topofroc
Well-known member
While I'm not the typical do-it-yourself type person, I found myself in a unique situation. Due to a group of ham-fisted movers, a stingy moving insurance company, and Martin Logan's FANTASTIC customer service, I found myself in possession of a spare 12 inch driver from a Dynamo 1000. While my original Dynamo 1000 was back up and working, I had always wanted two subwoofers to balance out the bass in my room. With the spare driver on hand, I figured that there would be no better opportunity to pursue my two sub dream, so I decided to go DIY.
Besides fulfilling my gear-lust, this project had other benefits. It would be an opportunity to get trained in the use of a CNC machine (both a personal and professional benefit). It would also allow me to improved my (dulling) prototyping skills (another professional benefit).
With the ML driver already select, my next task was to choose an enclosure design and an amplifier. I had heard great things about Rythmik Audio and their DIY section so I checked it out. Their 12 inch sealed cabinet design was well-braced and was sized just small enough to make it under WAF radar. That made the decision easy enough. As for amps, my desire was to go with a 500W amp, to match the power of a stock Dynamo 1000. A brief consultation with my wallet convinced me that a 300W BASH amp from Parts Express would be a better choice.
So, after completing my (brief) CNC training class and passing the qualifying test, I was OK'd to use the CNC at a local woodworking shop. I used 3/4" MDF, with a 1.5" baffle. Since I was using a CNC, I was easily able to countersink the amplifier for a cleaner look.
After all the parts were cut, I went straight into gluing. Since I didn't have a set of bar clamps, I went with screws to pull everything together. I recessed the screw heads to keep the surface smooth. The box went together well enough, but there were a few squareness issues that would come back to haunt me later.
After lining the box interior with heavy poly-fill and filling the holes with wood filler, I test fit the driver and amp to make sure everything would fit properly. With everything put together, my impatience got the better of me so I hooked the sub up and tested it.
It sounded great. Since there was limited room in my space for it in front-firing orientation, the placement was off and the sound wasn't as good as I had hoped. That was probably a good thing, because if it had sounded too good, I would still have a raw MDF subwoofer in my living room
.
Final steps were sanding and finishing. Between the two, finishing was the hardest part. I decided to go with a simple roll-on vinyl laminate (walnut). I knew I didn't have the patience, money, or tools for legit wood veneer, so the vinyl was the best compromise. It was a bear to get on without creases or bubbles. I also added 4" aluminum legs I found online. They match well with the silver plate amp and the walnut laminate.
In the end, there are still some screw-ups in the vinyl surface, but from 4+ feet away everything looks great. Here's the final product:
So how does it sound? I'm still testing it out, but right now I'm very pleased. Both the Kinda Dynamo and the original Dynamo 1000 are hooked up, so I'm "living the dream". As far as head-to-head performance goes, I can't say which one is better at this point. The Dynamo has the advantage of corner placement, so it's output seems much louder that the DIY sub. I really need to get them set-up in a room where both are on equal footing before I judge.
Once I balanced their output levels, I really began to appreciate the benefit of dual subs. I can't explain why, but my stereo imaging really opened up. The soundstage is huge and more balanced. I'm also hearing atmospheric sounds that add to the depth and realism of both music and movies. For example, I was watching a re-run of 30 Rock last night. There was a scene where Liz and Pete get on an elevator. While they were talking, I was able to clearly here the low-level hum of the elevator during the scene. That's the type of new detail I'm able to hear. Great stuff.
Anyway, I'm pleased with my new Kinda Dynamo sub and the new skills I've been able to acquire. I don't see any new upgrades in the future, but hey - I've said that before
Besides fulfilling my gear-lust, this project had other benefits. It would be an opportunity to get trained in the use of a CNC machine (both a personal and professional benefit). It would also allow me to improved my (dulling) prototyping skills (another professional benefit).
With the ML driver already select, my next task was to choose an enclosure design and an amplifier. I had heard great things about Rythmik Audio and their DIY section so I checked it out. Their 12 inch sealed cabinet design was well-braced and was sized just small enough to make it under WAF radar. That made the decision easy enough. As for amps, my desire was to go with a 500W amp, to match the power of a stock Dynamo 1000. A brief consultation with my wallet convinced me that a 300W BASH amp from Parts Express would be a better choice.
So, after completing my (brief) CNC training class and passing the qualifying test, I was OK'd to use the CNC at a local woodworking shop. I used 3/4" MDF, with a 1.5" baffle. Since I was using a CNC, I was easily able to countersink the amplifier for a cleaner look.
After all the parts were cut, I went straight into gluing. Since I didn't have a set of bar clamps, I went with screws to pull everything together. I recessed the screw heads to keep the surface smooth. The box went together well enough, but there were a few squareness issues that would come back to haunt me later.
After lining the box interior with heavy poly-fill and filling the holes with wood filler, I test fit the driver and amp to make sure everything would fit properly. With everything put together, my impatience got the better of me so I hooked the sub up and tested it.
It sounded great. Since there was limited room in my space for it in front-firing orientation, the placement was off and the sound wasn't as good as I had hoped. That was probably a good thing, because if it had sounded too good, I would still have a raw MDF subwoofer in my living room
.Final steps were sanding and finishing. Between the two, finishing was the hardest part. I decided to go with a simple roll-on vinyl laminate (walnut). I knew I didn't have the patience, money, or tools for legit wood veneer, so the vinyl was the best compromise. It was a bear to get on without creases or bubbles. I also added 4" aluminum legs I found online. They match well with the silver plate amp and the walnut laminate.
In the end, there are still some screw-ups in the vinyl surface, but from 4+ feet away everything looks great. Here's the final product:
So how does it sound? I'm still testing it out, but right now I'm very pleased. Both the Kinda Dynamo and the original Dynamo 1000 are hooked up, so I'm "living the dream". As far as head-to-head performance goes, I can't say which one is better at this point. The Dynamo has the advantage of corner placement, so it's output seems much louder that the DIY sub. I really need to get them set-up in a room where both are on equal footing before I judge.
Once I balanced their output levels, I really began to appreciate the benefit of dual subs. I can't explain why, but my stereo imaging really opened up. The soundstage is huge and more balanced. I'm also hearing atmospheric sounds that add to the depth and realism of both music and movies. For example, I was watching a re-run of 30 Rock last night. There was a scene where Liz and Pete get on an elevator. While they were talking, I was able to clearly here the low-level hum of the elevator during the scene. That's the type of new detail I'm able to hear. Great stuff.
Anyway, I'm pleased with my new Kinda Dynamo sub and the new skills I've been able to acquire. I don't see any new upgrades in the future, but hey - I've said that before
