# Evan's BAMTM build.



## evan

It's cold outside so I needed something to do inside. I'm making my first attempt at some DIY home audio speakers with a pair of Zaph Audio BAMTM's. I didn't quite know what I was getting myself into but it's going well so far. 

Here are the pics to get you up to date.

Most of the cutting done. The 2L pop bottle is there for size reference.





























The parts list. (It works better if you get 8 feet instead of 4 :blush: )











Some Testing.


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## evan

I went over to a friends house to get some help with the crossovers.











The manlier version.





























Actual progress.


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## evan

The front baffle will be 1-1/2” thick.





























[off topic]
A quick break to take a picture of a recent delivery from Winnipeg. I’m still not sure what I’m going to do with it.









[/off topic]


Some assembly.





























That gets you pretty much up to date. I’m hoping to get a little done this weekend because I’m aiming for a completion date of 02/15/08.


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## bassfromspace

sweetness!


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## ///Audience

great work man! how long did it take you to use your router to flush mount the drivers like that?


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## evan

BassBaller5 said:


> great work man! how long did it take you to use your router to flush mount the drivers like that?


A little longer than I expected it would. I wasn't ripping through it too fast because I was trying to go easy on the router bits.

Here's the process I used:

-Install the jig on the router
-Measure material and layout center points
-Drill center point for the guide pin
-Set desired depth for the flush section
-I liked starting on the outside and working in toward the cutout diameter about 3/16" at a time (with the 1/4" bit)
-Once I reached the cutout diameter I adjusted the depth to cut through the material


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## ///Audience

ive always just used a rabbit bit with a custom short bearing or taken a piece of 1/4" MDF and glued that on top to make it appear flush and get the same acoustical properties of a flush driver.

Your way looks really good though!


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## jj_diamond

mini hot dogs, w00t!


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## kimokalihi

I can't believe you did that on those nice hardwood floors inside your house! I want my own house so I can do **** like that inside and not have to worry about someone bitching about it.


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## Abaddon

Looks REALLY good...

...this makes ME want to do this project.....


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## AzGrower

kimokalihi said:


> I can't believe you did that on those nice hardwood floors inside your house! I want my own house so I can do **** like that inside and not have to worry about someone bitching about it.


thats what I was thinking! imagine the dust clean up inside the house! I connect my shop vac with my router and I still manage to get covered in dust whenever making cuts.


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## AzGrower

BassBaller5 said:


> ive always just used a rabbit bit with a custom short bearing


That works somewhat, however if you want to do a wider section, I use the same method as posted, start on the outside and work in. This works great for mdf tweeter mounts


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## evan

kimokalihi said:


> I can't believe you did that on those nice hardwood floors inside your house! I want my own house so I can do **** like that inside and not have to worry about someone bitching about it.


Yeah, for a long time I was renting the basement but I just bought the house. The whole main floor is basically empty and will be like that until I can sand and refinish the hardwood this summer. ....but to do that I will need to replace the baseboards, and to do that I want to replace the interior doors, and if I do that I'll want to paint all the walls....  Yay for owning a house...

Edit: I should also mention that I taped off the heat vent and return air vent and I haven't seen or smelled any dust moving into any other rooms.


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## evan




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## aneonrider

Looking good fellow Saskie!


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## evan

aneonrider said:


> Looking good fellow Saskie!


..atchewan and atoon!


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## evan

Here's the bit I picked up to chamfer the woofer openings.




















To make the grills I cut an extra front baffle and then cut that in half. I sanded a bit off the sides so that they will fit nicely once they're wrapped with grill cloth.




















Here are the PE magnets I'm going to try.




















I cut out the middle with a jig saw and rounded the inside edges a bit with sand paper so that they are more invisible behind the grill cloth.


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## 60ndown

21" driver?



 woot


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## Sephiroth619

Very nice work Evan. You're getting me pumped to do a similar project. I have all the tools to do it, just lack motivation.


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## ///Audience

Man those look great! I read through this pretty fast, but im guessing the magnets are to hold on the beauty pannel?


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## bmaupin

evan said:


>


I just bought what looks like the same bit - an Irwin 1/2" drive bit - about 3.5" across. I was lucky and found someone selling it on eBay.

Cabinets look great so far. It is a good idea to brace the rear and front as well - even with the 1.5" baffle. I don't recommend going overkill on bracing - just some.


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## evan

60ndown said:


> 21" driver?
> woot


Naw, it's a Mach5 IXL-18.4.



BassBaller5 said:


> Man those look great! I read through this pretty fast, but im guessing the magnets are to hold on the beauty pannel?


