Some sound like jack hammers! I remember sitting at an organ console and listening to a 32 foot faggot lowest C. It's a reed. And it pounds! Some of the Skinner organs have very high wind pressure reeds that really speak with authority.
https://www.youtube.com/watch?v=vPGDiA3fidA
Sad recording but you get the idea a bit. This is a historically accurate restored french classical organ. Those are 8 and 16 foot ranks blasting.
https://www.youtube.com/watch?v=6hJJjOSqPoY
Same thing. Sad sound quality, but you can get the idea. Scroll over to 2:26 and watch the little people. Some of the reactions are priceless.
I can just see the evil grin on the organ designers face. Yeah, we'll put the really big reeds over here.. . Yeah that's the ticket.
https://www.youtube.com/watch?v=uP5YrADzK4U&list=PL337127C935647381
The innards of a Skinner bombarde. Take a good look and tell me what you see. I'll give you some tidbits. The little rush of air you hear is a compressed air assist to get the reed moving a little faster. And the big block on top of the reed is a weight. Yes lead actually. The tick metal you see moving back and forth is the tongue, or reed.
One of my favourite organs, and organist. Simply fun to listen to and seemingly limitless in dynamic range. This video is in french, but watch and learn. Lots of cool little things shown. And good audio this time.
https://www.youtube.com/watch?v=WlfcuawEUvg
To long, and to low!
https://www.youtube.com/watch?v=3Wpn7xyzUqg
Tongue firmly in cheek!
https://www.youtube.com/watch?v=vPGDiA3fidA
Sad recording but you get the idea a bit. This is a historically accurate restored french classical organ. Those are 8 and 16 foot ranks blasting.
https://www.youtube.com/watch?v=6hJJjOSqPoY
Same thing. Sad sound quality, but you can get the idea. Scroll over to 2:26 and watch the little people. Some of the reactions are priceless.
I can just see the evil grin on the organ designers face. Yeah, we'll put the really big reeds over here.. . Yeah that's the ticket.
https://www.youtube.com/watch?v=uP5YrADzK4U&list=PL337127C935647381
The innards of a Skinner bombarde. Take a good look and tell me what you see. I'll give you some tidbits. The little rush of air you hear is a compressed air assist to get the reed moving a little faster. And the big block on top of the reed is a weight. Yes lead actually. The tick metal you see moving back and forth is the tongue, or reed.
One of my favourite organs, and organist. Simply fun to listen to and seemingly limitless in dynamic range. This video is in french, but watch and learn. Lots of cool little things shown. And good audio this time.
https://www.youtube.com/watch?v=WlfcuawEUvg
To long, and to low!
https://www.youtube.com/watch?v=3Wpn7xyzUqg
Tongue firmly in cheek!
I have an "unusual" LP of organ music (I think, Bach's). On side B there are 3 tracks which - according to the sleeve notes - are of 3 organ pipes, delivering 16Hz, 12Hz ... and 8Hz (64' pipe)!
Of course, on all 3 of these, not a sound comes from my speakers (although I can plainly see the cantilever wiggling hugely from side to side)!
However, at the end of the year, I am adding 2x 15" subs to my Maggies, so I look forward to whether I'll be able to hear the 16Hz tone as a result!
Regards,
Andy
I'm almost positive that J.S. Bach never played (or heard) an organ with a 64 foot stop. I'm not even sure if he ever played an organ with a 32 foot stop. 16 foot stops were pretty much the norm for bass sounds in Germany within his era. Bigger pipes and more thunder came in the musical periods after Bach.
But Bach's organ music has been played on modern organs - a few of which had either 64 foot pipes - OR - digital versions of those ranks.
I've played lots of organs with digital 32 foot ranks. I've never played the real thing in 32 foot pedal ranks. And I've never played or experienced 64 foot ranks in a live setting.
I think Cameron Carpenter's new touring organ has some 64 foot ranks. AND he has additional notes on the low end of the pedalboard of his organ (also extra notes at the high end). So some of the sounds would be even lower than the 8 hz. for the low 64 foot rank C on most organs with this capability.
I remember the Stone Age when movie theaters experimented with sound devices that would cause the floor to shake for special effects sounds in some movies. Seems like it was called Sensurround, or some such thing. I never saw one - but I think I've read that it was a huge vibrator that was physically bolted to the floor. It didn't produce sound as much as it just shook the floor. Speakers sounded at the same time for - say - the rumble of an earthquake.
I guess 64 foot ranks, and even 32 foot organ ranks may be a little bit like that.
