Time to build my new towers.
***EDIT - FINISHED***
Got my MiniDSP, my 250ft Speaker Cable, 7 new interconnects, my Emotiva 5175 (For Atmos duties)...
Today I set out to calibrate hopefully once and for all the towers in their current position.
REW 6 point averaging was used, it made the process very easy, and I am pretty happy with the results now. That middle seat (lets face it, the only one I care about in my small room) now has a smooth frequency response.
Here is the pre-calibration averaging for both speakers across 6 positions in the middle seat. Now that the imaging is fixed (roughly 20 degrees toe in) this is actually not a bad average considering the only EQ on these is based on outdoor driver measurements!
Here is the Calibrated Averages, measured in 6 positions again after Eq to the summed averages above. Really good!
The towers have a tweeter roll off at 18khz which I have done myself, I noticed they don't like to really play above there, they naturally want to roll off, so in the X-Over settings for the DSP I simply created a 48db/Octave filter to roll off at 18k. You will clearly see that on one of the tower measurements above, I did the other tower after the measurements. I also added a 25hz roll off also 48db to save the driver from any over excursions since I am going to run these full range in my AVR.
*** Original Post***
I have had the 15" drivers for these for over a year, and just occurred to me the other day that I should build it modular for easy, negates the need for large CNC cutting I was going to do, and I think actually will look pretty cool.
Its been done before, I have seen a sealed and ported version of this, none of them used the 12" mid I am going to use though. For obvious reasons I guess.
Check my sig for my past builds, the thing with this is I am going to be recycling my TPL and 12P80 from my existing towers, I really like the sound I have right now, just wish there was a little more output down low, and this time I would like to cross the mid closer to 1250hz or so to reduce beaming a little, will check out the best area around there with now polar graphs when I get one box built.
The last box had OK bracing, but this being modular, that aim this time was to do the bracing a little better, more LF output, give the mid a LOT more room in a sealed section to breathe, and likewise with the TPL-150. The towers I have although large, really don't leave enough room for all those drivers to do their thing.
Here is the front face design.
The other build I have seen, which is sealed.
I have already cut one side mostly, and have one mid chamber built and glued, I also had a tweeter chamber built but I am going to redo it shaving off 2cm in height so that will be coming together today.
I am going to have the crossover completely out of the box in its own nice wooden box, I havent decided yet if I will just have that sitting on top or where I will put it, my room is HT centric, so laying them off to the side of one of the boxes will not do. I also just want to keep it all out of the modular boxes, I want those to be as solid and as simple as can be, just some nice terminals on the back of each of them. I will probably make up a thin 100mm high box in the same dimensions as the rest of the modules and use that.
I will build two, though the plan is to build a third down the track when I finally get to use an AT Screen setup to have identical towers.
Here is the bassbox pro model of one of the bass modules:
With the two LF drivers in parallel wired for 8ohms the design should be good for 122db at the -3db point of 45hz.
My current towers in yellow, and new modular towers in red... Approximate.
First port resonance is at about 700hz. I hope to cross over the main woofers at about 200-250hz or so at 24db/Octave. Which brings me to one consideration for the overall design, I know I need to try to cross the main woofers as low as possible due to the CTC spacing rules. The way they are now spaced at 1050mm, exactly one wavelength is 323hz.
Unfortunately the design wont allow a 1/4 wavelength crossover in the mains of 80hz, that's just of no interest to me, I will experiment with this heavily when designing the crossover, I do want these 15's to cover the majority of the impact midbass range, at least up to 150hz if I can. The problem is, given the spacing, I guess I am going to have a cancellation at the 160hz half wavelength yes?
I have some nice jarrah paper backed here, I may use that for the modules in terms of finish, I will cross that bridge when I come to it!
I dont even know how these are going to fit in my room, but stuff it, im going to build them anyway because I am bored! I will make them fit!
Current main towers are 1360Hx360Wx380D
More to come as I go!