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Dual Opposed 18" LMS's..... "The XLerators"

33K views 50 replies 16 participants last post by  Vin Vendel 
#1 · (Edited)
Design Criteria

3 Dual Opposed Boxes - 6 x 18" LMS drivers

Double Wall top, bottom and sides 3/4" 13 ply birch
13.3 gross 9.5 CuFt net without bracing and drivers.
Box dimensions external - 25x28x33
Magnetic Grills
Extensive Bracing
Large Rounded Corners
Aluminum Legs
Mahogany Veneer

Room size is 8200^3 open to everywhere, need extreme clean deep output.
Sealed is preferred.

Power - 6 x 4000w (1 Crest 8002 per driver)
EQ - DCX 2496
3 x 30 amp circuits

Contracted John from AE Speakers to build the boxes, I couldn't do this nice of work, nor did I have the time.






Amp rack with Supermicro server - 24 hot swap bay for streaming media













Still awaiting the last box, and then measurements will start and be posted.
 
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#4 ·
Nice!!!.....Real Nice!! That D2v is about as good as it gets as far as processors go. Make sure you post your measurements, you may not need to EQ the subs. I am running a Maelstrom X 18" and a Dayton 15" in sealed enclosures with a DCX-2496 for bass management and EP-4000s for power and as of now I am not using any EQ. I will be starting room measurements soon too. I will get my preamp back from being modified at the end of the month and will then begin measurements.
 
#5 ·
This room def needs EQ, at least it did with 3 x LMS's + 15" TC3K

Too many sound waves bouncing around and colliding in here mushing things up.

I'll be running sweeps when I get the last box and results will be posted, certainly feels good now though... but thats just not good enough for me - gotta make sure everything is just right...
 
#6 ·
Yep, I know just what you mean. I'm running a total of 5 subs, the two mentioned above plus a 12" peerless that work with the min speakers for 2 channel listening and then a pair of 15" Daytons in sono tubes with 18" passive radiators for the H/T. So for movies I have all 5 in operation. I thought I would have to go with 3 circuits like you have but I am getting away with 2 circuits. My room is a little "deader" than yours appears to be it will be interesting to see the measurements from the two rooms.
 
#10 · (Edited)
Thanks guys.... I was trying to go for something that would work well and look good in my room. You really have to give John @ AE Speakers the credit for doing such a nice looking job on the boxes, he truly is a genius with CAD and his building skills are spectacular. I highly recommend his boxes for his kits.

BTW, the Sigs have no problems keeping up with these subs - they get plenty loud and are very clean, It was more important for me to get the subs to give me at least 10db over the mains and maintain it with integrity, in a room this size - that was asking quite a bit.
 
#12 ·
BTW, the Sigs have no problems keeping up with these subs - they get plenty loud and are very clean, It was more important for me to get the subs to give me at least 10db over the mains and maintain it with integrity, in a room this size - that was asking quite a bit.
I was riding the fence on that one, i have Monitor series 11's and they are stupid loud, i just don't have anywhere near that subwoofer piston area. It's almost like my 11's over power my sub.:scratch:
 
#17 ·
:sn: And then there were 3 !!!! "Book of Genesis" :sn:

Took a nice trip up to Green Bay today and picked up the last box, got it home and worked on it this afternoon. Got the speakon in and wired it up for both drivers, stuffed 4 pillows in, yanked the drivers from my old boxes. Dropped in the first driver and started taking picks of the final older version driver.

Not the final resting place for the box, but I'm exhausted. It'll be moved to behind the plasma. EQing starts on friday...... :hsd:







 
#20 ·
Thanks guys.... its been a fun project....

John at AE Speakers builds a wicked box and I couldn't have done this without him - his skills and attention to detail in every aspect of the box is simply incredible, I highly recommend him for custom box work, my expectations were blown away when I got the finished product...

Can't wait to get it dialed in -
 
#22 ·
Final Sweep, Waterfall and spectogram...




Sweeps along the way...
Original OLD EQ, new subs


Main behind plasma






Getting things together, EQing and adding subs along the way. These are the measurements we kept which looked the best throughout the trials and errors of 50-75 sweeps or so I think....









We spent alot of time going through about 50 to 60 sweeps at least... 4 hours running multiple different sweeps and some varying placement options, moving the main sub behind the plasma and back out to the left of the entertainment console. I think the measurements came out very nicely with what we have to work with in there.

There is alot of balancing acts to perform... once getting phase and delay setup, getting one sub EQ'd and then introducing the second and then third and forth - the interactions that come into play are astounding - it gets somewhat overwhelming...

Ya can't EQ too much before introducing the next sub - which will add different peaks and dips that can become drastically worse if EQ was applied previously. So you have to do a great deal of before and after measuring and adjustments just starting with 1 sub and moving on to the next...

I tried to boost the low end with the DCX, ran with 7 - 9db, but I think I may need to do more tweaking and experimentation. My room is so large and I get absolutely zero gain down low..... Don't get me wrong - the bass in this room is super clean and the output is staggering, I am by no means disappointed with the SQ or output, I can be 15-20db hot and it'll keep up with no problems at all... I like to run about 5-10db hot so the additional drivers and amps have been and will be priceless for the future.

I may have to look into something more for the signal shaping of the sealed cabs here... I have never been one who chases the single digits output and trust me when I tell you that things are seriously shaking in my house.
 
#25 ·
Cheers thanks.

I had been lead to believe that the drivers would need to be physically attached (metal rods etc) to completely eliminate vibrations.
 
#27 ·
These are great looking subs and this in one off the reasons why I went back to ported. I had a dual FI Q18 sealed sub and felt I never had enough low end. A great response but I would have expeceted more down low. I had a qtc off 0.9 hence having to boost the bottom end. It looks like you are 12db down between 20 and 15hz so you're probably not getting a great deal below that. Music wise I bet they sound great but I would feel like I am wanting more.

Sorry for the negatives but great subs all the same.

cheers


Graham
 
#29 ·
lets remember that he is using the best driver for the job so he gets a bit more on the low end than others would. Still sealed subs have there place and in many cases can sound better. I've found it's typically a matter of personal preference. I've found sealed preferable in most cases do to the savings in size, labor, materials.
I'm glad you finally got your hands on these Warp.
 
#28 ·
I agree graham, no offense taken.... Personally I really don't care for ported with port contributing to the sound at or near tuning.

My room is 8200^3 open to everywhere (so like 10-15K cubed or more) so no room gain down low for me, but I am not finished here... I still have to do the low end boost to work out the final details. This first run was to see what we could come up with for eq and placement, ran out of time to get started in boosting... I'm pretty confident I'll be able to sqeeze a little more performance out of them down low.

I'll be working out the details as to low end boost and see where things lie after that...
I'm in no hurry as I just got the last cab in place and I haven't gone the extra mile on the rest just yet.
 
#30 ·
These are really nice looking subs warp. John has defo done a great job on those babies. I remember on my first dual sealed I did with two Q18 drivers I had to boost the bottom end which is normal with sealed subs and I got it flat to 12hz after playing with filters on my BFD. Look forward to your next results.
Just out off interest how many subs did you use in the end.

cheers

Graham
 
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