Bach On
Maybe we'd be safe since we don't have any skyscrapers within 10 miles of our church. But I suspect many animals in our vicinity might find it distressing.
Bach On
He played in Hamburg (Schnitger Organ in St Jakobi Kirche) on an 85 stop organ with 2 32 foot ranks Posaune and Principal . And he examined many organs with 32 foot ranks.
They were definitely around. Hoffkiche in Dreseden had a 32 foot unterstatz.
Basically there is nothing new under the sun.
And world wide you can count the organs with real 64 foot stops on one hand. It really does not give the organ much more umph.
Bach On,
"Sensurround" was a noise source from 17-120 Hz played through Cerwin Vega folded horn "W bin" subs using 18" woofers, not vibrators. They may have been bolted down in some installations to keep the cabinets from "walking". The usual bins were 48" x 48" x 24", with a 4' extender the horns 12' path length probably would have output to around 23.5 Hz.
The folded horns were capable of shaking anything in the theater, and some theaters did sustain structural damage, plaster does not like to stay in place when excited by certain frequencies
. That said, the random nature of the Sensurround noise is less likely to cause resonance damage than a sustained low frequency pedal tone which may excite sympathetic vibrations.Sensurround - Wikipedia, the free encyclopedia
Art
Pity if a person can't make it to St. John the Divine* in New York City to hear the Prince of Denmark March... but Michael Murray has a recording made there and some of the pieces have the lowest notes I think I have on a CD. Band 9, near end. His "Organ Blaster" is a hoot as well.
For sure, Bach can be impressive on big organs but hardly a tasteful way to play Bach. It is the French literature that uses the pedals best... esp. at the Toronto Halloween Bash. A visit to St. Eustache in Paris any Sunday is a real treat.
http://en.wikipedia.org/wiki/Saint-Eustache,_Paris
Not feasible to make a horn that goes super-low. But within their band, far superior in stirring all the air in your room or hall in a most visceral way.
While purist like me can only smirk, there are "theatre organ" enthusiasts and clubs who think of their electric instruments as organs.
Ben
*claims to be the world's largest stone gothic cathedral
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Well, I added the port this afternoon (7 3/8 at 30 inches). Put it in the bottom of the cabinet. I'll put 3.5 inch feet on the cabinet. I'm waiting now for the glue and the caulk to set. I also cut another hole for that second Dayton ST385-8 15 inch speaker (which arrived yesterday). I decided to go on and try both in the same box with the port. I had to remove the original speaker to move an internal support that was blocking the port tube. I'll go back tonight and wire and install both speakers in the cabinet. Then I'll do some testing. At least we'll having something operating when the organ work and sound engine install gets done - hopefully sometime in late June.
I have some men from the church coming in the morning to help me put the speakers into the speaker chamber. If the 15 inch speakers don't quite cut it, I'll enlarge the holes and switch to the 18 inch speakers later. But the 18 inch speakers are back ordered. I can do this now. If this proves inadequate, I'll just buy the two 15" drivers myself. I'm sure I can find a use for them - or sell them somewhere.
We're going to try one of the HC12 speakers for the other channel of the pedals. It will be on it's own Crown XLS1000 amp. I'll eventually tinker with the crossover point for it as we do voicing. Many have suggested that the 15" woofer on that speaker could do the 16 foot stops - and the upper frequencies of the sounds can be reproduced by the mid-ranges - and maybe even the tweeter will have something to do. If needed, maybe there will be room to add another HC12 later in parallel.
Keep your fingers crossed!
BO
I have some men from the church coming in the morning to help me put the speakers into the speaker chamber. If the 15 inch speakers don't quite cut it, I'll enlarge the holes and switch to the 18 inch speakers later. But the 18 inch speakers are back ordered. I can do this now. If this proves inadequate, I'll just buy the two 15" drivers myself. I'm sure I can find a use for them - or sell them somewhere.
We're going to try one of the HC12 speakers for the other channel of the pedals. It will be on it's own Crown XLS1000 amp. I'll eventually tinker with the crossover point for it as we do voicing. Many have suggested that the 15" woofer on that speaker could do the 16 foot stops - and the upper frequencies of the sounds can be reproduced by the mid-ranges - and maybe even the tweeter will have something to do. If needed, maybe there will be room to add another HC12 later in parallel.
Keep your fingers crossed!
An externally hosted image should be here but it was not working when we last tested it.
