Audiopulse/Tc sounds LMS enclosure help

[72Impala 10+ year member]

I have a 15" D2 audiopulse LMS ULTRA currently in a 4.5 net box tuned to 29hz with 3 4" round ports, I know that's not what it should be in, I just did a direct swap to see how it would perform in that box. I would like to know if anybody knows optimal box specs to match this sub. It is the same one in the ad below (not mine, but mine is identical, even the condition of it).

My goals are loud daily driver, the sub is in an ext cab nnbs silverado on 3k.

TC Sounds/Audiopulse LMS Ultra 5400 15"

Thanks in advance!

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[T3mpest 10+ year member]

How does it sound in the box you have? What frequencies are too loud, which are too quiet, any port noise? Cabin gain plays more of a role than anything else will so really that's the main question to ask when you want an "optimal" box. I can tell you what's optimal in terms of an open field or large room, in your exact car, on the music you like, no idea.

 

[72Impala 10+ year member]

How does it sound in the box you have? What frequencies are too loud, which are too quiet, any port noise? Cabin gain plays more of a role than anything else will so really that's the main question to ask when you want an "optimal" box. I can tell you what's optimal in terms of an open field or large room, in your exact car, on the music you like, no idea.

No frequencies are too loud. Anything above 38hz it falls off very quick. I can hear air moving out of the ports, air is coming out very fast. Exact car is 2008 ext cab silverado, music is mostly decaf and other rap, would like a flatter response that goes down in the low 20's, and up to at least the mid 40's but higher would be better.

 

[T3mpest 10+ year member]

The LMS ultra uses shorting rings and is 90db/1w/1m. It should be able extend much higher than that. Sounds like you lower frequencies are too loud or you have an orientation problem? Which way is the sub facing, you may want to mess with that and see if it makes a difference.

Anyway, I'd shrink the box volume some and go with a much larger port. 2 6inch aero's (actual areos, so flared ends) should be enough area, or if you go with a slot port you'll want around 60 square inches of port, give or take a bit, more wouldnt' hurt. If you can squeeze at least 3 cubes of volume with a port of that size you'll be in good shape, that sub does not need a huge box to drop low, but it WILL need port area to sound good and low with 3k going to it. Tuning between 25-32hz, depends how peaky you want it, personally 28hz works well IME.

In summation right now it sounds like at lower volume your low end is too loud and is making your 40hz+ seem too quiet. At high volume it's not moving air as well as it should and probably still doesn't sound balanced. Shrink the airspace, keep the low tuning up the port area and possibly fire the sub another direction. Even if you end up blocking your port off, just to test, reorient the woofer and then play some 40-60hz tones and see if they get louder. If they do you'll know where to aim the woofer for the next box.

 

[72Impala 10+ year member]

The LMS ultra uses shorting rings and is 90db/1w/1m. It should be able extend much higher than that. Sounds like you lower frequencies are too loud or you have an orientation problem? Which way is the sub facing, you may want to mess with that and see if it makes a difference.
Anyway, I'd shrink the box volume some and go with a much larger port. 2 6inch aero's (actual areos, so flared ends) should be enough area, or if you go with a slot port you'll want around 60 square inches of port, give or take a bit, more wouldnt' hurt. If you can squeeze at least 3 cubes of volume with a port of that size you'll be in good shape, that sub does not need a huge box to drop low, but it WILL need port area to sound good and low with 3k going to it. Tuning between 25-32hz, depends how peaky you want it, personally 28hz works well IME.

In summation right now it sounds like at lower volume your low end is too loud and is making your 40hz+ seem too quiet. At high volume it's not moving air as well as it should and probably still doesn't sound balanced. Shrink the airspace, keep the low tuning up the port area and possibly fire the sub another direction. Even if you end up blocking your port off, just to test, reorient the woofer and then play some 40-60hz tones and see if they get louder. If they do you'll know where to aim the woofer for the next box.

Right now I have sub up/port up.

Thank you for the input I'll try it out.

 

[DonH 5,000+ posts]

LMS drivers are far better in a sealed enclosure application. 4.5ft^3 sealed is actually right on point for that driver, SEALED.

-Don

 

[72Impala 10+ year member]

LMS drivers are far better in a sealed enclosure application. 4.5ft^3 sealed is actually right on point for that driver, SEALED.
-Don

4.5 sealed for the 15" version?

 

[DonH 5,000+ posts]

4.5 sealed for the 15" version?

4.35-4.5 yessir

 

[Imtjnotu 5,000+ posts]

LMS drivers are far better in a sealed enclosure application. 4.5ft^3 sealed is actually right on point for that driver, SEALED.
-Don

....idk don....have my lsm-r in 3.8@28 and it does really well

 

[DonH 5,000+ posts]

....idk don....have my lsm-r in 3.8@28 and it does really well

great, seal it up, thank me later