BeerParty AviaTrix TM Build

So, I'm building some AviaTrix TMs using the plans from Curt C. These will replace/supplement the AviaTrix MTMs I have already. I have a build thread for MTMs over on the HTGuide forum, I'm posting this build here to 'spread the love' as it were.

The build started out as a set of speakers for my living room. The MTMs are too large for the entertainment center (ok, ok, the truth is they scored too low on the WAF) so I thought the TMs would be a better fit.

I built a pair of cabinets using some left over 1/2" MDF and 1/2" plywood for the front baffles:



Don't worry, this is a build thread, just not a typical build thread.

to be continued...

Edit: After seeing all the posts and pictures it took to get to the point, I decided to took too long. So here it is:

I'm building three pairs of cabinets, one pair using 1/2" MDF, one pair using 3/4" plywood, and one pair using 3/4" melamine. I am getting enought parts for 4 crossovers and plan to compare them (in pairs) side by side.

As you can see the cabinets were already done. Then I read in another thread some concern about using 1/2 material for the AviaTrix MTMs. I don't know if it would be an issue with the TM, but I figured it would be a good idea to find out. So I acquired some 3/4" plywood for another set of cabinets.

And, this time I took pictures during the build. Starting with the obligatory wood pile...



...and the first glue up:

Gluing the backs and bottoms on.

This picture is for Passing Interest, he and I have the same attitude when it comes to clamping (more is better):



A couple of other views:

Gluing on the other side:



...and the front baffle...

Set up the router table with a straight trimming bit, and cut down all the edges flush:

Before:





After:

This is where things get interesting.

I used a handy panel (3/4" Poplar) and got all the pieces for both TMs. For those that aren't aware, handy panels are 2 foot by 4 foot panels sold at the big box stores. They fit perfectly in the back of my car. My truck was in the shop and when I got it back, it rained for three days straight. I took it as a sign that I shouldn't be so picky about the wood I use. Thus the Poplar handy panel.

When I finished the new cabinets I set them up for this picture (new 3/4" cabinets on the left, 1/2" cabinets on the right):



It occurred to me that with a few 'borrowed' parts from the MTM and another set of crossovers I could run both pairs side by side, compare the two, and figure out for myself if the 1/2 inch material is going to be a problem. So a quick trip to Parts Express and another few bucks charged to the ol' credit card and I'm back down in the basement.

I looked at the cabinets and thought about the new build. I was going to start cutting out the driver holes when I had a thought....

The thought I had?

The new cabinets were build entirely from a 2'x4' handy panel, and I had a 2'x4' piece of melamine in my wood pile. I wonder how a pair of AviaTrix TMs built with melamine would sound? I was planning to compare the 1/2" build the 3/4" build, so it wouldn't be that hard to compare a third set of speakers. Would it?

So, one thread - two builds...

Melamine cut and labelled:



The lines I use to align the pieces are more visible on these pieces. I like to draw out the internal lines before I start the glue up. I have enough non-square boxes in the scrap pile to know I need to pay attention to keeping things square.

And gluing up the pieces again:



I went to all the trouble to mark up where the pieces should go, and then after the first piece was glued on I realized I had mis-measured for the backs. Oh well, at least I caught it before I glued the back in:

And this is where I am now (9pm Sunday night):





The front baffles are going to have to wait until I figure out how I'm going to attach the drivers. The melamine will not hold standard wood screws well enough, so I am thinking that I'll drill out holes where the screws go and glue in dowels. They should provide enough grip to hold the drivers without having to use T-nuts. Once with the T-nuts was plenty, thank you.

I have enough crossover parts for a pair of speakers, but I'll probably wait for the other parts and build all four at the same time.

My main concern is that I'll be installing/removing the drivers several times as I try out different pairs of speakers and I am not sure how well the holes will hold up (even with the glue). If I use hardwood dowels I know I will not have a problem.

But, I'll try that on some melamine scrap I have and let you know how it works out. Thanks for the suggestion.

So, I received my order from Parts Express and set about building the crossovers. I ordered extra parts so I could build 5 crossovers, I'll switch between them and make sure they all sound the same before I start comparing the boxes. This OCD is getting a little expensive...

I cut some pegboard for the crossovers so they would fit in the bottom of the cabinet and go through the woofer hole. After that, I followed Curt's drawing as close as possible since I am a complete noob when it comes to this stuff.