BO
Hi Bach On,
So your first try will be w/ 2ea. ST385s, and the 7-3/8"I.D. x 30"long vent. This should give you a very good idea as to where you are with your project. It's a lot of effort, but I think it will be worth it. I recommend you use a lot of fiberglass in the bottom of the enclosure. It should be far enough away from the drivers not to give you any problems, or you can use polyfill too. I'll attach a Hornresp SPL comparison @ Xmax for single v. dual driver. It's important to remember that these simulator programs do not address losses; you can simulate something like losses in Hornresp, but at best it's only an approximation, I went w/ the simple simulation (no losses).
As to the HC12s, I used to run 4ea. Eminence 15" of a similar vintage sealed in corner soffits in a control room. They were more than sufficient for me, but did not really go down to 20Hz, they did 32Hz just fine. But, that was for 4ea. 2ea. per side. Just something you'll have to play with. At least the HC12 were designed for your application.
When you are talking about 2ea. 18", are you talking about the UM18 or the SI18? Either driver will move enough air to overload the port, so it may take another look at that subject. (Passives anyone?)
Gotta just love it when a plan comes together.
Regards,
So your first try will be w/ 2ea. ST385s, and the 7-3/8"I.D. x 30"long vent. This should give you a very good idea as to where you are with your project. It's a lot of effort, but I think it will be worth it. I recommend you use a lot of fiberglass in the bottom of the enclosure. It should be far enough away from the drivers not to give you any problems, or you can use polyfill too. I'll attach a Hornresp SPL comparison @ Xmax for single v. dual driver. It's important to remember that these simulator programs do not address losses; you can simulate something like losses in Hornresp, but at best it's only an approximation, I went w/ the simple simulation (no losses).
As to the HC12s, I used to run 4ea. Eminence 15" of a similar vintage sealed in corner soffits in a control room. They were more than sufficient for me, but did not really go down to 20Hz, they did 32Hz just fine. But, that was for 4ea. 2ea. per side. Just something you'll have to play with. At least the HC12 were designed for your application.
When you are talking about 2ea. 18", are you talking about the UM18 or the SI18? Either driver will move enough air to overload the port, so it may take another look at that subject. (Passives anyone?)
Gotta just love it when a plan comes together.
Regards,
Attachments
How? I was thinking of using light filling in the sim as an approximation for losses, but I wasn't sure if it would be a good approximation for losses.
Hi Brian,
Yes, using filling would be one thing, especially if one simulates the enclosure as a OD-MLTL, that way you can pick where to insert the filling. Let's see, David has added the power compression feature, where you can type in a coice coil temperature, and the program will calculate the new Re, and re-simulate. You can also try increasing Le, and see what that will do (there seems to be concensus that the Le @ subwoofer frequencies is higher than Le(1kHz)). You could decrease the duct I.D. to get an idea of what turbulence might do.
Obviously, all that will loose accuracy, so ultimately you just have to measure. I don't know of any other way.
Regards,
Yes, using filling would be one thing, especially if one simulates the enclosure as a OD-MLTL, that way you can pick where to insert the filling. Let's see, David has added the power compression feature, where you can type in a coice coil temperature, and the program will calculate the new Re, and re-simulate. You can also try increasing Le, and see what that will do (there seems to be concensus that the Le @ subwoofer frequencies is higher than Le(1kHz)). You could decrease the duct I.D. to get an idea of what turbulence might do.
Obviously, all that will loose accuracy, so ultimately you just have to measure. I don't know of any other way.
Regards,
I didn't have in mind the OP. I had on mind the many people offering guidance in this thread.
Surely all the people giving advice on designs could each produce example(s) of how they built something loosely resembling the OP requirement and post how it measured when they were done. Surely.
Seems to me, if someone is just speaking theoretically, their post should honestly begin with a disclosure like, "Although I have never built and/or measured a speaker like this, here's my opinion...." That way, readers of this thread can tell apart the real card-players from the otherwise well-intentioned sitting around the table.
Ben
Post #3 in link below shows response of a 1955. 1.4 cu ft woofer pooping out somewhere below 21 Hz. I am not suggesting this bears hardly any relation to OP's venue, just showing that it takes no time to whoomp-up a low frequency curve and even show distortion. But it takes some intestinal fortitude to post the modest results we get at home.
http://www.diyaudio.com/forums/subwoofers/261090-freq-response-1955-ar-1-a.html
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Seems to me that you do not believe in audio/acoustical theory/laws. If someone recommends something which is firmly based on audio/acoustical theory, than it is just as good as a real world measured loudspeaker.
A sim-ignostic can conclude whatever he likes but I would conclude that the OP hasn't got a chance to even listen yet, and his budget is already shot and he probably can't squeeze a measurement mic in. The cheapest decent all in one mic is $95, a fifth of the already depleted budget.
