Puzzled

[Len]

I have a Sony 4 channel amp that works the front door speakers and 2 channels bridged to a sub.

Was checking my sysytem and the front speakers were working fine but the sub wasnt!
So I checked the speaker cable to the sub and was fine. Checked the earth and all the terminals on the amp and all seemed fine.

So in a bit of a tizz I slammed the hatch down hard, the sub sprang into life!

So my question is should I be looking for a new amp?

[B-chi]

Try switching it around. See what happens.

[Len]

What? The outputs from the amp? Swap the fronts with the sub? That what you mean?

[B-chi]

Yeah 4ch amp. Ch 1 front left, ch 2 front right, 3&4 sub.

Try 1&2 sub and 3&4 front left and right.

Does it have adjustable x over on all channels? You'd need to lpf 1&2 for the sub and hpf for 3&4 on the fronts.

[Len]

The fronts are bass speakers, that make any difference?

[B-chi]

I'm lost now sorry mate.

What do you mean by bass speakers?

I thought you said it was front door speakers.

[Len]

I have coax mid/tweets in the dash run off the HU and the front door speakers are mid/BASS run off the amp.

They are SPL Dynamics HF-6.1

Second edit:- 45 - 5000 HZ is the frequency response of those door speakers.

[B-chi]

Ok so your kind of running active.

That's fine. On the 4ch do you have the same controls (filters) on ch1&2 as on ch3&4. If so when you change them over to test ch3&4 just mirror them. Ie make 3&4 the same as 1&3 were and vise versa. Were just trying to establish if the problem happens on all 4 ch or just 2.

[Len]

Active?

Not sure!
Think it only has one "volume" control on the amp. Not sure about filters?

[B-chi]

All they do is stop nasty freqs speakers don't like destroying them.

You don't want to play a 30Hz tone through a tweeter. It's not going to last very long.

Any luck finding out the problem?