May I come in on the side with an alternative suggestion? Try the following:
Use the Targa 15 Inch "Viper Series" DVC Subwoofer (TG-V154D) drivers, either 4 units or 6 units, in a vented enclosure tuned to 16Hz. These Here are the sims:
Note, the dip in the response is an x-max dip. With the 4-driver version it dips to a low of 122dB at circa 23Hz, but at 16Hz it is up at 128dB. With the 6-driver version it dips to a low of 125.5dB at circa 23Hz, but at 16Hz it is up at almost 132dB.
Now if you increase the x-max to 21mm (150% of rated, but well within reach I think), the situation changes a bit. Here is what that looks like:
Now the situation has changed quite a lot. With the 4-driver version it dips to a low of 125.5dB at circa 23Hz, but at 16Hz it is up at slightly over 128dB. With the 6-driver version it dips to a low of 129dB at circa 23Hz, but at 16Hz it is up at almost 132dB. So with the sim of the increased x-max the dip is a lot shallower.
Now to do this you will need a lot of power, but Class-D power is cheap these days. Here is one possible solution:
For the 4-driver version:
2x 2500 Watts Switching Power Supply for Audio Power Amplifier
8x IRAUD350 High Power 700W Class D Amplifier
That will provide 1400W per driver, 5600W in total.
For the 6-driver version:
3x 2500 Watts Switching Power Supply for Audio Power Amplifier
12x IRAUD350 High Power 700W Class D Amplifier
That will provide 1400W per driver, 8400W in total. That should be more than enough to get you high.
Given this amplifier solution, here is what you get:
The sims then indicate 126.65dB at 16Hz for the 4-driver version, and 130dB at 16Hz for the 6-driver version. Is this loud enough for you?
Deon
PS. It seems these drivers are getting more scarce, but there are still a few available here in SA. The price per unit is in the $100 range.
Use the Targa 15 Inch "Viper Series" DVC Subwoofer (TG-V154D) drivers, either 4 units or 6 units, in a vented enclosure tuned to 16Hz. These Here are the sims:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Note, the dip in the response is an x-max dip. With the 4-driver version it dips to a low of 122dB at circa 23Hz, but at 16Hz it is up at 128dB. With the 6-driver version it dips to a low of 125.5dB at circa 23Hz, but at 16Hz it is up at almost 132dB.
Now if you increase the x-max to 21mm (150% of rated, but well within reach I think), the situation changes a bit. Here is what that looks like:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Now the situation has changed quite a lot. With the 4-driver version it dips to a low of 125.5dB at circa 23Hz, but at 16Hz it is up at slightly over 128dB. With the 6-driver version it dips to a low of 129dB at circa 23Hz, but at 16Hz it is up at almost 132dB. So with the sim of the increased x-max the dip is a lot shallower.
Now to do this you will need a lot of power, but Class-D power is cheap these days. Here is one possible solution:
For the 4-driver version:
2x 2500 Watts Switching Power Supply for Audio Power Amplifier
8x IRAUD350 High Power 700W Class D Amplifier
That will provide 1400W per driver, 5600W in total.
For the 6-driver version:
3x 2500 Watts Switching Power Supply for Audio Power Amplifier
12x IRAUD350 High Power 700W Class D Amplifier
That will provide 1400W per driver, 8400W in total. That should be more than enough to get you high.
Given this amplifier solution, here is what you get:
An externally hosted image should be here but it was not working when we last tested it.
The sims then indicate 126.65dB at 16Hz for the 4-driver version, and 130dB at 16Hz for the 6-driver version. Is this loud enough for you?
Deon
PS. It seems these drivers are getting more scarce, but there are still a few available here in SA. The price per unit is in the $100 range.
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"Loud enough for you?" Is that some kind of joke? Sims don't make any noise. Or if they do, better check your computer.
Seeing properly conducted REW mic plots is what the question, "Loud enough for you?" can be based on. Not theoretical models playing pure tones in perfect rooms using the imaginative specs of driver manufacturers.
Ben
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Hi Ben
I did not mean to offend. That was meant in jest, as a lighthearted comment. I meant is 130dB loud enough. This is a cheap solution for high SPLs low down.
Deon
No, I'm the one who should apologize for making a cheap pedantic joke just because you didn't say the needlessly long-winded "...loud as predicted by...." or something like that.
But my essential comment is that sim results are presented as if everybody knew the assumptions that come along with them and limit them.
Really, sim results should not be definitive looking lines (like your attractive charts). Rather they should be gray areas showing expected results in light of practical variations.
Ben
But my essential comment is that sim results are presented as if everybody knew the assumptions that come along with them and limit them.
Really, sim results should not be definitive looking lines (like your attractive charts). Rather they should be gray areas showing expected results in light of practical variations.
Ben
This design will get you there with a 100 watt amp!
