Hi Bach On,
Post #1040: "...the PP and the HC12s are both 8 ohms, than a parallel connection would create a 16 ohm circuit..."
The series v. parallel got you again.
Two ea. 8 Ohm in parallel equals 4 Ohm.
We need to know the internal crossover of the Presence Presenters, if they have an internal blocking capacitor they will not affect the low end, but will reduce the impedance in the mid/high ranges. Best to run an impedance curve for the woofers, the PPs by themselves, and also when connected.
For a first connection try - at low power, to run an impedance check - connect the commons of the speakers ( - )to the common of the amplifier, and the plus inputs ( + ) of the speakers to the plus output of the amplifier.
Keep in mind, that you can buy very cheap amplifiers these days on aliexpress or ebay, so multiple amplifers are an option, and will give you much better control.
Regards,
Post #1040: "...the PP and the HC12s are both 8 ohms, than a parallel connection would create a 16 ohm circuit..."
The series v. parallel got you again.
Two ea. 8 Ohm in parallel equals 4 Ohm.We need to know the internal crossover of the Presence Presenters, if they have an internal blocking capacitor they will not affect the low end, but will reduce the impedance in the mid/high ranges. Best to run an impedance curve for the woofers, the PPs by themselves, and also when connected.
For a first connection try - at low power, to run an impedance check - connect the commons of the speakers ( - )to the common of the amplifier, and the plus inputs ( + ) of the speakers to the plus output of the amplifier.
Keep in mind, that you can buy very cheap amplifiers these days on aliexpress or ebay, so multiple amplifers are an option, and will give you much better control.
Regards,
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OK. So connecting the two 8 ohms speakers in parallel will give us 4 ohms. Good. Yep I do keep getting that mixed up.
The crossover on the Presence Presenters cut off the low sounds. We have a pair on our home organ used as antiphonals (with a separate woofer for low sounds). They handle full organ with aplomb.
Remember too that the HC12s are only being asked to play sounds from the manuals. Rarely will they be asked to play sounds that utilize the 15 inch woofers. This is one reason some felt my use of these boxes was misguided. A big point that was raised was that by using such large cabinets, they were blocking the sound from the bass speakers. I believe that one of the phrases was that they were the "wrong speakers for the assigned purpose".
We'll only have one 16 foot reed on the manuals. And the reeds for the manuals will be going to only one pair of the HC12s (channels 5 and 6).
Short of disconnecting the woofers from the built-in crossovers, I can't see a practical way to utilize the six 15 inch woofers in those HC12 boxes.
Architecture has limited the space I have in the speaker chamber. The speaker pair for channels 1 and 2 will only be about 18 inches apart. Pairs 3 and 4 and 5 and 6 will be about four or five feet apart. That's probably less than optimal for this setup. It is true that none of the organ samples we ordered are "stereo". So the same signal will go to each box of the pairs.
The concept of utilizing the PP speakers is that they are small (perhaps 10 inches high and 5.5 inches wide and 4 inches deep. I bought adjustable brackets that allow mounting them on the ceiling or wall in the pipe chamber. This could potentially add to the sense of width of the sounds for each pair.
Remember that these were thrown in for free when we bought the 10 HC12s. I didn't expect to get them. Four were placed in a box the size of the HC12. And there were two of those. So I came out with eight PPs. I've used two for parts for a dimpled tweeter and a dented mid-range dust caps on a couple of the HC12s. But we have six I put in small cabinets.
My thinking is to start off without them. Then I felt it would be a good test to add them to the mix and see what it sounds likhe. The only cost is for the brackets and the wire to go to them. I used some scrap wood for the open back cabinets. I tested them with the subwoofers. They aren't sonic powerhouses, but they do sound pretty good. And they do add to a sense of spaciousness of the soundfield.
Time and my ears will determine whether they get used. But I like having options - especially when they don't cost anything.
BTW - I'm adding some re-enforcement to the triangular box top. Hope to get it remounted when the big pipes are removed next week. Your design seems to have worked well. Thanks for passing it on to me.
Bach On
The crossover on the Presence Presenters cut off the low sounds. We have a pair on our home organ used as antiphonals (with a separate woofer for low sounds). They handle full organ with aplomb.
