Modula MT

[derekbannatyne]

I just got back from vacation and I've decided to build some speakers sometime this month. I've got $250 to build a pair of speakers (boxes/finish included), but I'm not sure of what to build yet. They will mainly be used for music listening because my Athena Point 5s that I have right now aren't very satisfying for music. I was thinking of building the Modula MTs

[KeithM]

The Dayton III was good, but the dayton RS projects put them to shame. Look in the Mission Accomplished forum here and look at the Natalie P or Modula MT, maybe the modula MTM. They might be a bit more expensive, but the results will be better. Also I think your receiver could handle those impedances.

[jkrueger]

Great place to start

I am pretty new to this forum, and to speaker building. I have built the Dayton IIIs, and I can only compare them to my new B&W 603 S3s. I prefer the Dayton's, and when I came to that realization I was shocked. I am sure that the Mission Accomplished speakers are even better (I plan on building a few of them soon), but you just can't go wrong with a cheap set of speakers as good as the Dayton III's. Go for it. :T

[derekbannatyne]

Thanks for the responses, I might just go for the Modula MT. It's great to know that even the Dayton IIIs compare to speakers that cost that much! I could probably build the Modula MT with the Seas TDFC for around $250 if I don't spend as much on the crossover parts. It seems the caps and inductors seem to take up the most money. For the caps, could I just combine some of the GE Polypropylene caps (ex. 10uf + 10uf to make 20uf)? And for the inductors, what gauges do I need to use? It says under the mH value on the crossover schematic .2ohm for the 2.4mH and .1ohm for the .22mH. Does that mean the DCR can't be higher than that, or is there a slight tolerance for a DCR above that? Thanks for the help!

[WillyD]

I can definitely recommend the Modula MT. I absolutely love my pair.

And yes, you can combine those caps. Not sure about the inductors, but I think its best to use the higher gauge (16, 14, etc) if you can afford them. Not sure though.

[nerd of nerds]

Bad bad idea!

The tweeter used in the D3 has since been replaced by a new and slightly improved version. this cross over most likely won't work right with the new driver and it wouldn't sound nearly as good as it could.

[Dan B]

I've built both and think the extra money spent on the Modulas is well worth it. Especially considering the time that is put in to building a speaker. I think my perspective on value has changed. When I built the D3s I was happy with building the best sounding speaker I (a blue collar shmuck) had ever heard, for 150 in parts. But with the Modula I think I've got a speaker better than most audiophiles have heard for not much more! The only concern I had, was the RS 180s responce at the top end, when I read about how Jon had dealt with it I was ready to build.

I sure did enjoy my D3's though

http://mysite.verizon.net/res6vgmm/danspage/id8.html

Have fun, Dan B

[derekbannatyne]

Thanks, it looks like i'll be building the Modula MTs(with the 27TDFC) now. I'm trying to keep the whole project under $250, so I'll have to use budget crossover components.



Modula M/T BOM

(2) RS180 woofers $32.70 each $65.40
(2) Seas 27TDFC tweeter $30.80 $61.60

Caps:
(4) 20.0 uF GE Caps (10uf + 10uf) $2.80 $11.20
(2) 16.0uF GE Caps (10uf + 5uf + .68uf + .33uf) $2.55 $5.10
(2) 8.2uf Dayton caps $2.75 $5.50
(2) 3.0 uF Dayton caps $1.67 $3.34
(2) .68 uF GE caps $0.30 $.60

Inductors:
(2) .22 mH(.1 ohm) Sidewinder 16awg $4.10 $8.20
(2) .5 mh 19awg $7.00 $14.00
(2) 2.5 mH(.2 ohm) 15awg SH $11.20 $22.40

Resistors:
(4) 8.0 ohm Eagle Metal Oxide $1.20 $4.80
(2) 6.0 ohm Eagle Metal Oxide $1.20 $2.40
(2) 2.0 ohm Eagle Metal Oxide $1.20 $2.40

Misc:
Fiberglass Insulation (already have)
(4) Binding Posts $1.45 $5.80
(2) 2" Adjustable Ports $1.95 $3.90

Total $216.64 + S/H($9.53 from PE & ?? from Madisound)

Does everything in that list look alright? For the .5mH inductor value, is it alright if I use that 19awg inductor? I assumed it was since it didn't have a DCR value next to it. And is it alright if I use this foam(cheaper) instead of the eggcrate foam from PE? Thanks!

