TC Sounds Sub Project

[Fr3ak]

Hey all, I'm designing a single 18'' bass reflex cabinet for live/professional application with the TC sounds Pro 5100 driver. I want this project to be solid so I have a few questions for the more experienced gents.

my design: front loaded 18'' cabinet (about 6 cubes ) with a 1'' slot port spanning the bottom of the cabinet tuned to about 30hz.

My questions...

Is port volume subtracted from total internal volume?

Will a 1'' slot port be feasible with this monster of a driver (over 2'' peak to peak excursion) or will there be way too much turbulence from the relatively small but wide port opening?

Should I use sound dampening material on the inside?

I'm using 3/4'' A1 plywood with a double thick front baffle. the size of the box shouldn't call for more internal bracing but I've heard the better braced your cabinet, the more energy is converted to sound. Is more bracing necessary?

Thanks a lot ahead of time. This has been a project I've always wanted to tackle and your help is much appreciated!

 

[cantonguy]

Hey all, I'm designing a single 18'' bass reflex cabinet for live/professional application with the TC sounds Pro 5100 driver. I want this project to be solid so I have a few questions for the more experienced gents.

my design: front loaded 18'' cabinet (about 6 cubes ) with a 1'' slot port spanning the bottom of the cabinet tuned to about 30hz.

My questions...

Is port volume subtracted from total internal volume?

Will a 1'' slot port be feasible with this monster of a driver (over 2'' peak to peak excursion) or will there be way too much turbulence from the relatively small but wide port opening?

Should I use sound dampening material on the inside?

I'm using 3/4'' A1 plywood with a double thick front baffle. the size of the box shouldn't call for more internal bracing but I've heard the better braced your cabinet, the more energy is converted to sound. Is more bracing necessary?

Thanks a lot ahead of time. This has been a project I've always wanted to tackle and your help is much appreciated!

I can't answer your question, but I have one of my own.
Is the 5100 better than the LMS-Ultra 5400? Which one is the one that people are always talking so highly of?

 

[GranteedEV]

I can't answer your question, but I have one of my own.
Is the 5100 better than the LMS-Ultra 5400? Which one is the one that people are always talking so highly of?

They are very different, both very excellent drivers.

The 5100 is a neodynmium pro audio driver. It still uses the TC sounds low distortion linear motor and still has 31mm of x-max and is around 95db efficient. Feed it watts and it can get louder than you can imagine. It's made for getting loud.

The 5400U, while right now it costs less, is the driver we all rave about. It's only 90db efficient, but fs is lower, and box size requirements are just tiny. You won't get the same midbass punch with the same amplification but that's kind of irrelevant - it's the difference between 120db and 127db or whatever. Way more power than a person would ever need.

BUt it's got 38mm of actual x-max and like 50mm of xmech...

distortion is riduclously low.

 

[GranteedEV]

In response to the OP

my design: front loaded 18'' cabinet (about 6 cubes ) with a 1'' slot port spanning the bottom of the cabinet tuned to about 30hz.

My questions...

Is port volume subtracted from total internal volume?

Absolutely. The port is a resonator which is effectively "using" the same internal air volume as the driver.

Will a 1'' slot port be feasible with this monster of a driver (over 2'' peak to peak excursion) or will there be way too much turbulence from the relatively small but wide port opening?

To get peak air velocity down to 22m/s a 1" tall slot port would need to be 125" wide and 52" long. You would need to cross over at 60hz in order to keep vent resonance down enough in level so as not to audibly excite it.

I would recommend a 5" x 30" x 36" port instead, if possible... tuning will rise to about 35hz but that's negligible for PA. A 2nd order butteroworth filter center at 23hz is necessary.

Should I use sound dampening material on the inside?

Line the walls with abour 6" of OC703 in order to keep internal standing waves under control.

I'm using 3/4'' A1 plywood with a double thick front baffle. the size of the box shouldn't call for more internal bracing but I've heard the better braced your cabinet, the more energy is converted to sound. Is more bracing necessary?

Bracing is very important, otherwise the panels will resonate at their given frequencies and color the sound. Kind of a waste for a $1200 driver.. sure you don't want to use a less expensive driver by eminence, acoustic elegance, beyma etc?