Remember too that the HC12s are only being asked to play sounds from the manuals. Rarely will they be asked to play sounds that utilize the 15 inch woofers. This is one reason some felt my use of these boxes was misguided. A big point that was raised was that by using such large cabinets, they were blocking the sound from the bass speakers. I believe that one of the phrases was that they were the "wrong speakers for the assigned purpose".
We'll only have one 16 foot reed on the manuals. And the reeds for the manuals will be going to only one pair of the HC12s (channels 5 and 6).
Short of disconnecting the woofers from the built-in crossovers, I can't see a practical way to utilize the six 15 inch woofers in those HC12 boxes.
Architecture has limited the space I have in the speaker chamber. The speaker pair for channels 1 and 2 will only be about 18 inches apart. Pairs 3 and 4 and 5 and 6 will be about four or five feet apart. That's probably less than optimal for this setup. It is true that none of the organ samples we ordered are "stereo". So the same signal will go to each box of the pairs.
The concept of utilizing the PP speakers is that they are small (perhaps 10 inches high and 5.5 inches wide and 4 inches deep. I bought adjustable brackets that allow mounting them on the ceiling or wall in the pipe chamber. This could potentially add to the sense of width of the sounds for each pair.
Remember that these were thrown in for free when we bought the 10 HC12s. I didn't expect to get them. Four were placed in a box the size of the HC12. And there were two of those. So I came out with eight PPs. I've used two for parts for a dimpled tweeter and a dented mid-range dust caps on a couple of the HC12s. But we have six I put in small cabinets.
My thinking is to start off without them. Then I felt it would be a good test to add them to the mix and see what it sounds likhe. The only cost is for the brackets and the wire to go to them. I used some scrap wood for the open back cabinets. I tested them with the subwoofers. They aren't sonic powerhouses, but they do sound pretty good. And they do add to a sense of spaciousness of the soundfield.
Time and my ears will determine whether they get used. But I like having options - especially when they don't cost anything.
BTW - I'm adding some re-enforcement to the triangular box top. Hope to get it remounted when the big pipes are removed next week. Your design seems to have worked well. Thanks for passing it on to me.
Bach On
I would assume they were designed with it in mind, though in that case why not just make the cones heaver? I would expect it to be easier than what they do, which is glue a large disc of very thick cardboard to the centre of the cone. Maybe there's one driver design and they adjust the size of the cardboard disc to suit. (The suspension is typically very stiff, so the added mass shouldn't cause significant sag.)
But I get your point, adding significant mass to a driver not designed for it will rarely end well.
BTW, that HT18 driver? I've been fiddling around with a few sims. If you can give up 2 sq.ft. in a corner of the church for a box that's about 6 cu.ft. high, for a 21 cu.ft. single-fold TH, you can coax 125dB@16Hz out of the thing @ about 350W. Two of them (one in each corner) will likely get you over 130dB@16 Hz for 700W input. Bandwidth only extends to 50 Hz though, so you'd better have something else that can take care of the balance of the spectrum
I'm serious, Brian. Looking down the road, this might be an interesting project to work on. I would guess the Devil would be in the details.
1. You mention that it needs to be in a corner. Would this parameter be met if the opening of the cabinet was in a corner?
2. That SI HT18 has a pretty large rear motor. It extends back about 9 inches. I notice that most of the drivers in the drawings at that link had a much smaller motor. Aside from that issue, I would need to know more about the dimensions and angles for the horn. Does your Hornresponse sim provide such details? If so, would you mind sharing them with me?
3. We really don't need 125 dB. Would a lower power (watts) simply diminish the SPL of this type of design, or would the whole concept collapse?
I'm still HOPING we can have all the sounds coming out of the speaker/pipe chambers where volume is controlled by the shades. I have discovered that there is an area over the speaker chamber ceiling that is sufficiently large that it could be used for an Infinite Baffle system. But IB - so I've been led to believe - probably won't provide the kind of volume you've described here. We are short on floorspace in the speaker chamber. That's just a reality of architecture and the choice of speakers we have. But we do have ceiling space that isn't as crowded. I'm wondering about mounting the bulk of this cabinet in the area above the ceiling, but leaving an opening in a corner where the sound would project down - either in the speaker chamber - or the pipe chamber.
