The Official AV123 Subwoofer Owners Thread

[StimpsonJCat]

Good to hear you came up with a great solution after your v2 amp failed.

Even with all the trouble with the cap fix and eventual upgrade to the Turbo kit I'm happy I went with the MFW-15. I was very happy with this subs performance when running the v2 amp and original driver, but the MFW Turbo blows it away.

It was a great sub design from Seaton with some cheap part choices by AV123.

After a few months with the Turbo I can't imagine a sub coming anywhere close for what I have invested. I doubt I'll ever upgrade again...unless I put together enough money for a Seaton SubMersive.

It is hard to recommend anyone going with a MFW-15 now days. But if you can find a deal on a used one (because of amp issues) and have money left over... The Turbo kit or upgrading the amp (and maybe the driver) will give you one hell of a sub.

[red_5ive]

Originally Posted by StimpsonJCat

Good to hear you came up with a great solution after your v2 amp failed.

Even with all the trouble with the cap fix and eventual upgrade to the Turbo kit I'm happy I went with the MFW-15. I was very happy with this subs performance when running the v2 amp and original driver, but the MFW Turbo blows it away.

It was a great sub design from Seaton with some cheap part choices by AV123.

After a few months with the Turbo I can't imagine a sub coming anywhere close for what I have invested. I doubt I'll ever upgrade again...unless I put together enough money for a Seaton SubMersive.

It is hard to recommend anyone going with a MFW-15 now days. But if you can find a deal on a used one (because of amp issues) and have money left over... The Turbo kit or upgrading the amp (and maybe the driver) will give you one hell of a sub.

Glad to hear you're still enjoying the Turbo Kit. I'm certain it's still a better solution considering it's properly tuned & tweaked for the MFW. It's probably a good thing I haven't experienced it or I might not be happy with the Crown amp.

Anyway, after a week with the Crown, I'm still VERY impressed with the results considering I still haven't run a calibration and have the sub EQ set flat in the AVR/preamp. I've made a few other adjustments, and it's rockin' nicely. It's evident the 350W in the original plate amp wasn't enough for the MFW. The bass now is ridiculously powerful (not that it wasn't already with the plate amp), yet still clean, and even at lower volume levels the Crown pushes the MFW with plenty of control. It's weird, it's like I still get clean, strong bass - just not as loud - when I wouldn't normally expect it at low volumes, like "mini bass" lol.

The Crown being a stereo amp, I'm using the other 525W amp channel solely for music to drive a 10" AV123 Rocket sub that also had a - surprise - dead amp. I bought the sub like this for $70, it's a gorgeous little sub and of course it's made to go with my Rocket 850s, and being sealed it works nicely with music considering I normally don't like subwoofers with music .



So as of right now, the Crown amp is the best solution for me as I can use it to drive both the MFW and the Rocket sub. However, I'm considering adding a 2nd MFW as soon as I can find someone selling one locally (preferably with no amp), which I'll run off the other channel in the Crown amp in place of the 10" Rocket sub. I'd much prefer this solution with dual subs vs. the turbo kit, which is really the reason why I didn't want to go that route. If I can't find an MFW, then I'm considering upgrading the driver in the MFW and bridging the Crown, which will provide a whopping 1,550W into 4 ohm RMS. But then again, I am extremely happy having a separate and smaller sealed sub just for music, and using the MFW just for HT. It may stay this way.

[irishsaab]

I just came across all the posts here regarding AV123 MFW-a5 repairs! Woot! I'm in need of your help. If you were to do it again what would you suggest as the best solution to repair a MFW-15 amp issue. (I too have the hum from hell)
Here is the info off my amp:
Part No: 3649600492
Model: MFW-15-EU
I'm curious to see if anyone have posted a how to video or tutorial somewhere regarding repairs or by-passing the amp and modifying for an external amp.

Thank you so much for all your posts! You have given me hope!

