Dual 18" PA subs for live sound in club...

So.... I can't get the 36-40 hz response I need in the package I want with diy tapped horns.

Is there a reason to break a dual 18" sub into 2 separate chambers? I'm Ok with shutting down the box if one sub blows. My 2x10" ports are already pretty long.

Fixed install in 120 capacity bar

Do you think 3/4, MDF, plywood bracing, titebond II, 1 1/2" brads will be ok? Probably carpet or that roller grade duratex.
I'm thinking 10" sonotube for the ports. Can one miter those?







I really wanted to build a couple of these but the kappalite 3015lf is much lumpier in this and the b&c driver cost is too high for 2 subs. If anyone can make a 3015lf version or guide me with some hints!
THAM15-01.jpg
 

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tb46

Member
2006-01-09 7:04 pm
Texas
Just one more 3015 TH Sub

Hi,

Try these values in Hornresp:

ID=28.00
Ang=2.0 x Pi
Eg=2.83
Rg=0.00
Fta=4.07
S1=540.00
S2=542.26
Par=5.00
F12=0.00
S2=542.26
S3=633.00
Par=201.00
F23=0.00
S3=633.00
S4=1669.24
Par=94.30
F34=0.00
S4=1669.24
S5=1900.00
Par=21.00
F45=0.00
Sd=881.10
Bl=18.50
Cms=1.40E-04
Rms=3.90
Mmd=85.40
Le=0.90
Re=5.30
TH=1
Vrc=0.00
Lrc=0.00
Ap1=542.00
Lpt=1.80
Vtc=1800.00
Atc=1000.00
Pmax=500
Xmax=11.0
Comment=TH_Eminence_3015LF_by tb46_Try_chamber_270 L

Regards,
 

CuttaBoi

Member
2009-10-16 12:17 am
hellonwheels, there is another option, and one I'm considering to hit the low 30's! And its the HOG scoop, you can finds lots of info on this on speakerplans and freespeakerplans, google.

The rated drivers for this are the Void 1000/1200, PD1850, B&C 18tbx... If I build it I will be going with a fane 18xb as this has been said to be a good budget option. The only downfall for this design is that it doesn't play high 90-110, so an upper bass cabinet may be needed depending on you're taste.

The hog scoop is not like common scoops, and has been said to have more of a folded horn sound.
 

tb46

Member
2006-01-09 7:04 pm
Texas
Hi CuttaBoi,

The last time I checked out the Hog scoop (by staiper?) it was with a PDA1650, and the Hornresp net volume was 550 L. The SPL response would fall under: "it's the kind of thing you like, if you like that kind of thing", and that is modelled as a tapped horn, or normal. Definitely usable, but not in the same league with a properly designed tapped horn of the same volume using the same driver. But then again, I might be wrong.

Any specific links?

Regards,
 
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CuttaBoi

Member
2009-10-16 12:17 am
Hi CuttaBoi,

The last time I checked out the Hog scoop (by staiper?) it was with a PDA1650, and the Hornresp net volume was 550 L. The SPL response would fall under: "it's the kind of thing you like, if you like that kind of thing", and that is modelled as a tapped horn, or normal. Definitely usable, but not in the same league with a properly designed tapped horn of the same volume using the same driver. But then again, I might be wrong.

Any specific links?

Regards,

Plans can be found here

Yep correct mate, designed by staiper, don't quite get you on the spl responce, care to elaborate a little mate?
Plans can be found at, Hog Scoop, theres also alot of build threads / info on speakerplans.com forum..

I've not actually seen any HR plots for it, but does have a huge amount of respect on Speakerplans - Was told that standing in front of (one or may have been a few) was like a full body massage! lol

The reason I'm leaning towards them is I can get hold of second hand Fane 18xb's for around £90, which would make them quite a cheap build.

If you come up with a better alternative, please do share :)
 

tb46

Member
2006-01-09 7:04 pm
Texas
Hi CuttaBoi,

Here are the SPL response plots I had seen before. I don't recall the source for the Hornresp input data. When I get "a round to it" I'll try to take a look at the hopefully up-to-date data on freespeakerplans. Thanks for the link.

Regards,
 

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tb46

Member
2006-01-09 7:04 pm
Texas
HOG Scoop

Hi again,

As close as I can simulate: the HOG Scoop has a net volume of 511 liter, is externally about 35.5"Dx25"Wx38.8"H, and the SPL response in Hornresp simulation (using the PD.1850, factory T/S) is attached:

Regards,
 

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Hi again,

As close as I can simulate: the HOG Scoop has a net volume of 511 liter, is externally about 35.5"Dx25"Wx38.8"H, and the SPL response in Hornresp simulation (using the PD.1850, factory T/S) is attached:

Regards,

For this application, this driver is one of my choices as well.
In a larger cabinet the PD 2150 will give you more 'punch' if you want it.

