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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => LAB Subwoofer FUD Forum Archive => Topic started by: Craig Leerman on September 27, 2004, 01:53:48 AM

Title: 4X15" sub designs
Post by: Craig Leerman on September 27, 2004, 01:53:48 AM
I am putting together a dedicated system for second stages at festivals, main stages at small fairs, etc.  Mostly outdoor shows with local acts, with the occasional regional or small national artist.  

I have the highpacks already, and have been using some single 18" W bins with them for now.  The highpacks are horn loaded Northwest Two cabinets, loaded with 2 JBL 2226 15" and a JBL 2445 2" horn.

It takes at least 2 of the 18" subs to keep up with the highpacks for most music, and more if I will be doing real bass heavy music. My main problem are:
* I don't want to take out tons of boxes, just 2 subs and 2 highpacks. (unless I need to cover a larger than normal area or bigger crowd that is)
* I don't like the look of odd sized boxes, I want the subs to be the same width (about 34" if I remember correctly) so the stack looks neat, and the subs don't end up being drink tables!
* I would like to use my existing inventory of 2226J drivers that were left over from an ill fated double 15 project.


I have been looking around for designs and ideas of what types of subs to build that would go good with the horn loaded highpacks.

I was thinking of simple quad 15" front loaded boxes  similar to the Community quad 15" cabinets.  I have heard the Community boxes at exactly the same type outdoor shows that I plan to use them in and they would work.

But, I was hoping that somebody would know of a 3 or 4 15" horn loaded sub design, or manifold type box design that I could look at while I am still in the planning stage.  Something like EAWs SB1000 for 4 15" instead of 2 18"  or a 4 X15" version of the SBX220 would probably be cool as well.

Something in the 35Hz to about 80Hz or higher range.  It would be really nice to just have to buy some wood and a few steel grills instead of spending money on new drivers!

Any box designs or styles I should look into?

Craig

Title: Re: 4X15" sub designs
Post by: Marjan Milosevic on September 27, 2004, 02:48:34 AM
Hi Craig,

Unfortunately I dont have any design that can help you, but if You are loking for a design similar to the EAW SB-1000 than  the calculation of the box is not that complicated.
It is still a front loaded box just the speakers dont look directly forward.
Try some calculation with  WinIsd or some similar program.

If you are not completely sure how SB - 1000 looks here is a picture that can help.

Regards
MarjanM
Title: Re: 4X15" sub designs
Post by: Craig Leerman on September 27, 2004, 04:56:25 AM
Thanks,

I've seen and worked with the three boxes I mentioned. I was just wondering if there were any more interesting or different type boxes around.

So far I have drawn plans for a front loaded quad, as well as what looks like a stacked sb1000 with all 15's instead of 18's.  both look OK on my bassbox pro program.

Still looking for more ideas before I buy some more birch and order the grills!

Craig
Title: Re: 4X15" sub designs
Post by: Mac Kerr on September 27, 2004, 10:02:24 AM
Apogee has a version with 4 18's that matches the footprint of their old 3x3. It is also an "articulated baffle" design like the SB1000 and SBX220, although in a more vertical box because of the 4 18's. I don't see why it couldn't be scaled to fit 15's. They mount the speakers magnet out to save space.

http://www.apogeesound.com/prod_spec.php3?type=products/loud speakers/F_Series/&prod=FH-18

Mac Kerr
Title: Re: 4X15" sub designs
Post by: Elliot Thompson on September 27, 2004, 01:22:40 PM
Craig Leerman
I am putting together a dedicated system for second stages at festivals, main stages at small fairs, etc.  Mostly outdoor shows with local acts, with the occasional regional or small national artist.  

I have the highpacks already, and have been using some single 18" W bins with them for now.  The highpacks are horn loaded Northwest Two cabinets, loaded with 2 JBL 2226 15" and a JBL 2445 2" horn.


It takes at least 2 of the 18" subs to keep up with the highpacks for most music, and more if I will be doing real bass heavy music.

Elliot Thompson

So, other words, in order to get sizable amount of punch,
you need one top to two subs ratio.



Craig Leerman
My main problem are:
* I don't want to take out tons of boxes, just 2 subs and 2 highpacks. (unless I need to cover a larger than normal area or bigger crowd that is)
* I don't like the look of odd sized boxes, I want the subs to be the same width (about 34" if I remember correctly) so the stack looks neat, and the subs don't end up being drink tables!
* I would like to use my existing inventory of 2226J drivers that were left over from an ill fated double 15 project.

Elliot Thompson

Is that 34" total width for both boxes  standing side to side,
or laying down, stacking one W over another?

