TC Sounds LMS5400 ultra efficiency question

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Power is a constant, a watt number can be converted to decibel watts which will allow you to compare drivers based solely on their sensitivity.

4000 watts = 36db watts.

add that number to the sensitivity spec and you have a "theoretical" volume.

limits of power compression and excursion limitation between drivers assuming identical enclosures make the rest of the difference.

there begins the art/science/magic of enclosure design and construction.
 
What I was looking for was an estimate of power reached at xmax for both tuned to 25hz. I did forget to say they would all be in a 4.3 cubic foot enclosure for each driver. I think the 15 is close to xmax at 4000watts (2K each).

4kW?:yikes:Here we go again :violin:

What conclusions do you find from these submitted pictures:

Note: You provided the prerequisites.:D

b:)
 

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Yup at that power input the drivers become pretty xmax limited LOL. Hey spinmonster do you have a dedicated 40amp service to your listening room to provide enough current, or does your car(if it is in car) have the alternator and extra batteries and caps to support 4K Watts. I've built many a subwoofer and never used more than 1k per side, it's really not needed. Yes there is no replacement for displacement but many subs would fail miserably with that kind of power being fed to them. Just my .02$.
 
Yup at that power input the drivers become pretty xmax limited LOL. Hey spinmonster do you have a dedicated 40amp service to your listening room to provide enough current, or does your car(if it is in car) have the alternator and extra batteries and caps to support 4K Watts. I've built many a subwoofer and never used more than 1k per side, it's really not needed. Yes there is no replacement for displacement but many subs would fail miserably with that kind of power being fed to them. Just my .02$.

I have 3 20 amp circuits. Each Peavey CS4080 has its own line and the two remaining 2 channel amps run off a single 20 amp line for the MT active mains. The CS4080's are run bridged at 8 ohms. The LMSr 15's have never bottomed out.

I didnt think a LMS Ultra would bottom out at 2k watts tuned to 25hz. Run in series on a single CS4080 bridged is thus 2K watts.

I have 2 15's for the 4000watt input now and it isnt bottoming out. I was looking to see if someone could run the ported sim so I could see what increase in clean SPL I could get in my theater using the 18's. Regardless, the added power is still going to make it sound cleaner on peaks even if you dont use it.
 
Hi SpinMonster,

If it is High Output you want then maybe you should look at using bass horns like the Bass Maxx B-Zero BASSMAXX B ZERO/D SUBWOOFER

That will give you some slam... :)

Thanks but the sub boxes I have now for the 15's will fit the 18's so it was an issue of just swapping to a bigger hole/driver. My sub enclosures are 320lbs and I'm not looking to replace them. I also have no idea what a bass horn sounds like. I like the SQ/SPL mix I have now. I was just looking to have a more efficient sub to be cleaner on peaks with the same power. I love the amps.
 
4kW?:yikes:Here we go again :violin:

What conclusions do you find from these submitted pictures:

Note: You provided the prerequisites.:D

b:)

Here we go again? I imagine you're referring to my car also 4K watts from a RF 4000BD? This thread is about my home theater w 2 CS 4080hzs per side. Each side runs 2 15's now looking to go to 2 18's per side in series to share 4000watts. If it wasnt Xmax limited, I would go to two CS4000's per side or 4000watts per 18 X 4. If the SPL increase from the 2 18's was decent, I would stay with the current power level. Unlike all the theoretical proposed builds on this forum that never get built, I actually built everything I posted questions about here and for my car. Here is the current sub box with the two 15's in it along with that side's CS4080hz on the floor next to it.

DSCN0811.jpg


16 foot screen with the second sub in the right corner along with it's CS4080:
DSCN0807.jpg


The Car's 12" LMSr 12" in one of the three boxes I built with input (some from you last time):
TCS06.jpg


The sealed box for the same 12":
DSCN1015.jpg


The Hummer's RF 4000.1Bd 4000watt amp:
DSCN1013.jpg

Anyway, its 4000watts for 2 drivers in series so 2000 each not 4000 so I guess I'm fine for the swap and will get a bump in efficiency along with far less distortion from the drivers. Personally I always use the biggest amps for more headroom. You can damage a speaker way sooner with underpowered amps that clip than with overpowered amps that dont. You control damage with the volume control. Clipping amps still make far more power than their rated limit and exceed power limits.
 
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Spin you're nuts!! What's the size of that theater room? There's no need for 4x18's and 8000watts!! :D

I would still keep what you have driver wise, and do two large push pull horns per side. It will increase output without spending any $ on new amps and drivers, and it will lower distortion as well!
Then if youn don't want to toss your current boxes use them for a music system elsewhere in the house! (if the wife allows)
 
Spin you're nuts!! What's the size of that theater room? There's no need for 4x18's and 8000watts!! :D

I would still keep what you have driver wise, and do two large push pull horns per side. It will increase output without spending any $ on new amps and drivers, and it will lower distortion as well!
Then if youn don't want to toss your current boxes use them for a music system elsewhere in the house! (if the wife allows)


Nuts is why I went to 959rwhp on my corvette. Its not about what you need.

The theater/stereo/man cave is 21x21x9.5T. It has a single row of really comfy seating with a bigger perspective than most theaters. Epson 3D ect.

The reason for this particular proposed change is that the sub boxes are built already. I have no desire to build huge horns. The hard part is done. (other than moving the 320lb sub boxes to the garage for surgery to fit the 18's)

Gaing 4db in efficiency is one benefit. The other is that the 5400ultras in this box cuts the group delay in half and I can add power later when I upgrade houses in the near future. I will have 100amp service in the new construction's theater.

I know a lot of people talk a lot when posting about projects that never actually come to pass but I wasnt wasting anyone's time here asking these questions because this build is a fact.
 
I hear ya.
The group delay shouldn't be a problem if you're using DSP to delay the rest of the speakers in the system. If not, then yes the bass might sound slow and muddy.
I just know myself and always like trying out new stuff, and once I got on here and started reading about horns all day, I just had to build some and see how they sounded! (no one in my area, besides clubs which use various FLH BLH etc, which I've heard plenty of times)
 
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