In the May 2007 issue of Sound&Vision, Tom Nousaine is quoted as saying that an authentic subwoofer must reproduce the bottom two octaves (5-10Hz, and 10-20Hz)...

Nousaine's idea of an authentic sub is the Eminent Technology TRW-17, starting at $12,900.

I know this has been discussed before. I wonder if Nousaine has the Thigpen Rotary Woofer? I remember his article in Sound&Vision about his IB subwoofer that was driven by a Crown Macro Reference amp. I think his IB had 8 fifteen inch drivers, or maybe it was only 6 fifteen inch drivers.

Nousaine said the Thigpen Rotary Woofer "was producing more than 110db at 4-25 Hz in a real room at CES".

Too bad I'm only flat to 12 Hz.

Kind Regards

Is Tom Nousaine the new flavor of the month for you this time? ;)


Darn. :(

I was hoping for another:


"Hi guys

I may be a broken record, but the 112 db @20Hz with the HSU VTF3.3 plus Turbo for $899 delivered, measured by Howard Ferstler, is more than satisfactory to me. He tested the SVS PC-Ultra...

Kind Regards"

or


"That is some great output. In the test by Howard Ferstler he hit 112 db at 20Hz with the HSU VTF-3Mk3 plus Turbo. That was a new record.

Kind Regards "

or

"
I think that perhaps the most underrated sub around is the HSU VTF-3.3 (plus Turbo). For $899 delivered, this thing can do 112 db @20Hz.

Kind Regards"



So... how many dBs can HSU VTF-3.3 (plus Turbo) hit at 20hz?, I must have missed it.
Also, Is it white and longer than your average cloak or cape?

Hehe
:p I'm just teasing.

Considering the human ear can't hear below 20hz and how much of actual music or movies are below that, it is about as much as a non issue as there is. Sure we can feel lower Hz below 20, but as we get older, not only do we lose the ability to hear certain higher frequencies, but I think as far as music, only Pipe Organ foot pedals are around 30 or below. :confused:

Oh brother. :mad: He just won't quit. :D

A standard 6-string bass is tuned to B 30.8Hz. A lot of 4-string's are steped down to this note as well.

In the May 2007 issue of Sound&Vision, Tom Nousaine is quoted as saying that an authentic subwoofer must reproduce the bottom two octaves (5-10Hz, and 10-20Hz)...

Nousaine's idea of an authentic sub is the Eminent Technology TRW-17, starting at $12,900.

I know this has been discussed before. I wonder if Nousaine has the Thigpen Rotary Woofer? I remember his article in Sound&Vision about his IB subwoofer that was driven by a Crown Macro Reference amp. I think his IB had 8 fifteen inch drivers, or maybe it was only 6 fifteen inch drivers.

Nousaine said the Thigpen Rotary Woofer "was producing more than 110db at 4-25 Hz in a real room at CES".

Too bad I'm only flat to 12 Hz.

Kind Regards

your flat to 12hz with HSUs huh?

interesting.

-Eli

your flat to 12hz with HSUs huh?

interesting.

-Eli

Eli, in his world he is. :D Of course, so is his world. :D

Nothing wrong with defining things differently as technology improves.

Art

Definitely not, just consider the source of the definition. :D
Tom Nousaine?

Is Tom Nousaine the new flavor of the month for you this time? ;)


Darn. :(

I was hoping for another:


"Hi guys

I may be a broken record, but the 112 db @20Hz with the HSU VTF3.3 plus Turbo for $899 delivered, measured by Howard Ferstler, is more than satisfactory to me. He tested the SVS PC-Ultra...

Kind Regards"

or


"That is some great output. In the test by Howard Ferstler he hit 112 db at 20Hz with the HSU VTF-3Mk3 plus Turbo. That was a new record.

Kind Regards "

or

"
I think that perhaps the most underrated sub around is the HSU VTF-3.3 (plus Turbo). For $899 delivered, this thing can do 112 db @20Hz.

Kind Regards"



So... how many dBs can HSU VTF-3.3 (plus Turbo) hit at 20hz?, I must have missed it.
Also, Is it white and longer than your average cloak or cape?

Hehe
:p I'm just teasing.

I would love to see some /THD/room size/distance from sub/ numbers with all of these readings above @20Hz :D

I would love to see some /THD/room size/distance from sub/ numbers with all of these readings above @20Hz :D

If nothing else, he provides consistent entertainment! :D

:D :D Spyboy.
I guess I don't get it. He posts 10 or so sentences regarding Tom Nousaine, one about 12hz in his room, and you guys get on his case for what he has posted in other threads.

Clearly there are others that do similar things and can't even point to a reference like Ferstler.

In the very least, Nousaine's comments are interesting, but you guys are more interested in railing spyboy?

I guess I don't get it. He posts 10 or so sentences regarding Tom Nousaine, one about 12hz in his room, and you guys get on his case for what he has posted in other threads.

Clearly there are others that do similar things and can't even point to a reference like Ferstler.

In the very least, Nousaine's comments are interesting, but you guys are more interested in railing spyboy?

Yeah, I guess it is a bit off-topic. I apologize for that, but a little rattling of the cage usually never hurts anyone.... :p If it does, I'll stand down. I find that part of forums entertaining as long as I see no claws :D

I guess I don't get it. He posts 10 or so sentences regarding Tom Nousaine, one about 12hz in his room, and you guys get on his case for what he has posted in other threads.

Clearly there are others that do similar things and can't even point to a reference like Ferstler.

In the very least, Nousaine's comments are interesting, but you guys are more interested in railing spyboy?

No, you are right we/I should not get on spyboy's case (or anyone else's)

It is just that he has guerrilla posted the exact same things in threads that have nothing to do with HSU or his claims of performance. It just doesn't seem to matter with him, someone has a ground loop problem or whatever and it's " I have dual VTFs and could have bought Maple DD-18s, and do 135 db @ 12 Hz"!

I mean, it just gets tiresome. And ultimately, it becomes difficult to take anything from him seriously.

Then put him on "ignore".

And like I posted....there are others that seem to be just as tiresome, and you know who they are.

Then put him on "ignore".

And like I posted....there are others that seem to be just as tiresome, and you know who they are.

Point taken, on "ignore".

Considering the human ear can't hear below 20hz and how much of actual music or movies are below that, it is about as much as a non issue as there is.
Wow; yours is a rather black-and-white position on this subject, and it's NOT correct, Hugh. Certainly our hearing acuity decreases as frequencies approach and go below, say, 25Hz, but that doesn't mean we can't hear frequencies below 20Hz, we merely require higher levels for them to be audible. Also, frequencies lower than, say, 15Hz can be felt if not heard.

Also, the bass requirements of music are NOT the same as for movies. Keith Yates, in his 3-part series of subwoofer tests for the AV version of 'stereophile', published in 2004, used 3 movies to test SWs and found substantial energy below 20Hz. My earlier post on that is in this http://www.avsforum.com/avs-vb/showthread.php?t=786803&page=11&pp=30 page.

I wish I had $20K or so to spend on my HT; it'd sure have a Thigpen Rotary Woofer in it, as I have attic space.

Considering the human ear can't hear below 20hz and how much of actual music or movies are below that, it is about as much as a non issue as there is. Sure we can feel lower Hz below 20, but as we get older, not only do we lose the ability to hear certain higher frequencies, but I think as far as music, only Pipe Organ foot pedals are around 30 or below. :confused:

With a real Pipe Organ, full range that is, the lowest note is 18hz. Many of them are not full range though, and the bottom octave is the first thing they leave out. The 18hz pipe is ridiculously long. Where I went to college our church had a full range organ. I think the roof was at least 60 - 70 feet, and that still wasn't tall enough. The largest pipes extended into the basement and had to be installed at an angle so they could fit below the roof.

