Reproducing a 16Hz pipe organ note

[xrk971]

Freddi,
If you are happy with solid 25 Hz extension, you can achieve this using a single Faital Pro 18XL1600 driver in a K15 scaled up to about a 48 in tall x 20 in wide x 24 in deep cabinet, driven by about 600 watts. Stack 4 of these together and you can get 126 dB at 25 Hz and have the clean dynamics and punch that a Karlson is known for. Here is the response from one box (with K-aperture top slit going to a cusp and starting 5.3 inches from the top) with 23 Hz HPF and 80 Hz LPF (48 dB/oct) applied. Interesting result that a Karlson bandpass box can serve as a sub woofer.
X

 

[tb46]

Hi Old Ears,

Happy that got you a step forward. Next - after you get the combined SPL - click on Filter Wizard under Tools, that'll open up the Filter Wizard: for the bottom right window pick Active, for the middle pick Bandpass, and for the left pick Displacement. Now you can set the lower displacement peak to be the same or smaller than the upper one by adjusting the Lower Cutoff Hz in the upper right hand box, and the Order right below it. Switch the lower left hand box to Response, and use the Upper Cutoff Hz and Order to set the upper frequency response.

Regards,

 

[Cask05]

...The TH is kind of like a box and port all in one, so it does not suffer from port turbulence even with low tunings.

This is an interesting point of view. I'd turn it around: a ported box is a direct radiator still wanting to be mated with a good horn, but having to settle for a resonating box/port instead. It doesn't enjoy the same level of output SPL gain for a given level of diaphragm motion.

I really don't prefer the sound from a ported box sub: all ported boxes that I've heard have sounded sloppy, opaque, and overbearing once turned up to concert levels.

 

[myhrrhleine]

Hello,
A basic question.
Pipe organs often go as low as 8hz.
Have you checked out how low your intended organ goes?
Electronic organs do not go as low as pipe organs.

 

[weltersys]

Have you checked out how low your intended organ goes?

Yes, Steve did, results in post #12.

 

[weltersys]

This is an interesting point of view. I'd turn it around: a ported box is a direct radiator still wanting to be mated with a good horn, but having to settle for a resonating box/port instead. It doesn't enjoy the same level of output SPL gain for a given level of diaphragm motion.

In a ported box, driver excursion is at minima at Fb, just as it is in a horn at Fc.
For a FLH to provide an excursion minima and 125 dB at 16 Hz it would have to be huge, TH and BR don't require as much volume, and would fit in the OP's designated chamber and provide the SPL he specified.

 

[Old Ears]

Hi Old Ears,

Happy that got you a step forward. Next - after you get the combined SPL - click on Filter Wizard under Tools, that'll open up the Filter Wizard: for the bottom right window pick Active, for the middle pick Bandpass, and for the left pick Displacement. Now you can set the lower displacement peak to be the same or smaller than the upper one by adjusting the Lower Cutoff Hz in the upper right hand box, and the Order right below it. Switch the lower left hand box to Response, and use the Upper Cutoff Hz and Order to set the upper frequency response.

Regards,

Oliver,

Thank you for your patience. I've been using loudspeaker wizard and filter wizard for some time working with TH. Hornresp is a powerful tool for those of us not ready to jump into Akabak.

Your BR design is perfect for what I need. And even using the $200 Dayton UM15-22 (since the 18 is not yet available) I can accomplish what I need with only 2 drivers. If I don't get a 1pi result from my strange speaker location, I'll just add 2 more.

Thank you again for all your help. It's forums like this that restore my faith in the internet.

Gratefully,
Steve Archer

 

[tb46]

Hi Old Ears,

It might be worth it to wait for the 18" driver, on the other hand if the 15" will do the job you could use a smaller box. Just make certain that you get the port velocity down into a rational range, that's all the output you've got at the bottom range of what you are shooting for. If you decide to give the 15's a try go with four, you'll loose a few dB because of power compression and port compression. Those losses are not accounted for in the simulations.