Craig Leerman
I have been looking around for designs and ideas of what types of subs to build that would go good with the horn loaded highpacks.

I was thinking of simple quad 15" front loaded boxes  similar to the Community quad 15" cabinets.  I have heard the Community boxes at exactly the same type outdoor shows that I plan to use them in and they would work.

Elliot Thompson

That would work, but, a Quad 15? Why not two Dual 15's
which would be easier to transport?

Craig Leerman
But, I was hoping that somebody would know of a 3 or 4 15" horn loaded sub design, or manifold type box design that I could look at while I am still in the planning stage.  Something like EAWs SB1000 for 4 15" instead of 2 18"  or a 4 X15" version of the SBX220 would probably be cool as well.

Elliot Thompson

A four 15" hornloaded sub, would be enormous!!! Taking
in consideration you need to have the right amount of
Horn Length (For The Frequency) and, Large Enough Mouth
(For the High SPL) you are looking at a box weighing
more than the EAW KF 940 (365 pounds -> Ouch!)

Craig Leerman
Something in the 35Hz to about 80Hz or higher range.  It would be really nice to just have to buy some wood and a few steel grills instead of spending money on new drivers!

Elliot Thompson

IMHO I think 2 Dual Fifteens will be the wiser choice.

1. Two Dual Fifteens are easier to move, than one Quad 15.

2. You'll have better flexability, to achieve 35Hz using
two Dual Fifteens, than one 4 driver horn-loaded sub.

You'll need a 8 foot horn (Quarterwave) and, a 32 foot
mouth to achieve 35Hz.  Shocked

The only obsticale you'll have are those Hornloaded Tops.
Two Dual Loaded Midrange Horns, are equivalent to 6 - 8
non horn loaded midrange cabinets. And, if they are loading
in the horn, make that more toward 8 non horn loaded midrange
cabinets.

Craig Leerman
Any box designs or styles I should look into?

Elliot Thompson

Under your requirements;

Quote:


* I don't want to take out tons of boxes, just 2 subs and 2 highpacks. (unless I need to cover a larger than normal area or bigger crowd that is)
* I don't like the look of odd sized boxes, I want the subs to be the same width (about 34" if I remember correctly) so the stack looks neat, and the subs don't end up being drink tables!
* I would like to use my existing inventory of 2226J drivers that were left over from an ill fated double 15 project.


I see Two Dual Fifteens as the only alternative.

Just feed them alot of power, and, have those Dual Horn Loaded
15 cabinets supply more low mid - mid bass.

Best Regards,


Title: Re: 4X15" sub designs
Post by: Mark Seaton on September 27, 2004, 06:11:10 PM
Craig,

Many thoughts come to mind, not the least of which would be to sell off the 2226J's and buy/build something directly suited for what you need, or just go with an intelligently designed vented box.  If you mean to ground stack these, I can't imagine less than 45" of height being desireable.  I guess it depends on what you are transporting everything with, but if you need something 34" wide and 45" tall, I would go for two horizontal boxes stacked on top of eachother.  Make them maybe 30" deep with a pair of the 2226Js per box.  Make a big slot style port between them as large as possible (i.e. one per pair of drivers).  You should be able to hit ~150L per driver and tune it to about 38Hz.

If you actually model out the parameters of the 2226J, you find the sensitivity is quite over stated at the frequencies of interest.  More importantly, programs which give rough estimations of port and power compression give a better indication of what you really get out of the box.  The pair of dual 2226J's would likely work quite well as I had in mind above, but I think you might be able to serve your need with as little as 2 appropriate 18s which would likely be lighter and potentially better low end output.
Title: Re: 4X15" sub designs
Post by: Mark Seaton on September 27, 2004, 06:21:06 PM
I should also note that if you were looking for a horn design, I would expect a single or pair of 15" per box to be the likely option if any.  For a super cheap option, Adire Audio did a "short horn" for their Tempest.  The driver sells for only $150.  A pair next to eachother would make for a 36" cube.  I can't speak to the performance, but I know the guys there and they will tell you exactly what it does and doesn't do.  Looks to me like it may be worth giving a try.
Title: Re: 4X15" sub designs
Post by: Craig Leerman on September 27, 2004, 09:56:38 PM
Quote:

 
Many thoughts come to mind, not the least of which would be to sell off the 2226J's and buy/build something directly suited for what you need, or just go with an intelligently designed vented box. If you mean to ground stack these, I can't imagine less than 45" of height being desireable.      