IMO any "Authentic" sub should at least be flat down to 18hz. But I can't see any real reason to want high output much below that.

Wow; yours is a rather black-and-white position on this subject, and it's NOT correct, Hugh. Certainly our hearing acuity decreases as frequencies approach and go below, say, 25Hz, but that doesn't mean we can't hear frequencies below 20Hz, we merely require higher levels for them to be audible. Also, frequencies lower than, say, 15Hz can be felt if not heard.

I heard/felt the Eminent Technology set-up a the Vegas THE Show. Quite impressive feeling the pressure pulses at 5hz.

Also, the bass requirements of music are NOT the same as for movies. Keith Yates, in his 3-part series of subwoofer tests for the AV version of 'stereophile', published in 2004, used 3 movies to test SWs and found substantial energy below 20Hz. My earlier post on that is in this http://www.avsforum.com/avs-vb/showthread.php?t=786803&page=11&pp=30 page.

In the grand scheme of things, the percentage of movies with energy below 20hz is still quite low. If you want to say it is a requirement, then for music you should also include the 16hz organ note. In this forum, we "see" these movies because people seek out the bass, regardless if the movie is good or not.

Heck, that's what God (or Buttkicker) invented LFE units for ;)

i think that many miss the point of extended low frequency response and mostly it's those that don't have the capability and so in turn don't have the requisite experience to judge whether or not it enhances the presentation...the biggest issue missed is soundstaging...simply put, the soundstage expands as the f3 of the system drops...is there a law of diminishing returns?...probably, but it won't deter the overzealous among us from the pursuit of the lowest octave of the bass range... ;)

your flat to 12hz with HSUs huh?

interesting.

-Eli
exactly my thoughts!!!! http://www.hometheatershack.com/forums/images/smilies/rofl.gif

Wow; yours is a rather black-and-white position on this subject, and it's NOT correct, Hugh. Certainly our hearing acuity decreases as frequencies approach and go below, say, 25Hz, but that doesn't mean we can't hear frequencies below 20Hz, we merely require higher levels for them to be audible. Also, frequencies lower than, say, 15Hz can be felt if not heard.

Also, the bass requirements of music are NOT the same as for movies. Keith Yates, in his 3-part series of subwoofer tests for the AV version of 'stereophile', published in 2004, used 3 movies to test SWs and found substantial energy below 20Hz. My earlier post on that is in this http://www.avsforum.com/avs-vb/showthread.php?t=786803&page=11&pp=30 page.

I wish I had $20K or so to spend on my HT; it'd sure have a Thigpen Rotary Woofer in it, as I have attic space.

Something that is a fact like human hearing limits are black and white. Although grey exists as a color, people "color" concrete facts grey to fit their opinions, but "coloring" something grey doesn't change the fact when it is black and or white. Human hearing for 99.9% of us DOES NOT have the ability to go below 20hz. More importantly, there is little music or movies most of us will ever even feel below 18hz.

I can only speak for myself in the end and so for me it is a non issue, but have fun "feeling". :D

With a real Pipe Organ, full range that is, the lowest note is 18hz. Many of them are not full range though, and the bottom octave is the first thing they leave out. The 18hz pipe is ridiculously long. Where I went to college our church had a full range organ. I think the roof was at least 60 - 70 feet, and that still wasn't tall enough. The largest pipes extended into the basement and had to be installed at an angle so they could fit below the roof.

IMO any "Authentic" sub should at least be flat down to 18hz. But I can't see any real reason to want high output much below that.

Bottom C on the organ with a 32ft stop is about 16.35Hz. The length of an open-flue pipe needed to generate that frequency happens to be about 32ft long, hence the name. :cool:

The need for these fan type subs is hocus bogus and wasted money.

Fact is the human hearing is not very capable below 16Hz and no person alive can hear any definition below 16Hz or validate the need for fan type subs capable to near DC.

Do not tell me 8Hz is present in musical instruments. No fake special effects are here to sell bigger and gigger subs. What is next a sub capable of 0.1Hz yes 0.1Hz.

What the industry should focus on is accurate linear reproduction

down to 16Hz or the lower limit of the largest pipe organ. The rest is for those with money to burn.

The need for these fan type subs is hocus bogus and wasted money.

Fact is the human hearing is not very capable below 16Hz and no person alive can hear any definition below 16Hz or validate the need for fan type subs capable to near DC.

Do not tell me 8Hz is present in musical instruments. No fake special effects are here to sell bigger and gigger subs. What is next a sub capable of 0.1Hz yes 0.1Hz.

What the industry should focus on is accurate linear reproduction

down to 16Hz or the lower limit of the largest pipe organ. The rest is for those with money to burn.

So, how do you really feel? ;)

Hugh and TheEAR,
There is a difference between hearing and perceiving. Hearing is 1 element that we use to perceive sonic events. For example, an explosion is perceived by more than your ears. If I took you to a concert and plugged your ears, would you still be able to tell if a bass drum was playing? I think that you would be able to perceive this event. Some people would like to reproduce these sounds so they can perceive them in their listening environments.

The next fallacy is that musical instruments magically have some sort of limiter that prevents them from producing sounds less than ~20Hz. Have you ever seen the frequency spectrum from a live concert feed? Breathing into a mic, pedal noises from a piano, any strike from a concert bass drum, the ambient sound of the actual building, etc. all produce <20Hz frequencies (along with artificial sounds like movie soundtracks, digital cannon blasts, etc.).

I like subs and all but can a sub be accurate to 4hz with low THD...what a joke.Sure, even a tweeter can do this. Now if you are talking about at a certain minimum dB-SPL then I'd say the rotary sub easily accomplishes this (the thread in the 20k forum has the measurements).

Bottom C on the organ with a 32ft stop is about 16.35Hz. The length of an open-flue pipe needed to generate that frequency happens to be about 32ft long, hence the name. :cool:

Strange. I'm pretty sure the longest pipes were more than 32 feet.

Aha, found a picture.

http://www.collegedalechurch.com/resources/organcover.gif

There are a lot more pipes than you can see. Behind it are the really big ones, and the largest are angled and extend below the floor.

"But with the Turbo, the room response is flat to about 12 Hz. This is superb."

See the review by John Johnson in Secrets of Home Theater and High Fidelity, March 2006, Part IV.

Well good for you and John Johnson.

Is that the wannamaker organ? I have one of its recordings, pretty phenomenal.

There is a lot to be perceived even below 5Hz IMO, a set of bass shakers readily reveals this. There are tons of presence frequencies wayy below what you can hear and they all contribute to the live feel of a concert or movie. The problem is that you start getting into a rule of diminishing returns, you have to massively up the budget in order to really get any difference down deep, I am thinking below 10Hz btw. There becomes a problem with super low frequencies though, often times the entire sound effect will come and go before your subs driver has even moved to its maximum excursion, for example, if you were trying to reproduce an earthquake at .2Hz with the ideal set of subs, say 10000 18" woofers, the entire sound may come and go in less than a second, leaving that army of subs, stopped wayy short of what they can do. Movies even have a good deal of content below 1Hz, so you could say that there are tons of octaves waiting to be produced. .625Hz to 1.25Hz, 1.25Hz to 2.5Hz, 2.5Hz to 5Hz, there now you have 3 more octaves, good luck. I bet not even an HSU VTF-3 Turbo couldn't produce the last one. :p ;)

Nearly every musical transient has content to DC. This has been measured many times.

