Seos 12 Faitalpro 8"MTM 12" Subwoofer Towers

[JavadS]

Everyone thank you for the feedback in another thread about my first pro woofer project, I wanted to post my latest configuration and my initial progress. I've done dozens of builds with audiophile raw drivers like Vifa, Morel, Dynaudio, Peerless and Dayton drivers, but having recently gotten back into speaker building wanted to try some of the great new pro driver options out there.

These speakers are solely intended for 2 channel audio. I wanted to build something very loud, dynamic, transient and clean with flat response, home audio drivers sound good at reasonable volume levels but aren't very efficient and don't always have the fastest transient response or "attack". P

lus it will be a new experience and I'm sure to learn some stuff. =)

The Drivers

Initially I was thinking a build with the Seos 12, a decent horn driver, a 12" mid and 18" pro subwoofer. After spending weeks researching/modeling different drivers and options, I finally settled on the following: Seos 12 horn with B&C DE250 compression driver



Dual Fatal 8FE200 8" in MTM configuration, final impedance 4ohms, price is right and they were well rates and had good response too, also the smaller drivers should reduce issues with lobing.



Magnum 12" Subwoofer from DIYSG, I nauseated over this choice the longest, I wanted 18" initially because well, they're freaking cool and I was really eying the B&C 18TBW100 but ultimately decided I really didn't need that much bass (I know, some of you are ROFLing right now), plus I can always build some bass modules later on if I want. I was hesitant on the Mag 12 as I really wanted to use something with an accordion surround, I was down between the Kappalite 3012LF as it modeled really well and very close to the Mag 12, but advice from Erich put me over the edge.

Crossover/Amps

These will be active run off my miniDSP 4x10, compression drivers will run off an Adcom GFA-545II, mids off an Adcom GFA-555, subs off a GFA-5800. Crossover points will be initially 1500hz and 120HZ but everyone will be REW'd and EQ'd

The Enclosure

I decided on a largish tower, OD are 50" tall, 15.5" wide and 15" deep. Mids will see about 1.75ft in a sealed enclosure, they will go flat to 90hz, Subs will get about 3ft each with port tuning around 30hz with two 4" ports each.

Construction is heavily braced 3/4" maple plywood, bracing is 1/2" thick pine plywood. I cut 1/2" dado grooves for the internal bracing, the bottom is only screwed in so I can remove it, that allows bracing panels to slide in from the front and bottom and stack in precisely how I need. I'll post more as it develops so you can see what I'm doing. Bracing will be vented to maximize air space and rigidity.







I'm thinking of a 1.25" roundover on the front edges and possibly a 3/4" bevel on all other edges, I love the look of the exposed plywood layers.

Fun to note I have no CAD drawings, I literally do this all out of my head as a thought exercise and challenge, it takes an almost meditative focus (no distractions like someone talking to you) to keep track of everything and get it all right in one shot.


BTW I build all my speakers with this cheap and portable table saw, incredible piece of equipment if you're looking for a simple, accurate and cheap setup




More to come, I welcome any comments or feedback, Thanks!

Sent from my iPhone using Tapatalk Sent from my iPhone using Tapatalk

[badman]

looks great so far- I wonder how well the veneer on your ply will hold up to the roundovers on the front, given the look of the bracing dadoes. The removeable bottom- are you planning to leave the bracing un-glued? It seems like it from your description but that would be a mistake (which I honestly think you're NOT making, just worded it in a way that SOUNDS like that to me). Should be a big kickin' rig- think about doing a PPSL setup for the magnums- distortion and force cancellation, you only need a limited bandwidth anyway, and I can assure you that the performance boost would justify the extra effort in re-working a little of the bracing scheme.

[JavadS]

looks great so far- I wonder how well the veneer on your ply will hold up to the roundovers on the front, given the look of the bracing dadoes. The removeable bottom- are you planning to leave the bracing un-glued? It seems like it from your description but that would be a mistake (which I honestly think you're NOT making, just worded it in a way that SOUNDS like that to me). Should be a big kickin' rig- think about doing a PPSL setup for the magnums- distortion and force cancellation, you only need a limited bandwidth anyway, and I can assure you that the performance boost would justify the extra effort in re-working a little of the bracing scheme.

