[seanblee]

Originally Posted by nmf69

Why do I need to use a 40A fuse on the positive cable since there is already one inserted in the amp? If one chooses to use the power cables provided within the harness (yellow and black) then no extra fuse will be needed....weird

You should always fuse as close to the battery as possible. Otherwise, if your power cables chafe and short to the body, there's no fuse to blow to isolate the wiring, so it gets extremely hot and potentially causes the trim around it to catch fire. The fuse on the amp is to protect the car from the amp; the fuse on the feed cable is to protect the car from the cable.

[illingworth22]

Originally Posted by nmf69

The subs are fed by the 5th channel, still I could frie an egg or two on the amp - it's that hot!!!
I must say I still have the OEM subs running...but this shouldn't be a problem, I will disconnect them tomorrow to see if any effect occurs

So you disconnected the Subs (from the front 2 door speakers) and then re wired them directly to the Amp?

[LW]

Can somebody explain to me why a digital amp should not be hot after use?
It are still electrical parts, so it should get warm/hot?

[nmf69]

Originally Posted by illingworth22

So you disconnected the Subs (from the front 2 door speakers) and then re wired them directly to the Amp?

This is exactly what i did!

[nmf69]

Hi,

I am getting worried about the amp work temperature, as I sad previously, it gets very, very hot after an hour of riding...I didn't puzzle out the cause so far:
- could it be the OEM subs I still use (direct connected on the sub channel), I have "heard" they contain a sort of resistence which might "upset" the amp...
- could it be the position, I have installed it in the trunk under the carpet - not much air to breathe...
- could it be the power cables I used to connect to the battery/ground - I used the yellow/black cables from the original harness...should i have used something thicker? I happen to have some 10 squaremm cables
Is there anyone who can help me with a bit of advise on this matter? Thanks in advance!

[seanblee]

How have you connected the subs to the sub channel? If you've wired them in parallel, their impedance is halved, which could be taking the amp out of spec. Have you tried wiring them in series instead?

[nmf69]

Originally Posted by seanblee

How have you connected the subs to the sub channel? If you've wired them in parallel, their impedance is halved, which could be taking the amp out of spec. Have you tried wiring them in series instead?

From each sub I connected 2 wires to the plus/min connections on the amp, in other words I have 4 wires going to the 4 connector socket on the amp...

[seanblee]

I thought the sub channel was mono, i.e. there is only one set of terminals?

[illingworth22]

Originally Posted by nmf69

From each sub I connected 2 wires to the plus/min connections on the amp, in other words I have 4 wires going to the 4 connector socket on the amp...

My Amp is the 475 & I have 2 input plugs from the head unit (4 wires on each plug) and 4 output plugs (again 4 wires on each plug).
I assume you should have the same input as mine but an additional 2 wires for the Subs, now these have to be wired in the right way. I don't know the Impedance of the Subs in the BMW's, if they are 2 Ohm and you have them in Paralel (=1 Ohm Load) then the Amp will be overloaded. I seem to remember these Amps are 2 Ohms minimum, but check on line.

Have a look here http://www.bcae1.com/spkrmlti.htm and calculate the load on your Sub's (which in the 475 CAN NOT go below 2 Ohms!).

[nmf69]

fe0wap79.bosch.de/intershoproot/files/serviceDocuments/7607792132001_EA_DE.pdf


I have my subs connected like in fig. 5...This morning I removed the carpet in the trunk to allow some air circulation around the amp but it still gets pretty warm

[seanblee]

OK. Think the stock subs are less than 4 ohms impedance, so that's not going to do the amp much good. Try taking the wires off the two central sub terminals and join them together, thus connecting the subs in series to the bridged amp terminals.

[nmf69]

Originally Posted by seanblee

OK. Think the stock subs are less than 4 ohms impedance, so that's not going to do the amp much good. Try taking the wires off the two central sub terminals and join them together, thus connecting the subs in series to the bridged amp terminals.

I'll try that tonight...meanwhile an email from Blaupunkt:

"Dear customer ,

Thank you for you email .
You can installing one more time over again and if there is hot then 70 degres Is better if u send him to service partners for reparetion

Thank you. Is there still any question you wish to ask? Please call us. You can reach our hotline team from Monday to Friday from 8:00 AM to 5:00 PM under the phone number 0900/188 44 10. Always keep yourself up to date and subscribe to the Blaupunkt Newsletter. [for more information please click www.blaupunkt.com ]

With kind regards,
your Blaupunkt Service Team"

[nmf69]

So far i have received an RMA number and my tha555 is on his way to Blaupunkt technical service in Germany....Two days ago I was able to measure the surface temperature with some professional thermometer - it showed 64 degrees after one hour of usage on a well ventilated spot!!!

[nmf69]

I have received a new THA 555...guess what, the same working temperature - it's driving me nuts!!!!
So I imagine, being the only one with this proble, something must be wrong in my configuration...I will replace also the power cables with thicker ones but I don't expect to solve anything
I also disconnected the subs for one day, no change!

[gIzzE]

Originally Posted by nmf69

I have received a new THA 555...guess what, the same working temperature - it's driving me nuts!!!!
So I imagine, being the only one with this proble, something must be wrong in my configuration...I will replace also the power cables with thicker ones but I don't expect to solve anything
I also disconnected the subs for one day, no change!

Only just seen this.

You sure you have the correct subs??

Which did you buy, the 4 or 8 ohm ones?? and how have you wired them?

[gIzzE]

OK, just seen you have wired the subs correctly, however you are using the OEM subs.

I would run the amp with the subs disconnected and see what happens, if it runs a lot coller you know that is your problem.

[nmf69]

Originally Posted by gIzzE

OK, just seen you have wired the subs correctly, however you are using the OEM subs.

I would run the amp with the subs disconnected and see what happens, if it runs a lot coller you know that is your problem.

I also disconnected the subs for one day, no change!

[gIzzE]

I know you have already posted this info, but it is a bit spread out, so can you answer again? Sorry!

What speakers are you using?

Where is the amp now??

If under the floor have you tried playing it with the floor up and seeing what happens??

Do this with the subs disconnected first and if it stays cool, then hook them back up and try again.

[nmf69]

In the doors: Audio System X--Ion 200 for BMW (the subwoofers rest in the garage)
pbase.com/rkoelewijn/audio_system_xion_200_bmw

Subs: OEM Bmw woofers

The amp rests on the trunk floor but the carpet has been removed
As power cables i used the harness supplied black/yellow ones with the original connectors - I always suspected the cables could be the problem but an american user complained over the same problem and he uses an 8 gauge cable!

And, yes, I disconnected the oem subs for one day - no change, it gets hot, i did the same with the first amp I had!

The last thing I could try is to disconnect the front speakers

[gIzzE]

I really don't know??

Maybe the speakers?? What load are they?? 2 or 4 ohm?

[gIzzE]

Have you got a link for the speakers??

I had them with a Deutsch supplier but that link is at work and I can't find them again.

[nmf69]

Originally Posted by gIzzE

I really don't know??

Maybe the speakers?? What load are they?? 2 or 4 ohm?

4 ohm

but i even disconnected them for 1 hour - the same result