I prefer to consider the bottom octaves for DVD according to the Dolby spec, which begins at 3Hz, but enough spectrogram graphs have shown content to below that.

A transient is much different than a pipe organ note, which is static and therefore is more like a sine wave, whereas, as I've said, most transients contain spectra to DC and far above the fundamental.

Is there a difference in perception when the low end is truncated vs reproduced to DC? Not much out there in the way of research. Does the VLF have to be much higher than the fundamental in dBSPL to be perceived?

I find the results of the Thigpen TRW demos to be interesting, to say the least.

Having a system that's flat to 3.5Hz, in-room, and capable of very high output down there, I have been experimenting with several source discs of unfiltered music with very little processing with interesting results. When I've completed the listening tests, I'lll start a thread to hopefully explore this last frontier.

Kram is spot on, IMHO. If the closing of a car door contains spectra to DC in real life (and, of course, the content in single digits is not very loud relative to the fundamental center frequency), why would it's reproduction not sound more realistic without the lowest octave content being filtered by an incapable system or HP filter protection?

It's a bit presumptuous to decree anything without having heard the difference, no?

Bosso

"But with the Turbo, the room response is flat to about 12 Hz. This is superb."

See the review by John Johnson in Secrets of Home Theater and High Fidelity, March 2006, Part IV.i'd be careful here...i've read this review and a few things to note...the spl tests are limited to 100 dB at 1 foot...the FR is taken at 1 meter from the sub...so his flat to 12 Hz in-room won't wash at extended listening ranges...his maximum spl with all ports open was 116 dB, again at 1 meter...subtract 6 dB every time you double the distance to the listening position...

...curiously no data was given at 16 Hz...judging by the elevated THD numbers at 20 Hz with the lowered extension, one would expect this...i can only wonder what the THD is below 16 Hz with port and driver decoupling/unloading...

in any event, the Turbo, arguably, has an adverse effect on the listening range...THD at 25 Hz is >9.5% in max extension mode...this at 100 dB @ 1 foot from port...this is the price of extension

the readings were taken 12" from the port, when normal listening ranges tend to be ~3 meters are greater...i would think that you'd have to sum this with the driver output though...still it's one foot from the subwoofer...

as for 12 Hz extension?...at what level and THD?...none of this is given...just "it extends to 12 Hz in-room...and in his room at that...

i'd be careful here...i've read this review and a few things to note...the spl tests are limited to 100 dB at 1 foot...the FR is taken at 1 meter from the sub...so his flat to 12 Hz in-room won't wash at extended listening ranges...his maximum spl with all ports open was 116 dB, again at 1 meter...subtract 6 dB every time you double the distance to the listening position...

...curiously no data was given at 16 Hz...judging by the elevated THD numbers at 20 Hz with the lowered extension, one would expect this...i can only wonder what the THD is below 16 Hz with port and driver decoupling/unloading...

in any event, the Turbo, arguably, has an adverse effect on the listening range...THD at 25 Hz is >9.5% in max extension mode...this at 100 dB @ 1 foot from port...this is the price of extension

the readings were taken 12" from the port, when normal listening ranges tend to be ~3 meters are greater...i would think that you'd have to sum this with the driver output though...still it's one foot from the subwoofer...

as for 12 Hz extension?...at what level and THD?...none of this is given...just "it extends to 12 Hz in-room...and in his room at that...

But haven't you heard?!

"Howard Ferstler hit 112 db at 20Hz with the HSU VTF-3Mk3 plus Turbo. That was a new record."!!!!!!!111

:p

What I've never understood about the Secret's review is that, if I recall, it was a review of the original amp/driver HO which I understood was pretty subpar??

simply put, the soundstage expands as the f3 of the system drops...is there a law of diminishing returns?...probably, but it won't deter the overzealous among us from the pursuit of the lowest octave of the bass range... ;)

Not if there's no meaningful signal there. I only own a few disks (speaking strictly of music, not blow-em-up blockbuster nonsense; the closest my DVD collection comes to that is the West Wing boxed set, so I have no idea what's in that kind of fluff...) with <12Hz content. Two of those are the parlor trick Telarc disks of the 1812 and Beethoven's Wellington's Victory march, which are perhaps the two most musically uninteresting recordings I own. The only VLF content is the artillery. The others are disks of the Royal Philharmonic recorded in Royal Albert Hall. The VLF content is simply the Tube passing underneath, and has nothing to do with the music at all. (Having sat in Royal Albert Hall and heard concerts there, I found it barely perceptible but annoying. Had I not known in advance, I may not have noticed.) Normal music recordings just don't have content there, so I personally don't see the point of having extended response below the 16Hz of an organ pedal, or mid-20's if one doesn't listen to organ music much.

Not if there's no meaningful signal there. I only own a few disks (speaking strictly of music, not blow-em-up blockbuster nonsense; the closest my DVD collection comes to that is the West Wing boxed set, so I have no idea what's in that kind of fluff...) with <12Hz content. Two of those are the parlor trick Telarc disks of the 1812 and Beethoven's Wellington's Victory march, which are perhaps the two most musically uninteresting recordings I own. The only VLF content is the artillery. The others are disks of the Royal Philharmonic recorded in Royal Albert Hall. The VLF content is simply the Tube passing underneath, and has nothing to do with the music at all. (Having sat in Royal Albert Hall and heard concerts there, I found it barely perceptible but annoying. Had I not known in advance, I may not have noticed.) Normal music recordings just don't have content there, so I personally don't see the point of having extended response below the 16Hz of an organ pedal, or mid-20's if one doesn't listen to organ music much.this is'nt going to be like the inductance silliness is it?...I noticed that you were corrected on the TC Sounds forum...and if you like, i can correct with in-room response measurements of the TC3000 system...your ears are different from mine...i appreciate the qualification of only including music but DVD media has source material that some want to reproduce, including music...if you have equipment capable of legitimate, high level VLF and find it distasteful then that is your issues...i'll comment no further on this...

this is'nt going to be like the inductance silliness is it?...I noticed that you were corrected on the TC Sounds forum...

I was? That is a rather interesting interpretation, because I didn't see any such post by anyone. Kyle posted something in the inductance thread that basically repeated what I wrote, except spun a bit. (IOW, he was doing his job, and doing it well.) The TC3k still came out with a large multiple of the inductance of the TC2+ and other known good-sounding woofers (e.g. Peerless XLS12, JBL W15GTi) no matter how the numbers were spun, did it not? The central issue of inductance affecting the 40-80Hz octave, which is my entire point on that subject, was roundly ignored by all concerned in the TCS forum thread, present company excluded.

your ears are different from mine...i appreciate the qualification of only including music but DVD media has source material that some want to reproduce, including music...

Hey, if other people want to hear artifacts - few if any recording studios have subwoofer systems that can go that low at meaningful SPL, and in the case of movies basically no cinemas have equipment that can reproduce it, so one can't really claim that it is part of the package the artists involved intended to convey - and they have program material with that kind of content, I certainly don't want to stand in anyone's way. Perhaps in the future, as gear gets better in general and hopefully recordings contain more meaningful lows - I agree they're present in live music, but I've not seen them on disk - we won't disagree on this issue anymore.

As for VLF content in music, do you (or anyone else) have a list of serious material with VLF content that's not amusical garbage (the Telarc/Knunzel waste-of-polycarb disks I mentioned above) or tertiary artifacts (e.g. grumbling from the Tube running under Royal Albert Hall)?

if you have equipment capable of legitimate, high level VLF and find it distasteful then that is your issues...i'll comment no further on this...

