You can do an RTA in REW like I showed in post #22. At maximum (sensible) volume I saw these numbers:
30Hz: 98dB
25Hz: 100dB
20Hz: 102dB
15Hz: 92dB
10Hz: 85dB
BTW @ 10hz there was not a single audible sign of stress.
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One of my favorite test tracks of 80s music is 'Oil on Canvas" by Japan. It has some sub 20 hz content throughout the album. Mick Karn also happens to be a phenomenal fretless bassist.
You'll need a CD or Vinyl copy, as it doesnt exist ( to my knowledge ) on streaming services, not to mention the compression codec used may remove the infrasonic content.
You'll need a CD or Vinyl copy, as it doesnt exist ( to my knowledge ) on streaming services, not to mention the compression codec used may remove the infrasonic content.
@profiguy Which specific tracks? The "Japan - Oil On Canvas" 2003 remaster is available on Spotify 
I did an RTA measurement on various Jean Guillou organ works available on Spotify and they also contain infrasonic content. The lowest notes are 16Hz and even the low background rumble can be heard and measured.
I did an RTA measurement on various Jean Guillou organ works available on Spotify and they also contain infrasonic content. The lowest notes are 16Hz and even the low background rumble can be heard and measured.
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Dolby would provide a 10dB boost via the LFE channel but it would be tailored to suite. In other words say there was a need to play music nicely within it FR boosting it by 10db over the entire range wouldn't be a good idea. Hence the E for effects rather than just LF.
Dolby is pretty clear about production monitoring kit, all -3db at 20Hz. That doesn't mean there isn't some lower - however.
TBH honest I have some doubts about monitoring with mic's and the listening via a transducer that tends to have increasing problems at lower frequencies. As some one mentioned are people hearing harmonics or true tones?
REW has a generator on board and if I select a 10Hz tone and the microphone records 10Hz with a 100dB SPL this should be a harmonic? I'd like to refer to post #22 which was an 11Hz tone in REW close to the speaker. The harmonics are there but exactly @ 22, 33, 44Hz and up.
The track "Ghosts" is where a bit of sub 20 hz energy is. I'd be surprised if the MP3 version had the infrasonics intact, as it wouldn't fair well with just about any speakers used by the mainstream.@profiguy Which specific tracks? The "Japan - Oil On Canvas" 2003 remaster is available on Spotify
I did an RTA measurement on various Jean Guillou organ works available on Spotify and they also contain infrasonic content. The lowest notes are 16Hz and even the low background rumble can be heard and measured.
What cracks me up is how alot of electronic music is dumbed down and doesn't have much of anything under 40 hz. The kick they use has typically no lower than a 50 hz sine riding on it.
Just about any well recorded piano will have infrasonic content if the mic on either string group was high passed. What drives me nuts is when the engineer lets this go through to the final mix down, which cancels the lower end from phase inversion. It makes the piano sound like its 50 ft wide... horrible.
Yes, alot of pipe organs have the 16.3 hz low C note. The 32 ft pipe is quite the amazing thing to behold. Some larger organs have 64 ft, 8.15 hz "C", which I've heard (felt) on rare occasion at demos if the organist decided to explore that register. Its definitely not a commonly scored note out of obvious reasons. They used to claim it was played during the time the collection plate was passed around... lol.
@Frank207be Be careful with those levels of super low end. It doesn't take much to bottom out an LF driver, especially in a ported enclosure.
The extreme lower notes have very small increments separating them thanks to logarithmic scaling. Very small steps are only needed being the first octave is from 16.3 to 32.6 hz C to C. Im not sure if Rew rounds the numbers to some degree, but it should be very accurate as such.
The extreme lower notes have very small increments separating them thanks to logarithmic scaling. Very small steps are only needed being the first octave is from 16.3 to 32.6 hz C to C. Im not sure if Rew rounds the numbers to some degree, but it should be very accurate as such.
Which might be what you are hearing. Post #22. My normal listening levels are circa 70dB. Link to the image
https://www.diyaudio.com/community/attachments/subwoofer-1-rta-11hz-jpeg.1154978/
That last sentence made me ROFLMAO.
I'll listen to Ghosts and report back
There is electronic music that goes deeper. Just listen to Alan Braxe with Addicted or Never Ever Land from Infected Mushroom.
I'm not afraid. The 21" drivers are all in sealed boxes for sound quality and have 12mm and 15mm X-Max. Especially the B&C 21SW152 is tested by Data Bass and came out unflappable in a 20Hz tuned BR box. My only concern is the 30yo 15" Visaton drivers in front of my set that could bottom out but I'm looking for a reliable replacement.
Pink Floyd's Welcome to the machine has some infrasonic content. It does test my tone arm settings and cartridge with the part at the end of side 2. Some cartridges can't track that "thud" at the end and may skip. The LF wave from the closing door sound is around the arm resonance of the turntable. I have a KAB fluid damper which helps alot and it really tightened up the low end on vinyl, which now sounds better than some digital stuff. The RME pro adi2 already has amazing low end. It's at 1 dB down around 5 hz. Vinyl won't go that low out of obvious reasons. The arm resonance defines the cutoff point.
It's interesting watching you guys attempt to adjust the definition of sound to suit your own ends. The existence of a vibration and the record of affect of the same does not qualify it as sound.