You will need to cross-brace, and I would not leave any 8" section of wood unbraced... for example if you've got 10" of wood then it needs bracing.

 

[cantonguy]

They are very different, both very excellent drivers.

The 5100 is a neodynmium pro audio driver. It still uses the TC sounds low distortion linear motor and still has 31mm of x-max and is around 95db efficient. Feed it watts and it can get louder than you can imagine. It's made for getting loud.

The 5400U, while right now it costs less, is the driver we all rave about. It's only 90db efficient, but fs is lower, and box size requirements are just tiny. You won't get the same midbass punch with the same amplification but that's kind of irrelevant - it's the difference between 120db and 127db or whatever. Way more power than a person would ever need.

BUt it's got 38mm of actual x-max and like 50mm of xmech...

distortion is riduclously low.

Where can you find drawings for how to build sealed a box with one of the LMS drivers? I'm sure there are many different types...but I'm thinking as small as you can get without affecting performance.

I read somewhere that people were hoping the LMS driver came out in a neo design...why? Are they just lighter?

 

[GranteedEV]

Where can you find drawings for how to build sealed a box with one of the LMS drivers? I'm sure there are many different types...but I'm thinking as small as you can get without affecting performance.

I read somewhere that people were hoping the LMS driver came out in a neo design...why? Are they just lighter?

Basically..a neodymium magent is lighter, so sensitivity and fs are both higher.

A ferrite magnet is heavier, which doubles as mass loading to let us have those 64ft organ stop notes we desire oh so badly

 

[TLS Guy]

Hey all, I'm designing a single 18'' bass reflex cabinet for live/professional application with the TC sounds Pro 5100 driver. I want this project to be solid so I have a few questions for the more experienced gents.

my design: front loaded 18'' cabinet (about 6 cubes ) with a 1'' slot port spanning the bottom of the cabinet tuned to about 30hz.

My questions...

Is port volume subtracted from total internal volume?

Will a 1'' slot port be feasible with this monster of a driver (over 2'' peak to peak excursion) or will there be way too much turbulence from the relatively small but wide port opening?

Should I use sound dampening material on the inside?

I'm using 3/4'' A1 plywood with a double thick front baffle. the size of the box shouldn't call for more internal bracing but I've heard the better braced your cabinet, the more energy is converted to sound. Is more bracing necessary?

Thanks a lot ahead of time. This has been a project I've always wanted to tackle and your help is much appreciated!

Give me a link to that driver and I will model it after the holiday.

The port volume is added to Vb along with bracing, amp volume and driver displacement to get Vt. I suspect it will need more than 1" for the slot vent.

 

[cantonguy]

Basically..a neodymium magent is lighter, so sensitivity and fs are both higher.

A ferrite magnet is heavier, which doubles as mass loading to let us have those 64ft organ stop notes we desire oh so badly

Thanks for the info.

Do you know where I can find plans to build a sealed box with one of those drivers? As simple of a box as possible.

Thanks again for taking the time to answer my questions. Sorry to the OP for taking your thread hostage for a minute.

 

[GranteedEV]

Thanks for the info.

Do you know where I can find plans to build a sealed box with one of those drivers? As simple of a box as possible.

Picturing slot bracing is the hardest part, but it's really nothing you can't design yourself. The important part for a sub is figuring out how big you want to go. For an LMS5400U i would go with 4 cu ft sealed, and realize that you will need to add EQ boost in the form of a linkwitz transformed for a sealed LMS... otherwise it's a good 12db down at 20hz.

There is a guy over at home theater shack who's really good with doing google sketchup models with full slot bracing... if you want he'll design it for you.

 

[Warpdrv]

TLS... TC's are sold at PE and the spec sheets are there

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=293-666

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=293-674


I would suggest going with Passive Radiators if your planning ported.... but with the way the prices on those just skyrocketed, I'm not sure I would go that route myself now....

 

[lsiberian]

If you haven't already purchased the driver. There are other options especially if this is an installation project.

If this is not for installation we will need to consider size and weight. If it is for installation then we need to know the application and room size. For example if you bought this for your bedroom for music listening sealing would be acceptable. If you bought it for a cathedral we'd need to do a horn design. Requirements determine design parameters.