I never said distasteful. The issue is much more an issue of relevance than taste. Having capability is better than not having capability, generally speaking. However, in terms of relevance to real world program material, there are so many other aspects of music reproduction that are so much more important than the sub-20Hz stuff that I feel there's a tendency on this forum to encourage rather wanton resource misallocation. For instance, how many people are building he-man subs but suffering with center channels of an idiotic toppled-MTM design? The only difference is that getting deep bass is easy. It's basically a paint-by-numbers game: take amp A and driver(s) B, stuff in box C, perhaps experiment with tuning frequencies D and E before deciding, EQ with processor F to taste, and done. The other stuff, like optimizing speaker placement and room treatment, or modifying mains crossovers to suit one's room, is orders of magnitude more taxing from intellectual or creative standpoints.

i'd be careful here...i've read this review and a few things to note...the spl tests are limited to 100 dB at 1 foot...the FR is taken at 1 meter from the sub...so his flat to 12 Hz in-room won't wash at extended listening ranges...his maximum spl with all ports open was 116 dB, again at 1 meter...subtract 6 dB every time you double the distance to the listening position...

...curiously no data was given at 16 Hz...judging by the elevated THD numbers at 20 Hz with the lowered extension, one would expect this...i can only wonder what the THD is below 16 Hz with port and driver decoupling/unloading...

in any event, the Turbo, arguably, has an adverse effect on the listening range...THD at 25 Hz is >9.5% in max extension mode...this at 100 dB @ 1 foot from port...this is the price of extension

the readings were taken 12" from the port, when normal listening ranges tend to be ~3 meters are greater...i would think that you'd have to sum this with the driver output though...still it's one foot from the subwoofer...

as for 12 Hz extension?...at what level and THD?...none of this is given...just "it extends to 12 Hz in-room...and in his room at that...

Actually 12hz extension is easily possible. Here is the frequency response of my VTF-3 HO without EQ:

http://img151.imageshack.us/img151/1642/noeqafterbigtv41807qt7.jpg (http://imageshack.us)

and this is with EQ:

http://img151.imageshack.us/img151/5610/witheqafterbigtv41807fb5.jpg (http://imageshack.us)


These were both measured about 10 feet away from the sub.

I don't know why that review didn't measure 16hz, but there is no doubt that the THD is lower at 16hz in max extension (with or without turbo) mode than it is in max output mode.

Also it isn't true that you subtract 6dB for every doubling of distance IN ROOM. In fact, the output at the opposite side of the room can be nearly as high as if you measured from 1 meter away from the sub.

Well good for you and John Johnson.

Is that the wannamaker organ? I have one of its recordings, pretty phenomenal.

There is a lot to be perceived even below 5Hz IMO, a set of bass shakers readily reveals this. There are tons of presence frequencies wayy below what you can hear and they all contribute to the live feel of a concert or movie. The problem is that you start getting into a rule of diminishing returns, you have to massively up the budget in order to really get any difference down deep, I am thinking below 10Hz btw. There becomes a problem with super low frequencies though, often times the entire sound effect will come and go before your subs driver has even moved to its maximum excursion, for example, if you were trying to reproduce an earthquake at .2Hz with the ideal set of subs, say 10000 18" woofers, the entire sound may come and go in less than a second, leaving that army of subs, stopped wayy short of what they can do. Movies even have a good deal of content below 1Hz, so you could say that there are tons of octaves waiting to be produced. .625Hz to 1.25Hz, 1.25Hz to 2.5Hz, 2.5Hz to 5Hz, there now you have 3 more octaves, good luck. I bet not even an HSU VTF-3 Turbo couldn't produce the last one. :p ;)

Hi

I am not positive that is the Wannamaker organ. I am pretty sure it is. I used to do a lot of shopping at the John Wannamaker store in Philadelphia, close to City Hall. The sound of the organ was a treat. Their toy department was wonderful. It had a monorail train for the kids. I never rode on the monorail, IIRC.

All the Best

I agree with Kram and Bosso about the very low frequency being present all around you and in rare recordings.

Also if a sub to deserve the label of authentic subwoofer has to be flat no dear DC,lets say 3-4Hz most of us own bass modules. ;) Save for those with Thigpen subs.

The reality is you would have to use a large quality of very high displacement drivers(classic piston drivers)to come close to a Thigpen.As the fan can move huge quantities of air compared to what we have on the market using classic piston drivers.

And we know the lower the frequency the more air has to be displaced to sustain a given SPL. We are doomed people,as the only realistic and viable solution are fan subwoofers,and these so far are made in tiny quantities (high price) and you must use them in IB configurations(in other words have two rooms,side by side to make it happen).Fan subs will not work in small cabinets as fans cannot compress the air like piston subs and create enough pressure without secondary effects (prop noise increasing with pressure,and even with all the R&D there is no much you can do using the fan sub).

Fan subs will remain for a few who are willing to mod the home a bit and have too rooms side by side or a basement they can use.In this case even at $15000 per unit it makes sense if you must have the infrasonics to near DC to hear the non musical rumble of life.

Nousaine's idea of an authentic sub is the Eminent Technology TRW-17, starting at $12,900.


Seriously....are you kidding $13000. Are we all Lebron James now??

ps....Spyboy are you having a little too much fun with your turbo attachment ;)

Nousaine's idea of an authentic sub is the Eminent Technology TRW-17, starting at $12,900.


Seriously....are you kidding $13000. Are we all Lebron James now??

ps....Spyboy are you having a little too much fun with your turbo attachment ;)

At least that 13 grand is buying technological innovation and acoustic capability not available anywhere else. IOW, it's far less morally objectionable than a $13k stereo amp or a pair of $1300 cables...

Actually 12hz extension is easily possible. Here is the frequency response of my VTF-3 HO without EQ:

http://img151.imageshack.us/img151/1642/noeqafterbigtv41807qt7.jpg (http://imageshack.us)

and this is with EQ:

http://img151.imageshack.us/img151/5610/witheqafterbigtv41807fb5.jpg (http://imageshack.us)


These were both measured about 10 feet away from the sub.

I don't know why that review didn't measure 16hz, but there is no doubt that the THD is lower at 16hz in max extension (with or without turbo) mode than it is in max output mode.

Also it isn't true that you subtract 6dB for every doubling of distance IN ROOM. In fact, the output at the opposite side of the room can be nearly as high as if you measured from 1 meter away from the sub.just measure the spl/THD at all frequencies from 25-12 Hz then...measure spl 12" from the cone then at whatever distance you'd prefer...don't know about your room but as i approach my subwoofers the spl meter rises in output (1800 ft3 sealed)...below 16 Hz this subwoofer is unloading and judging by the rolloff depicted in the graph it is occuring rather rapidly...meanwhile, in max extension, you have elevated THD at 20 and especially 25 Hz, also making bottoming more likely in this audible range...at 12.7 Hz you are -6dB and you are -5 dB @ 13 Hz without eq...if you are boosting the low frequencies you are simply aggravating an already tenuous situation in max extension mode...if this is a 500 watt subwoofer, it's going to take much more than 125 watts to make a clean showing at 12 Hz with a decoupling/unloading driver...

