Just bought a pair of defunct Mackie monitors for less than $3. Mackie MR5 Mk2 Reference Monitor (Single) | Music Matter The vendor believes he's blown both woofers. (They are supposed to be protected).
From my perspective I see two very viable plate amps.
My first question is: other than installing a passive coil to create a low-pass filter what can I do to change the crossover point?
My second question: The Mackie contains two amps; 55w bass, 30w treble. Any ideas on how I can utilise the second amp?
A circuit diagram is on page 13. https://www.fullcompass.com/common/files/14072-MR5MKIIOwnersManual.pdf
From my perspective I see two very viable plate amps.
My first question is: other than installing a passive coil to create a low-pass filter what can I do to change the crossover point?
My second question: The Mackie contains two amps; 55w bass, 30w treble. Any ideas on how I can utilise the second amp?
A circuit diagram is on page 13. https://www.fullcompass.com/common/files/14072-MR5MKIIOwnersManual.pdf
There's a built-in active crossover which will send HF to one amp channel and LF to the other.
Chances are there'll be driver-and-cabinet-specific EQ and limiters in place. Hopefully they'll be done in the analogue domain, so you'd be able to modify the circuits.
Chris
Chances are there'll be driver-and-cabinet-specific EQ and limiters in place. Hopefully they'll be done in the analogue domain, so you'd be able to modify the circuits.
Chris
In no particular order:
* that is not a schematic by any means, just a very basic block description.
* crossover point is active, you must dig into the board and change some component values.
No schematic? Forget it
* neither of those amps is full range, but are fed from Hi and Lo crossover outputs respectively.
You can use that plate amp as-is by driving your own 2 way cabinet, if 3kHz crossover frequency matches your drivers, not hard to do, or, best bet, replace that woofer by a similar one and enjoy your restored active monitor.
* all this is based on problem being actually as described, of course.
I would check that woofer is actually dead (hook it to any other amplifier you have around) and, way more important, that plate amp works, hook woofer out to any spare speaker you have around for testing.
Do some testing to avoid an ugly surprise or sinking money into a bottomless hole.
And try getting the actual schematic, even asking Mackie themselves, asking is free.
* that is not a schematic by any means, just a very basic block description.
* crossover point is active, you must dig into the board and change some component values.
No schematic? Forget it
* neither of those amps is full range, but are fed from Hi and Lo crossover outputs respectively.
You can use that plate amp as-is by driving your own 2 way cabinet, if 3kHz crossover frequency matches your drivers, not hard to do, or, best bet, replace that woofer by a similar one and enjoy your restored active monitor.
* all this is based on problem being actually as described, of course.
I would check that woofer is actually dead (hook it to any other amplifier you have around) and, way more important, that plate amp works, hook woofer out to any spare speaker you have around for testing.
Do some testing to avoid an ugly surprise or sinking money into a bottomless hole.
And try getting the actual schematic, even asking Mackie themselves, asking is free.
JMFahey: the question was asked in the context of subwoofers. I have no intention of rebuilding monitors.
The same info applies. Chances are there'll be a highpass filter to cut the low bass and prevent over-excursion for the Mackie midbass unit, and of course the lowpass filter will need modification. Don't try to do a speaker-level crossover for a subwoofer.
I'm hoping there'll be a couple of quad op-amps which have a few caps and resistors around them to provide the necessary EQ etc, and you'll be able to recognise those circuits and change the values to suit you.
It's entirely possible they'll be surface-mount components, which will likely present problems for someone trying to alter the values.
Chris
I'm hoping there'll be a couple of quad op-amps which have a few caps and resistors around them to provide the necessary EQ etc, and you'll be able to recognise those circuits and change the values to suit you.
It's entirely possible they'll be surface-mount components, which will likely present problems for someone trying to alter the values.
Chris