I'd need to buy another amp. And I'd need another SI HT18. The other bass cabinets can take care of the sounds beyond the range of this box. I'm not talking about trying to do this in our initial install, but it would be an interesting Winter project and might be useful for down the road - especially if the existing cabinets cannot quite project enough low sounds to balance all the higher sounds from the pipes and speakers. I like options.
Does anyone else have a thought on this kind of box to cover those lowest sounds? 125 dB at 16 Hz is well beyond what I expect to get out of the two existing cabinets we'll have.
Hey! Everybody needs a hobby.
Bach On
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Oh sure, a tapped horn or 4 would certainly provide more output and efficiency, but the added complication of diy-ing one usually keeps that suggestion quiet, unless you're fairly well seasoned at building loudspeaker enclosures.
There's a lot less margin for error on cabinet construction.
But yeah, I mean...a couple of gjallerhorn type enclosures would give you discotheque level 16-60 performance.
There's a lot less margin for error on cabinet construction.
But yeah, I mean...a couple of gjallerhorn type enclosures would give you discotheque level 16-60 performance.
Since this thread is already VERY long. I've decided to start a new one in this same forum for the tapped horn concept Brian has suggested.
Here's a link to it:
http://www.diyaudio.com/forums/subw...-cabinet-16-hz-organ-speaker.html#post4398140
Anyone who wants to weigh in might make our faithful Administrator happier by posting ideas on a tapped horn design in the other thread.
I'll continue to post here on the existing project. This new one is for a potential future project.
Bach On
Here's a link to it:
http://www.diyaudio.com/forums/subw...-cabinet-16-hz-organ-speaker.html#post4398140
Anyone who wants to weigh in might make our faithful Administrator happier by posting ideas on a tapped horn design in the other thread.
I'll continue to post here on the existing project. This new one is for a potential future project.
Bach On
Brian already posted this link, Ben. But thanks. None of these experiments seem to be listed as being specifically for 16 Hz.
BO
Our organ tech just sent me this drawing of the new arrangement on our organ console. It's in the form of a PDF, if the board allows me to upload this. This is as viewed from the organ bench. The rectangular things above the top manual (keyboard) are called tabs. We needed to increase the number of these to allow for the new sounds for the 'digital sound engine.
If you zoom in you can actually read the names on the tabs. The round buttons under the manuals are for the organ presets. This allows the organist to program ahead of time which tabs will be active. This changes the sounds that are played.
The MIDI Control Center tot he right of the tab rail is new. It is part of the MIDI system that will allow us to control the digital sound engine from the console.
View attachment Elm City Console additions (2015-06-24) gjh.pdf h
The the new stop rail and the MIDI system is what will be installed in Tennessee when our organ console is taken there next week.
BO
If you zoom in you can actually read the names on the tabs. The round buttons under the manuals are for the organ presets. This allows the organist to program ahead of time which tabs will be active. This changes the sounds that are played.
The MIDI Control Center tot he right of the tab rail is new. It is part of the MIDI system that will allow us to control the digital sound engine from the console.
View attachment Elm City Console additions (2015-06-24) gjh.pdf h
The the new stop rail and the MIDI system is what will be installed in Tennessee when our organ console is taken there next week.
BO
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DrDyna - are you trying to diplomatically suggest that my usual woodworking craftsmanship may not be up to the task?
I actually can follow a blueprint.
BO
HAHAHAHA, naw, just suggesting that given your necessity to cut that one enclosure to fit it up there, you wouldn't be able to get away with that in a TH.
Been busy.
Still a lively discussion going on.
I see a wish list in terms of low end reproduction.
I have done design work for digital pipe organs before. And I did the design with a few goals in mind.
Even response.
High efficiency.
High head headroom.
These were the problems I found inherent in the existing designs.
The lack of head room and dynamics in the digital organs I have heard were not due to the samples, but due to compression on the loudspeaker system they were connected to.
So creating a dynamic responsive playback system was the key.
But, as some of you guys have pointed out. What is being sold to reproduce pipe organ sounds by the various companies is sadly lacking. And lacking in spending the money where it really matters. Proper drivers.
