Moving forward. Looking good.
Once back inside, you can fit all that good carpentry together - without using glue - and give it a test run with a mic and REW.
Tiny leaks or vibrations might be present during test. But they represent just little pains during this test; those minor leak pains bear no comparison to the big pain from kicking yourself later on for forgetting to benchmark performance under conventional, design-target room conditions before installation in the organ pipe space.
Ben
Once back inside, you can fit all that good carpentry together - without using glue - and give it a test run with a mic and REW.
Tiny leaks or vibrations might be present during test. But they represent just little pains during this test; those minor leak pains bear no comparison to the big pain from kicking yourself later on for forgetting to benchmark performance under conventional, design-target room conditions before installation in the organ pipe space.
Ben
I'm about ready to do the wiring for this box. I'd like to confirm that I'm thinking correctly before closing up the box.
.
The speaker has two sets of 2 ohm voice coils. My goal is to connect the voice coils in a series - which should create a 4 ohm output from the amp.
Please confirm that this is the correct circuit. (Yes. I'm not all that great with MS Paint. But maybe you get the point.)
Bach On
.
The speaker has two sets of 2 ohm voice coils. My goal is to connect the voice coils in a series - which should create a 4 ohm output from the amp.
Please confirm that this is the correct circuit. (Yes. I'm not all that great with MS Paint. But maybe you get the point.)
Bach On
16 hz for church organ
I have read with interest the discussion on this topic. FWIW, many pipe organs have a few sounds that are generated electronically. Some use older technology and some use digital methods. Some even have more electronic sounds than pipes, depending on space, money, preferences, etc., etc. Mixing the two is no problem. Keep in mind that a single pipe produces only one pitch of one tone color at one volume level. That's why organs have hundreds and even thousands of pipes. For the pedals (where 32' pipes producing 16 hz for the lowest pitch are usually located) there have to be 32 pipes, one for each pedal on a standard church organ. That requires LOT of material and real estate.
Most organists really want this sound if at all feasible. In a well-regulated set of pipes at this pitch it needn't be really loud to be heard under the loudest sounds of the organ, yet it can sit under the softest sounds without overpowering them. The pipes at this pitch don't speak instantaneously either, so transients aren't so important as they are in home theater and stereo. Maybe it's because the point is to produce rather than to recreate sound. Anyway, one pipe organ builder a few generations ago was criticized for how slow some of his lowest pipes were. He replied that the slow start was compensated for by an even slower release!
Pipes have been put behind walls (with openings into the seating area), above the ceiling, and even under the floor. Finding space might not be too much problem. Electronics won't be as sensitive to temperature fluctuations as pipes will be either, another plus.
I'm interested to read the rest of this thread. I have a rig that does well to about 23 hz and I'm eager to get the last half octave at the bottom. I can send even specific notes to a specific amp and speaker, so I'm interested to learn what you think the best way to do it is.
Have fun.
John
I have read with interest the discussion on this topic. FWIW, many pipe organs have a few sounds that are generated electronically. Some use older technology and some use digital methods. Some even have more electronic sounds than pipes, depending on space, money, preferences, etc., etc. Mixing the two is no problem. Keep in mind that a single pipe produces only one pitch of one tone color at one volume level. That's why organs have hundreds and even thousands of pipes. For the pedals (where 32' pipes producing 16 hz for the lowest pitch are usually located) there have to be 32 pipes, one for each pedal on a standard church organ. That requires LOT of material and real estate.
Most organists really want this sound if at all feasible. In a well-regulated set of pipes at this pitch it needn't be really loud to be heard under the loudest sounds of the organ, yet it can sit under the softest sounds without overpowering them. The pipes at this pitch don't speak instantaneously either, so transients aren't so important as they are in home theater and stereo. Maybe it's because the point is to produce rather than to recreate sound. Anyway, one pipe organ builder a few generations ago was criticized for how slow some of his lowest pipes were. He replied that the slow start was compensated for by an even slower release!
Pipes have been put behind walls (with openings into the seating area), above the ceiling, and even under the floor. Finding space might not be too much problem. Electronics won't be as sensitive to temperature fluctuations as pipes will be either, another plus.
I'm interested to read the rest of this thread. I have a rig that does well to about 23 hz and I'm eager to get the last half octave at the bottom. I can send even specific notes to a specific amp and speaker, so I'm interested to learn what you think the best way to do it is.
Have fun.
John
keys,
Welcome to the discussion. I came to this forum to learn how to reproduce a quality sound down to 16 hz. I'd been discussing it at the organforum.com prior to that. Many there suggested ideas to do it. But some suggested I come to this site for more definitive ideas.