And here you can see one of them in a cabinet:



I still need some connectors for the wire ends and Velcro for installing the boards but the hard part (for me) is now done.

Earlier this week I decided to install the last panels on the Melamine cabinets and test out "screw solutions" on some scrap. PI's suggestion would make things much easier, so I'll try that first.



Unfortunately the whole family has come down with the flu, so I don't know if I'll be able to work in the basement this weekend. If I feel well enough, I'll trim down the edges and start cutting holes this weekend.

I'll be stealing some parts from my MTMs to put together two pairs of the TMs, but I think I have enough parts to run a pair of MTMs and a pair of TMs at the same time. I'll put it on my list of things to try when I have everything ready.

Thanks for the suggestion!

So do I. Everyone seems to be on the road to recovery, so hopefully we will be 'functional' again tomorrow.

I was able to get down into the basement and work a little more this morning. I got the holes in the back of all the cabinets cut out for the terminal cups, and I drilled the screw holes in the melamine and filled them with glue per PI's suggestion. I'm giving it a few hours to harden then I'll try the screws again to see how well the chipboard inside the melamine holds up.

I'll take some pictures to post later.

So, my test pieces with glue in the holes seems to hold up OK, so that is what I am going with. I started with the backs, cutting recesses and holes for the terminal cups:



and then repeated on the other new boxes. Here you can see a couple with the terminal cups in them for reference:

I didn't document the process when I cut the holes for the terminal cups, but I remembered to take pictures when I cut the hole for the tweeter.

I put blue tape on the melamine because the pencil marks didn't show up well. Once I had the pencil marks in the right place I went over them with ink before drilling the holes:



I tried cutting with the blue tape still on, but the spiral up-cut router bit pulled the tape off the cabinet and gummed up the Jasper jig.

I measured the tweeter flange and set the plunge router so that the highest notch would cut the right depth. Then, I made two passes for the through hole so I'd have a reference circle deeper than the flange thickness:



Then I reset the router to the highest notch and started widening the cut for the tweeter flange:



The bit does a fairly good job of cutting the Melamine without chipping, but just to be safe I cut a circle 1/32" smaller than the final size and then cut the final circle:

The tweeters in the AviaTrix need notches for the connectors. In the originals I just used a Dremel tool to grind them out, this time I wanted to use the plunge router for a somewhat more even notch.

So I marked the spaces:



Then I used the plunge router to cut the holes:



Not a smooth as I had hoped, but a lot better than what I got with the Dremel. A little work with some sandpaper to cut the sharp edges and it will work fine.

Reset the cut radius for the through hole, and after two more passes (1/4" deep each time) the center is gone:



It fits!



If you look close you'll see there is a bit of a gap, but this is as close as I can get. The tweeter is just sitting in there for now; once it is centered and drilled in I don't think the small gap will have much of an effect.

The mid driver is flush mounted, so there is nothing special about cutting the hole. Just set the Jasper jig to the correct cutting width and make multiple shallow passes. Here is a test fit after cutting the hole in the first cabinet:



Repeat on the other cabinets and here is where I am as of 6pm Sunday night:



If I can keep up this pace, I'll have several ready for the New England get together on the 15th.

I don't know how long you are willing to wait, but I should be able to provide a hands-on comparison of the MTM vs. the TM before the end of the year.

...and from the posting I saw from Exojam's get together, I'm very jealous of his setup. Maybe I subconsciously want to duplicate a part of it?

So, I have been struggling with a dilemma all this week. I had planned to using my 3/4" round-over for the cabinets, as it leaves more 'meat' in the corners, even for the 1/2" material as you can see here:





The problem is the melamine cabinets. If I just cut the corners on them, I can finish them with some speed tape. But then these cabinets don't match the other cabinets I want to compare too. If I round over the corners like my other cabinets, finishing becomes a lot more difficult.

I though about just cutting the corners on all the cabinets, but that would create an unfair disadvantage to the 1/2" material since it would weaken the front baffles. It also means they wouldn't match my MTM, since those cabinets have a 3/4" round-over already.

In the end, I decided to go with the 3/4" round-over across the board. Of course, I made a minor goof on the melamine (the hardest one to patch ) which you can see here in the left hand corner. It is going to take some work to fix that one.