There are a lot more pipes than you can see. Behind it are the really big ones, and the largest are angled and extend below the floor.
This conversation had me interested, so I looked for low organ notes. I had found a page (http://www.spacedog.biz/infrasonic/background.htm) that talked about two different organs at Sydney Town Hall, Australia, and the Atlantic City Convention Hall, USA (Wanamaker organ), both with a 64' pipe producing 8.2 Hz. Now, that has to be something to hear! :D

This conversation had me interested, so I looked for low organ notes. I had found a page (http://www.spacedog.biz/infrasonic/background.htm) that talked about two different organs at Sydney Town Hall, Australia, and the Atlantic City Convention Hall, USA (Wanamaker organ), both with a 64' pipe producing 8.2 Hz. Now, that has to be something to hear! :D

Interesting. 64 feet sounds about right from what I remember. I played cello in the orchestra at that church and spent a lot of time sitting in front of that organ. The picture I posted is really bad, doesn't give you a good sense of scale. The stage in front of the organ can easily fit a 90 piece orchestra. The church itself could seat about 700 people. And with it packed to capacity the low notes on that organ would make the pews in the very back vibrate.

just measure the spl/THD at all frequencies from 25-12 Hz then...measure spl 12" from the cone then at whatever distance you'd prefer...don't know about your room but as i approach my subwoofers the spl meter rises in output (1800 ft3 sealed)...below 16 Hz this subwoofer is unloading and judging by the rolloff depicted in the graph it is occuring rather rapidly...meanwhile, in max extension, you have elevated THD at 20 and especially 25 Hz, also making bottoming more likely in this audible range...at 12.7 Hz you are -6dB and you are -5 dB @ 13 Hz without eq...if you are boosting the low frequencies you are simply aggravating an already tenuous situation in max extension mode...if this is a 500 watt subwoofer, it's going to take much more than 125 watts to make a clean showing at 12 Hz with a decoupling/unloading driver...


Obviously THD will increase below the tuning point. Everybody knows that. THD at 25hz is also obviously higher in max extension mode than in max output mode. You are saying nothing new.

I think you need to take some more measurements of your subwoofers. You should find that as you move near the middle of the room, the spl will decrease. Then as you move closer to the other side of the room, spl will increase.

I am not boosting the low end at all. You should be able to see that by looking at the first graph. In fact, I made cuts around 20hz to make the response flatter.

I'm not trying to say anything about my sub vs yours. You DIY folks are so sensitive. I'm just pointing at that the VTF-3 HO does in fact hit 12-13hz. Maybe not as cleany or with as much authority as your subs, but show me another commerical sub for <$1000 that does.

As many know here, my sub set up is flat to 10 Hz to 12 HZ with a ton of output (over 110 db & 120 db at 20Hz).....but that said, the Thigpen has redefined a reference subwoofer set up. Where as I'd easily consider my own set up as reference bass, with the advent of the Thigpen, paper drivers (like mine) cannot compete...I believe you can go to 1 Hz on the Thigpen with less than 200W of power and have far less distortion that a conventional system. That is what I'd call ass kickin'!

Personally, I think this device has altered what I have perceived as excellence in terms of a reference low end output. I have been on top for a couple years.....I am no longer in the same league as this device. Simple as that.

I might have to install one@!

I believe you can go to 1 Hz on the Thigpen with less than 200W of power and have far less distortion that a conventional system. That is what I'd call ass kickin'!


As you know the Thigpen is not exactly a conventional woofer. You are neglecting to take into account the power supplied by the massive motor that drives the fan blades.

This conversation had me interested, so I looked for low organ notes. I had found a page (http://www.spacedog.biz/infrasonic/background.htm) that talked about two different organs at Sydney Town Hall, Australia, and the Atlantic City Convention Hall, USA (Wanamaker organ), both with a 64' pipe producing 8.2 Hz. Now, that has to be something to hear! :D

Genuine 64 foot organ stops are indeed rare as hen's teeth. As far as I am aware, you are correct and only two examples exist - the Sydney Town Hall organ and the organ in the main auditorium at Boardwalk Hall, Atlantic City. The former is a conventional loud reed stop and the latter uses "diaphone" pipes. Incidentally, the Atlantic City (http://www.acchos.org/html/introduction.html) organ was "built between May, 1929, and December, 1932, by the Midmer-Losh Organ Company of Merrick, Long Island, New York, to designs by Emerson L. Richards, a native of Atlantic City and State Senator for Atlantic County". This organ holds the official record as the largest in the world.

The Wanamaker organ is this one: http://www.wanamakerorgan.com/index1.html

The term 64ft describes the pitch at which the stop plays. 8ft is piano pitch, 16ft is 1 octave below piano, 32ft is 2 octaves, and 64ft is 3 octaves. The physical open pipe needed to achieve the lowest note in the rank (the longest pipe) is of approximately these lengths. The Wanamaker organ boasts a 64ft Gravissima stop. However, this is actually a so-called "resultant", also called a "quint" rather than a genuine 64ft pitch which would require real 64ft pipes; something that is generally considered uneconomic to produce for something that can only be so poorly heard. Therefore, they "cheat" and use a quint or resultant in which two pipes from the octave above (in this case 32ft pitch) sound together for each pedal pressed. These are separated by a perfect fifth (e.g., pressing C sounds C and G). These correspond to frequencies x and 1.5x. The resultant is the difference between these. i.e., 1.5x - x, or 0.5x. The ear hears this pulsation in intensity as the two frequencies beat together as if the 0.5x frequency was genuinely there. But it is an illusion.

Most other organs boasting 64ft stops adopt the same strategy, including for example the Royal Albert Hall organ. Some smaller organs have to adopt the above strategy to generate even 32ft pitch. Some more modern instruments also resort to generating this bottom octave electronically using the sort of technology with which we are all familiar.

Since the lowest real frequency being generated by the vast majority of organs (with the notable exception of the two listed above) is 16.35Hz or so, provided your subwoofer can reproduce the 16.35Hz and 24.5Hz cleanly, the ear should be fooled in the same way and perceive the 8.175Hz difference signal. :cool:

As you know the Thigpen is not exactly a conventional woofer. You are neglecting to take into account the power supplied by the massive motor that drives the fan blades.

Acually, the 'massive' motor is 1/3 HP... Regardless, it does what no other conventional (or unconventional) design has ever done.

Obviously THD will increase below the tuning point. Everybody knows that. THD at 25hz is also obviously higher in max extension mode than in max output mode. You are saying nothing new.

I think you need to take some more measurements of your subwoofers. You should find that as you move near the middle of the room, the spl will decrease. Then as you move closer to the other side of the room, spl will increase.

I am not boosting the low end at all. You should be able to see that by looking at the first graph. In fact, I made cuts around 20hz to make the response flatter.

I'm not trying to say anything about my sub vs yours. You DIY folks are so sensitive. I'm just pointing at that the VTF-3 HO does in fact hit 12-13hz. Maybe not as cleany or with as much authority as your subs, but show me another commerical sub for <$1000 that does....all i'm saying is that you need enough output at the listening position (~100 dB @ 12 Hz)...and this output needs to be of low THD levels...definitely <10 %...and i'm saying that i'm skeptical that one 12" driver can accomplish this in an unloaded/decoupled state...

I'd be willing to bet, that at 12hz, all other things being equal, anyone would be hard pressed to feel the difference between 5% THD and 10% THD. As you move up the FR, it becomes more evident, but at 12hz....I doubt it.

Acually, the 'massive' motor is 1/3 HP... Regardless, it does what no other conventional (or unconventional) design has ever done.

Well I guess I just consider anything used for home theater that is literally instead of figuratively measured in HP to be pretty massive :)

In the May 2007 issue of Sound&Vision, Tom Nousaine is quoted as saying that an authentic subwoofer must reproduce the bottom two octaves (5-10Hz, and 10-20Hz)...

Nousaine's idea of an authentic sub is the Eminent Technology TRW-17, starting at $12,900.

