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thadman
11-08-2006, 06:44 PM
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?

Beat_Dominator
11-08-2006, 11:18 PM
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
11-08-2006, 11:21 PM
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
11-13-2006, 12:18 PM
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
11-13-2006, 12:20 PM
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
11-13-2006, 02:23 PM
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
11-13-2006, 02:27 PM
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
11-13-2006, 04:12 PM
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
11-13-2006, 05:51 PM
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
11-13-2006, 06:39 PM
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
11-13-2006, 06:43 PM
err? a cardboard tube with an 18 and 500wrms? me thinks it will implode and or flex badly, ? might wanna glass the thing?

djman37
11-13-2006, 06:57 PM
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
11-13-2006, 07:23 PM
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
11-13-2006, 09:18 PM
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
11-13-2006, 09:51 PM
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 < Behringer < Crown < QSC/Crest < Lab.Gruppen

Thank you that is all....

thadman
11-13-2006, 10:14 PM
not to be rude, but can we get back on the subject matter? Simple feuding is getting us no where...

would a BASH 500 watt amplifier suffice? Its 1/2 the price of all of those and its got a load of features. (Im not looking for comments on sound quality, but I am wondering if 500 watts will get the Ava in a massive 25'+^2 ported enclosure to maximum excursion without clipping)

ballstothewall
11-13-2006, 10:35 PM
a massive 25'+^2 ported

Volume is cubed ( ^3)... :)

joetama
11-13-2006, 10:43 PM
not to be rude, but can we get back on the subject matter? Simple feuding is getting us no where...

would a BASH 500 watt amplifier suffice? Its 1/2 the price of all of those and its got a load of features. (Im not looking for comments on sound quality, but I am wondering if 500 watts will get the Ava in a massive 25'+^2 ported enclosure to maximum excursion without clipping)

Yea, It would probably be just fine for what you are doing... And if it wasn't you could always upgrade ;)....

thadman
11-13-2006, 10:56 PM
sorry... then ^3:D

Where would I mount a plate amp on a sonotube?

mrogowski
11-14-2006, 07:10 AM
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?


Its all in the power supply. I would take a Crest over a Behringer any day.

If you choose a BASH amp, you can make a mount for it and punch a hole in the side. Silicone will do fine for attaching the mount to the tube.

mrogowski
11-14-2006, 07:17 AM
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.

It was Hsu who brought the simple design to light all those years ago. He found that a simple Sonotube had more strength given its cylindrical shape than a comparable box made of wood. There are a ton of folks out there using Sonotubes for 18" subs with great success. A prime example is my Baker's Dozen:
http://www.mach5audio.com/download/bakers.jpg



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

Peavey/Carver < Behringer < Crown < QSC/Crest < Lab.Gruppen

Thank you that is all....

I have used Peavey amps in professional setups. They are solid performers.

desertheat
11-14-2006, 08:18 AM
Yeah your nuts man, I have used peavey cs800s amps "6 total" for a MASSIVE setup I had back in the day. Most rock solid amps I ever used or ran. NEVER died no matter what I did to them. Simply brutal power for there size. I tried them in a HT setup a long long time ago, two of them powered aurasound 1808's. First time I ran a 40hz test tone through the setup it cracked the drywall in places *LOL* man that was fun!

joetama
11-14-2006, 11:04 AM
Yeah your nuts man, I have used peavey cs800s amps "6 total" for a MASSIVE setup I had back in the day. Most rock solid amps I ever used or ran. NEVER died no matter what I did to them. Simply brutal power for there size. I tried them in a HT setup a long long time ago, two of them powered aurasound 1808's. First time I ran a 40hz test tone through the setup it cracked the drywall in places *LOL* man that was fun!

I am curious to what a "MASSIVE" setups is that you used the Peavey amps on. I have worked in the Pro-Audio industry since I was just a lad (being on the road all summer since I was about 7 with my father and grandfather), and I have NEVER seen anyone use a Peavey Amp. Even Peavey stage gear is looked down upon. I hate to rail road the topic but I can't let people say things that I am sure to be incorrect.

thadman
11-15-2006, 08:17 PM
How much maximum SPL would I lose in a Linkwitz Transform setup (equalized down to 14hz) vs a Vented Design (ported at 14hz)