Here's a link to the organforum.com discussion.
Organ Subwoofer Design & Construction
Here's a link to the original discussion of overall project I'm trying to do.
Wanted Dead or Alive (Prefer Live)
Looking back, the discussion has sometimes been all over the map. But I have received what I think was good input from many here. I've also begun to see that using math based simulators like REW can SOMETIMES save having to build based on a suspicion. I'm still learning how to use some of the tools. But many have posted data that has been very helpful in my quest.
There are at least some on this forum who know sound equipment very well, but know a lot less about organs. Others have more of what might be called an more experienced organ IQ. Like you've said, often the lows on an organ don't need to be that loud to be effective. Sometimes the differences may just be a matter of the tastes of the organ builder and/or the organist.
I'm currently in the last stretch of trying to build speakers capable of reproducing those pedal sounds down to 16 hz. My earlier box can do it, but the volume level (what folks here refer to as SPL - Sound Pressure Level) isn't very loud. Many felt (and still feel) it will be inadequate to project the sound with authority into our Sanctuary. They posted results from the simulators that convinced me that more might be needed.
The latest box I'm building is based on a larger woofer with different characteristics. The prognostication is that this may produce the sounds I'm trying include with a higher SPL. My hope is that these two fairly large bass cabinets will be adequate for the task.
I have played many electronic organs that could come close to 16 hz. But, as you've experienced, reproducing that last half octave is really tough.
I bought some lower cost tools to measure the results. I hope to be able to post figures that will provide a visual record of what I am hearing.
Keep your fingers crossed.
Bach On
Welcome to the discussion. I came to this forum to learn how to reproduce a quality sound down to 16 hz. I'd been discussing it at the organforum.com prior to that. Many there suggested ideas to do it. But some suggested I come to this site for more definitive ideas.
Here's a link to the organforum.com discussion.
Organ Subwoofer Design & Construction
Here's a link to the original discussion of overall project I'm trying to do.
Wanted Dead or Alive (Prefer Live)
Looking back, the discussion has sometimes been all over the map. But I have received what I think was good input from many here. I've also begun to see that using math based simulators like REW can SOMETIMES save having to build based on a suspicion. I'm still learning how to use some of the tools. But many have posted data that has been very helpful in my quest.
There are at least some on this forum who know sound equipment very well, but know a lot less about organs. Others have more of what might be called an more experienced organ IQ. Like you've said, often the lows on an organ don't need to be that loud to be effective. Sometimes the differences may just be a matter of the tastes of the organ builder and/or the organist.
I'm currently in the last stretch of trying to build speakers capable of reproducing those pedal sounds down to 16 hz. My earlier box can do it, but the volume level (what folks here refer to as SPL - Sound Pressure Level) isn't very loud. Many felt (and still feel) it will be inadequate to project the sound with authority into our Sanctuary. They posted results from the simulators that convinced me that more might be needed.
The latest box I'm building is based on a larger woofer with different characteristics. The prognostication is that this may produce the sounds I'm trying include with a higher SPL. My hope is that these two fairly large bass cabinets will be adequate for the task.
I have played many electronic organs that could come close to 16 hz. But, as you've experienced, reproducing that last half octave is really tough.
I bought some lower cost tools to measure the results. I hope to be able to post figures that will provide a visual record of what I am hearing.
Keep your fingers crossed.
Bach On
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Very helpful post from Keys.
Monumentally hard to hear 16 Hz* and doubly-monumentally hard to produce it so anybody can hear it. (Actually, nobody hears it anyway, just a matter of bodily sensations and building shakes. If the windows in your music room don't rattle, you aren't playing below 20 Hz.)
I bet most electric organs don't even bother putting out a 16 Hz signal, instead depending on the brain to create the fundamental.
But a chance Bach On's speakers could make a 16 Hz sound at some detectable if quite low level, if the tone-generator produces it (who knows???). If it were my organ, I'd crank up the EQ like everybody does at home to produce a house curve. No sense being a purist.
When an amp is putting a necessarily strong 16 Hz tone into a speaker, you are getting 10% total, if harmonic, distortion. That 10% will be heard louder than the 16 Hz. On a good day, you'll say, "My speaker plays 16 Hz because I (imagine) heard it." To make a long story short, only a mic can tell for sure.
Ben
*like 30dB below mid-range loudness
Monumentally hard to hear 16 Hz* and doubly-monumentally hard to produce it so anybody can hear it. (Actually, nobody hears it anyway, just a matter of bodily sensations and building shakes. If the windows in your music room don't rattle, you aren't playing below 20 Hz.)