For enclosure design, see Rog Mogale's contributions at:
1850 and 186 horns - Speakerplans.com Forums - Page 1

Regards,
WHG
 
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Again!

Hi Bill,

Welcome back - it's nice to see you posting on the forums again.

Kind regards,

David

Hi David,
The last few years have been turbulent and during that period all my hobbies went on hold.
Lost my wife to cancer in 2005 and have recently remarried (2008).
I got lucky and found a second sweetheart.
While my schedule is still busy, I have decided to renew my interest in subjects acoustic.
I notice you are still actively supporting your horn simulation program.
What a pleasant surprise that is.
Regards,
Bill
 
Notches

QUOTE=tb46;2308603]Hi again,

As close as I can simulate: the HOG Scoop has a net volume of 511 liter, is externally about 35.5"Dx25"Wx38.8"H, and the SPL response in Hornresp simulation (using the PD.1850, factory T/S) is attached:

Regards,[/QUOTE]

This is probably a closer approximation.
Regards,
WHG
HOGScoopdownscaled-12LW1400-SPL.jpg
 
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jbell

Member
2003-04-02 4:34 am
.
Plans can be found here
Yep correct mate, designed by staiper, don't quite get you on the spl responce, care to elaborate a little mate?
Plans can be found at, Hog Scoop, theres also alot of build threads / info on speakerplans.com forum..
I've not actually seen any HR plots for it, but does have a huge amount of respect on Speakerplans - Was told that standing in front of (one or may have been a few) was like a full body massage! lol
The reason I'm leaning towards them is I can get hold of second hand Fane 18xb's for around £90, which would make them quite a cheap build.
If you come up with a better alternative, please do share :)


I'll hopefully not show my ignorance on rear loaded scoops here.... However, most scoops I've heard have this weird 'phase' thing going on, where the front and back waves of the driver meet and interact with each other in the listening space. In my mind.... a tapped horn, where the driver is inside the horn path allows that interaction to happen within the horn. What exits the horn has nulled/summed/interacted in whatever manner -- and its output is consistent within itself once leaving the cabinet. It's this interaction that must give a TH its directionality and other properties. It's also what prevents 'horn extensions' 'v-plates' etc from working like they do for front loaded horns.

The hog is an interesting design, because it's almost tapped horn and almost scoop. (at least it is visually)

I'm with oliver on this one though -- With huge respect to staiper, I believe in the same space as a scoop, a well designed TH can equal or beat a scoop for output, and do it with (in my mind) a more pleasing, less 'phasey' output. (as evidenced by danley's commercial designs) This is speaking in generalities only, as scoop/bandpass/tapped horn is a slippery slope, and determining exactly where you are on that slope is an iffy proposition at best sometimes.
 

tb46

Member
2006-01-09 7:04 pm
Texas
Posts #10/11/14

Hi CuttaBoi,

I hope that hellonwheels doesn't mind all the HOG Scoop discussion.

To get some, hopefully not completely wrong, data I overlayed the HOG Scoop plan (in ACAD), and scaled it until the height and depth measurements fit. I then made some assumptions as to where I wanted to place S2/3/4 to arrive at a Hornresp Input, what the volume of the troat chamber is, how much volume the driver displaces in the throat chamber,.... Working backwards from a drawing like this, there are actually a few options, and I didn't want to take more time than the Sunday night football game. I got the data for the PD.1850 from the manufacturers website, and used Hornresp to compare how close this data is to calculated values. The result is the SPL response in Post #11, better than the responses posted in Post #10, but I think it can be improved. At similar size jbell's stadium tapped horn is clearly better, and its simulation can be marginally improved too.

This gave me a little extra time to think about the general classification of the HOG Scoop, and my conclusion is still that it is a tapped horn, and not a scoop. A great thread to read up on is screamerusa's thread that resulted in the fury box. The tools for designing tapped horns have been getting better and better, especially because of David McBean's continuing effort. It stands to reason, that at least the box simulations should be getting better too.

Regards,
 

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I have no problem with expanding the scope of discussion, esp. when DMcB, WHG, et al are involved. In 270 liters its hard to beat a direct radiator design. With two 8" vents the max air is a leisurely 15m/s. No port compression there...
125db [email protected] [email protected]

From what I can see is 2 of the Martinsson boxes will exceed it in only 320l and more than 2x the driver cost... tb46 how come you can't get the same thing with the 3015lf in 160l?? it actually has a bit more xmax. Lumpy is ok if it has the extension.

Of course its not possible for me to move the 150 lb 270l 2x18" vented. I would like to see the 3015lf in a very well braced, extremely light yet stiff enclosure around the size of the martinsson horn. That would be the pound for pound performance winner, also in a small package, yet hitting [email protected] and going up from there.

One thing that I think that I've learned is that the max SPL numbers on the Danley site are calculated, not measured.