An earthquake may shake the earth @1hz. I am aware of the vibration because I feel it but I cannot hear it,
Conceptually, powerful low vibrations can confuse. Audio travelled to you at from source via air at 750mph. Other vibrations travelled through solids at up to 10x the speed of sound.
An earthquake may shake the earth @1hz. I am aware of the vibration because I feel it but I cannot hear it,
Conceptually, powerful low vibrations can confuse. Audio travelled to you at from source via air at 750mph. Other vibrations travelled through solids at up to 10x the speed of sound.
The fundamental frequency 11Hz is called the first harmonic, multiples up to the 11th harmonic at around -40 daB from the first harmonic are visible. The second harmonic being more than -20dB (THD of less than 10%) indicates the drivers are at or under Xmax, not near mechanical limits.
At 100dB, the upper harmonics of 11Hz would be more audible than the fundamental, comparing the harmonic distortion curve to equal loudness contours makes this visible, the third harmonic (33Hz) at 75dB is just a bit above the minimum "hearing" perception level.
That said, the transition between "hearing" and "feeling" varies by large amounts between individuals, the ISO 226:2003 is just an average of normal hearing people. The 10dB "twice as loud" perception at 1kHz drops to less than 5dB below 20Hz, so relatively small increases down low make more audible difference.
@weltersys thanks for the clarification. Today I played around with REW just did some testing from 10Hz and up at higher level. Of course my subs only come really into action from 16Hz but that frequency clearly put pressure on my ear drums.
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After a lot of thinking I finally decided to renew and rearrange all the subwoofers in my room. My goal is having clean and meaningful 10-150Hz output to be ready for Dirac ART.
First action will be the renewal of the front subwoofer that reside behind my AV wall. I'm fairly happy with the four old Visaton TIW400 in their sealed enclosure but they're excursion limited and drop off quickly under 20Hz. Driver choice proved to be harder than I first thought. I wanted to keep the depth of that sub limited to 40cm and extend it from floor to ceiling (248cm) so staying with 15" woofers seemed logical. But as I live in the EU, affordable 15" subwoofers with decent specs are hard to find so I extended my search to 18" woofers. As I already have a very good experience with PA drivers I ordered 4x Faital Pro 18XL1800 with 20mm x-max earlier this week. They were delivered today and you can easily see that their build quality is top notch and they're capable of moving a lot of air.
Their enclosures will be ported this time. The volume will be 1200L (divided in 2 stacked boxes for practicality) and the tuning 12Hz so GD will only rise under 20Hz. As expected WinISD simulates an excursion limit under tuning @ 450W but with that power the sub will already output >110dB from 10Hz and up. Furthermore there is not a lot of bass under 10Hz in movies and the suspension will keeps things in check down low so I probably won't need a HPF for protection.
Second action is building a huge riser. We have put our back seat on a temporary riser for a few months and the whole family likes the concept. The exisiting 21" subwoofers will be built-in. Maybe the old 15" subs can be reclaimed too. I've read that Dirac ART allows you to choose the support frequency of each sub?
First action will be the renewal of the front subwoofer that reside behind my AV wall. I'm fairly happy with the four old Visaton TIW400 in their sealed enclosure but they're excursion limited and drop off quickly under 20Hz. Driver choice proved to be harder than I first thought. I wanted to keep the depth of that sub limited to 40cm and extend it from floor to ceiling (248cm) so staying with 15" woofers seemed logical. But as I live in the EU, affordable 15" subwoofers with decent specs are hard to find so I extended my search to 18" woofers. As I already have a very good experience with PA drivers I ordered 4x Faital Pro 18XL1800 with 20mm x-max earlier this week. They were delivered today and you can easily see that their build quality is top notch and they're capable of moving a lot of air.
Their enclosures will be ported this time. The volume will be 1200L (divided in 2 stacked boxes for practicality) and the tuning 12Hz so GD will only rise under 20Hz. As expected WinISD simulates an excursion limit under tuning @ 450W but with that power the sub will already output >110dB from 10Hz and up. Furthermore there is not a lot of bass under 10Hz in movies and the suspension will keeps things in check down low so I probably won't need a HPF for protection.
Second action is building a huge riser. We have put our back seat on a temporary riser for a few months and the whole family likes the concept. The exisiting 21" subwoofers will be built-in. Maybe the old 15" subs can be reclaimed too. I've read that Dirac ART allows you to choose the support frequency of each sub?
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REW testing, as much as I like it, is close to useless sub-sonically because human hearing sensitivity drops off so much. You need vast amounts of air movement to experience/hear very low frequencies and only your sternum knows for sure.
Hard to guess what's on your source (typically a movie). Did they boost the thunder and military explosions to incredible high levels for the movie theatres or something different (and louder) for the home theatre customer?
Klipschorn's despite their high cut-off (like 35 Hz) produce more gut-satisfying room-filling bass than the usual boxes.
Ben
Hard to guess what's on your source (typically a movie). Did they boost the thunder and military explosions to incredible high levels for the movie theatres or something different (and louder) for the home theatre customer?
Klipschorn's despite their high cut-off (like 35 Hz) produce more gut-satisfying room-filling bass than the usual boxes.
Ben
You don't have to guess- post #59 gave links to available titles and the response levels, etc:
Plenty of pants flapping frequencies available well below what most commercial theaters are capable of.