The Allen subwoofer mentioned is a very good example of how to get people to part with their money and get little in return.
It is an inexpensive driver that is used to it's limits. A design based more on cost constraints than on design goals.
As an example.
I modeled a dual 18 inch horn loaded subwoofer capable of reproducing 14 hertz at 120 db in 4 pi space. Free field.
Why?
Because in an actual building, 100 feet from the organ you will be able to reproduce what a real pipe organ can deliver. And still have headroom to add in other electronic stops.
Trade offs?
Big enclosure, in two parts.
Complicated enclosure. And expensive drivers. $789 each at wholesale.
A lot of power input. 4800 watts per driver. Not for continuous use, but for purposes of having enough headroom for dynamics.
The upper bass and midrange cabinets were designed in the same line. Attention to dynamic low distortion reproduction. And having a great deal of headroom inherent in the design. How? 105db/watt efficiency from the basement to the top end. That's how.
The main sticking point is that few companies can build these kinds of enclosures.
I happen to be able to.
Still a lively discussion going on.
I see a wish list in terms of low end reproduction.
I have done design work for digital pipe organs before. And I did the design with a few goals in mind.
Even response.
High efficiency.
High head headroom.
These were the problems I found inherent in the existing designs.
The lack of head room and dynamics in the digital organs I have heard were not due to the samples, but due to compression on the loudspeaker system they were connected to.
So creating a dynamic responsive playback system was the key.
But, as some of you guys have pointed out. What is being sold to reproduce pipe organ sounds by the various companies is sadly lacking. And lacking in spending the money where it really matters. Proper drivers.
The Allen subwoofer mentioned is a very good example of how to get people to part with their money and get little in return.
It is an inexpensive driver that is used to it's limits. A design based more on cost constraints than on design goals.
As an example.
I modeled a dual 18 inch horn loaded subwoofer capable of reproducing 14 hertz at 120 db in 4 pi space. Free field.
Why?
Because in an actual building, 100 feet from the organ you will be able to reproduce what a real pipe organ can deliver. And still have headroom to add in other electronic stops.
Trade offs?
Big enclosure, in two parts.
Complicated enclosure. And expensive drivers. $789 each at wholesale.
A lot of power input. 4800 watts per driver. Not for continuous use, but for purposes of having enough headroom for dynamics.
The upper bass and midrange cabinets were designed in the same line. Attention to dynamic low distortion reproduction. And having a great deal of headroom inherent in the design. How? 105db/watt efficiency from the basement to the top end. That's how.
The main sticking point is that few companies can build these kinds of enclosures.
I happen to be able to.
Sheshhh! You just had to bring that up. One little mistake and I'm to be branded as a complete woodworking failure? Woe is me!!!
And besides, I've fixed that problem. I can do better work. I just got in a hurry on that part of the box. If I can get good plans, I'll try to be good!
BO
Sheshhh! You just had to bring that up. One little mistake and I'm to be branded as a complete woodworking failure? Woe is me!!!
I can do better work. I just got in a hurry on that part of the box. If I can get good plans, I'll try to be good!
BO
I'm not trying to pick on ya, honestly..just trying to say tapped horns are quite a bit more temperamental about precision than a vented enclosure...it's not meant to say you can't accomplish it...I'm sure you can
Indeed. I used to tell students that a day in the life of a church is a month long.
These two projects sound like they'd be a grin to build and play with.
Can you give more info on this? It sounds like a Bose Bass Cannon design. Using the attic would be a problem, but I have plenty of basement space. Possibilities abound.
July 27, 2015 Progress report:
Long day. The console has now gone to the hospital. The big Bourdon pipes are gone. I'm going to need to build a small support frame to get over an uneven floor transition from the speaker chamber to the pipe chamber. Then the last two HC12 speakers will be mounted on the frame.
The organ tech has acted reluctant about this project from the beginning. But today he was talking and acting like it was all his idea. I think he was surprised and a little bit impressed with our sound speaker system. In fact, he's a little concerned the bass might be too full. He suggested I turn them around to face the back wall. Go figure!!!
