineer, I can't see what burned.

 

[hispls 5,000+ posts]

I would guess if the amp broke it's a factory defect. That being said it is highly likely that the fuse they gave you was far too large to protect the amplifier (virtually everybody uses too high value fuses).

Something that small should not be very sensitive to things that would kill the big amps, and your "2.5V" head unit very probably does make 2.5V

 

[dogy49]

The fuse on the power cable is for the wire only. I'm not sure if that amp has protection circuitry in place. I've had a burnt ground once - it happened because the cable got loose and was connecting/disconnecting. The whole terminal melted, however, the amp continued to function fine. You may've had a bad ground. Where are you grounding the amp? Picture?
From the 2 pictures above, and I'm no engineer, I can't see what burned.

Here is a pic from a different angle..

ground cable is attached to a screw, that is attached to cars body - metal under the back seat.

technicly it is possible that it may have got loose, so that may be the reason.

but if the ground has burned, would the sub still turn on when i turn on my radio, just without any sound? Because it did - the red power indicator turns on with the radio as always, but it just don't give any sound.

seriously, this is a first time i see a sub without itš own fuses. the oly fuse i have is only on Power cord...

 

[fly_marlin]

The cable may've also gotten shorted. Do you have a new ground cable you can use?

 

[dogy49]

I would guess if the amp broke it's a factory defect. That being said it is highly likely that the fuse they gave you was far too large to protect the amplifier (virtually everybody uses too high value fuses).
Something that small should not be very sensitive to things that would kill the big amps, and your "2.5V" head unit very probably does make 2.5V

And is it possible, that by tuning up aditional bass boost and stuff in radio the voltage increases? Because the settings in my car were that all of my speakers worked basicly only as treble and hight notes, but subwoofer was turned on +12 of +15, that my radio allows. But on the sub Gain level was aproximately 3/4 of max.

 

[fly_marlin]

And is it possible, that by tuning up aditional bass boost and stuff in radio the voltage increases? Because the settings in my car were that all of my speakers worked basicly only as treble and hight notes, but subwoofer was turned on +12 of +15, that my radio allows. But on the sub Gain level was aproximately 3/4 of max.

You're saying your radio has 2.5V pre-outs? What's the input voltage range on that amp? I see it says min/max, but that doesn't tell me anything. Yes, it's possible it was overdriven.

 

[dogy49]

The cable may've also gotten shorted. Do you have a new ground cable you can use?

I can buy one of those, when i will get the sub fixed. Also, šould i maybe attach the wire somewhere else? Sorry, can't provide a pic of where it is attached right now..

 

[fly_marlin]

Ideally, it should be a clean metal place with paint scraped off. Are you sure the sub itself is not working as well?

 

[dogy49]

Pre-out Output Level 2.5V

That's what it said in spec's of the radio.. but on the other side of the radio is not written "Hight voltage" (i read that they write it, if the voltage is more than 4v, but i could be wrong)