I know I said I was done here, and I am done with the original topic, but this young whipper snapper needs to provide a response to this, and to the thread you linked to, btw thanks for posting that, I missed it the first time around. If you are going to continue to take pokes at me and at simulators I am going to continue to respond.
The real card players sitting around this table are GM, Sine143, TB46, Brian Steele. I don't know Dr Dyna well enough but he seems to know what he's talking about, and I might have forgotten or missed a few, this has been a long thread.
GM taught himself how to do this with a little help from Leach. IIRC in an 8 month period he built more stuff than most of the people on this forum just to learn, and also applied this knowledge to other things like racing. He uses simulations extensively, and I assume he's measured stuff and compared to sims. TB46 is a pillar of this community, and although I have no idea what he's built and measured, he constantly simulating and comparing sims to measurements. Brian Steele goes the extra mile, where most people only compare frequency response sims to measurements, he compares impedance sims to measurements and is a leader when it comes to educating about proper bracing, things learned through the impedance sims vs measurements. He's very particular about comparing sims to measurements. Sine is the "new guy" but he's built more than any random 10 guys you can mention. He sims and measures too.
The guys I have disagreed with, like Deward and Mark also use sims. Mark is a top fan of Hornresp, he measures too. Deward - I have no idea if he sims or not but he is a big fan of OB, specifically Linkwitz designed OB. And Linkwitz probably does not sim, but his extensive math skills make him a human simulator.
I'm pretty sure almost everyone that has posted here has simulated, built, measured and compared sims to measurements of a project very much like OP's.
And to varying degrees, I think everyone will agree that when accurate sims are compared to measurements (measurements performed outside, close mic or gated in room), the measurements will match the sims quite closely, especially at small signal levels.
Where do you think your 1955 speaker design came from? It was designed by people that knew the math. The math is the basis of simulation.
There are hundreds of examples on this forum of sims matching measurements to a high degree of accuracy. Like +/- 1 or 2 db across the passband, and within 1 or 2 hz of tuning. There are thousands of examples on the internet.
There's even a couple dozen examples that I have directly showed you. Remember the time you said that a simulator couldn't possibly predict the behavior of an OB line array so I simulated 12 Dancing Shivas OB project and matched a 12 driver manifold array sim to the owner's measurements from BOTH the front side (living room) and the back side (bassment)? Or the time I showed you with sims how your 1 meter square midrange panels couldn't possibly produce a realistic image anywhere except inside a very tight and narrow sweet spot? And so many more I don't even know why I bother anymore.
No one is saying simulations are perfect. But they are an incredibly useful tool. You've made it pretty clear that you've never even tried using a simulator before, don't understand how they work, and don't understand how trained users can work around their limitations. We know all about room issues, power compression, port compression and dozens of other factors.
I've even gone as far as finding out where my simulators can't produce a reliable accurate simulation and found a way to force a reliable accurate prediction. Simulations of high inductance drivers won't match measurements, this is a well known fact and easily seen by browsing around data-bass.com for just a few minutes. I developed a tweak to force an accurate reliable sim for these drivers. It works with any high inductance driver in any enclosure. It's not 100 percent accurate but it's most of the way there.
This is what I do, Ben. I design enclosures and I measure them and I compare.
This is the closest thing to a resume you will see from me. In early 2009 I made a website featuring a few builds done by me and a buddy in a 3 year timespan. Keep in mind, 2009 marked my 3rd year of semi-serious learning about audio. Before 2006 I really didn't know anything about anything. 5 out of 10 speaker projects on the projects page were measured using an impedance jig I made out of spare parts for the driver, and a measurement mic I made from an old computer mic capsule for frequency response measurements. This mic capsule was wicked accurate compared to all others I tested.
The 5 projects that were not measured predate my mic except for one, which was made by my buddy and given away as a gift before I had time to measure it.
https://sites.google.com/site/amateuraudio/projects-1
Most of these were measured in room, some at the listening spot ungated, as that was what I was interested in at that time, and as such the sims won't match the measurements. Some of the subs were measured properly in a way that sims will match, either outdoors or close mic inside in the middle of winter.
So you see Ben, it doesn't take intestinal fortitude, it just takes a mic and internet access. And while you can comb my old site for errors (and you will find errors, I was only 3 years in at that point) it's there and it's been there for years. And I'm exponentially smarter than I was back then.
So please tell me Ben, what have you simulated, built and measured? As far as I can tell the only thing you've ever built was a hole in a board, into which you stuck an antique woofer with 2 mm xmax. And if I remember correctly you just got your measurement mic a couple of years ago. So what were you doing over the other 60 years that you've had hifi aspirations?