Regards,

 

[tb46]

Hi,

One more thing, Just wanted to point out another 21" driver that caught my eye at US Speaker, the RCF LF21X451 - $599.95. One of those comes really close to the design goal in a BR or a TH. Looks like one heck of a driver. Wonder if anyone has any experience with this one?

US SPEAKER Home Page Menu - Speaker Cabinets, Guitar & amp; Bass Amps, upgrades and custom design. The world’s widest choice of speaker parts. “If you have listened to live music, you have almost certainly listened to Eminence”

Regards,

 

[freddi]

wonder how this PRV performs ? PRV Audio 21SW4000 21" High Power PA Subwoofer Speaker 8 Ohm | 294-2756

 

[tb46]

Hi freddi,

Post #50:"...PRV Audio 21SW4000 21"..."

This one doesn't want to go that low in a BR, but will get close in a TH, again, would be nice if somebody had any personal experience with this one. It used to be quite difficult to build that large a voice coil, and make it work in the long run, maybe all that has been solved by now.

Regards,

 

[DeonC]

Forgot to add this. A friend of mine uses a 6m (19.7ft.) tube with 4x 18" drivers to reproduce the low frequencies of a pipe organ. And he should know how one sounds- he has one built into his dedicated listening room. Have a look at this article:

Chris Templer - TNT-Audio South Africa

Enjoy,
Deon

 

[Old Ears]

2-D drawing program

What program are people using to make a 2-D drawing like the one below.

Steve

 

[bear]

The entire idea depends on the presumption that the *organist* is ever going to actually press the footpedal that *is* the 16Hz. note!

Still would love to see an actual picture of the location/wall/church whatever the building happens to be...

And, then too there is the heretical idea of (gasp) installing a few actual solenoid controlled air operated PVC made *organ pipes*!!

 

[weltersys]

What program are people using to make a 2-D drawing like the one below.

Steve,
Not sure what was used to make that one, but Sketchup is a free program that can do 2-D or 3-D.

Sketchup for Woodworkers - Home

Art

 

[tb46]

Post #53

Hi Old Ears,

The example you are showing in Post #53 is by Don Snyder, and I don't know which drafting package he uses.

I use AutoCAD (an old version: 14). There are a lot of 2D drafting packages out there, a very full featured free 2D program is from Siemens (Solid Edge Free 2D):

Free 2D: Siemens PLM Software

Maybe do a Google search on "free 2D CAD"?

Regards,

 

[myhrrhleine]

Yes, Steve did, results in post #12.

Hello,

My understanding was that was the existing organ but not the intended organ. Perhaps I misunderstood?

 

[Old Ears]

Hi Old Ears,

The example you are showing in Post #53 is by Don Snyder, and I don't know which drafting package he uses.

I use AutoCAD (an old version: 14). There are a lot of 2D drafting packages out there, a very full featured free 2D program is from Siemens (Solid Edge Free 2D):

Free 2D: Siemens PLM Software

Maybe do a Google search on "free 2D CAD"?

Regards,

Thanks. I did search for a 2d program and just wound up with Sketchup which I've used for years, I just wanted something a little simpler for 2d.

By the way, I've been massaging the BR cab to utilize a 4x8 sheet the best and with a proper high pass and 80 volts (3200 watts!) I can get a theoretical 130db from 2 drivers! Might ought to put an extra fan on that Crown amp. I hope Eminence hits the June release date for the UM18-22.

Steve

 

[weltersys]

I hope Eminence hits the June release date for the UM18-22.

The UM18-22 is a Dayton product, made in China, Eminence is made in the USA.

22mm Xmax for the published price is an outstanding deal, regardless of where it is made.

 

[tb46]

Hi,

I second weltersys's statement on the Dayton UM 18-22, for that price and with the great customer support from Parts Express that's a very good deal. It may be a good idea to ask customer support what they think about that kind of installation.

Regards,