It's about time Dayton RS WWMT build.

[mmoeller]

Well I've lurking around this forum and the DIY events for a few years now and thought it was about time to get off my butt and try and build a set of speakers. Now I have to tell you it will be more of assemble it yourself build, but as you will see I am a rookie at wood work. The assembly should be an adventure.

I took one of the 3D sealed models off the site and transferd a cut list to a 2D .dxf file. This file is being fed into an industrial size CNC routing machine to produce some wonderful cutouts. I have my clamps and my glue, and my components are on the way. I plan on a nice natural cherry veneer to match my DIY home entertainment center.

I know I'm not on the cutting edge but I really loved these speakers and always wanted a set. We all have to start somewhere.

I look forward to all your input.

[HareBrained]

Input on what? We need some specifics or questions to respond to. You're just a speaker-tease, aren't you?

[mmoeller]

A little tease.

I was searching looking through the monster thread for some construction pics and such. I was planning on just gluing them together, but was curious if that was the best way to go. Going to do a little homework before I pester too much. I could post my DXF's if anyone was interested.

[don9146]

Definitely post the .dxf files. You'll find that everyone here likes as much information as possible during build threads.

Later,
Don

[mmoeller]

Here are the DXF files I sent. They are not the most clean files. The manufacturer told me to specify "outside" and "inside" cuts. These are contained on separate layers for the translation in to the machine code. There is an acces panel planned for the bottom rear of the cabinet.
I also specified the countersinks for the drivers. There are depths specified on a dimension layer. They were taken from the master thread. I will remeasure the acutal drivers prior to cutting. I also will attempt to estimate the thickness of the veneer I plan to use. One question, is it better to counter sink shallow or deep?
I am assuming that I would be able to add a sealing material and compress to the correct depth, so I would make the counter sink a tad deeper, but I am not sure. These are contained on separate layers for the translation in to the machine code. There is an acces panel planned for the bottom rear of the cabinet.


I should have the panels next wednesday, and the components today. I'm looking forward to digging in to the crossovers this weekend.

[orbifold]

Your best bet is to glue up a scrap of veneer on a pc of mdf, run a router over at a slightly light depth, (estimated) then test it with a scrap of seal material on the flange, assuming you have the drivers. You can then increase the depth as necessary to get the EXACTO correct setting for you particular stuff. There are several things you do that are best checked at the actual execution stage. The above test will show how sharp your router bit is also.
Sorry for the kind of Duh post, it's just that I remember how I should have done this myself, instead of estimating.
Also, my RS TMWW's drivers are in way too tight. I did piano black and after I put enough coats of Black on to polish, I had to put the drivers in using the machine screws to draw them in. The laquer made the recess a tad smaller. A full test with a hole, the driver, and the seal material would have solved that.
A process to apply for more than one issue. Also

[mmoeller]

Thanks for the insight. I'm also curious as to how the drivers are screwed in, and sealed. What do you use for a gasket? Did you use machine screws with T-nuts, and if so how? I thought about installing the T-Nuts and using long screws. Would they require a loctite bond?

Anyone?

[orbifold]

PE sells the gasket. It's 3/8" and about 1/8" thick, I think. But you can use weather strip from HD, etc. But it's kinda thick. The RS tweeters have a gasket attached if I remember.
I like machine screws and hurricane nuts, but they really should be anchored some way. If one spins, you are in for spending time on getting it out. I drilled a very small hole and put in a brad from the back on some. T-nuts never. Not for MDF at all. Epoxy I've seen applied to the back of hurricane nuts on some pics. But dont get it anywhere close to the threads.
No loctite would be needed.
Most guys seem to just use screws into the MDF using a pilot hole. I prefer the insert because MDF in compression is a solid joint. The wood screw into bare mdf fiber isn't as satisfying, I guess. Care in either case.

[mmoeller]

Thanks for the insight.

The tweeter does come with a gasket. I did find a thread that had some explanation about the type of screws used. I still haven't really made up my mind.

Going to start building my xovers today. Got a hot glue gun on the cheap. I'm going to look around to see how others laid them out.

[mmoeller]

I've been busy over Christmas.

I have almost completed the project. My father in law was here for the holidays and helped me with the wood work. We needed to cut the counter-sinks, and it proved somewhat difficult after the driver holes were already cut. The machined panels didn't have the countersinks.

Apart from that everything went together fairly well. I learned a few lessons, and have now mounted all the drivers, and crossovers. There in lies the issue.

One of the speakers sounds wonderful, very smooth as I expected. The other seems to have some problems with the tweeter. I verifyed the connections on the mid and tweeter. I even hooked a mid up out of phase on purpose to make sure I had it correct. It's hard to discribe. It seems very bright, but also distorted. I'm under the assumption that the "red dot" sticker is the positive on the RS28a. I would think that it may be that the resistor and inducter leg in Dennis' crossover circuit has been left open.