So I have until Aug. 11 to get everything connected and tested. I did a dry connection on all the speaker cables to the amps. I've labeled all of them at each end. Now need to put labels on the speakers. I've left about 8 feet of slack at the amp end to allow us to roll the rack out of the closet and get to the rear for tinkering
We now have electricity in the amp closet. And we have the remote switch that will power up/down the amps when the organ switch is turned on/off. The uninterruptible power supply and the Artisan Sound Engine (actually a computer) will run 24/7. I've got to run an RJ45 network cable from the console pit to the amp rack. And the tech wants a two conductor cable for the remote switch.
I'll be connecting the cables to the speakers this week as I get the last speakers in the speaker chamber I'll connect them and begin performing some adjustments. Need to place the re-enforced upper part on the triangular box. I think the reverberation will be better. I'm also going to mount those Allen Point of Presence speakers on the wall of the pipe chamber. Got more wall space for the mounting brackets with the big pipes gone.
I've got lots to do, but it looks like the advance planning might pay off. But there's always the chance that the light I think I see at the end of tunnel is an oncoming train.
Got Honey-do jobs to do at the house Tues. and Wed. during the day. But I may be able to slip over to the church at night for some work.
I like the plan tb46 has posted for an additional bass box. And I may just try Crown to see if they'll do a custom amp for us without the roll off below 20 Hz. Chutzpa!!!
Bach On
Long day. The console has now gone to the hospital. The big Bourdon pipes are gone. I'm going to need to build a small support frame to get over an uneven floor transition from the speaker chamber to the pipe chamber. Then the last two HC12 speakers will be mounted on the frame.
The organ tech has acted reluctant about this project from the beginning. But today he was talking and acting like it was all his idea. I think he was surprised and a little bit impressed with our sound speaker system. In fact, he's a little concerned the bass might be too full. He suggested I turn them around to face the back wall. Go figure!!!
So I have until Aug. 11 to get everything connected and tested. I did a dry connection on all the speaker cables to the amps. I've labeled all of them at each end. Now need to put labels on the speakers. I've left about 8 feet of slack at the amp end to allow us to roll the rack out of the closet and get to the rear for tinkering
We now have electricity in the amp closet. And we have the remote switch that will power up/down the amps when the organ switch is turned on/off. The uninterruptible power supply and the Artisan Sound Engine (actually a computer) will run 24/7. I've got to run an RJ45 network cable from the console pit to the amp rack. And the tech wants a two conductor cable for the remote switch.
I'll be connecting the cables to the speakers this week as I get the last speakers in the speaker chamber I'll connect them and begin performing some adjustments. Need to place the re-enforced upper part on the triangular box. I think the reverberation will be better. I'm also going to mount those Allen Point of Presence speakers on the wall of the pipe chamber. Got more wall space for the mounting brackets with the big pipes gone.
I've got lots to do, but it looks like the advance planning might pay off. But there's always the chance that the light I think I see at the end of tunnel is an oncoming train.
Got Honey-do jobs to do at the house Tues. and Wed. during the day. But I may be able to slip over to the church at night for some work.
I like the plan tb46 has posted for an additional bass box. And I may just try Crown to see if they'll do a custom amp for us without the roll off below 20 Hz. Chutzpa!!!
Bach On
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iThese two projects sound like they'd be a grin to build and play with.
Can you give more info on this? It sounds like a Bose Bass Cannon design. Using the attic would be a problem, but I have plenty of basement space. Possibilities abound.
Hi Keys,
The T-TQWT concept was developed by an experience poster to this forum. This is an adaptation of his concept. I don't think the Bose Bass Cannon can go this low at this sound pressure level.
Here's a link to a T-TQWT box design tb46 posted using the Stereo Integrity HT18 driver. It has exterior dimensions of roughly 20" Wide x 27.5" Deep x 60" High - that's an internal volume a bit short of 19 cu.ft. This is currently looking likely as a Winter project for our use. The drawing is a PDF attachment in post #24.
http://www.diyaudio.com/forums/subwoofers/277489-tapped-horn-cabinet-16-hz-organ-speaker-3.html
The sims are SUGGESTING that the SPL at 16 Hz. could be around 100-115 dB. But that is predicated on accurate construction and enough amp power to be able to provide a nominal 600 watts.
There are some who feel a different driver might be better. But the $174 HT18 was used for this design.
Bach On
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