sonotube construction tips

[thadman 10+ year member]

Im picking up a 24-36" sonotube tomorrow for a HT subwoofer project and would like some tips on construction.

First off, Im using an Avalanche 18 and would like a port tuning between 14-16hz. Whats optimal for ports to avoid chuffing (surface area or depth)? It will be downfiring along with the sub so I have lots of options. I will be using PVC pipe for the ports.

How do I attach the caps to the tube itself? How thick should I go (2 x 3/4 mdf for each cap and 2 x 3/4 for the inside of the tube?)

Secondly, it being a HUGE enclosure (8 feet tall and at least 24" wide) how much power would I need to reach maximum excursion?

Would a Bash 500 watt amp work or should I go with the Behringer EP2500?

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[Beat_Dominator 5,000+ posts]

Everything sounds good. 500w amp is a good number to aim for. For ports, 3 4" PVC pipes or 2 6" pipes should get you plenty of port area.

 

[thatkidbob 10+ year member]

Im picking up a 24-36" sonotube tomorrow for a HT subwoofer project and would like some tips on construction.
First off, Im using an Avalanche 18 and would like a port tuning between 14-16hz. Whats optimal for ports to avoid chuffing (surface area or depth)? It will be downfiring along with the sub so I have lots of options. I will be using PVC pipe for the ports.

How do I attach the caps to the tube itself? How thick should I go (2 x 3/4 mdf for each cap and 2 x 3/4 for the inside of the tube?)

Secondly, it being a HUGE enclosure (8 feet tall and at least 24" wide) how much power would I need to reach maximum excursion?

Would a Bash 500 watt amp work or should I go with the Behringer EP2500?

for the cap i'd use 2 pieces of MDF, one cut to the ID of the sonotube, one to the OD. This would look great, but its difficult to do unless you've got a router and a jasper jig...

 

[mrogowski 5,000+ posts]

It might be too late, but I would recommend going with one large port rather than 3 smaller ones. You can get smaller Sonotube 8-10" in diameter that would be cheaper than PVC and be more effective. Since your tube is so high you can mount it in the top and noone will bother it.

The Behringer would be my choice over the BASH, but if you want something that will really power the sub properly, look at a Crest or Peavey.

Best,

Mark

 

[djman37 5,000+ posts]

Im picking up a 24-36" sonotube tomorrow for a HT subwoofer project and would like some tips on construction.
First off, Im using an Avalanche 18 and would like a port tuning between 14-16hz. Whats optimal for ports to avoid chuffing (surface area or depth)? It will be downfiring along with the sub so I have lots of options. I will be using PVC pipe for the ports.

How do I attach the caps to the tube itself? How thick should I go (2 x 3/4 mdf for each cap and 2 x 3/4 for the inside of the tube?)

Secondly, it being a HUGE enclosure (8 feet tall and at least 24" wide) how much power would I need to reach maximum excursion?

Would a Bash 500 watt amp work or should I go with the Behringer EP2500?

surface area is inversely proportional to port speed. more area= slower movement.

AEROPORT or acoupower port 10" !!!

 

[thadman 10+ year member]

Would firing into the ceiling cause the upper floors to rattle much more than down-firing the port? I'd like to avoid that if all possible.

How much are those 8-10" sonotubes, they sound like an excellent option.

Could you recommend a crest or peavey amplifier? Do they have xovers to limit the signal past 70/80hz?

I believe the Behringer EP2500 is a copy of the comparable QSC RMX2450, are you sure its not capable?

 

[JimJ 5,000+ posts]

Do they have xovers to limit the signal past 70/80hz?

Most don't, but you could always run external Xovers like Harrison Labs FMODs to serve that purpose.

 

[mrogowski 5,000+ posts]

Would firing into the ceiling cause the upper floors to rattle much more than down-firing the port? I'd like to avoid that if all possible.
How much are those 8-10" sonotubes, they sound like an excellent option.

