Stereo Integrity Mag 15" LLT Sonotube Design

[Luke G]

Just looking for some feedback on the volume and tuning frequency to see if it is where it needs to be. I modeled it in two different enclosures with different volumes and tuning frequencies.(see attached)

My main goal is good sound quality for music. They will be used for HT as well, but music is my main priority.

Stereo Integrity Mag 15:
Re (coils in series) 3.5
Fs 22
Le 3.7
Qms 3.7
Qes 0.39
Qts 0.35
Cms 197
Mms (grams) 262
Vas (liters) 184
Sd (cm^2) 810
BL 18.35
SPL (1W/1M) 88.8
Power handling RMS 950

Thanks for any help ahead of time.

[mgboy]

I'd go for 7.5 ft^3 ( ~212 L ) tuned to 18-20, if your main concern is music. Maybe tune to 17-18 if you wanted something for movies too. Depending on the xmax and thermal handling of that driver, it could be a good sub for an LLT design, or at least in my eyes. 11 ft^3 tuned to 15 would be reasonably flat, plus room gain and the lowpass (crossover) to take down the 80+. Anyways. . .

[Luke G]

Thanks!

Xmax is listed as "26mm of one-way linear travel" for the Mag 15 and people have been known to beat on the driver with quite a bit of power without any issues.

[ssabripo]

Luke,

as you can see in your graphs, you are going to have two choices: a smaller volume which will raise your tuning point and give you a bit for linear output from Fs up to mid 50's, OR, you could do a large low tuned approach which would give you more extension and better transient for the price of more volume and a slight reduction of headroom from Fs to 50's.

looking at your models there, you have a larger volume for a higher tuning point...that should not be the case! You want to model it with the 270L having the lower tuninig point of the two.

play with the simulations some more, using larger volumes with lower tuning points.

[Luke G]

Thanks Sherv! Volume isn't an issue, I could do 350 liters if need be. I've read all of the write-ups I could find on LLT design (including the very good one on here) and I'm still a bit unsure what I am modeling for with a music oriented LLT versus a SPL monster HT LLT.

Here are 12Hz, 15Hz and 18Hz with 300 liters.

[SteveCallas]

There is no distinction between a music or HT orientated LLT, the design parameters were created to always yield the best for both worlds. Also, as far as I know, there sholdn't be any LLT write up anywhere but on this forum

The 300 liter, 15hz tuning model is the one most representative of a LLT FR, so I'd go with that one. An 18hz tuning wouldn't make it a LLT anymore.

[mayhem13]

maybe you could consider a bass reflex design for mostly music then but i think that would also depend on what type of music to some degree-Any pipe organ stuff???

[Luke G]

Thanks Steve, great write-up btw!

300 liters at 15Hz it is.