Re: Repairing Alesis M1 Active mk2 Monitor Speakers

After taking the Monitor apart I notice that when the speaker is in an upright position. The caps are above the R3 and R4 resistors. It seems having them on their sides might not only be better for sound. Might be a bit of a stretch , but heat does rise, so in an upright position the caps might get hotter.

Re: Repairing Alesis M1 Active mk2 Monitor Speakers

I purchased the revised boards because I did not have time to deal with the problem last time. The original boards blew within a few hours of each other. Strange after years of use.

Of the revised boards one just blew with about 1/20th the use. This time I will replace the caps on the good one before it blows, and repair the three bad boards.

I just want to thank you guy's for this excellent thread (repair manual really)
Especially Krohn, and mamoka. You have gone to great lengths to help people...

Re: Repairing Alesis M1 Active mk2 Monitor Speakers

When I wrote the post I did not have the schematic in front of. The correct part was L4 which heated enough to discolor the glipt or what it is they globbed onto the parts.
I do not have a lot of time for this right now. I can get two full amps complete with crossover, basically the whole panel with all connectors intact. One working, one not for $89 US, or purchase a power supply replacement for $94 free shipping. If I went the ebay route I'd have all I need to build the monitors after repairing the supplies when I get...

Re: Repairing Alesis M1 Active mk2 Monitor Speakers

While waiting for my parts the other monitor decided to pop a few cap also.
Both of mine burned c6 also. This one did not burn the traces though on both L1 got real hot. Seems to be a hard size to find. If they heated up enough to discolor the but are still intact I'm thinking they are OK. I do not have much experience with inductors. Any thoughts?

I'm thinking of buying a few more amps from Ebay and maybe building a set of monitors with 8" cones since I'm going to have extra parts.

Re: Repairing Alesis M1 Active mk2 Monitor Speakers

[QUOTE=momaka;659054]I agree.


If the speaker motor for the 8 inch cone is sized accordingly, then yes.

The KRK rockit series arn't to shabby for the price.Re: Repairing Alesis M1 Active mk2 Monitor Speakers

[QUOTE=momaka;659054]I agree.


If the speaker motor for the 8 inch cone is sized accordingly, then yes.

The KRK rockit series arn't to shabby for the price.Re: Repairing Alesis M1 Active mk2 Monitor Speakers

[QUOTE=momaka;659054]I

Re: Repairing Alesis M1 Active mk2 Monitor Speakers

That is what I am referring to. I found the roll off spec in my m1 mk2 manual says 50 hz.

A better sub response would as you say be 20 - 40hz .

I do take into account the room placement and treatments to reduce boominess and muddy bass.
Near field monitors also help to reduce room problems.
There is a lot of sub base in modern mixing and it is real easy to over do it when your monitor rolls off at 50hz. An 8 inch cone would have a greater effect.

I was having wishful thinking...

Re: Repairing Alesis M1 Active mk2 Monitor Speakers

That is what I thought. I read on some other forum of a guy recapping another brand monitor with poly caps, and claiming it improved them a great deal. It did not sound right, but I felt it couldn't hurt to ask. Thanks

Improvement on bass response would seem to require a larger woofer. Someday I will buy some KRK Rokit 8's and use the Alesis as cross reference.

100 percent agreement about the room.

Re: Repairing Alesis M1 Active mk2 Monitor Speakers

I'm curious if recapping the crossover circuit in addition would improve the quality of the sound. ( bass response ). It seems high quality caps should bring the relation between the pair of monitors closer in response. At least bring it closer to the ideal that the engineers were trying to achieve.

What caps would have the most effect on quality of sound?

I understand some of the bass roll off was due to damping for a more even (flat) response causing a tendency to roll off below 50 Hz. Could the...