I bet most electric organs don't even bother putting out a 16 Hz signal, instead depending on the brain to create the fundamental.
But a chance Bach On's speakers could make a 16 Hz sound at some detectable if quite low level, if the tone-generator produces it (who knows???). If it were my organ, I'd crank up the EQ like everybody does at home to produce a house curve. No sense being a purist.
When an amp is putting a necessarily strong 16 Hz tone into a speaker, you are getting 10% total, if harmonic, distortion. That 10% will be heard louder than the 16 Hz. On a good day, you'll say, "My speaker plays 16 Hz because I (imagine) heard it." To make a long story short, only a mic can tell for sure.
Ben
*like 30dB below mid-range loudness
16 hz for church
Just a Guy
Some folk DO use a pipe of sorts, usually calling it a horn, folded horn, tapped horn, bass cannon, etc. depending on design. With a speaker, though, you need only one device (or array) to produce many notes. A pipe produces only one note of one tone color at one volume level. More notes = more pipes; it quickly becomes prohibitive.
Just a Guy
Some folk DO use a pipe of sorts, usually calling it a horn, folded horn, tapped horn, bass cannon, etc. depending on design. With a speaker, though, you need only one device (or array) to produce many notes. A pipe produces only one note of one tone color at one volume level. More notes = more pipes; it quickly becomes prohibitive.
Keys,
I think you said your rig would produce sounds down to 23 Hertz. That means only five or six notes in that lowest 32 foot octave aren't being played.
If a speaker was specifically designed and created for each of the frequencies of those five "pipes" then the sounds could be routed to one of those five speakers for optimal results.
We had a lengthy discussion of this kind of setup over at the organforum a few months back. The consensus was this was cost prohibitive and probably wasn't needed.
I've toyed with the idea of having this last box offline except when those lowest notes are needed. But I'll probably just use the software for our sound engine to adjust the volume note by note with all the speakers playing.
Time will reveal what results we will get.
Bach On
I think you said your rig would produce sounds down to 23 Hertz. That means only five or six notes in that lowest 32 foot octave aren't being played.
If a speaker was specifically designed and created for each of the frequencies of those five "pipes" then the sounds could be routed to one of those five speakers for optimal results.
We had a lengthy discussion of this kind of setup over at the organforum a few months back. The consensus was this was cost prohibitive and probably wasn't needed.
I've toyed with the idea of having this last box offline except when those lowest notes are needed. But I'll probably just use the software for our sound engine to adjust the volume note by note with all the speakers playing.
Time will reveal what results we will get.
Bach On
Hi keys,
I getting ready to go on vacation, so I don't have time to expand on this subject, but maybe just a guy can:
Post #750: "...folk DO use a pipe of sorts, usually calling it a horn, folded horn, tapped horn, bass cannon, etc...."
That is throwing a bunch of loudspeakers into one category that do not necessarily belong together, but it would certainly be possible to use horns or 1/4 wave resonators to produce the low end of an organ; they are not single note devices if properly designed. You should get at least two octaves of bandwidth if not more. The big advantage of the vented (bass reflex) design is its comparative size. You just have to pay attention to the size and design of the port. A very nice design was mentioned earlier, from data-bass.com (DIY XXX Ported):
Data-Bass
Also, the problem in Bach On's case was that the big box was already build and the loudspeakers choosen, and that there is only one small corner of limited height for the second (triangular) box; there also is no easy access to the location of the loudspeakers and a plethora of other loudspeakers and organ components in the same location. In a way, architecture determined the design.
Regards,
I getting ready to go on vacation, so I don't have time to expand on this subject, but maybe just a guy can:
Post #750: "...folk DO use a pipe of sorts, usually calling it a horn, folded horn, tapped horn, bass cannon, etc...."
That is throwing a bunch of loudspeakers into one category that do not necessarily belong together, but it would certainly be possible to use horns or 1/4 wave resonators to produce the low end of an organ; they are not single note devices if properly designed. You should get at least two octaves of bandwidth if not more. The big advantage of the vented (bass reflex) design is its comparative size. You just have to pay attention to the size and design of the port. A very nice design was mentioned earlier, from data-bass.com (DIY XXX Ported):
Data-Bass
Also, the problem in Bach On's case was that the big box was already build and the loudspeakers choosen, and that there is only one small corner of limited height for the second (triangular) box; there also is no easy access to the location of the loudspeakers and a plethora of other loudspeakers and organ components in the same location. In a way, architecture determined the design.
Regards,
Just tacking on to tb46's observations, we're back into confusion about instruments versus reproducers and some confusion about what cabs do.