They are for the grills. I'm hoping to be able to embed them into the speaker and finish over them but they will still show on the back side of the grills.




bmaupin said:


> I just bought what looks like the same bit - an Irwin 1/2" drive bit - about 3.5" across. I was lucky and found someone selling it on eBay.
> 
> Cabinets look great so far. It is a good idea to brace the rear and front as well - even with the 1.5" baffle. I don't recommend going overkill on bracing - just some.


I got that one from Lee Valley. I tried to find as many online reviews as possible and their bits seemed to do well in most comparisons and there's an outlet here in Saskatoon too.

I'm mostly following the plans that Krutke has on his website. The only way I've stayed so far is by doubling the front baffle. I'm going to do the bracing as per his plans and hopefully I'll get decent results.


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## Sr SQ

evan said:


> Naw, it's a Mach5 IXL-18.4.
> I got that one from Lee Valley. I tried to find as many online reviews as possible and their bits seemed to do well in most comparisons and there's an outlet here in Saskatoon too.
> 
> IQUOTE]
> 
> Very nice job!
> You cant beat Lee Valley bits for the money and they compete with the top dollar pieces. What are your plans for the exterior finish?


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## Oliver

Very nice work, Evan ! 


Bargain Aluminum MTM
October 6, 2006 - Initial preliminary posting
October 21, 2006 - Added the Options section



--------------------------------------------------------------------------------

Introduction
Every good project starts out with extensive driver tests to aid in the driver selection process and to help mate drivers with complementary characteristics. Referring to my 6.5" test group and the Tweeter Mishmash, this project is made up of a couple of the highest value drivers with great performance: The Dayton DA175 aluminum cone woofer and the Seas 27TBFCG aluminum dome tweeter. 

This design can be summed up in a few choice words - Cheap and simple with great sound. The Seas 27TBFCG is one of the best tweeters at any price, but thankfully only sells for $32. The Dayton DA175 can't be beat at $18 each, and it outperforms some woofers at several times the price.


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## chad

Man, if I walk in the house dusty my wife kicks my ass.

Project looks great! I may have missed it but what are the plans for the final finish?

Chad


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## MiniVanMan

Here's the link to Zaph's design. 

http://www.zaphaudio.com/BAMTM.html

And here's the link to the enclosure he's building. 

http://www.zaphaudio.com/BAMTM-cad-vented.pdf

Those are looking great Evan. Definitely keep up the good work. Looks like you're attention to detail and patience are way up there.

Thanks for sharing.


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## Oliver

Which tuning did you use ?

32 Hz... 69 mm
30 Hz... 83 mm
28 Hz.. 101 mm


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## evan

Thanks for the comments guys. For the finish, I think I'm going to try high-gloss black. It's going to be a pain in the ass to do but I really like the look. 



a$$hole said:


> Which tuning did you use ?
> 
> 32 Hz... 69 mm
> 30 Hz... 83 mm
> 28 Hz.. 101 mm


I'm actually building the sealed version he mentions under "Options".



> Options
> Sealed enclosure size options
> If you are not using a subwoofer and prefer a leaner but deeper bass, go for a larger sealed enclosure. You can go up 1 cu ft per driver - in other words, the same cabinet size as the vented box but sealed. The only limitations are that you must keep the design enclosure width the same. Get your extra volume by going deeper or taller.


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## evan

I installed some damping material today. A local guy recommended this product to me. He did some testing and found it to be almost identical to PE's Sonic Barrier, except without the attached adhesive. I got it from a local upholstery shop and one yard did both speakers as shown (sides and back except for bottom 6", and top & bottom). I liked the adhesive too, it's from Rick at RAAMaudio.com.


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## solacedagony

Awesome build, looks great! I can't wait til the weather gets back into the 40s or 50s so I can start building again. My dad flips when I even get the garage dusty so I have to cut out in the yard.


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## evan

Thanks solacedagony.

I installed the crossovers and hooked them up tonight. My girlfriend came home from work and found me working in the livingroom. She said "The workshop, the kitchen, now this... if there's ever speaker stuff in the bedroom you're dead!"  

Something I'd do differently: When we made the crossovers we cut the boards so that they would just fit inside the cabinets, but with damping material installed they didn't fit anymore. I'll cut them a bit smaller for my next project.


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## solacedagony

I'm really interested in a review of these once you get them done. I was considering building a set for a friend since he's got a tight budget.


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## evan

solacedagony said:


> I'm really interested in a review of these once you get them done. I was considering building a set for a friend since he's got a tight budget.


Funny you should mention that, these are for a guy I work with. 

