Anyway to improve / troubleshoot this sub & amp Frankenstein cobble up?


Novice Member
Hi all,

Ok so it's a bit of a horror hash up but it was a mini project I dabbled with based on some gear I had hanging around and it's provided some decent low end welly for a home 7:1 set up.

Signal chain =
Denon 1910 AV mp single sub pre out >
Y splitter cable to give 2 outputs >
JBL Synthesis S400 Stereo Power Amp >
2 x 10" Mordaunt Short 10" 4 Ohm drivers - mounted in their existing MS309i active sub cabinets (the amps were shot and I converted them to passive subs).

More recently the amp appears to trip out easier than it used to - I'm talking the opening scene from Live Die Repeat / Edge of Tomorrow at quite high levels - so I'm keen to know if the amp is on its way out or if I could improve things somehow with the hook up. I've visually checked all the amp's capacitors and all looks ok there.

The JBL is set to 4 Ohm setting and being a 200 watt per channel stereo amp driving 2 x 4 Ohm drivers from 175 watt active subs I'm thinking they are not too far mismatched and the drivers seem to handle everything effortlessly whereas it's the amp that has started to trip out more these days. If the amp is finally losing the will to live then so be it - one day I will treat myself to one or two decent active subs, but it I can keep this rig going or improve it somehow then great. I see it has a 400W 8 Ohm mono bridged option, if I picked up a suitable driver would that possibly work better?. I don't mind spending a bit on an interim solution.

Thanks in advance.
Last edited:


Novice Member
As a quick follow up - I have just put both drivers in series and wired the amp up in 8 Ohms bridge mode - and I can really push the drivers as far as I dare and the Amp behaved fine...... all the way through Edge of Tomorrow at high vol. Maybe an obvious thing I didn't realise but looks like the amp prefers being hooked up that way !

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