Home Theater Forum and Systems banner

1 - 14 of 14 Posts

·
Registered
Joined
·
30 Posts
Discussion Starter #1 (Edited)
I am building a single TC Sounds LMS ULTRA 5400 18" in a 4 cubic foot sealed box and plan on using it in my enclosed basement theater with dimensions of approximately 12’ x 19’ with 8’ ceilings.

This DIY hobby has left me with quite a few subs and no logical place to put them.

Is it even worth adding an additional sub/s or will I be limited to the least common denominator and better off running the single LMS-Ultra 5400? The room is certainly small enough.

Edit: I decided to build 2 ea. LMS-R 15" subs in 3 cubic foot sealed enclosures.

I intend to use a Crown CE 4000, bridged if recommended, but wouldn't mind powering a second sub with it if there is enough power.

What I am learning though is adding a second sub-woofer may hurt rather than help unless I use a second LMS-Ultra and I believe I bought the last one from parts express.

I use an Onkyo PR SC5508 with dual sub outputs and Audyssey MultEQ XT32 and could also use a DSPeaker Anti-Mode 8033B if it would help.

I have an old Velodyne FSR-15 I had planned on replacing with the LMS-Ultra but could keep it in the room if it would help smooth the bass response. I have a Leviathan 18" in a 4 cubic foot sealed box in the bonus room I prefer not to move since it sounds great in its current setup and with the down firing design and legs, would be a little too high and block the bottom edge of the screen.

I also have a number of smaller subs I have built over the years;

Two 10” Aura Sound NS10-513-4A’s in 1 cubic foot sealed enclosures
A 12” Aura Sound NS12-794-4A in a 2 cubic foot sealed box I don’t really have a place for.

My recently finished Scan-speak Revelator 23W 9” Sub w/9” Passive Radiator 23W in a 1 cubic foot enclosure is sounding great in my family room and is another option but it would likely suffer from the same challenges blending a ported and sealed sub would and could never keep up with the LMS-Ultra 5400.

I'll post some pictures when I get a chance.

Thanks
 

·
Registered
Joined
·
30 Posts
Discussion Starter #3 (Edited)
I have finished gluing the ½ x 4” oak on the 4 sides of my enclosure and am waiting for the 2” x 4” oak boards I glued together for the fascia to dry before using the circle jig for routing and then gluing to the front. Then I can round off the edges, fill, sand, stain and apply the finish coat.

Edit: Picture added after fascia progress. Still need to glue to front, flush trim, fill, sand, round edges, stain and finish.

I used 1/4" oak plywood on the back.

Before the oak finish work the front and back of the enclosure is made from ¾” MDF and ¾” BB glued together, the four sides are ¾” MDF and the bracing is ¾” BB.

I don’t think I can carry it down to my basement theater by myself. Just moving the box around while working on it has my back aching.
 

Attachments

·
Registered
Joined
·
1,633 Posts
Wow, that looks great snappy!

As far as the question of adding different subs to the LMS Ultra I agree with AJ, the more the better. The only time mixing subs can cause problems is ported with sealed as there can be phase problems around the ported's tuning frequency. Technically there can be too with sealed but I think the benefits outweigh the cons.

I use a pair of SI sealed 24" with a mix of 12" and 10" diy sealed subs and the results are outstanding. Took a little bit of time with my Omnimic to get them all working together but the end result is the best bass I have ever had. I use to own a pair of sealed LMS Ultra's as well, phenomenal subs which I wish I never sold.

For me the best way to incorporate the multiple subs was to start with 1 and make sure it blended with the speakers. I did calibrate the volume of each sub separately to make make sure they were at the same level. From there I added the next and make sure it is in phase with the first, if it is not the volume of the bass will go down instead of up. I did that with all 5 placements of subs and once that was done I calibrated them all as a single bass source since they all play the same signal.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #7
I am finished and hope to find time in the next couple of days to connect a Crown CE 4000 to an Onkyo PR SC5508 and see if it works.

I was advised not to bridge it from an engineer at Rane but I can’t remember his reason and not sure why it wouldn't be OK. In a small room I am probably fine with 1200w regardless.

I’ll get it set up and run Audyssey with the single LMS Ultra 5400 and decide how or if to add additional subs from there.

With a small and sealed room with dimensions of approximately 12’ wide x 19’ long with 8’ ceilings and two rows of theater seats there is not much wall space to install additional subs but I could put one ore two along the side wall in front of the second row of seats, another sub under the screen or on a windowsill behind the screen. I might be able to squeeze a smaller sub in a couple other locations but run the risk of someone running into it in the dark.

Which subs would you consider adding? (Velodyne FSR-15, One or Two 10” Aura Sound NS10-513-4A’s in 1 cubic foot sealed enclosures, 12” Aura Sound NS12-794-4A in a 2 cubic foot sealed box)

Thanks BeeMan458 and AJ.
 

Attachments

·
Registered
Joined
·
30 Posts
Discussion Starter #9
I had hoped I was finished with DIY for a while but two 15” LMS-Rs’ were delivered yesterday. I will be building 3 cubic foot sealed enclosures and will end up with three subwoofers if I can fit them in the room.

I am also attempting to fill in some lows for my center channel since Audyssey sets the crossover at 150 Hz and I am concerned that after I add subs behind and to the side of my listening position, the center channel sound stage could be compromised. I could hear male voices coming from the 18” but since it is close to the center it isn’t an issue with the single LFE sub.

I just added a Rane AC 22B active crossover between the center out and a couple amplifier channels with a 150 Hz High/Low crossover point and 24 db high/low slope. My Infinity Prelude Composition P-CC now handles 150 Hz and up and an AuraSound 10" NS10-513-4A in 1 cubic foot sealed enclosure handles 150 Hz and below. My hope is this will bring my center closer to the performance of the front L/R mains that have built in 12" powered subs that Audyssey sets 40 Hz crossovers for. I ran Audyssey again and the crossover is now set at 70 Hz for the center. The voices sound more natural now; still plenty deep but less boomy.

I am also going to test a Bryston 10B Sub crossover I have laying around. I had hoped to put it back in service in another room for a music optimized 2.1 setup but I am being told it may be a better solution in dealing with potential phase problems with the CC crossover. The Bryston doesn't have a 150 Hz option so I would need to move up to a 200 Hz High/Low crossover. The Bryston allows different slopes for the high and low crossovers so I could select a 200 Hz high pass with a 6 db slope and a 200 Hz low pass with an 18 db slope. It has been suggested this may handle phase issues better depending on the room.

Then again it might cause more problems and be more trouble than it is worth.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #12
A few more days; just need to install the spikes, let the silicone cure and install the LMS-R.


The enclosure's are upside down in these pictures so I can install the spiked feet.
 

Attachments

·
Registered
Joined
·
30 Posts
Discussion Starter #14
Had to RMA one of the drivers and received the replacement, installed it, ran Audyssey and watched my first movie. During the initial Audyssey sub level test the replacement sounded a little off but in a subtle way. Hopefully it just needs a few hours to break in and unless I am putting my ear right up to the speaker and comparing the two R-15's and I haven't checked again since the first movie.
 

Attachments

1 - 14 of 14 Posts
Top