They sound great except the bass is a little lacking. I think my opinion is a little skewed since I haven't listened to anything without a subwoofer in a long time and since he doesn't have one, that's how I've been listening to them. I've just been breaking in the woofers a bit and I'm going to talk to the guy I'm building these for to see if he wants me to try adding a vent. An extra $4 in port tube is no big deal, but it would be a pain in the ass to have to fix the hole if he decides to go back to the sealed version.


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## mtnickel

evan said:


> Funny you should mention that, these are for a guy I work with.
> 
> They sound great except the bass is a little lacking. I think my opinion is a little skewed since I haven't listened to anything without a subwoofer in a long time and since he doesn't have one, that's how I've been listening to them. I've just been breaking in the woofers a bit and I'm going to talk to the guy I'm building these for to see if he wants me to try adding a vent. An extra $4 in port tube is no big deal, but it would be a pain in the ass to have to fix the hole if he decides to go back to the sealed version.


That's what plugs are for 
I thought i read that zaph recommends just doing the ported version, and if it's too much for the room, just use one of those black rubber plugs.


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## mtnickel

mtnickel said:


> That's what plugs are for
> I thought i read that zaph recommends just doing the ported version, and if it's too much for the room, just use one of those black rubber plugs.


PS.
I should start a thread on my Zaph Mini-monitors. Although been busy with school, so they are held up at just the enclosure being built. Still need paint, some edge camfering, and crossover construction.


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## Sephiroth619

Evan, how's the midrange clarity and loudness of the woofers?

Would it be much difference to replace those Daytons with the Dayton RS180's?


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## evan

mtnickel said:


> PS.
> I should start a thread on my Zaph Mini-monitors. Although been busy with school, so they are held up at just the enclosure being built. Still need paint, some edge camfering, and crossover construction.


Yes, you definitely should.



Sephiroth619 said:


> Evan, how's the midrange clarity and loudness of the woofers?
> 
> Would it be much difference to replace those Daytons with the Dayton RS180's?


So far I've only heard them while they've been lying on the floor, but so far it's awesome. I was listening to the album I've probably heard the most in my life and I heard a few things that I didn't know were there. The loudness is hard to tell. I'd say they are on the quiet side so far, but I'm guessing things are going to change a lot once I get to set them up properly. I'm also going to try the vented version this weekend as soon as my order arrives from Solen. 

If you changed any of the speakers you would need to redesign the crossover too. That's one of the things that John emphasizes on his website because apparently he gets asked that a lot.


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## solacedagony

evan said:


> They sound great except the bass is a little lacking.


You're also using the sealed version of the project, not the ported, right? Did you model the ported and sealed and see what the difference in output on the bottom end was so you could see what you're losing?


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## evan

solacedagony said:


> You're also using the sealed version of the project, not the ported, right? Did you model the ported and sealed and see what the difference in output on the bottom end was so you could see what you're losing?


Yeah, John has that on the website.


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## aneonrider

hey evan, what shop did you pick up that dampening material from??


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## Aaron Clinton

*Looks awesome. Love your sub choice.*


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## npdang

Very nice work on the cabinets. How do you like the voicing on these? I've built a few Zaph designs and I do find them to be quite good.

One cheaper method I've found over the years is to use an active crossover to tune your speaker first, and then model the passive based on your experimentation. Saved me alot of time and money in parts.


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## buchaja

npdang said:


> One cheaper method I've found over the years is to use an active crossover to tune your speaker first, and then model the passive based on your experimentation.


I was wondering this very thing. 

Nice work Evan, thanks for this post.


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## cadaver

this build looks awesome. i loved the da-175s when i had a pair. the only weak point was the dust caps-they wouldnt stay on!


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## solacedagony

npdang said:


> Very nice work on the cabinets. How do you like the voicing on these?


x2, I'm about to build the L18 project.


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## evan

Thanks for the comments guys. I haven't had any quality listening time with them since the baffles still weren't adhered when I did the initial testing. I was mostly just checking to make sure I hadn't screwed anything up and that they were as Krutke intended. I'm in the middle of finishing them now. Hopefully I'll have them finished and reassembled by the end of this weekend.


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## evan

aneonrider said:


> hey evan, what shop did you pick up that dampening material from??


Must have missed this. I picked it up at Century Textiles on Avenue C. It was $34 for the yard.



I'm still not done, but here's a small update:

I picked up some adhesive that claims to work on wood, metal, and plastic so I'm going to use it for the grill magnets and the port tube.

I also broke out the router to flush the port tubes tonight.


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## Oliver

Nice job on the port !


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