I know this has been discussed before. I wonder if Nousaine has the Thigpen Rotary Woofer? I remember his article in Sound&Vision about his IB subwoofer that was driven by a Crown Macro Reference amp. I think his IB had 8 fifteen inch drivers, or maybe it was only 6 fifteen inch drivers.

Nousaine said the Thigpen Rotary Woofer "was producing more than 110db at 4-25 Hz in a real room at CES".

Too bad I'm only flat to 12 Hz.

Kind Regards

what page is that on?

also, take a look at the spine of that issue

never mind, found it on page 12

that thing that looks like an antique desk fan is a subwoofer?

how?

well, 1 horsepower is about 746 watts, so i have a 2.78 horsepower home theater setup. Consequently, my theater is enormous. I'm gonna guess it's about 40,000 ft^3.

The unusual feeling of room pressurization with the TRW defies description for me. We have all felt it with high SPLs with conventional subs but the magnitude of difference makes it almost an entirely different experience. I likened it a little to the cabin pressurization right before takeoff of a commercial airliner. :eek:

Art

If I have it correctly figured out the Thigpen works as follows:

The motor apparently just spins the blades. The blade pitch is then modulated by servomotors on the fan asembly pretty similar to a constant velocity propeller in an aircraft (or a helicopter).

So the main 1/3HP motor spins the "propeller" at a constant speed. The blade pitch motors provide the modulation. Much easier said than done BTW!

John, that is how it was explained at the THE show in Vegas. So I think you got it figured out. :)

This Thigpen fan sub is one revolutionary sub. What would be great if these subs drop to say $7000 per unit,then I would be VERY interested to try one. And it is possible to meet this price if more are built and some kind of mass production starts. And even improve the performance (SPL capabilities,at this point high).

Soon they may have 20" models with 1 HP motor and capable of reproducing the brown note to a diaper filling perfection. And prove the Myth Busters wrong. ;)

The key is having the space/configuration to install one correctly.

This Thigpen fan sub is one revolutionary sub. What would be great if these subs drop to say $7000 per unit,then I would be VERY interested to try one. And it is possible to meet this price if more are built and some kind of mass production starts. And even improve the performance (SPL capabilities,at this point high).

Soon they may have 20" models with 1 HP motor and capable of reproducing the brown note to a diaper filling perfection. And prove the Myth Busters wrong. ;)

I've noticed since I've had my four Seaton's that I've been a lot more regular.

Art

I seem to remember that Bruce Thigpen has another design. IIRC, the other design adds 10db output to the current model.

Best Regards

A standard 6-string bass is tuned to B 30.8Hz. A lot of 4-string's are steped down to this note as well.

30.8 is a D note, not a B note.
You might enjoy my freq-to-wavelength chart here:
www.soundoctor.com/freq.htm

Barry

This Thigpen fan sub is one revolutionary sub. What would be great if these subs drop to say $7000 per unit,then I would be VERY interested to try one. And it is possible to meet this price if more are built and some kind of mass production starts. And even improve the performance (SPL capabilities,at this point high).

Soon they may have 20" models with 1 HP motor and capable of reproducing the brown note to a diaper filling perfection. And prove the Myth Busters wrong. ;)

The need for these fan type subs is hocus bogus and wasted money.

Fact is the human hearing is not very capable below 16Hz and no person alive can hear any definition below 16Hz or validate the need for fan type subs capable to near DC.

Do not tell me 8Hz is present in musical instruments. No fake special effects are here to sell bigger and gigger subs. What is next a sub capable of 0.1Hz yes 0.1Hz.

What the industry should focus on is accurate linear reproduction

down to 16Hz or the lower limit of the largest pipe organ. The rest is for those with money to burn.


So which is it?

So which is it?

I have to flip a coin,have any change?

The Thigpen is revolutionary yes,it works very much a YES. Can be of use in a HT setup but of no real use in a music system where a very high performance classic sub is present...something like a Gotham or Velo 1812. Who wants to hear rumble not even part of the actual sound produced by the instrument???????


To all this I say,lets concentrate how to get the max quality in the audible range before starting to dig for 2hz and super duper tweeters capable of 50Khz.

Price this sub at $7000 and I might be interested.

I think PG had something going back in the day. Never took hold with the car audio crew though. They should've marketed it to the HT crowd instead!


http://www.phoenixgold.com/webfaq/cyclone.htm

Also appears here:

http://www.soundimage.dk/Different-col/LinearMotor.htm

Some people who are way into pipe organ music want to hear the fundamentals and the harmonics of the 64 foot pipe on the Wannamaker organ. I would take the Thigpen Rotary in a heartbeat. I may have to wait until it comes down to $7,000.

In the meantime I will have to limp along with flat response to 12 Hz.

Kind Regards

I heard/felt the Eminent Technology set-up a the Vegas THE Show. Quite impressive feeling the pressure pulses at 5hz.


In the grand scheme of things, the percentage of movies with energy below 20hz is still quite low. If you want to say it is a requirement, then for music you should also include the 16hz organ note. In this forum, we "see" these movies because people seek out the bass, regardless if the movie is good or not.I went with Tom Nousaine to visit the rotary sub at this years CES/THE show. I had to leave to go to the airport and he was still discussing it with Bruce when I left. I know Tom would like to test it but he does not have one. He long has felt that a true sub goes lower than 20HZ and he built his own to do just that. Tom likes bass, but he also likes his hearing as he wears ear protection when he attends concerts (or loud demos).

In addition there was a demo (and subsequent purchase) of two of these by one of the gentleman that frequents the ultra high end. Mark Seaton was at the demo. As I understand it, one of things that was impressive was that it did add something to the music. I am sure if you search you can find the thread for any of those interested. It appears to me that the real problem with the technology is "venting" it as it can cause the neighbors to think that there has been an earthquake in the near vicinity.

30.8 is a D note, not a B note.
You might enjoy my freq-to-wavelength chart here:
www.soundoctor.com/freq.htm

Barry

:confused:

Eh? Are you reading your chart incorrectly or is it just set up wrong? 30.8 is the wavelength in feet for D, not the frequency. You have 30.9Hz as the frequency for B.

Ok, I am new (less than 24 hrs) to this forum, and I cannot comment much for home audio or home theater stuff (hell, i am searching for my first "quality" subwoofer -- on a budget of course) but after reading these posts I do have a few comments, mostly related to live sound.

I am a live sound engineer and have a lot of experience in that end of things... Of course, pipe organs with 64 foot pipes are hard to come by and produce their own sound straight to the audience (without PA amplification) but most PA speakers will provide somewhere between 20-35hz as a low point, as most concerns are placed on the rest of the audio spectrum! Most sound consoles have adjustable high pass filters on each input, which usually adjust from 20 hz up to 400 hz (we usually set vocal mics between 75 and 150hz, so that throws out the muddiness in the vocal and the need for feeling the breath of a performer at 12hz!)
Most PA audio processors dump between 20 and 35 hz.. why? Because the energy there IS NOT PART OF THE FUNDAMENTAL sounds coming from the instruments being reproduced and if it is in the wire, it will just waste amp power and speaker heating! As live sound engineers, we want to reproduce the sound being made on stage, not waste power on vibrating the floor (when it will heat up our drivers and rob our 2500-5000 watt amps and ruin the performance of them at 30-70hz where we really need them!) Also, since tuned port speakers are the most efficient, and we need all the efficiency we can get at those frequencies, we dont want to waste power pushing the speaker under it's box tuning port (and boxes need to stay small enough to not take up too much trucking space, so we can efficiently get them to the gig! Also, did you know most touring shows bring their own rig, so from night to night at MOST theaters and amphitheaters it is a different sound system each time! not the same system night after night.)