Hey Mark,

The highpack is about 5' high (Northwest Two box) so any sub higher than 2 foot tall gets the horns well above the crowd's heads.

As for selling the 2226s and buying new, that is also an option. But, I just wanted to see what designs might works with the drivers I already have.  16 Ohm drivers are not on everybody's wish list!

My needs for bottom end are not that slamming for this system.  Many gigs I have simply used the highpack as a full range cabinet and placed it up on the stage or next to the stage on top of a section of scaffolding, or even an unplugged sub cabinet!  

Craig
Title: Re: 4X15" sub designs
Post by: Craig Leerman on September 27, 2004, 10:34:37 PM
Quote:

So, other words, in order to get sizable amount of punch,
you need one top to two subs ratio.



Only with the current subs that I use with these tops. The current sub is a large (48" wide X 24" high) single 18" W bin. They are not that efficient, and the current drivers that are loaded inside (Gauss) do not handle a ton of power. The highpacks are very efficient, and I think only a Lab, BDeap or Bassmax could really keep up with these highpacks on a 1-1 basis. I don't really need a ton of slammin bass, but I do want to be able to get some nice thump out to the crowd on occasion.  


Quote:

Is that 34" total width for both boxes standing side to side, or laying down, stacking one W over another?


The highpacks are 34"  wide and about 5 foot tall. They are a horn loaded dual 15" box with a 2" horn on top.  I would like a sub that is 34" wide so it would look nice when used in a 1 over 1 configuration.



Quote:


That would work, but, a Quad 15? Why not two Dual 15's
which would be easier to transport?


Transportation is not an issue. I have big trucks, and usually can back right up to the stage or scaffolding where the cabs will go outside, or pull into a dock.    


Quote:


A four 15" hornloaded sub, would be enormous!!! Taking
in consideration you need to have the right amount of
Horn Length (For The Frequency) and, Large Enough Mouth
(For the High SPL) you are looking at a box weighing
more than the EAW KF 940 (365 pounds -> Ouch!)


I was thinking more like a 2X15 horn box similar to a lab or Servodrive where the horn curved around the driver compartment.  For 4 drivers, I was looking at a more compact approach like a MTL Manifold type system or a front loaded system.

Size (except the 34" width) and weight are not really issues for me.  I have moved quad 18 manifolds in the past, and currently move big Northwest Highpacks.

Also, because this is a small system (small when compared to an A rig, large if you compare it to a club system I guess) I want to keep cable runs down.
Title: Re: 4X15" sub designs
Post by: Elliot Thompson on September 28, 2004, 10:38:30 AM
Quote:


Only with the current subs that I use with these tops. The current sub is a large (48" wide X 24" high) single 18" W bin. They are not that efficient, and the current drivers that are loaded inside (Gauss) do not handle a ton of power. The highpacks are very efficient, and I think only a Lab, BDeap or Bassmax could really keep up with these highpacks on a 1-1 basis. I don't really need a ton of slammin bass, but I do want to be able to get some nice thump out to the crowd on occasion




Those W's sound like the same ones, that were given to me
free, a few years ago. I made post about them on the old
board.

Since you'll have spare wood available (Upon making your
new subs) here's an idea I did to the four I have.

I scaled the box, in which the driver sits in. I noticed you
mentioned bass box pro, so the angles shouldn't be a problem
with this program.

Once you scaled the box in the software, tune the box to
various frequencies. (I believe I tuned mine around 52Hz)

Where the panel is located (Where the speaker is inserted in
box) replace it with a new panel with the tuned vent.

You should get a substational amount of boost on the lower
octaves. A,B the vented -vs- the sealed, to confirm the
difference.

While these boxes are old, they do have some potential,
when used in groups of 2 - 4 playing 90 - 50Hz (being
tuned of course) Not to mention, a parametric can do
wonders....

Actually, after further investigation, I found out my
W's were Cerwin Vegas which were popular in 1976.


Back To The Subject

If you go to Beyma ( www.beyma.com ) they offer horn
plans (A dual 15 Horn I believe) that should fit the bill.

http://www.mcsoundlight.com/horn.htm is another site with
a large amount of Horn Designs.

IMHO you would be better to throw those JBL's on
Ebay, and, build some Lab Horns. Although they are
16 ohms, I would imagine a lot of Home Audiophiles
would benefit from such drivers using tube amplifiers.

Kinda far fetch, but you could scale the Lab Sub
using those JBLs. But, your guess is good as mines
if the cones won't fall apart due to the amount of
pressure they will get.

Sorry For The Rambling  Very Happy

Hopefully you'll find something useful in this tangled
thread.

Best Regards,