[derekbannatyne]

Changed the title.

[ThomasW]

You can use fiberglass insulation it's cheaper than any foam. The foam in the link is to thin unless you plan on using several layers, then it will be fine.

Instead of paying for the expensive flared ports you can use regular PVC pipe

[derekbannatyne]

Great, thanks that should save me a few bucks. How much fiberglass should I pull off of the R13 stuff I have(3.5")? Thanks!

[ThomasW]

Like you did with the sub add it to taste. Too much and the efficiency goes down. Not enough and the sound won't be 'tight.

[derekbannatyne]

Thanks! Just placed my orders for all the parts a minute ago. Here's a list if anyone wants to copy my budget BOM:

Parts Express:
027-418 2 DAYTON DMPC-3.0 3.0uF-250V POLYPROPYLENE $3.34
027-426 2 DAYTON DMPC-8.2 8.2uF-250V POLYPROPYLENE $5.50
260-387 2 PORT TUBE 2" ADJUSTABLE PORT $3.90
295-364 2 DAYTON RS180S-8 7" REFERENCE SERIES $65.40
Total: $78.14

Madisound:
2 Eagle- 2 ohms $2.40
2 Eagle- 6 ohms $2.40
4 Eagle- 8 ohms $4.80
2 27TDFC (H1189) Textile dome $61.60
2 G-POSTBL Binding Post Black $2.90
2 G-POSTBL Binding Post Red $2.90
10 GE 10.0 mfd 40L Poly Cap 400V $14.00
2 GE 5.0 mfd 40L Poly Cap 400V $1.50
4 GE 0.68 mfd 40L Poly Cap 600V $1.20
2 GE 0.33 mfd 42L Poly Cap 850V $0.80
2 2.5mH 15 AWG Steel Laminate (.164 ohm) $22.40
2 Sidewinder 0.5mH 16AWG (.22 ohm) $14.00
2 Sidewinder 0.22mH 16AWG (.14 ohm) $8.20
Total: $139.10

Total Total: $217.24

[derekbannatyne]

Hm I placed my order on Thursday, but I still haven't gotten a confirmation email saying it has been shipped yet, should I let them know? All my other orders have had shipping emails the same day or the next.

[jdybnis]

Why post that question here and not on the parts express message board? Or just call them?

[WillyD]

Hm I placed my order on Thursday, but I still haven't gotten a confirmation email saying it has been shipped yet, should I let them know? All my other orders have had shipping emails the same day or the next.

I've had that happen and I thought they weren't shipped, but it was just PEs website for whatever reason, not updating its info.

[derekbannatyne]

I've had that happen and I thought they weren't shipped, but it was just PEs website for whatever reason, not updating its info.

Ok great thanks!

[WillyD]

Ok great thanks!

yeah, I think I even called them up. The customer service rep I spoke to was really nice, and she said my order had indeed been shipped.

[derekbannatyne]

Yep, their system just forgot to send me an email, I called and my order is supposed to be here tomorrow!

[derekbannatyne]

My parts arrived!

[ThomasW]

Hey look, somebody's going to build some really cool speakers... :T :B

[Exocer]

Cool cool. Now go ahead and build em already :T :P

[jdybnis]

Better hide those cored inductors before Jon gets back.

[WillyD]

Like they said...build them now! :twisted:

[derekbannatyne]

All right all right here you go:

[ThomasW]

Looking good....Your speaker making skill have certainly advanced in the last few months..... :T

You're going to be VERY impressed with the performance of these speakers.... :B

[derekbannatyne]

Haha I don't know if my speaker making skill is up there yet, I recently learned that soldering irons are VERY hot.

[WillyD]

Is this your first xover building experience? If so, not bad at all! I remember the excitement of hooking the xover and the drivers up, even before they were in the cabinet. It was a fantastic moment.

Edit:And what an upgrade (from Athena Point 5s to Modula MTs) that will be. :E

[derekbannatyne]

Thanks, this is my first crossover. Haha I'm preparing myself to be astounded. The top side of my crossovers look all pretty, but the back side is realllly messy. I was wondering if someone could check if it's all wired correctly?
Here's how I planned it out:



But here's how it turned out:



I wired it according to the diagram, but I'm not sure if it's alright to just group all the wires together in one place and then just lead a wire from that. Could someone check it for me please? That's how I wired all of my other crossovers. They seem to work fine(all higher frequencies come out of the tweeter, and vice versa.), I just want to make sure it's all wired correctly. Thanks!