[Steve]

Originally Posted by irishsaab

I just came across all the posts here regarding AV123 MFW-a5 repairs! Woot! I'm in need of your help. If you were to do it again what would you suggest as the best solution to repair a MFW-15 amp issue. (I too have the hum from hell)
Here is the info off my amp:
Part No: 3649600492
Model: MFW-15-EU
I'm curious to see if anyone have posted a how to video or tutorial somewhere regarding repairs or by-passing the amp and modifying for an external amp.

Thank you so much for all your posts! You have given me hope!

I've been running an external amp I got from Parts Express. It mostly fixed everything. I'm getting occasional and random thumps from it though and sometimes it just doesn't seem to have the same level of oomph that the original amp had. After we noticed the random thumps I exchanged the amp and the second one is doing the same thing. PE has assured me that they can not replicate the issue with the amp I returned, and now I'm beyond the exchange point so I'm stuck with this one. Maybe for some unknown reason this amp and my receiver don't play well together.....?

Having said all that I'm still pretty frustrated with it and I expect I will have replaced the MFW altogether by the end of summer. I'm looking hard at an XV15se from Power Sound Audio, but I haven't decided on anything for sure yet.

[Tom V.]

Originally Posted by Steve

I've been running an external amp I got from Parts Express. It mostly fixed everything. I'm getting occasional and random thumps from it though and sometimes it just doesn't seem to have the same level of oomph that the original amp had. After we noticed the random thumps I exchanged the amp and the second one is doing the same thing. PE has assured me that they can not replicate the issue with the amp I returned, and now I'm beyond the exchange point so I'm stuck with this one. Maybe for some unknown reason this amp and my receiver don't play well together.....?

Having said all that I'm still pretty frustrated with it and I expect I will have replaced the MFW altogether by the end of summer. I'm looking hard at an XV15se from Power Sound Audio, but I haven't decided on anything for sure yet.

1)If you disconnect the subwoofer cable between the receiver and the sub amp do the thumps still occur?

2)If they do not, that may indicate something upstream. Do the thumps occur with all inputs? (DVD, BR, Cable, Sat, etc?)

Tom V.
Power Sound Audio

[Steve]

Originally Posted by Tom V.

1)If you disconnect the subwoofer cable between the receiver and the sub amp do the thumps still occur?

2)If they do not, that may indicate something upstream. Do the thumps occur with all inputs? (DVD, BR, Cable, Sat, etc?)

Tom V.
Power Sound Audio

1) Yes.

2) Yes.

This is a problem that never occurred until I tried using the amp from PE.

[Tom V.]

Originally Posted by Steve

1) Yes.

2) Yes.

This is a problem that never occurred until I tried using the amp from PE.

That is very odd. If the thumping is occurring with nothing connected to the amp except the AC cord...then it is either...

1)Problematic amp(s).

2)Some other large draw device on the same circuit possibly kicking on/off? For example, a sump pump, large AC unit, Refrigerator, water heater, etc?

If you have a long extension cord you can try plugging the sub amp into a different room output(as far away as possible) to temporarily check this.

TV

[Steve]

Originally Posted by Tom V.

That is very odd. If the thumping is occurring with nothing connected to the amp except the AC cord...then it is either...

1)Problematic amp(s).

2)Some other large draw device on the same circuit possibly kicking on/off? For example, a sump pump, large AC unit, Refrigerator, water heater, etc?

If you have a long extension cord you can try plugging the sub amp into a different room output(as far away as possible) to temporarily check this.

TV

1) I'm hesitant to say this is the problem, as this is the second amp. When PE got the first one back they informed me that they could not replicate the problem.

2) There are no large draw devices on this circuit and I've never noticed any correlation between the thumps and anything else in the house turning on/off.

However, now that I think about it, I don't recall that I've noticed the thump while my system is turned off. However, when I removed the sub cable for testing purposes one time I recall that I got at least one random thump. Weird....

When I gutted the original amp and added a set of speaker terminals to it so I would have a means of connecting the external amp, is it possible that I screwed something up that could be causing problems? I don't see how or what, but who knows?

[Tom V.]

Originally Posted by Steve

1) I'm hesitant to say this is the problem, as this is the second amp. When PE got the first one back they informed me that they could not replicate the problem.

2) There are no large draw devices on this circuit and I've never noticed any correlation between the thumps and anything else in the house turning on/off.