For the most part, one speaker can play anything you want, allowing for constraints of power handling, doppler distortion, efficiency, and other parameters that aren't inherent determiners of sound quality if you are playing within the limits of the speaker. In practice, practical issues arise, of course.
The last thing audiophiles want is a speaker that has identifiable characteristics. Which is why some audiophiles diss systems that traffic in resonances.
Can you make an electric organ with a rank of tuned boxes... different size high-Q drivers, different box tunings....? Why not?
Ben
Bach On,
Although it is possible to tune a sub to a very specific bandwidth and increase output at that frequency, the enclosure must be still be individually be very large (about as large as a bass reflex) for these low frequencies.
Doubling enclosures and power results in 6 dB more output, at 20 Hz it only requires a 5 db increase to sound (or feel, for those of you who don't hear well that low ;^) "twice as loud", so you are better off just doing multiples of a sub capable of an octave (or two) rather than frequency specific devices covering only a few notes.
Art
Your main mandate on this forum is to reference the "evils of trafficking in resonances", despite the fact that you've never heard a tapped horn, have never heard a properly designed ported box, you actually LIKE front loaded horns and you've never actually said what exactly is wrong with resonances.
Enough is enough, let's hit this resonance issue head on, shall we?
As I've mentioned a few dozen times, a ported box can be designed to have the same response as a sealed box, and if you build both (with front baffles the same dimensions) and test them blind I'd be VERY surprised if you could tell them apart.
An externally hosted image should be here but it was not working when we last tested it.
That's a sealed box and a ported box response overlaid, same driver, same 1 watt input. If you add a small amount of stuffing to each, to get the higher resonances down to about +/- 1db, level match the 1 db difference, add a high pass filter to the ported (to protect it below tuning, which also rolls it off at tuning a bit to make the response curves match even better) and sit them side by side and blind test, do you think you could tell them apart? I doubt it.
I'll repeat that part again in case it's not clear - natural box losses and a small amount of stuffing will get BOTH of these designs to have no more than about +/- 1 db of ripple in those higher harmonics.
Details -
Sealed box - net volume ~= VAS, 200 liters
Ported box - net volume = 100 liters + port volume
A closer look that these boxes -
First row - frequency response
Second row - impedance
Third row - excursion
Fourth row - group delay
An externally hosted image should be here but it was not working when we last tested it.
There are three big differences.
1. The sealed box is almost 2x larger.
2. Group delay is a bit higher on the ported box, but only below tuning, and tuning is very low - in other words inaudible difference. The GD spikes higher in frequency are very narrow and won't actually show up in measurements or listening tests.
3. The ported box (once a high pass filter has been added) will go 10 db louder within xmax limits.
In other words the ported box will sound the same AND go 10 db louder. Resonances are not an issue (the sealed box has resonances too, both will be wiped out in real life by box losses and a small amount of stuffing), group delay is not an issue.
This ported box is "audiophile approved" in that it's got a sealed box style rising response (low q) aka not a whole lot of bass. No muddy, overwhelming, bloated bass. It's not the resonances that cause the problem, it's the design goals and methods.
So where is the issue?
This all might be a bit hard to swallow if all you've ever heard are max flat ported boxes (by far the most common design goal) where the flattest possible response to the lowest possible frequency is the goal target, but that will sound horribly boomy in room, leading you to believe resonances are a problem when in fact it's bad design that is the problem.
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Now let's take a look at sealed vs horns. You've never heard a tapped horn so we'll ignore those for now, you HAVE heard front loaded horns and actually like them.
Here's a sealed box vs a front loaded horn.
Details - same sealed box as shown above, same driver, same 1 watt input
FLH - ideal full size flh design, same driver, same 1 watt input
There's 10 db difference at 100 hz, 20 db difference at 30 hz, that's huge. How did this happen?
Now let's look at an undersized flh compared to that same sealed box.
In this example the sealed box and the flh are close to the same size, so naturally the flh doesn't have much (if any) advantage in any area these graphs show. The flh has a few more db in certain areas, but it also has big spiky resonant peaks and much higher group delay.
Yes, I said RESONANT peaks. Look at the impedance graph. These peaks are caused by resonances.
This undersized flh response isn't even really that bad. The Klipschhorn measured response is MUCH worse than the undersized flh I showed here, and you LOVED that horn.
So now let's take another look at the sealed box vs the full size flh I showed earlier.
The resonances are still there, you can see them in the impedance graph.
The flh's massive gain comes from RESONANCES. Some people call it an acoustic transformer, but it's really just really strong, wide bandwidth resonances that cause up to 3 octaves of gain and if the horn is big enough you get almost ruler flat response across those 3 octaves.