Could you recommend a crest or peavey amplifier? Do they have xovers to limit the signal past 70/80hz?

I believe the Behringer EP2500 is a copy of the comparable QSC RMX2450, are you sure its not capable?

I doubt it.

I bought an 8" 12' Sono 'kit' for $12. It came with 3 pieces - the 8" piece and one tube to fit inside it and one to fit around it, called -8 and +8 respectively.

Check these amps out. They are more expensive than the Behringer but you get what you pay for:

http://www.crest-performance.com/poweramps

While the EP2500 is a good budget amp, it is not a QSC. Those who bought a Behringer and then a QSC will attest to that.

Best,

Mark

 

[thadman 10+ year member]

Whats *better* about the crest amps?

I read in another thread on here, that the Behringer EP2500 was pretty close to the QSC and as long as I wasnt running it below 2ohm I should be fine. Im only going to be using 1/4 of the power...maybe 1/2 so I think it should suffice.

 

[mrogowski 5,000+ posts]

Its up to you whichever you want to go with, but when it comes to a professional amp costing $250 verses one at $1000, a watt is not a watt.

I too was contemplating to go with a Behringer, but when I heard it against a Crest there was no comparison. There was more strength in the music. You could tell the Crest had "control" over the drivers (probably due to their oversized power supply) and didn't run out of gas after operating for long periods.

Behringer amps are most favoured for their buck-for-watt numbers, but they come nowhere close to heavyweights like QSC, Peavey or Crest.

Best,

Mark

PS: Here's another link to Crest's new line - so popular they can't keep them in stock. I've been waiting for my CPX 3.0 for a month now...

http://www.crest-performance.com/press/index.cfm/action/view/id/20/

 

[60ndown 10+ year member]

err? a cardboard tube with an 18 and 500wrms? me thinks it will implode and or flex badly, ? might wanna glass the thing?

 

[djman37 5,000+ posts]

err? a cardboard tube with an 18 and 500wrms? me thinks it will implode and or flex badly, ? might wanna glass the thing?

i was guessing he'd found an example on a diy board. Resin is a MUST for this thing to last.

 

[thadman 10+ year member]

Yes, theyre 5/16" thick and are supposed to not flex at all. They have been used with Ava 18s with amazing results.

Hmm...

I dont have the budget for one of those high power Crest amplifiers

for my circumstances...

$370 shipped for a Crest CPX1500 amplifier that does 1500 watts bridged at 4ohms

vs

$300 shipped for a Behringer EP2500 amplifier that does 2400 watts bridged at 4ohms

Are you still sure the Crest would come out on top? The Crest would seem to be driven into clipping before the Behringer.

Amplifiers adding sonic characteristics before being driven into clipping just sounds silly to me and a bunch of audiophile hoohaa. Even if the Behringer is 60% overrated (1500 watts @ 4ohm vs 2400 watts @ 4ohm) it still comes out cheaper than the Crest and my money/time would be much better spent on individual drivers.

I probably dont even need this much power, the BASH 500 watt amplifier on partsexpress.com is on sale for $160 with free shipping and offers phase adjustments AND a lowpass crossover. The question is, how would I mount the plate amp to the sonotube?

Will 500 watts get me maximum excursion?

 

[ballstothewall 10+ year member]

Whats *better* about the crest amps?
I read in another thread on here, that the Behringer EP2500 was pretty close to the QSC and as long as I wasnt running it below 2ohm I should be fine. Im only going to be using 1/4 of the power...maybe 1/2 so I think it should suffice.

Behringer and QSC should not be mentioned in the same senctence IMHO.

 

[joetama 5,000+ posts]

Behringer amps are most favoured for their buck-for-watt numbers, but they come nowhere close to heavyweights like QSC, Peavey or Crest.

I don't know what your experience with Peavey is, but Peavey is junk.

Peavey/Carver

Thank you that is all....