RE: Bigger can be better when its small - Rafaro - High Efficiency Speaker Asylum
A 17 Hz front horn loaded design with over 110 Db @ 1 watt measures 5 ft deep 4 feet high and mouth 8 ft x 4 ft
Best
RE: Bigger can be better when its small - Rafaro - High Efficiency Speaker Asylum
A 17 Hz front horn loaded design with over 110 Db @ 1 watt measures 5 ft deep 4 feet high and mouth 8 ft x 4 ft
Best
4 x Dayton UM 18 will produce 130 dB and go FLAT down to 16 Hz with 1000 watts each. According to sims anyway. The ported enclosure would be rather large at 2000 liter but thats the price you pay. Those Targa subs will melt with 1400 ( proper ) watts so perhaps for the money just use 8 or 12. One note sub is pretty useless though. Those automotive SPL subs are nasty.
I didn't know pipe organs went that low, 16Hz you wouldn't hear it, that would be handy to introduce a "wrath of God" type of sensation at key points during a sermon, like the old Cerwin Vega "Earthquake" horns use to do at the movies, subsonic rumble triggered off an optical track on the film.
The 16Hz comes from pedal stops of 32' pitch played on the lowest C. There are several families of voices that are at that pitch, from soft flutes and strings, to loud principals, and finally the very bombastic Bombardes that sound like thunder!
There are a few pipe (and indeed virtual) organs that have 64' stops, an octave lower, which would mean an incredible 8Hz!!! However these are quite rare.
Organ voicing is quite like orchestration, in that one seldom uses something like a 32' stop alone. It is used more often to build and fortify other pitches, harmonics and timbres.
The sub-sonics are viscerally felt, increasing the sense of drama. I still remember in my youth (when mastodons walked the earth) the first time I heard Widors Toccata, all I could think of was "thunder and lightening!!!"
~Scott
http://www.diyaudio.com/forums/subwoofers/132377-phantoms-organ-halloween-bash.html
Comforting to remember that old-person sensory losses may not diminish our joy for the super low frequency stuff.
Your hearing system "hears" low notes if the partials are present but not the fundamental. Unless you have a lot of experience with mics and objective measurements, a lot of people are way lacking in judgment about how low their system goes. A lot of guys with loud audio booming at 45 Hz think they have great bass. Likewise for the screwball practice (arising from mindless use of sims) of putting sub drivers into small sealed boxes that raises their cut-off up to 50Hz.
Ben
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Hey Ben, that "Phantoms of the Organ" looked cool! I studied on a baroque styled Casavant in college.
You are correct about not being able to hear the fundamental of those lowest 32' notes. One mostly 'feels' them viscerally. Kind of like being in a swimming pool when someone sets off an M-80! Those slow waves actually shake your guts. this can be compounded with stops tuned to the harmonics of the 32' pitch, like 10 2/3', which is the 3rd harmonic. When added to a 16' stop, the 2 (16' and 10 2/3') will mix in the air and 'beat down' to the 1st harmonic of 32' pitch. This is referred to as a "Resultant" or Acoustic Bass". The effect works best on the lowest octave, but has a lot more rumble than a true 32'.
I was glad to see Boelmans Toccata get mentioned on the Halloween bash, that is a really spooky sounding piece!!!
~Scott
You are correct about not being able to hear the fundamental of those lowest 32' notes. One mostly 'feels' them viscerally. Kind of like being in a swimming pool when someone sets off an M-80!
Those slow waves actually shake your guts. this can be compounded with stops tuned to the harmonics of the 32' pitch, like 10 2/3', which is the 3rd harmonic. When added to a 16' stop, the 2 (16' and 10 2/3') will mix in the air and 'beat down' to the 1st harmonic of 32' pitch. This is referred to as a "Resultant" or Acoustic Bass". The effect works best on the lowest octave, but has a lot more rumble than a true 32'.I was glad to see Boelmans Toccata get mentioned on the Halloween bash, that is a really spooky sounding piece!!!
~Scott
What you are describing is pretty vague.
If people are putting subs in small sealed boxes and getting terrible in room frequency response as the end product then they simply don't know what they are doing, it has nothing at all to do with sims. If they can't figure out what alignment will give flat response in room, can't measure and can't eq, they simply don't know what they are doing and the sim cannot be blamed for that.
BUT on the other hand there are plenty of people putting 18 inch drivers into 4 cu ft boxes and getting flat bass down to low single digit frequencies.
How does that happen?
People that know very well what they are doing use simulators to find out how small the box can be and still reach xmax within the driver's rated power handling. THEN they take that response and eq it so it's measurably flat in room.
There are people that know what they are doing and people that don't. You are describing people that don't have a clue. But there are people that are quite smart and can use simulators to size a box to very small dimensions and still get it's full potential (minus power compression of course) out of that tiny box with flat bass almost down to dc.
Bigger boxes are better but don't fault people that prefer to use smaller boxes because it's quite acceptable.
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