I originally posted this over at AVS (
http://www.avsforum.com/avs-vb/showthread.php?t=1161766). This was my first attempt at a DIY sub. I have been looking at the M&K subs for a long time now but as I'm still in college I don't have that much money to blow on a sub so I chose to go the DIY route. I originally had a Sony SA-WX700 which is also a Push-Pull sub. Basically this was an attempt to take the sound from that and go bigger and better.
This is the build thread for my Peerless Push-Pull (Non-Isobaric) sub. The original design thread was here:
http://www.avsforum.com/avs-vb/showthread.php?t=1147609
First off, let me start by saying this was my first real wood working project. This was the first time I’d ever done any finishing work, including painting. I mean I built a catapult for a school science fair in junior high but that was going on 10 years ago and that was all hand sawed. This was my first experience personally using a circular saw and a router.
That being said I am really happy with the way it turned out, the finish is nowhere near perfect but everything else turned out great. It seems to perform very well, granted I’ve never actually heard any high end subs, Bose doesn’t count nor should it. I’ve heard some Klipsch, Polk and Infinity at the big box stores but that’s about it.
Starting out my father just bought a router so I had that to use on the project. I was also able to borrow a circular saw. I bought one of these:
http://www.sears.com/shc/s/p_10153_1...ord=bora+clamp
to make a makeshift table saw and one of these:
http://www.sears.com/shc/s/p_10153_1...rd=drill+guide
to use as a makeshift drill press. The Bora clamp really came in handy when using the circular saw, the router and the jig saw. Along with those and a couple orders from PE and a few orders from McMaster Carr this is what I ended up with:
After cutting all the pieces I started out making the window braces. I tried the hole saw in the corners method and that really sucked. I tried going slow as suggested here and no matter what I did the teeth kept getting gunked up and burned the wood.
I went back to Home Depot looking for something better and came across a Forstner bit. Man is that thing nice, it turned a three minute job into a 30 second job. I did 48 holes with that thing, 8 of which were through 1-1/4” MDF and it is still sharp. It turned the MDF into confetti and no burning what so ever regardless of drill speed.
I then used the Bora clamp and a jigsaw to cut between the holes. These were the final products:
I had decided from the beginning to make the walls thick. I decided to clamp and glue 1/2 inch MDF to 3/4, this would also allow me to flush mount the Peerless 830952 drivers. I cut the hole in the 1/2” bigger than the hole in the 3/4” and this is how the front and inner speaker baffles turned out:
After that I decided to cut groves in the front and rear walls of the box to put the braces in, made assembly easier.
I decided to use EZ-Lok threaded inserts instead of T-nuts. I read about the problems with the T-nuts and I saw the thread discussing how to glue them to the wood so they wouldn’t back out when removing the drivers. Because of that I decided to give these a shot and I think they worked out really well. These wouldn’t hold a Maelstrom but they do make them with different lengths. In this shot you can see the threaded inserts around the lower speaker baffle and around the edge where the removable bottom goes:
Assembled:
Prepped for paint with 3/8” round overs all around except for the bottom edge where I used an 1/8”:
Now this being my first time working with MDF I did not know the end grain was going to be such a problem. I put wood filler on the exposed ends and sanded them down even but in doing so in some places the end grain reappeared. These spots became a nightmare when trying to put primer on them. I tried to build the primer up as much as possible on these areas but sadly they did end up showing through with the final finish. I used Rustoleum textured black paint which I hoped would help hide some of the flaws. Luckily the bad spots are not horribly noticeable.
Old v.s. New (Sony SA-WX700 v.s. Peerless Push-Pull)
It isn’t in its final position in these pictures, it was in the living room for testing. It is now in my 1100 cubic foot bedroom hooked to my Denon 2808-CI and is more than enough bass for me. Hopefully I can get a hold of a Behringer ECM8000 so I can quantify the results.
Question: Does anyone else have experience with push-pull subwoofers like those of M&K? There is a high pitched squeaking I think may be coming from the sub when pushed hard. Either it’s something else in the room or both this new sub and my old Sony made the same sound. I just wondered if it was possibly a sound coming from the exposed driver as I know Michael Hurd mentioned I could have a problem with motor noise and I wanted to know if that’s what I’m hearing.
Thanks again for your help Penn, tlag, Mr. Hurd, and Mayhem13.