Thanks for the comments! Veneer holds up great, just doesn't like being dadoed across grain, here are some recent examples I've done:





Bottom will eventually be glued in, just removable to allow sliding in the bracing vertically. Bracing definitely glued, I can't even imagine how it would be doable w/o gluing, it's not called "rattling" after all =)

Will end up similar to this:



Interesting on PPSL, wasn't familiar with this config, would that require having two drivers in each enclosure?

Was only planning 1 12" for each tower at this point. Thanks!

[ani_101]

What is a PPSL configuration? Some sort of push pull???

[badman]

Odd, my reply didn't stick. It requires two per tower which may make things un-doable. Push Pull Slot Loaded is a manifold-loaded driver mounting, where the drivers are electrically out of phase, the magnet from one sits close to the cavity of the cone from the other (less clearance is better but one must respect excursion+ some safety margin), and by mounting this way, the manifold is small and provides some low pass filtration as well as significant force cancellation from equal but opposite masses moving, and even order distortion cancellation due to the inherent acoustic symmetry from the summed front/back arrangement. It's pretty sweet and is the only way I'll do things for direct radiators 200hz and down anymore (with the exception of dipole systems etc)

[JavadS]

Some progress on the baffling. This enclosure will be extremely well braced but will loose minimal space and gain minimal weight. Final sealed volume for the mid enclosure will be about 1.6 cubic feet, should result in an F3 of about 100hz.

Subwoofer will be at 3.0 feet and will be tuned to 35hz.











https://vimeo.com/163781223



https://vimeo.com/163781263

All the panels pictured are glued up and drying currently, tomorrow I'll finish up the bracing for the subwoofer portion.



Sent from my iPhone using Tapatalk

[badman]

That's really solid work there, maximizing your quality/material cost ratio sir!

[JavadS]

That's really solid work there, maximizing your quality/material cost ratio sir!

Thanks badman! And it is solid, the knuckle rap test is really good on this =) Javad

[JavadS]

Another little update, finished bracing for the subwoofer section







Next I'll attach the bottom and fabricate the front baffle, flush mount the drivers and ports, then router the corners.


Sent from my iPhone using Tapatalk

[JavadS]

All bracing finished and working on the front baffle, also got this Magnum 12" in from DIYSG and it's a beast! Front baffle will be 1.5" thick.










Sent from my iPhone using Tapatalk

[JavadS]

Got some work done on the baffles Here I'm flush mounting the 3" port tube from the rear.



Flush mounted the Mag 12 to the frame for cosmetics, including the front gasket this flange is 3/4" thick










I threw a 1/2" round over on the back of the subwoofer opening.

Sent from my iPhone using Tapatalk

[JavadS]

Got out to the garage last night for an hour, front baffle is coming along Flush mounted both Faitalpro 8" mids



3/4" roundover on back of baffle to allow mids to breathe.



Front baffle/s as it stands, next step is to roundover the port openings



Started working on the flush mount for the Seos 10 horn, here is my plan. Initially make a flush cut around the outside of the horn with a 1/4" flush cut bit, that will created a negative ID pattern that is 1/4" larger than the horn per side. Then using that oversized pattern, do another trim cut using a 5/8" trim bit with a 3/8" bearing on it, which will create and undersized ID pattern exactly the size of the horn.

Here is the start, more to come.



Sent from my iPhone using Tapatalk

[JavadS]

Got a bunch done today, these guys are really coming together =)

First off I worked on flush mounting the Seos 10 horns...man flush mounting shapes like this is SO much more work than a round driver using a circle jig. I went a different route than what I was planning before as this was much easier and well documented online.

The pictures are sort of self explanatory, let me know if you have any questions.







This is a pattern guide, I used a 3/4" which compensates for the 1/4" diameter of the router bit.





And this is the finished template positioned on the enclosure ready use



Test for to make sure



Using this bit set to .2"



And done



Test fit wala





Now that all the front baffle driver routing was done, I attached it to the enclosure



3" Port tubes glued into the baffle, you can see the inside entrance flare



From the front



And with 1.125" radius roundover



My fingers for reference



And making lots of dust, first lots of flush cutting, then 1.25" radius roundover on front baffle, back of enclosure got a .75" radius and other top edges .25" radius.

Come at me bro







Before roundovers



After and where things stand



Now lots of sanding and vacuuming!

Sent from my iPhone using Tapatalk

[ejh2854]

Nice project!

.

[JavadS]

Thanks ejh2854 glad you're enjoying it! Sent from my iPhone using Tapatalk