Build of Bagby Mandolin speaker

[Rick Sykora]

Hi folks! Have been sitting on these parts a bit while working on other projects. Now that I have some space, am gearing up. Am really interested to see how the Mandolin compares to others we have tested. Here is a look at the parts...

This is the base kit from Meniscus. Nice solid SB acoustics drivers with decent quality crossover parts. This all goes into a half cubic foot vented cabinet. The plans are on the light side, but include some interesting comments from Jeff. There is a contradiction between the plans and the drawing, so I had to make some design calls.

The written plans call for a double thick baffle (1.5 inch) and a braced cabinet. The drawing has a 1 inch thick baffle and does not have a brace shown. The thinner baffle with the brace seems the best combo to me, so cut the front baffle and painted with some wood glue on the back and added a layer of 1/4 inch MDF to it. Glue has set but will allow to completely dry before trimming. Will be doing a window pane style brace mounted between the woofer and tweeter. If it weren’t for the call for increased baffle thickness, would have been pretty happy building with the flat pack cabinet from Parts Express.

correction: the drawing does have a (barely visible) brace shown

 

[Rick Sykora]

after a bit of trimming, the 3/4 thick baffle is now 1 inch thick...

 

[Rick Sykora]

Ok, for those who want to build a simple cabinet, this one follows my same basic design. Just for fun, here are a couple of pics. One with the brace...

and one with the bottom...

I did not bother to draw layout as am not using full panels to build this one, but here is cut list (all .75“ thick except 1 inch thick front baffle):

back: 7 x 13.5
sides: 10.5 x 13.5
front: 8.5 x 15
brace: 7 x 9.75
top/bottom: 8.5 x 10.5

 

[Ron Texas]

Nice project, but you really have to love doing this with nothing but some loose parts and plans which don't agree with the drawings. Best of luck to you.

 

[Rick Sykora]

Nice project, but you really have to love doing this with nothing but some loose parts and plans which don't agree with the drawings. Best of luck to you.

Thanks Ron!

Shy of a fancy driver recess, find the cabinetry work pretty mundane. Running table saws and routers always keeps my blood pumping though. My favorite part is building crossovers and then hearing the final results. That never gets old!

 

[Rick Sykora]

Crossover in progress...

Input wiring is not complete and space in upper left is for a premium cap. Plan for it to be easily swapped with the Audyn (red one) in the tweeter circuit via switch.

 

[Rick Sykora]

After break to address house projects, getting back to this one.

Here is routed front baffle...

 

[Rick Sykora]

Crossover mounted, bottom glue is being attached, waiting on some dacron sheets to line cabinet as specified...

 

[Rick Sykora]

Looking at the mounted crossover, decided I wanted to better isolate the inductors on the right half of the board. So decided to reposition the the upper inductor...

 

[Kustomize]

A friend of mine is waiting for you build to complete! And get your initial impressions because you have tested a few DIY speakers now! Including the Zaphs I have!


I love what you are doing for the DIYers like me by all these designs, getting a chance to see them all being compared against commercial offerings! Thankyou!

 

[Rick Sykora]

If I was building these for myself, would have used some other damping material. I inch dacron is not all that common and so ended up ordering from Meniscus. Their price was pretty reasonable but paid just as much for shipping and ordered way more than I need for this build. Also was shipped USPS and is taking 5 days to get from them, UPS has run about 2 days....

While the ship time may be unusual, the cost issue is not. My advice is to make sure you order damping with the rest of the speaker parts if possible. While this should lower the cost to ship looser material, may matter less for others. The better Sonic Barrier needs to ship in flat sheets and so needs a bigger box to ship than fluffier stuff!

In any case, this one should be ready for a test drive later this week.

 

[Rick Sykora]

Stuffed!...

and glue is setting overnight for front baffle. Plan to wire and do final assemble in the morning.

 

[Rick Sykora]

Ready for some testing and listening!

Passed initial electrical and impedance checks. Was floored by the bass until I realized I had left loudness comp on.
Also passed a quick listening check, but need some more time to listen to more genres.
Will share the measurements once am able to measure the frequency response.

 

[Kustomize]

Wow. That was quick!!!

Can’t wait! Thankyou!!!

 

[wje]

Is that the same tweeter that Tekton uses in their builds, or from the same manufacturer? On their speakers, the tweeter has the same/similar dimple in it.

 

[Rick Sykora]

Is that the same tweeter that Tekton uses in their builds, or from the same manufacturer? On their speakers, the tweeter has the same/similar dimple in it.

If you are asking about the ring radiator in the Enzo, that one has a smaller faceplate and deeper back chamber than the one in the Mandolin.

 

[Mattcc22]

I'm interested in your listening impressions of these. They are on my short list of speakers for a build I will be doing for my Brother-in-Law. I'm kind of between these and a Dayton RS design or maybe something smaller/cheaper like the C-Notes.

 

[andreasmaaan]

Is that the same tweeter that Tekton uses in their builds, or from the same manufacturer? On their speakers, the tweeter has the same/similar dimple in it.

I suspect that the tweeters used in the Mandolin are SB29RDAC-C000-4 and that the tweeters used in the Tekton Enzo are SB29RDNC-C000-4, which IIUC share the same diaphragm, surround and basic design, but differ in terms of faceplate, magnet size/material, and back chamber volume.

 

[Kustomize]

I'm interested in your listening impressions of these. They are on my short list of speakers for a build I will be doing for my Brother-in-Law. I'm kind of between these and a Dayton RS design or maybe something smaller/cheaper like the C-Notes.

Go for these!

 

[Rick Sykora]

I'm interested in your listening impressions of these. They are on my short list of speakers for a build I will be doing for my Brother-in-Law. I'm kind of between these and a Dayton RS design or maybe something smaller/cheaper like the C-Notes.

It is a little hard to judge as have only one to evaluate. That said, they are quite a step above C-Notes. For me, the C-Notes are a decent nearfield monitor. The Mandolin was designed to be a stand-mounted monitor. If you can handle the woodworking, it is a much more solid performer (and value).