So where is the issue here?
Group delay is still much worse here than in the sealed box, but it's fairly constant until down near tuning so it can mostly fixed by delaying the mains.
In all performance aspects the flh kills the sealed box, and the flh uses resonances to achieve this high performance.
Where is the issue, Ben?
You like flhs in particular you like the massively undersized flhs you have heard, with their massive spikey resonant response and bad group delay.
Flhs are much the same as tapped horns, with a few key differences, but both are driven by resonances, so how can you like one but not the other, especially when you've never heard a tapped horn?
Here's a sealed box vs a front loaded horn.
An externally hosted image should be here but it was not working when we last tested it.
Details - same sealed box as shown above, same driver, same 1 watt input
FLH - ideal full size flh design, same driver, same 1 watt input
There's 10 db difference at 100 hz, 20 db difference at 30 hz, that's huge. How did this happen?
Now let's look at an undersized flh compared to that same sealed box.
An externally hosted image should be here but it was not working when we last tested it.
In this example the sealed box and the flh are close to the same size, so naturally the flh doesn't have much (if any) advantage in any area these graphs show. The flh has a few more db in certain areas, but it also has big spiky resonant peaks and much higher group delay.
Yes, I said RESONANT peaks. Look at the impedance graph. These peaks are caused by resonances.
This undersized flh response isn't even really that bad. The Klipschhorn measured response is MUCH worse than the undersized flh I showed here, and you LOVED that horn.
So now let's take another look at the sealed box vs the full size flh I showed earlier.
An externally hosted image should be here but it was not working when we last tested it.
The resonances are still there, you can see them in the impedance graph.
The flh's massive gain comes from RESONANCES. Some people call it an acoustic transformer, but it's really just really strong, wide bandwidth resonances that cause up to 3 octaves of gain and if the horn is big enough you get almost ruler flat response across those 3 octaves.
So where is the issue here?
Group delay is still much worse here than in the sealed box, but it's fairly constant until down near tuning so it can mostly fixed by delaying the mains.
In all performance aspects the flh kills the sealed box, and the flh uses resonances to achieve this high performance.
Where is the issue, Ben?
You like flhs in particular you like the massively undersized flhs you have heard, with their massive spikey resonant response and bad group delay.
Flhs are much the same as tapped horns, with a few key differences, but both are driven by resonances, so how can you like one but not the other, especially when you've never heard a tapped horn?
Now a quick word about audiophiles.
This term may have had a positive meaning at some point, but since I've been involved in audio it's synonymous with a uniquely uneducated group of people that spend the cost of a new sports car on a short piece of wire, don't believe in crossovers or tone knobs or anything else in the signal path, strive to find the drivers with the most unnatural frequency response dominated by cone breakup for their uncanny levels of "detail", and prefer the lowest q bass possible (aka no bass, also for the level of "detail" that no bass provides). As a group, the people that identify as audiophiles these days have way more money than brains, and no more common sense than the average toddler.
You are quite correct, there are masses of people who call themselves audiophiles that completely agree that resonances are evil. They have no idea what they are talking about.
Let's discuss science here, not what audiophiles prefer. Let's actually discuss this resonance issue this time. Usually you just ignore my comments and evidence and then pop up in any number of other threads with the same "trafficking in evil resonances" rhetoric.
This term may have had a positive meaning at some point, but since I've been involved in audio it's synonymous with a uniquely uneducated group of people that spend the cost of a new sports car on a short piece of wire, don't believe in crossovers or tone knobs or anything else in the signal path, strive to find the drivers with the most unnatural frequency response dominated by cone breakup for their uncanny levels of "detail", and prefer the lowest q bass possible (aka no bass, also for the level of "detail" that no bass provides). As a group, the people that identify as audiophiles these days have way more money than brains, and no more common sense than the average toddler.
You are quite correct, there are masses of people who call themselves audiophiles that completely agree that resonances are evil. They have no idea what they are talking about.
Let's discuss science here, not what audiophiles prefer. Let's actually discuss this resonance issue this time. Usually you just ignore my comments and evidence and then pop up in any number of other threads with the same "trafficking in evil resonances" rhetoric.
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Sounds more like audiofools than audiophiles, LOL.
All subwoofer alignments involve some sort of resonance.
Oh, BTW, did I tell you that I believe I've worked out how TD got the TH118 down to 28 Hz? Hint - it's in the impedance plot.
I saw that you mentioned that you figured it out in some different thread I think but I didn't see the explanation. I've been waiting for you to spill the beans. I can't recall if I ever even looked at the impedance, if I did it was awhile ago.
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