After over a year lurking around the forums, researching and trying to learn as much as I can, I decided to finally put saw to wood and build a speaker cabinet. My first attempt is this THAM12 subwoofer loaded with B&C 12PS100-8.

I learned a lot in the process, and I'm absolutely thrilled with the results! This little speaker sounds amazing, and I can't wait to start building some top speakers to compliment this sub.

My ultimate plan is to build a "full stack" 4-way roots-reggae style soundsystem (using scoop style subs)...but I've got a way to go before I'm ready to start that project- lots more to learn, and money to save.

In the meantime my plan is to build a "mini" soundsystem using this THAM12 subwoofer with a pair of 2-way mid/top boxes with the goal of having a small, portable PA capable of entertaining groups of 25-50 people. The whole thing will be battery powered using LiFePo cells and inverter(s), and installed on an electric cargo bike that I built a few years ago. I'm fairly confident in the battery power part of the project (and that's a discussion for another thread), the part I need help with is choosing the right mid/top speakers to use with this project.

The mid/top speakers need to be small-ish and capable of being crossed from somewhere around 120hz all the way up to 18-20khz. I think something like the Soundgear Orbit 4 would be a good option, but since they are sold commercially I don't think that detailed DIY plans are available. The only DIY plans that I've found that look promising are https://www.eighteen.it/media/W1siZiIsIjIwMjIvMDMvMDkvMTlfMDFfMTNfMTU1X0tJVDhfMldBWV92MS5wZGYiXV0 - these 8" 2-way boxes from Eighteen Sound. Since I've only built one speaker, I don't feel like I have enough experience to try and design my own cabinet- I don't know how to use the simulation software, and I don't really have the time to learn as I'd rather focus on the woodworking, signal processing and amplification parts of the project. Does anyone have any knowledge or experience with the Eighteen Sound design...or maybe can recommend other DIY plans that I could build to compliment the THAM12 sub(s)?

Thanks for the help and inspiration!

-Eric

Trying to figure out how to post larger images:

I also built the simple amp rack to keep things organized.

I didn't bother to cut the circles out of the internal braces because the weight savings was negligible and I had limited time to work on the project

Cheers!

About soundgear orbits: lovely little boxes, light, pack a punch and sound nice, only downside is narrow dispersion. Very good for the money!!! Mate has four of them, amazing for what they are! But probably not an option for you due to geography?

You'd probably do best with getting some second hand small pa mid highs to get going. For a more ambitious diy option you could look into MEH (multiple entry horn) designs, also referred to as "synergy". 

Loads of discussion and designs over at diyaudio.com. 

Often copied, the syntripP is popilar, but might be a bit too large for your purposes.

Multiple people have suggested that I consider the VBS 10.2 from MTG Designs:

https://www.mtg-designs.com/diy-speaker-plans/vbs-10-2 - https://www.mtg-designs.com/diy-speaker-plans/vbs-10-2

The components are easy to source here in the U.S. and it would be a relatively inexpensive option to build a pair to go with my THAM. I don’t have any experience building passive crossovers, and this would be a good project to learn how to do that. My only concern is that it looks a little more like a Hi-fi speaker than a PA speaker…but for my use case it would probably work just fine.

Main thing is I just want to continue building and learning and finishing a few more projects before I attempt the larger stuff like scoops or SyntripP’s. 

Cheers, 

Eric

A forum member from the balkans did such a project. 

Would be very simple amd easy, perfect for a mini/compact application. 

https://www.martinsson.cc/blog/index.php?m=01&y=17&entry=entry170116-132709" rel="nofollow - https://www.martinsson.cc/blog/index.php?m=01&y=17&entry=entry170116-132709

If yes, why have you discarded it?
Thanks!

I did see those on Martinsson's blog. I think they would be a great option for backyard or camping style events, but I'm looking for something a little smaller that might be easier to transport on my cargo bike. Cheers

Unfortunately I have been very busy with work & family so I haven't had any chance to start building the mid tops yet. The parts for my Maslow 4 CNC machine came in the mail last week so I am very excited to get that all setup and working! My first project will most likely be some small speaker boxes...but it will probably be a month before I can get started due to the fact I have to leave town for three weeks of work.  

Right now I am planning on building either the VBS 6.2 or 10.2 from MTG Designs, or the 8-inch 2-way loudspeaker from 18Eighteen sound. I think all of these options would be relatively easy to build, and suit my needs well. The Eighteen sound drivers are a little more difficult to source here in the US for some reason, so I will most likely build the VBS design due to availability of sourcing the parts...and because I want to learn how to build my first passive crossover and MTG has plans (and PCBs) for that project as well.

Links to both designs are in my first post. When I finally get around to building speakers sometime around the end of April I'll post updates here. Cheers

I have considered the 12-inch coaxial plans from Eighteen Sound:

https://tinyurl.com/yyuscecm

The main reason that I choose to not use these plans is because the Eighteen Sound drivers are harder to source in the US, or cost extra to ship from Europe. Also, I don't think that I need 12-inch size for this project. Do you know of any coaxial plans that use 8-inch drivers?

Quick update on the mid/tops for this project: I ended up building a pair of 10" two-way boxes based on the https://hwww.mtg-designs.com/diy-speaker-plans/vbs-10-2" rel="nofollow - VBS 10.2 plans from https://www.mtg-designs.com/diy-speaker-plans" rel="nofollow - MTG Designs . They have a 10" woofer and 1" compression driver with horn waveguide. I also built my first pair of passive crossovers based on the plans recommended for this speaker, using PCBs from Matt's ebay page.

https://postimg.cc/F7LyyCYs" rel="nofollow">

https://postimg.cc/gXnRnxvT" rel="nofollow">

https://postimg.cc/tY8HfJRN" rel="nofollow">

I have a detailed https://www.avsforum.com/posts/63468327/" rel="nofollow - build thread posted over at AVS Forum if anyone is interested in more details about this build. Note: these speakers were originally designed for home theater use, but with some modification to the passive crossovers (as suggested by the designer) they have no problem playing reggae and electronic beats at high volume for hours and sound great with my THAM12...they are perfect for the mini-system that I wanted to build. I learned a lot in the process and now I can't wait to start my next project!

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Contour wrote: Nice job! Pretty complex crossovers it seems.

I didn't design the crossover, and I certainly would not have attempted to build them if not for the PCBs and detailed parts list/instructions from Matt at MTG Designs. This was my first crossover build and it wasn't too difficult. I think anyone with modest soldering skills can put one of these kits together without too much trouble. Not too expensive either, and they sound great!

KDW32 wrote: Looks awesome 😎 what do you have in your rack?

Thanks for the reply! My rack is all second-hand gear, and I'm always looking to add more amps whenever I can afford them. 

I currently have a Yamaha P2500s which is powering the pair of VBS speakers, and a Crown XLS 1502 which powers my THAM12 in bridge mono mode. I also have the older RANE ME15 graphic equalizer and AC22 crossover which I was using before I built the two VBS speakers. Now I'm using the low pass filter at 100hz on the Crown amp for the sub, and sending the full-range signal to the VBS tops. I recently acquired a dbx DriveRack PA which I will use for all signal processing as soon as I learn how to use it. I'm really excited to dig into what the DriveRack can do and start experimenting with it.

Ahhh this makes more sense now  I have never been a fan of the sound of driverack pa. If it's first your first dsp you will definitely learn a lot of good info experimenting