However, now that I think about it, I don't recall that I've noticed the thump while my system is turned off. However, when I removed the sub cable for testing purposes one time I recall that I got at least one random thump. Weird....

When I gutted the original amp and added a set of speaker terminals to it so I would have a means of connecting the external amp, is it possible that I screwed something up that could be causing problems? I don't see how or what, but who knows?

Do you have any type of program that could measure the FR of the thump? It may be a 60hz cycle but just guessing here. If the thump is intermittent I wouldn't count on them duplicating it.

Does the sub have any sort of auto-off/on? If so, when set to AUTO...does it "wake up" with one of these thumps?(or no thumps at all).

Lastly, what is a best guess on how frequent these thumps are? Once a day, once a week, once an hour?

TV

[Steve]

Answers in red.

Originally Posted by Tom V.

Do you have any type of program that could measure the FR of the thump? No. It may be a 60hz cycle but just guessing here. If the thump is intermittent I wouldn't count on them duplicating it.

Does the sub have any sort of auto-off/on? Yes. The only options are Auto and off. There is not option for continuous on. If so, when set to AUTO...does it "wake up" with one of these thumps?(or no thumps at all). Yes. It wakes up and shuts down with a thump.

Lastly, what is a best guess on how frequent these thumps are? Once a day, once a week, once an hour? I would guesstimate about once every 30-45 minutes or so.

TV

I've never been inclined to think there is a problem with my AV receiver or any other component since this issue never occurred until the new amp was put in use.

[Tom V.]

Originally Posted by Steve

Answers in red.



I've never been inclined to think there is a problem with my AV receiver or any other component since this issue never occurred until the new amp was put in use.

If the amp also thumps when it shuts off/goes into sleep mode...I'd say its the amp itself. Do you have a second system / neighbor's system you can try the subwoofer/amp out in for a couple hours? If the thump remains that would definitely indicate it is the amp. There's not going to be an easy fix for this unless PE has tracked it down to a resistor value or something like that. You may be able to minimize the annoyance factor by experimenting with the sub gain control versus the bass level setting in the receiver. Lowering the gain on the sub amp and raising the bass level control in the receiver for example.

TV

[Steve]

Originally Posted by Tom V.

If the amp also thumps when it shuts off/goes into sleep mode...I'd say its the amp itself. Do you have a second system / neighbor's system you can try the subwoofer/amp out in for a couple hours? If the thump remains that would definitely indicate it is the amp. There's not going to be an easy fix for this unless PE has tracked it down to a resistor value or something like that. You may be able to minimize the annoyance factor by experimenting with the sub gain control versus the bass level setting in the receiver. Lowering the gain on the sub amp and raising the bass level control in the receiver for example.

TV

No unfortunately I don't have access to another system for testing purposes.

I've tried playing with the amp's gain vs the bass level setting in the AVR and can't tell any difference.

I very much appreciate your assistance in trying to troubleshoot this.

[Tom V.]

Originally Posted by Steve

No unfortunately I don't have access to another system for testing purposes.

I've tried playing with the amp's gain vs the bass level setting in the AVR and can't tell any difference.

I very much appreciate your assistance in trying to troubleshoot this.

Try googling the amp model and various phrases that describe the problem. You may bump into someone who tracked it down to something you can change on your end(a single resistor value for example). I'll check with Jim here(he handles the circuitry of our amps) to see if he has any experience with those amps too.

TV

[Steve]

Originally Posted by Tom V.

Try googling the amp model and various phrases that describe the problem. You may bump into someone who tracked it down to something you can change on your end(a single resistor value for example). I'll check with Jim here(he handles the circuitry of our amps) to see if he has any experience with those amps too.

TV

I'll look around and see what I can find. Thanks.

[Tom V.]

Originally Posted by Steve

I'll look around and see what I can find. Thanks.

I forgot to ask, which model amp from PE are you using?

TV

[Steve]

Originally Posted by Tom V.

I forgot to ask, which model amp from PE are you using?

TV

http://www.parts-express.com/dayton-...ifier--300-807