As for the 6db per doubling of distance, this is an ACOUSTICAL RULE (At all frequencies) which has been broken by the introduction of Line Array speakers (which have very tight horizontal patterns of <10 degrees per box -- these have a 3db/doubling rule, and a properly coupled system of more than 3 boxes will smoothly fill an entire audience area within +/-2db of the entire audio bandwidth!) This 6db rule (for standard sources of sound) DOES NOT TAKE INTO ACCOUNT reflections, only the traveling of sound waves over distance (so add walls and you will have combing at some frequencies, and reflections will add to the main wave to make positive or negative coupling to different frequencies -- end result is it might be louder near a wall or corner, and lower in the middle, or vice versa, all related to distance and frequency!) That is why some people perceive that it doesn't get louder at the opposite end of the room! That is also why theres spots where it seems twice as loud, and other spots where the sub "disappears"!
Getting back to the main focus of my post, Professional Live Sound and recording gear: Many condenser mics have high-pass rolloff (some selectable, some preset) and I have yet to see any mic that is "rated" under 18-20hz (so the pipe organ might produce it, but it might not be accurate in the recording to begin with!!) These mics might pick it up, but who is to say it is an accurate reproduction? As for movies, I have not done audio on any, but I doubt theres anything purposely in the recording under 18hz!! Are you guys measuring the room response when you list these recordings, or are you measuring the actual audio signal off the recording? Once you excite a room, you will get all sorts of resonances at different frequencies and your bose acoustimass which might easily do 40 hz might create resonances at 20 hz if placed in the room properly! Your 22hz speaker will make resonances at 11 or even 6 hz! Look at the L-acoustics DV-dosc! IT is a line array speaker with dual 6 1/2" lf drivers per box. An individual dv cabinet is specced to around 140 or 150hz (not published .. they are made to be used as 3 or more cabinets). IF you build an array of 8 dv cabs, you will now get down to 50 or 60hz with no problem!!!!! (note these are made to be used with subs for music reproduction). Also if you want to see some serious subs made for the professional audio market, look at bassmaxx. They are re-defining cabinet design by using a tuned horn AS the cabinet, so both directions of the driver make it out at full level to the room, and couple for extended spl! These monsters wont do 8 hz, but their original design used a single 18" driver and produced over 100db spl 1w/1m, into the sub range (Remember, there for pro audio use so they don't need 18hz response!). Their B-0 cabinet uses a single 18" driver and is +/-3db from 35hz to 80hz at 108db @ 1w @ 1m! It will produce a constant max output of 133 db and a peak output (long term, not once per day) of 139db -- from a single 18" speaker!!! Why 35hz? Because that is fine for a pro audio environment (the concert you felt all that bass from)! Put one in your house, and I GUARANTEE you will be happy!!! They now have new products that put this one to shame using 2 or 3 12" speakers! These puppies are new technology to the pro audio world and not very common, as most PA companies use subs from the same company as their tops (fullrange speakers-- many to choose from), or a set of EAW SB-1000's or something small like that which packs a punch! The bassmaxx have higher efficiency "per driver" AND flat frequency response down low than anything I have seen before on the pro audio market or anywhere else.

What it all comes down to is this:
IS there audio under 20hz? YES
IS it supposed to be there? NOT LIKELY
IF you want a CLEAN ACCURATE sound system is it important to produce audio in this range? Probably Not -- since there is not SUPPOSED to be anything in that range to begin with.
Should we hear from someone who does the mixdown and/or mastering of movie soundtracks for more info on presence of 5-15hz audio in movies? Definitely!!!!

ps.. How many digital to analog converters actually play under 15 hz without high pass filtering? I haven't researched that, but I doubt many do!
Also what are you using to measure accuracy under 20hz? I hope its not a radioshack spl meter?????? Even the Behringer 9000 has filtering in it that keeps its response (relatively) flat but at the same time ruins the phase response across the mic, and different 9000's dont have the same response!!! I have a Superlux ecm-999 that I like and is cheap, but for real performance a real audio test mic would make a difference (and they are all spec'ed to measure down to 15 or 20 hz, so who knows whats really happening under that spec??

-- Audioguy78

Here is one of the links on the demo's etc.

http://www.avsforum.com/avs-vb/showthread.php?t=786803&highlight=rotary

Ok, I am new (less than 24 hrs) to this forum, and I cannot comment much for home audio or home theater stuff (hell, i am searching for my first "quality" subwoofer -- on a budget of course) but after reading these posts I do have a few comments, mostly related to live sound.

I am a live sound engineer and have a lot of experience in that end of things... Of course, pipe organs with 64 foot pipes are hard to come by and produce their own sound straight to the audience (without PA amplification) but most PA speakers will provide somewhere between 20-35hz as a low point, as most concerns are placed on the rest of the audio spectrum! Most sound consoles have adjustable high pass filters on each input, which usually adjust from 20 hz up to 400 hz (we usually set vocal mics between 75 and 150hz, so that throws out the muddiness in the vocal and the need for feeling the breath of a performer at 12hz!)
Most PA audio processors dump between 20 and 35 hz.. why? Because the energy there IS NOT PART OF THE FUNDAMENTAL sounds coming from the instruments being reproduced and if it is in the wire, it will just waste amp power and speaker heating! As live sound engineers, we want to reproduce the sound being made on stage, not waste power on vibrating the floor (when it will heat up our drivers and rob our 2500-5000 watt amps and ruin the performance of them at 30-70hz where we really need them!) Also, since tuned port speakers are the most efficient, and we need all the efficiency we can get at those frequencies, we dont want to waste power pushing the speaker under it's box tuning port (and boxes need to stay small enough to not take up too much trucking space, so we can efficiently get them to the gig! Also, did you know most touring shows bring their own rig, so from night to night at MOST theaters and amphitheaters it is a different sound system each time! not the same system night after night.)

As for the 6db per doubling of distance, this is an ACOUSTICAL RULE (At all frequencies) which has been broken by the introduction of Line Array speakers (which have very tight horizontal patterns of <10 degrees per box -- these have a 3db/doubling rule, and a properly coupled system of more than 3 boxes will smoothly fill an entire audience area within +/-2db of the entire audio bandwidth!) This 6db rule (for standard sources of sound) DOES NOT TAKE INTO ACCOUNT reflections, only the traveling of sound waves over distance (so add walls and you will have combing at some frequencies, and reflections will add to the main wave to make positive or negative coupling to different frequencies -- end result is it might be louder near a wall or corner, and lower in the middle, or vice versa, all related to distance and frequency!) That is why some people perceive that it doesn't get louder at the opposite end of the room! That is also why theres spots where it seems twice as loud, and other spots where the sub "disappears"!
Getting back to the main focus of my post, Professional Live Sound and recording gear: Many condenser mics have high-pass rolloff (some selectable, some preset) and I have yet to see any mic that is "rated" under 18-20hz (so the pipe organ might produce it, but it might not be accurate in the recording to begin with!!) These mics might pick it up, but who is to say it is an accurate reproduction? As for movies, I have not done audio on any, but I doubt theres anything purposely in the recording under 18hz!! Are you guys measuring the room response when you list these recordings, or are you measuring the actual audio signal off the recording? Once you excite a room, you will get all sorts of resonances at different frequencies and your bose acoustimass which might easily do 40 hz might create resonances at 20 hz if placed in the room properly! Your 22hz speaker will make resonances at 11 or even 6 hz! Look at the L-acoustics DV-dosc! IT is a line array speaker with dual 6 1/2" lf drivers per box. An individual dv cabinet is specced to around 140 or 150hz (not published .. they are made to be used as 3 or more cabinets). IF you build an array of 8 dv cabs, you will now get down to 50 or 60hz with no problem!!!!! (note these are made to be used with subs for music reproduction). Also if you want to see some serious subs made for the professional audio market, look at bassmaxx. They are re-defining cabinet design by using a tuned horn AS the cabinet, so both directions of the driver make it out at full level to the room, and couple for extended spl! These monsters wont do 8 hz, but their original design used a single 18" driver and produced over 100db spl 1w/1m, into the sub range (Remember, there for pro audio use so they don't need 18hz response!). Their B-0 cabinet uses a single 18" driver and is +/-3db from 35hz to 80hz at 108db @ 1w @ 1m! It will produce a constant max output of 133 db and a peak output (long term, not once per day) of 139db -- from a single 18" speaker!!! Why 35hz? Because that is fine for a pro audio environment (the concert you felt all that bass from)! Put one in your house, and I GUARANTEE you will be happy!!! They now have new products that put this one to shame using 2 or 3 12" speakers! These puppies are new technology to the pro audio world and not very common, as most PA companies use subs from the same company as their tops (fullrange speakers-- many to choose from), or a set of EAW SB-1000's or something small like that which packs a punch! The bassmaxx have higher efficiency "per driver" AND flat frequency response down low than anything I have seen before on the pro audio market or anywhere else.

