Re-Build of M&K V-1B Sub?

[GFOviedo]

So, I bought a 2.1 M&K set up for $100 bucks. The speakers sound awesome, but I found the sub to have some intermittent audio drops. I noticed the the Amp gets pretty hot, but if I move the gain knob it usually starts working again. It appears that the amp might be the culprit.

So I was thinking of buying a new woofer and amp to re-use the housing since it is in excellent condition and it is pretty heavy.

Now, I wanted to ask which amp and woofer would you guys recommend? Here are some picture of the sub.

Thank you in advance for your help.

 

[Sonnie]

I would probably reach out to Ken Kreisel at Kreisel Sound and see if he has any drivers that would work, or what he might recommend. It will need to have the correct T/S Parameters for that particular enclosure, or will need to model to something you would like. I am not familiar with the plate amps available right now, but that may be something else Ken could recommend, as well as others here may know of some various models available.

 

[GFOviedo]

Sonnie thanks for the suggestion I’ve been searching online for a couple days now, and I can’t find anyone who has done what I want to do.

I will contact him and see what he recommends.

 

[Wayne A. Pflughaupt]

Since the driver is good, I’d just replace the amplifier.

Regards,
Wayne A. Pflughaupt

 

[Matthew J Poes]

If the driver is good then just a replacement amp may be good. A number of us who have built many diy subwoofers have had a common problem of plate amp failure. If you are comfortable doing it, I suggest making a wooden plate with speaker connectors for the plate amp and sealing the enclosure up. Then use an external amp.

It is possible and even likely that the plate amp had some eq to boost the low end. I wouldn’t know without measurements of the amp what was done. You may need to replicate this with whatever amp you get.

If you really want a new sub driver too, please share the internal dimensions of the enclosure and I can give you some suggestions, response graphs, and suggested eq.

 

[GFOviedo]

If the driver is good then just a replacement amp may be good. A number of us who have built many diy subwoofers have had a common problem of plate amp failure. If you are comfortable doing it, I suggest making a wooden plate with speaker connectors for the plate amp and sealing the enclosure up. Then use an external amp.

It is possible and even likely that the plate amp had some eq to boost the low end. I wouldn’t know without measurements of the amp what was done. You may need to replicate this with whatever amp you get.

If you really want a new sub driver too, please share the internal dimensions of the enclosure and I can give you some suggestions, response graphs, and suggested eq.

The sub has an odd shape.

Top: 15.5 inches
Bottom: 18 7/8 inches
Height: 17 inches
Depth: 15 inches

If I get an external amp I’ll probably leave the current plate on and just remove the amp itself since it’s screwed on to the plate.

Thanks for your help.

 

[Matthew J Poes]

The sub has an odd shape.

Top: 15.5 inches
Bottom: 18 7/8 inches
Height: 17 inches
Depth: 15 inches

If I get an external amp I’ll probably leave the current plate on and just remove the amp itself since it’s screwed on to the plate.

Thanks for your help.

Oh I didn’t realIize they made such shaped subs. That’s ok a little math can get us the volume.

If you leave the plate but remove the amp make sure it’s air tight. Also you will need to install speaker terminals and be sure they don’t make a metal to metal contact with the plate. That’s the main reason for switching to a wooden plate. None the less your plan is doable.

So are you interested in replacement sub options?

 

[GFOviedo]

Yes I am interested in changing the woofer as well. From my research I found this woofer recommendation.

http://www.mavin.com/store.php/feat...mandk-miller-and-kreisel-dual-voice-coil-subs

I’m not really sure if there’s anything better for the same price or less.

 

[GFOviedo]

I just remembered I’ve got an Outlaw M200 monoblock amp sitting in my garage. Can I use it to power up the sub?

 

[Matthew J Poes]

Yes the M200 would work for a subwoofer amp. Into a 4ohm load it puts out 300 watts, which I'm fairly sure is a lot more than the M&K factory amp put out. A few of the drivers I'm going to show could handle a much beefier amp.

Color coding is as follows:
Yellow: Dayton Audio 12" DVC (Made by Eminence, good driver)
Red : Dayton Classic 12 (Decent driver, low xmax, most similar to original driver I suspect)
Aqua Blue : Dayton Reference High Output 12 (Most expensive but most significant upgrade, handles 700 watts RMS and >12mm xmax)
Green : Mavin 12


Here you can see that the Mavin looks like it eeks out a tad more SPL, but that is largely due to the strange T/S parameters. The Dayton Reference has the most clean output in the low bass range, and it also would be the cleanest and lowest distortion of the bunch. It is more expensive (call it a ringer)

The rest are mostly the same in my opinion. The Dayton 12DVC will have a few db's more output down low due to the higher xmax and higher power handling. In a sealed box like this none of these are going to have a ton of low output without a lot more XMAX and power.

This next chart shows the max output in this box without EQ before the driver hits XMAX using a steady state signal. Call this the worst case scenario max spl chart.

