[thebuckaman]

What do you guys recommend? I have an Ep2500 to power them and want them to be as high output as possible with relatively flat response to below 18hz. This will be for 90% movies.

Thanks.

 

[thebuckaman]

From what I have read, an LLT. I would like a box less then 10 cu/ft per sub if possible with no port noise above 15Hz. Any ideas?

 

[Mike P.]

In a box 10 cu/ft tuned to 15 hz with 1200 watts input the port would need to be 8" diameter and 54" long to keep air speed under 26 m/s. A rectangular slot port 5" x 10" x 54" long would achieve the same goal. This would not be an LLT due to the 10 cu/ft size restriction.

 

[fackamato]

From what I have read, an LLT. I would like a box less then 10 cu/ft per sub if possible with no port noise above 15Hz. Any ideas?

LLT would be the way to go I think. If you can afford some PRs you can get away with an easier build. You'd need 4 of them though.

I think one EP2500 is a bit weak, don't you think? What are your M-X, dual 2ohm or dual 4 ohm? If dual 4 ohm you could parallel the VCs and run the EP2500 in stereo mode, and you'd get, I don't know, 1000 watts or so per woofer. Perhaps that is enough...

If you go with 8cu ft tuned to 18Hz. a subsonic filter at 11Hz (4th order), you don't reach excursion with 1000 watts. With two 6" ports each 54,15" long, port speed isn't really an issue (18m/s @ 16Hz full output), which AFAIK a 6" port can handle without chuffing or noise.

The bigger the enclosure the better, as the port length decreases with box size. 9cu ft with 2 6" ports perhaps?

Why don't you build an EBS , 16cu ft, that would give you INSANE output in the low 10's.

Maybe a single 8" port is enough? Then the lengths are 46.18" and 40.41". Then you never reach 20m/s on the 8cu ft box.

 

[steve nn]

If you do decide to go sealed, it would be wise to factor in LT. You could build two smaller units, or place both drivers in one larger enclosure around 10cu ft internal give or take. 8 internal would work just fine with LT.

 

[Warpdrv]

If you haven't seen the sealed builds, a good size is 24" cube, gets ya just above 6^3 internal.
You will certainly get more output from ported.

See this thread for the sealed..
http://www.hometheatershack.com/forums/exodus-audio/12134-my-sealed-maelstrom-x-build.html
The sealed units will require 1 EP2500 for each box for max output....

 

[thebuckaman]

Thank you so much for the responses. I want to go ported simply because of my power limitations with the EP2500. I guess I am flexible on the size of the enclosure. I just want this to be an overwhelming amount of clean LOW LOUD CLEAN bass. I like the looks of the ported frequency curves. I have a crossover with an adjustable Sub-sonic filter, and have 2 bands of parametric Eq. I have access to 8" sonotube as well.

Thanks a bunch guys. A bit new to the high output DIY sub arena.

 

[Mike P.]

Depending on how "flexible" you are on the size of enclosure, there are gains in the low end to be had with a bigger box. Same power of 1200 watts applied to both models.

 

[thebuckaman]

Quick update. I was able to find a supplier that can source me 30" or 24" sonotube for $9.31/ft. Any designs that would transfer over to these tubes well? This might help with my sub WAF.

Thanks guys. This forum is excellent!!!!!:bigsmile:

 

[fackamato]

Quick update. I was able to find a supplier that can source me 30" or 24" sonotube for $9.31/ft. Any designs that would transfer over to these tubes well? This might help with my sub WAF.

Thanks guys. This forum is excellent!!!!!:bigsmile:

Wow

The 24" tube, 4 feet tall, yelds ~12.5 cubic feet. Put in a 8" port 40" long (one end flared, the top, of course both sides flared = best but then the length differs a bit) and you'll need a SS filter @ 9-12Hz. (this is at 1500 watts input). You'll get 120dB @ 15Hz. Port air speed is never a problem... perhaps you could even go with a 6" port. If you can find a 8" I'd use it though.


edit: of course you'd have to subtract the volume of the driver and the port from the enclosure, so it'd actually be taller than that for the same volume.

 

[Mike P.]

There wouldn't be enough room between the end of the port and the back of the sub.

 

[fackamato]

There wouldn't be enough room between the end of the port and the back of the sub.

Good point. :dumbcrazy:

Might go with a smaller port, or narrower tube, or just extend the port outside the sonotube.

 

[Mike P.]

bucka, we can make it work in a tube, you might have to go bigger then 10 cu.ft. Would that be a problem?

 

[thebuckaman]

Do you have to brace the sonotube, or is it rigid enough? I will have two 72" x 24" sonotubes to play with if I have them cut the 12 footer in half. So about 18.85 cu. ft to play with (without taking the driver or port displacement out). Using an 8" port, how long should it be?:huh:

Thanks.

 

[Mike P.]

No bracing ia required in a sonotube. 14 cu.ft. would be the smallest size that will fit a 8 inch port and have enough clearance between the port and sub in a 24" tube. Here is a graph with the original 10 cu.ft. tuned to 15 hz compared to 14 cu.ft. tuned to 15 hz and both with 1200 watts input power. You're getting more low end output with the bigger box.

And here are all the dimensions you need for the sonotube. You'll need a minimum of 4 inch legs on the bottom. Disregard the numbers of the sub in the bottom right hand side. That was just a sub in the program database.

 

[Mike P.]

My Mistake. 13 cu.ft would also work and have enough room for the port clearance. The 14 cu.ft. box would give more output. Your choice.

 

[salvasol]

I was able to find a supplier that can source me 30" or 24" sonotube ... Any designs that would transfer over to these tubes well? This might help with my sub WAF. :bigsmile:

Beleive it or not ...to me, is the easiest way to build a sub (I finished mine like a month ago) :bigsmile:

No bracing, just cut the wood for caps, insulation, port, legs (there's some really nice at Lowes 6") and wherever you decide to cover the tube ...and you're done :yes:

 

[thebuckaman]

Well, i now have two sections of 24" by ~6 foot sections of sonotube. I also have two sections of 8" by 6 foot sections for port. I also bought some 3.4 mdf. Getting close to picking a final design. Any final tidbits to help me choose which enclosure size and tune? Thanks so much for your help guys:clap:

My wife just saw the bare sono in the garage. I don't think she was prepared. haha

 

[Mike P.]

My wife just saw the bare sono in the garage. I don't think she was prepared.

Wait until she hears them!

 

[thebuckaman]

Is the port speed a bit high on the 14 cu/ft 15hz tune with an 8" port?

I am not sure if I am interpreting the info correct.

Please help.

Thanks