I know you worked at Bell Labs and I know you worked as an engineering professor, you've mentioned this so many times in lieu of technical responses that I know your resume better than my own. In fact on two separate occasions now you've apologized for failing me in your class, which I never attended.
At this point I could publish a book with the sheer volume of posts full of technical information I've provided you, and you've ignored ALL OF IT.
All I really want, Ben, is one simple thing. A simple answer to a simple question. Can you PLEASE explain how adding a leak and some stuffing would do anything to OP's box other than alter the q a bit in a way that would do absolutely nothing at all to improve his 16 hz situation?
I'm not going to hold my breath but sometimes miracles do happen.
Oops, forgot about weltersys, he's a heavy hitter too (and I still probably forgot a few people that posted here). Although he doesn't quite believe in the accuracy of sims he does use sims as a tool. He has shown that he doesn't take the time to simulate accurately, and that's probably where his trust in sims falters, but this is more than made up for by his willingness to build, measure, tweak (x100) until he gets what he's looking for.
Not sure why he doesn't take the extra time to do accurate sims, they do produce accurate results, as indicated when I showed that the BC line of DSL subs is not magic, it's just a bit of extra boundary loading. IIRC I showed that even weltersys' barn door array boundary loading could be pretty accurately simulated.
So many sims, so many measurements, so many correlations, Ben. All out there for anyone that cares to do a simple search.
Not sure why he doesn't take the extra time to do accurate sims, they do produce accurate results, as indicated when I showed that the BC line of DSL subs is not magic, it's just a bit of extra boundary loading. IIRC I showed that even weltersys' barn door array boundary loading could be pretty accurately simulated.
So many sims, so many measurements, so many correlations, Ben. All out there for anyone that cares to do a simple search.
What I can add to this is possibly interesting.
I have over the many years of using Hornresp posted simulations versus measurements.
Quite a few have been eerily correct. And none have been off the mark by much.
As for exact boxes, well I did 15 isobarics in the late 80's for clients. I did 15 inch open baffles alla Celestion system 6000 in 1990. Did a monster 400 litre 5 pc 15 inch box tuned to 8 hertz in 1997. And drove that with a 400 watt class D amp back then.
What else.
Recent decade I have basically done either sealed sub design or horn design. And there are quite a few measurements floating around.
Enough to have confidence in the value of a properly constrained simulation.
As an example I'll post this one:
This is the actual output available from the power amplifier quoted.
Note that it is not a nice flat line. And the reasons are patently obvious to a thinking person when you consider that an amplifier is a voltage source. To keep the same output of power into a varying impedance you need almost unlimited current capability. No amplifier has that luxury.
It is how you use your simulator to design and milk information from that matters. I have had the privilege to be using Hornresp since 2000. Lets say I have learned how to use it, and trust it.
I have over the many years of using Hornresp posted simulations versus measurements.
Quite a few have been eerily correct. And none have been off the mark by much.
As for exact boxes, well I did 15 isobarics in the late 80's for clients. I did 15 inch open baffles alla Celestion system 6000 in 1990. Did a monster 400 litre 5 pc 15 inch box tuned to 8 hertz in 1997. And drove that with a 400 watt class D amp back then.
What else.
Recent decade I have basically done either sealed sub design or horn design. And there are quite a few measurements floating around.
Enough to have confidence in the value of a properly constrained simulation.
As an example I'll post this one:
This is the actual output available from the power amplifier quoted.
Note that it is not a nice flat line. And the reasons are patently obvious to a thinking person when you consider that an amplifier is a voltage source. To keep the same output of power into a varying impedance you need almost unlimited current capability. No amplifier has that luxury.
It is how you use your simulator to design and milk information from that matters. I have had the privilege to be using Hornresp since 2000. Lets say I have learned how to use it, and trust it.
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I did, on both counts. I had the first reply with the only answer necessary, which was based on having done exactly what the OP wanted (and has now done), with the same size driver, and the exact same enclosure.
I don't feel like looking back right now, but I'm pretty sure I posed a sim, and a measurement. If I neglected the measurement and there's some challenge as to whether or not I'm fibbing about it meeting the OP's requirements, I'll take a fresh measurement tomorrow and post it.
The back and forth that's going on...I mean..can't we just hug it out? It's starting to seem like the argument is the interesting part of this thread, when really the interesting part is the organ and all the equipment used...at least to me it is.
Edit: For reference, the OP's subwoofer and my subwoofer(s).
Attachments
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