What it all comes down to is this:
IS there audio under 20hz? YES
IS it supposed to be there? NOT LIKELY
IF you want a CLEAN ACCURATE sound system is it important to produce audio in this range? Probably Not -- since there is not SUPPOSED to be anything in that range to begin with.
Should we hear from someone who does the mixdown and/or mastering of movie soundtracks for more info on presence of 5-15hz audio in movies? Definitely!!!!

ps.. How many digital to analog converters actually play under 15 hz without high pass filtering? I haven't researched that, but I doubt many do!
Also what are you using to measure accuracy under 20hz? I hope its not a radioshack spl meter?????? Even the Behringer 9000 has filtering in it that keeps its response (relatively) flat but at the same time ruins the phase response across the mic, and different 9000's dont have the same response!!! I have a Superlux ecm-999 that I like and is cheap, but for real performance a real audio test mic would make a difference (and they are all spec'ed to measure down to 15 or 20 hz, so who knows whats really happening under that spec??

-- Audioguy78

Do you know if any of the attached lists are "real" or more to the point-intended?

http://www.lymanfamily.org/lyman/randy/audio/low_hz.html

As I said, I am new to this forum, and I cant read EVERYTHING in 1 day (trust me I am trying!)

I just gave a few facts about acoustics and the world of professional audio, which may tie in to home audio since home audio is re-producing what was produced (or reproduced by a PA system for the audience) by professional audio loudspeaker (for a live show) or studio speakers in the recording studio (for studio-recorded content or movies).

As for this list, I do not doubt there is measurable low frequency content below 20hz there, and with the right "pressure machine" you can feel it. As for if it is intended to be there, I would be sceptical about that, since I have an inside into the production of audio programs. Most production houses dont employ subs FLAT TO 5 HZ, or even flat with no distortion to 15hz! The engineers mixing your soundtrack may be aware or may not be aware of the existance of such sub-sonic activity! They may get rid of it, or lower it if they knew it was there!! or they may like it and push it up on the other hand!!

All I am saying is that here you are reproducing sound that in MANY (not all) cases are not supposed to be (or unknowingly were) there from the point of the producer! I may be wrong and there may be more programs where they intended it, but as far as I know, 20hz, or MAYBE 15, is as deep as any production studio ever considered monitoring the audio soundtrack they were producing.

Most of us want to ACCURATELY reproduce the soundtrack the way it was intended to be heard, and producing artifacts that were not considered part of the original production might be a big waste of money (depending on what your wallet feels like!) IF you have thousands of dollars to spend on a vibration to improve your home audio reproduction center, by all means go for it, but consider you might be feeling feelings that nobody (including the producers / makers of the program) felt before!!! (this might be a good thing??? up to you)
-- Audioguy78

As I said, I am new to this forum, and I cant read EVERYTHING in 1 day (trust me I am trying!)

IAs for this list, I do not doubt there is measurable low frequency content below 20hz there, and with the right "pressure machine" you can feel it. As for if it is intended to be there, I would be sceptical about that, since I have an inside into the production of audio programs. Most production houses dont employ subs FLAT TO 5 HZ, or even flat with no distortion to 15hz! The engineers mixing your soundtrack may be aware or may not be aware of the existance of such sub-sonic activity! They may get rid of it, or lower it if they knew it was there!! or they may like it and push it up on the other hand!!


-- Audioguy78Welcome and thanks. Just wanted your impressions of the list. I have heard some of the CD's on the list but certainly not all and I don't have a system (or a rotary sub) that can go much below 18HZ- 20HZ with any useable energy. I would be interested in getting Mark Seaton's take though as he seems to think plumbing those depths is definitely worthwhile.

As far as Tom Nousaine's opinion, it is here--
http://nousaine.com/The%20Truth.htm

Audioguy78,

Well put,I agree to some extent. Who cares if there is some subsonic rumble around 6Hz in recording X and a 7Hz rumble in track Z?



This is getting into a nonsense,with the supporting parties pushing a unit that YES works but would reproduce non musical program.And with all the limitations to deal with unless using special gear capable of linearity down to single digits.


JL Audio's Fathoms,Mark Seaton's Submersive and Velodyne's DD18 are very adequate in extension for all but those who want to find imaginary needs to play non musical information(rumble) their brains cannot process as anything else than pulsating air!

I think 10hz is a reasonable cutoff for what a "true" subwoofer should be able to play at reference levels. 20hz is absolutely not far enough as some very exciting stuff happens in the 10-20hz range that cannot be replicated by harmonics in the 20-40hz range. But 5-10hz is uncharted territory as far as value goes.

You guys need to get over this obsession that music has nothing under 30hz. Synthesizers are still music and many CD's go below 20hz. Organ music can hit 18hz on 32' tubes and supposedly there is an organ with a 64' tube (8hz). As well, things like the 1812 overture have cannons, which may not be an instrument but are still part of the soundscape. Not to mention that this forum is mostly about home theater, making this entire arguement about <30hz totally irrelevant.

Personally, I think those who argue that under 20hz isn't important are just compensating for their lack of woof :eek:

As for this list, I do not doubt there is measurable low frequency content below 20hz there, and with the right "pressure machine" you can feel it. As for if it is intended to be there, I would be sceptical about that, since I have an inside into the production of audio programs. Most production houses dont employ subs FLAT TO 5 HZ, or even flat with no distortion to 15hz! The engineers mixing your soundtrack may be aware or may not be aware of the existance of such sub-sonic activity! They may get rid of it, or lower it if they knew it was there!! or they may like it and push it up on the other hand!!

All I am saying is that here you are reproducing sound that in MANY (not all) cases are not supposed to be (or unknowingly were) there from the point of the producer! I may be wrong and there may be more programs where they intended it, but as far as I know, 20hz, or MAYBE 15, is as deep as any production studio ever considered monitoring the audio soundtrack they were producing.
I agree. There are not many mixing stages that have that kind of extension, and I don't know of any theaters. I believe in many instances, the director is not even aware the information is there.

On the otherhand, I also believe that some LF is added at times just to increase sales of a lousy movie DVD.

In the end, the amount of extension a person wants is a value judgement, and at some point it is just like SPL racing.