I have been able to switch back and forth between the towers. The "good" one performs very well at higher volumes, where the "bad" one doesn't.

I guess I could switch the tweeters from box to box to rule out the driver, before I go hacking up my xover. Have these drivers had any history of being defective??

I know I should be documenting better, but the pictures have taken a back seat. I figured work as much as possible when I had help.

[chrisn]

It could be a defective driver, or it could be the crossover. I would put the "bad" tweeter in the good cab and listen for a change. If your crossover isn't right, you may possibly damage the tweeter, and it would suck to damage both. Can you measure the impedance curve of the drivers, or for that matter, the speaker as a system? I had a similar problem, and it showed up in the impedance curve. The impedance curve wasn't drastically different with the crossover in place, but on its own became obvious. It was with a different tweeter, one that managed to defy gravity and hit the floor. Twice. Don't ask how, please

Do you have any pictures you could share of the build process and the completed product? I bought all the parts to build Curt's version of the towers, and so far have mangaged only to build a pair of TM's from the mid and tweeter, which sound quite good. I can't wait to hear them when complete. I am planning to build mine vented, which option did you choose for your towers?

Oh, it could also be a problem somewhere in the amp/pre/source and related paraphanalia (which I am sure I mispelled), though less likely. Try the suspect speaker on the opposing channel and see if things change.

Good Luck, hope you get it all sorted out soon so you can listen to some great music

[mmoeller]

I don't have a way to measure impedance curves of the speakers. I'm sure that would point to my issue.

Thanks for the suggestion about the source. I need to check the connections, maybe even reverse channels to see if one is not performing well on the "good" cabinet.

I'll try and take some pic's today. I've been trying to get them completed over the holidays. There was alot more work than I expected. We glued and clamped everything together. There was alot of time to wait for glue to set up. If I would do it again I would use a small gauge brad nailer and hold the thing together. It would have sped up construction.

[mmoeller]

I switched the bad driver to the good box, and it was still suspect. So the driver is most likely the culprit. The tweeter seems a little better now that I soldered all the crossover connections and verified connectivity. I still think the one is bad. It's not so much a problem anymore since I put my drill through the last midrange that I put in. I thought I had pilot holes drilled for everything, but I guess not. The screw toppled and the drill fell into the cone. OOPS!! There is a nice pic posted on the web page. So I ordered another mid as well as another tweeter to see if I get a better one.

I managed to get some foam from a JoAnn fabric at 50% off. That stuff is still expensive. I think the stuff I got is correct. It's a petrolium based product. I attached it with some generic spray adhesive. Very easy. It's amazing the difference between just clamping together and dry running and the final buttoning up of the enclosure. The tightness and efficency seems to be much improved. Even in the bad shape mine are in I can tell that once they are corrected completly they will be outstanding.

They are extremely heavy. I could guess they are a good 150lbs. I'm going to get a hand truck to get them up the stairs.

I haven't decided on the finish yet. I believe I'm going to see how smooth I can get the surfaces and try and veneer them. Possibly painting the bottom and back a nice black, to save a little money on the veneer.


Pics: (Photos Tab)

http://home.mchsi.com/~mmmoeller/wsb/index.html

I'd like to comment about the use of the CNC router technique. All the pieces were square and perfect. However, the way in which the construction was completed left somethign to be desired. I glued and clamped everything without using any brad nails. It was a very time consuming process and the dry glue adds some dimension to the box. There is alot to be said for cutting a little fat and flush triming. Next time I would assemble from the top down and use a brad nailer and clamps to help reduce additive gluing error. This only showed up with the last few pieces, back and top. One other thing we had to deal with is that the countersinks were left to be cut by me. The thing is that the countersinks specified need to be cut befor the THRU. Countersinks greater than 1/2" need to be done ahead of time. We had to open the holes on the front baffle to allow us to cut the countersink, after the holes were cut. I believe one of the pictures shows this on the woofer hole. The mid hole was done in the same manner, but the inner baffle was cut down as well.

[Jim Holtz]

Lookin' good Merrick! :T

Jim

[---k---]

Yeah, that is a pain to do the countersinking afterwards. Did your CNC guy just not want to do it, or was in an oversight? Seems like an easy thing for a CNC to do.

[mmoeller]

Yeah, that is a pain to do the countersinking afterwards. Did your CNC guy just not want to do it, or was in an oversight? Seems like an easy thing for a CNC to do.

Ya. He was just worried they wouldn't be the correct depth. I guess I can understand. I used a micrometer on them to make sure everything was correct on the actual drivers. The depths in the actual DXF files are just a note. I wanted to leave about 0.020" light to account for veneer.

[mmoeller]

Lookin' good Merrick! :T

Jim

Thanks Jim.

It's been a great experience. I hope there will be more to come. I will most likely build a center channel next if everything works out ok.