Again you can see that the higher power handling and higher XMAX allows the Dayton Reference to put out a lot more spl. After that the rest are all very similar, but the Dayton Classic looks the best. I really think that the DVC 12 would actually be a better driver though and with a little EQ and a high pass filter, I am certain it would put out more spl than the classic.

And just for fun, here is the Dayton 12 DVC, the Dayton Reference HO, and a B&C 12TBX100 in that same box at their max output before hitting xmax at 20hz.


I'm not being totally fair in this comparison as the Reference would still put out more bass below 50hz if you had sufficient power and a high pass filter. Goes to show you that a pro driver (if you select the right one) can make for a great subwoofer too, and be quite a bit more efficient while doing it.

 

[GFOviedo]

I don’t want to put too much $$ in this since the wife might get a little upset since it’s for the garage.

I’m thinking of going with the Dayton Audio 12” DVC that’s about $60 plus the speaker connector should be less than $100 for this set up.

Thank you for your help.

 

[Wayne A. Pflughaupt]

Check ebay. An auction for a V1 B offered for parts due to the cone needing a re-foam recently expired. The seller said it powered up and made sound, which means the amp is good. Since it didn’t sell, you might make him an offer for the amp only.

Regards,
Wayne

 

[GFOviedo]

Check ebay. An auction for a V1 B offered for parts due to the cone needing a re-foam recently expired. The seller said it powered up and made sound, which means the amp is good. Since it didn’t sell, you might make him an offer for the amp only.

Regards,
Wayne

I've looked at those listing, but if I don't want to take a chance on getting a used amp that won't work.

 

[Wayne A. Pflughaupt]

Well, the chances of finding replacement plate amp that will perfectly drop in are pretty slim, so be prepared to modify the cabinet. Not hard to do with a jig saw, though.

Another solution is to just cover the amp hole with a good piece of aluminum plate with speaker connections installed, and use an outboard amplifier

Regards,
Wayne

 

[GFOviedo]

Well, the chances of finding replacement plate amp that will perfectly drop in are pretty slim, so be prepared to modify the cabinet. Not hard to do with a jig saw, though.

Another solution is to just cover the amp hole with a good piece of aluminum plate with speaker connections installed, and use an outboard amplifier

Regards,
Wayne

I do woodworking as a hobby so modifying the the cabinet won't be too difficult to do. I might look into a plate amp as well, but we will see. I don't want to put too much $$ in to this sub since it will be for my 2.1 garage set up hooked up to a BlueSound PowerNode G1 and using Spotify.

 

[BassSounder]

I replaced the MK plate amp with a BASH 500W. All I had to do was make the opening larger, drill some pilot holes, and screw it down. Works great!

 

[GFOviedo]

I replaced the MK plate amp with a BASH 500W. All I had to do was make the opening larger, drill some pilot holes, and screw it down. Works great!

Sounds good. Thanks for the info. I had to put this on hold since other things came up that were of more importance. I still got it sitting in the garage. I’ll look into the Bash amp.

 

[Grayson Dere]

It was great finding this thread! Many years back I abandoned a project rebuilding this exact sub...I was able to replace the driver (a Dayton) and some parts for the original amp but it kept having a whistling noise when played. I never was able to fix it so into the garage it went : P

 

[GFOviedo]

It appears that it will be cheaper to buy another sub than trying to fix this one.

 

[Grayson Dere]

It appears that it will be cheaper to buy another sub than trying to fix this one.

This is the exact reason I didn't bother going deeper into replacing parts.

 

[NBPK402]

I read somewhere recently where the plate amp on a sub was bad, and they wired the sub internally to the speaker jacks on the sub plate, and then ran an external amp. By doing this the amp is entirely out of the equation, and it makes a quick fix.

 

[Grayson Dere]

Thanks for the tip, Negatron! I hadn't thought about that work-around before : )

 

[GFOviedo]

I read somewhere recently where the plate amp on a sub was bad, and they wired the sub internally to the speaker jacks on the sub plate, and then ran an external amp. By doing this the amp is entirely out of the equation, and it makes a quick fix.

That's a pretty good idea. I've got a M2200 or M200 Outlaw amplifier collecting dust in the shed. I wonder if that would be good enough for it?

 

[NBPK402]

As long as you have speaker connectors on the plate amp..it should work fine. No need for any power either, since you are wiring direct from the speaker terminals to the speaker. you just need to make sure your external amp has enough power. It should not take long to try out.

 

[GFOviedo]

As long as you have speaker connectors on the plate amp..it should work fine. No need for any power either, since you are wiring direct from the speaker terminals to the speaker. you just need to make sure your external amp has enough power. It should not take long to try out.

So, I went to my shed, and noticed that the amplifier is way under a lot of other boxes and miscellaneous items. I would have to move and take out a lot of stuff to get to it. So, this project will be delayed for now--too lazy---. A friend of mine let me use his old Sony 8" subwoofer, and it sounds pretty good for my garage set up for now.