[derekbannatyne]

So far they sound good! I haven't added fiberglass or anything but they work!

[opt-e]

So far they sound good! I haven't added fiberglass or anything but they work!

Looking good man! :T I just ordered parts for a pair of Modula MT's myself.

[derekbannatyne]

Thanks! Just put the fiberglass in and everything sounds great! Listening to them right now, but I need to get some (or build some) speakers stands for these.

[Exocer]

Lookin' very good!

[derekbannatyne]

I'm going to veneer the cabinets and paint the fronts black like the PE cabinets, but I'm not sure where to get the veneer. I was looking at tapeease veneers because of the low cost and ebay. Is it safe to buy veneer off of ebay? They seem to have really good prices and all of the sellers have good feedback, I'm just wary cause I've never bought anything off of ebay before. Thanks.

[ThomasW]

With all the rounded edges veneering will be quite trickey.

I've had good luck getting stuff from ebay as long as the feedback was good.

[derekbannatyne]

Thanks, all of the veneer I was looking at was being sold by ebayers with about 100% feedback. I'm going to just veneer the sides, tops, bottoms, and back of the cabinet (not rounded over) so it'll look like the PE cabinets. Any tips on getting a nice gloss black finish? I've read that I should use a fine foam roller and sand with progressively higher grit sandpaper in between layers, all the way up to 2000 grit and use auto body polish to get a nice sheen. Does that sound about right? Thanks!

[derekbannatyne]

I just bought some veneer, curly maple and curly anigre(about $50 total including shipping for 84sf). I'm going to use the curly maple for my speakers and then build speaker stands/component rack with the anigre. Here's the maple:

Image not available


and here's the anigre:

Image not available


Does anyone have any staining recommendation for the maple? I'm trying to go for a nice golden color, like birdseye maple. I also want to put a glossy finish on top of it, I bought some 600 and 2000 grit sandpaper; any tips? Thanks!

[yousuredo2]

deffinatly try out on some scrap peices first...
I Love toung oil...some more work, and upkeep but man, It looks good...
It realy makes the grain POP out at ya...

[ThomasW]

If you use a stain, before you stain apply a sanding sealer. Otherwise you'll have blotches in the finish.

I'm lazy so I use the solvent baseed clear poly. It slowly turns a nice amber/yellow color over time...

[derekbannatyne]

Finally finished!



It's a piano black front with lacquered curly maple sides.

[jonathanb3478]

Very nice finish on the baffles. What brand/type of paint did you use? I plan to use Benjamin Moore enamel, "133".

Is this what you did?

I've read that I should use a fine foam roller and sand with progressively higher grit sandpaper in between layers, all the way up to 2000 grit and use auto body polish to get a nice sheen.

[derekbannatyne]

Thanks, actually I used this writeup: http://www.diyaudio.com/forums/showt...141&highlight=

I used a 50/50 mix of yellow glue and water for sanding sealer (2 coats), followed by about 6 coats of cheap black spray paint from Wal-mart. Then I sanded that to 600 grit, put 3 coats of Rustoleum Gloss Black Enamel, sanded that to 600, then around 8 coats of Rustoleum Crystal Clear Enamel. Then I sanded that to 2000 grit to get rid of all the blemishes, and applied Meguiar's Scratch X to get rid of all the fine scrateches, then Meguiar's Deep Crystal Polish and Carnuba Wax. Took awhile but I think it turned out pretty good.

[syzygylock]

Hi all, I'm a newb and is confused as to what fiber glass will do and where to add it. I was able to follow the build steps, but I think I miss something when you guys mention fiber glass.

[JonMarsh]

Fiberglass could be used for acoustical damping of the midrange back wave. A preferred solution is Acousta-stuff or similar Dacron polyester, loosely stuffing the area behind the midwoofer, with damping pads like Whispermat on the rear and side walls. Don't have any damping material near the port exit in the enclosure. Checkout the ModulaMT build thread in Missions Accomplished, there's about a bazillion posts. Couldn't believe so many questions might come up! :W

[zzzz]

Good looking work on the MTs! I just started cutting my MDF for my own pair last weekend, no drivers or anything else yet. Came to an end when She Who Must Be Obeyed started searching for me.

One quick question - I noticed a pair of "notches" being cut into the circle in which the tweeter will be mounted. Why the "notches" - the tweeters appear be round. Is there a good way to cut the "notches" other than with a jigsaw?