About to Start Modula MT Project - Have Questions

[Troy R]

I'm going to take my first shot at a DIY speaker. I've built a few subs, but I've always wanted to try speakers. I want something low cost and I've read a lot about the Modula MT so I figured that would be a good start. I have the mids, Seas 27TDFC tweets, but I still need to buy xover parts. I'm a bit "nervous" about putting together my first xover, but we'll cross that bridge when I come to it. First, I have a few questions before I get started on the enclosures.

Can I make the Modula MT a small floorstanding speaker? Or does the height of the baffle matter? I know the width is important...

Is the internal volume .82 cubic feet the correct internal volume before adding the port and drivers? Or is it .75 cu ft?

I've been tossing around the idea of making a curved sided cabinet and was wondering what would be suitable material for the sides? I've seen the "wiggle wood" used but what does that stuff usually cost? Could hardboard (pegboard like material) be used?

I've seen the word masonite thrown around here a lot, are hardboard and masonite the same thing?

Thanks in advance for any help! :T

Troy

[ThomasW]

Yes you can make it a floorstander. There's little benefit to doing this other than not needing stands.

The stock PE box has a gross internal volume of .75cu ft

Wiggle wood is very expensive. Last time I bought it (many years ago) it was $50 a sheet.

Masonite is a type of hardboard.

[Troy R]

Thanks for the reply Thomas!

Yes you can make it a floorstander. There's little benefit to doing this other than not needing stands.

I'm only doing it so I don't have to mess with stands.

The stock PE box has a gross internal volume of .75cu ft

Wiggle wood is very expensive. Last time I bought it (many years ago) it was $50 a sheet.

Masonite is a type of hardboard.

Thanks for the info!

So would multiple layers of the hardboard be a sufficient side panel? I'm hoping the 1/4" stuff will make the bend, if not then 1/8" will do.

Thanks again!

[Dennis H]

So would multiple layers of the hardboard be a sufficient side panel? I'm hoping the 1/4" stuff will make the bend, if not then 1/8" will do.

Sure, that will work. I saw a pic, but can't remember where now, where someone alternated layers of solid masonite and pegboard for curved sides. I thought it was a slick idea as the excess glue squishes into the holes in the pegboard.

[Troy R]

Sure, that will work. I saw a pic, but can't remember where now, where someone alternated layers of solid masonite and pegboard for curved sides. I thought it was a slick idea as the excess glue squishes into the holes in the pegboard.

That is a pretty good idea. I like it! :T I think I'm going to HD or Lowes tonight to brainstorm.

Should I just use wood glue for layering the side panels? I have some Tite Bond II. Or should I use something else.

[JoshK]

yeah, that will work fine. I like using my glue roller (glue bottle with roller pad) for spreading glue about.

[Troy R]

Thanks for the help, guys!

I really have love/hate feelings with this site. It's so helpful but it makes me want to build, build, build! 8O

[berlin07]

Can I make the Modula MT a small floorstanding speaker? Or does the height of the baffle matter? I know the width is important...

I just finished the Modula MT as a floorstander (internally closed off at .82 cu ft) and I can assure you they sound great. :T I'll be posting picks soon.

[Troy R]

I just finished the Modula MT as a floorstander (internally closed off at .82 cu ft) and I can assure you they sound great. :T I'll be posting picks soon.

Please do post pics. I'd really like to see pics of them as a floorstander. I can't wait to start building. I'm curious how they will sound compared to my Dynaudio's.

[berlin07]

I'll start a thread and post better/more pics when I have some more time.

[cgr]

Just curious on your impressions of the MT vs MTM. Which crossover is in the MTM?

[berlin07]

Which crossover is in the MTM?

It's the Natalie P.

Just curious on your impressions of the MT vs MTM.

I just finished them yesterday so listening time and break in are limited. That being said they are both great but Natalie gets my vote. Slightly more detailed with an open sound stage not to mention it can play
louder. :twisted:

[Troy R]

I'm digging this thread up from the grave. I started to build the Modula MT many years ago but my needs changed so I built the Modula MTM instead. Well now I am getting around to building the Modula MT again...

I have a question on the Seas version Xover. Are there rules for steel laminate inductor placement? I took a picture of what I plan to do. Will this layout work or do I need to turn the inductors at all? Thanks!

The values are:
Steel Laminate 2.5mH inductor, 15 awg
Sidewinder 0.22 mH Air Core Inductor 16 AWG

[JonMarsh]

That should be OK- the core tends to concentrate the flux and there's less radiation/coupling at a distance than for an air core inductor. What kind of power level is that steel core inductor rated at? I've found I get the best results if high grade core inductors are used at less than half their rated power- soft saturation and increase in distortion usually kicks in above that. You probably will have no issue with this size system.

[Troy R]

Thanks for the reply! I'm not sure of the power level of the inductor. this is all the info I have on it

http://www.madisound.com/catalog/product_info.php?manufacturers_id=139&products_id=863

[JonMarsh]

Yeah, that's hard to know, when they don't publish any spec, unless you can measure for yourself- which I've done from time to time. For a smaller system like the Modula MT, should be OK. Nice size and DCR, of course. The originals used air core inductors, but those are pricier.

[Not2Evil]

It looks like there is exposed copper on the top part of the sidewinder inductor. Is that just from the camera, or are there some defects?

[1Michael]

It's the lighting...