Worthwhile to upgrade sub amp?

[TimRawson]

I have a middle aged M&K 90 sub that I bought used in excellent condition- 12" push pull. It's amp is somewhat weak, comparing to other models in the series, I'm guessing it's either 100 or 125 watts. Would it be worthwhile for me to switch it out with one of the 250 watt amps from PartsExpress? And maybe better yet, a 500 watt one? Then maybe replace woofers down the road. I like the box and had used an isobaric in my car stereo days that hit extremely hard - so, would not rule out just reusing the box in the end.

So... 250 or 500? Make a significant difference? Also, any other recommended sub (plate config) amps?

[junior77blue]

First will the speaker be able to handle the extra power?

Second is the sub not loud enough for you?

Do you lose the crossover when doing this 'upgrade'? I remember the MK having one hell of a great LP crossover...

[TimRawson]

I recall from back in car stereo days, artifically enhancing bass via gross eq adjustment, boosters (+12db at 45Hz etc.) and max corner loading. Then came power, more power always made it better.

I'm fairly certain the subs could handle more power - also being in a sealed design helps I would think. I would imagine each sub (2 12"- pushpull) could handle 100 and possibly 150. Woofers don't looked to have high excursion though. I'm suspect that models only varied by amp size on nearby models (mx 100 had 200watt , mx 80 had 75 watt)

The new amps also have a xover as well as the prepro doing the bass management.

[ThomasW]

You'll find that most factory subs are designed with fairly tight tolerances with regard to matching the driver's power handling with the amp's output. So strapping on a bigger amp wll probably destroy the drivers.

Also may mfgr's put specific EQ into their amps that match the woofers. So adding a generic amp and it's EQ maybe a recipe for bad sound.

You don't really want to use both the XO in the pre/pro, and the one in a plate amp. That has the potential to really muddy the sound quality.

Generally speaking sealed designs handle less power than ported ones.

My recommendation is sell the sub and use the funds to bankroll a new design.

[robertwb70]

I also have an MX-90 and I'm pretty sure there's some EQ built into the stock amp-I mean 2 12s in a box that small just isn't going to work without it

as for more power I'm not real sure it would be able to handle it-these are fairly old design drivers-they were great for their time but pale in comparison to the new stuff

just build an IB and sell the M&K-or would you like to buy another for a matching pair?