After 4 pages, i think the answer of this thread, in the absolute way is: 1 hertz.
Any high-fidelity sound reproduction system should be able to reproduce everything. HT or music, there is no difference. Soundtracks are considered music.
But that is the absolute. The no-compromise answer. Nice to know but i'm sure there is some in-between like the Porsche 911 is for daily-driver vehicle and F1 car...
SPL-wise, i'm pretty confident anywhere between 95 and 105db in-room would be considered ''loud'' by most people, regardless of which frequency. So that is settled.
But the question of the highest roll-off point remains to me. For PA it seems to be 40hz and for commercial Hi-Fi it seems to be in the 35-40hz, which gives good clues but maybe not definite answers since they have other considerations (cost, marketing, mobility, etc... so i guess 35-40hz would be the MINIMUM acceptable but not the OPTIMUM sweetspot, just before diminishing returns law kicks in...
I frankly don't know the answer yet, because i don't know how low we can go with, say, a pair of 20-30 liters cabinets, for a 95-105 in-room SPL, given all of the most advanced technologies combined, together in action (passive radiator, DSP, class D amps, modern drivers, etc..).
My guess is: 20-30 liters cabinets probably won't cut it. Especially if the goal is 105db+ @ 20-25hz.
So, either bigger volume or higher frequency. Or maybe just another technology that is yet to come.
Any high-fidelity sound reproduction system should be able to reproduce everything. HT or music, there is no difference. Soundtracks are considered music.
But that is the absolute. The no-compromise answer. Nice to know but i'm sure there is some in-between like the Porsche 911 is for daily-driver vehicle and F1 car...
SPL-wise, i'm pretty confident anywhere between 95 and 105db in-room would be considered ''loud'' by most people, regardless of which frequency. So that is settled.
But the question of the highest roll-off point remains to me. For PA it seems to be 40hz and for commercial Hi-Fi it seems to be in the 35-40hz, which gives good clues but maybe not definite answers since they have other considerations (cost, marketing, mobility, etc... so i guess 35-40hz would be the MINIMUM acceptable but not the OPTIMUM sweetspot, just before diminishing returns law kicks in...
I frankly don't know the answer yet, because i don't know how low we can go with, say, a pair of 20-30 liters cabinets, for a 95-105 in-room SPL, given all of the most advanced technologies combined, together in action (passive radiator, DSP, class D amps, modern drivers, etc..).
My guess is: 20-30 liters cabinets probably won't cut it. Especially if the goal is 105db+ @ 20-25hz.
So, either bigger volume or higher frequency. Or maybe just another technology that is yet to come.
Not until you asked but google knows a thing or two.
NASA -
Preventing Fires on the Launch Pad
It doesn't specifically say that the astronauts experience 180 db, but they are on the payload bay area. And note that they had to cut the noise DOWN to 180 db from whatever hellraising volume it starts at. This is actually a pretty interesting read, I knew nothing of all this water.
http://www.rfidjournal.net/masterPr...np/margasahayam_may2_900_defense_aviation.pdf
The sensors are on the same shuttle that the astronauts are on.
This link is crazy interesting too, it even includes this cute little image.
An externally hosted image should be here but it was not working when we last tested it.
So I'd say yeah, astronauts do experience a lot more than 140 db with no long lasting ill effects, and some astronauts do the takeoff thing a few times in their career.
Those were just a couple of the first links that came up in a search, I'm not going to spend any more time on astronauts.
Back to that:
Rotary woofer - Wikipedia
Too bad it can't get a little bit higher than 20hz... 27-28hz would be nice, it could be paired easily with conventional cone drivers for a true fullrange system, in a somewhat ''compact'' way.
Rotary woofer - Wikipedia
Too bad it can't get a little bit higher than 20hz... 27-28hz would be nice, it could be paired easily with conventional cone drivers for a true fullrange system, in a somewhat ''compact'' way.
F(3) is only usful for filters, Toole has shown that it is meaningless for what the ear/brain perceives. Better to look at F(6) or F(10)
dave
No it's not settled. 95 db is about the low volume limit where you start to be able to even notice that there's a single digit frequency being played. Single digits come alive at 130+ db.
If you do IB you can fit five 18s on a 18x18x18 inch manifold. That's not very big. And in IB it won't take much power at all to get them to xmax. Small, cheap, decent single digit performance. You don't need to wait for some alien technology to be invented, you can do this tomorrow. Even if you have bad credit you should be able to order the stuff to make this happen on a low limit credit card.
I agree. But I have noticed on forums in recent years, a tendency for some posters to start these threads, get some sort of 'average' number from them and repeat it over and over as if it were fact for everyone. From a post later than the one I'm replying to, I can see that that is his intention.
jag posted the AVS threads I was going to, but as there are so many betas masquerading as men there I don't often and didn't want to give them any more 'clicks'. The threads show the measured levels and there are some who've then compared those to the actual SPL at the LP and founds the responses very, very similar.
There is a surprising amount of LF content on movie tracks and especially on 'blockbuster' type fillums a great deal of it on surround channels as well as much higher level content than most would believe to be carried there.
just a guy, to be honest i would not even trust a mic below 10hz. At least, not a standard mic.
In fact i doubt about measurement's microphones accuracy for anything below 30hz and beyond 15khz. Even my M50 is doubtful, what can the mic's transducer really cover accurately + or - 1db ? that large of a bandwith ?
Measurements tools and ISO226 are doubtful, IMO. We have no solid reference.
In fact i doubt about measurement's microphones accuracy for anything below 30hz and beyond 15khz. Even my M50 is doubtful, what can the mic's transducer really cover accurately + or - 1db ? that large of a bandwith ?
Measurements tools and ISO226 are doubtful, IMO. We have no solid reference.
My UMIK from Cross Spectrum Labs is professionally calibrated 5 hz - 25000 khz. It's $100.
What decade are you living in, dude?
Brett and Pano, you're missing the point. Completely.
You're wrong on both my intentions and the whole general concept on how answers are found, discussions are working and how things evolves among people and ways of doing things.
How did you put it, Just a guy? Oh yeah: ''out of touch''
you're out of touch with humans, guys.
Treatable but it involves alcool.
You're wrong on both my intentions and the whole general concept on how answers are found, discussions are working and how things evolves among people and ways of doing things.
How did you put it, Just a guy? Oh yeah: ''out of touch''
you're out of touch with humans, guys.
Treatable but it involves alcool.
''professionally calibrated'' HOW ?
More details please. Please feel free to explain in great great details how a transducer is CALIBRATED PROFESSIONALLY ?
can't wait for the answer, dude.
It's surprising to find all the extreme LF content, since most systems and rooms can't reproduce it. Maybe it's bonus material for the chosen few.
There's a huge and growing audience for this type of media. People spend huge amounts of time making measurements, creating lists of favorable content. People purchase media solely for the LF content. Like Brett mentioned, some people there have 32 18 inch drivers. The average system there is probably eight 18s.
It's not surprising at all if you hang out on forums that live for this kind of stuff. People are even willing to pay $3200 for this 32 inch sub driver, something like 35 mm xmax, it's a beast.
W0W-32 - 32 inch Subwoofer - Mach 5 Audio - the place for bass
Baby for scale.
An externally hosted image should be here but it was not working when we last tested it.
As low as you can go
Eminent-tech claims that 20 Hz was merely a "generally accepted" low frequency limit, dating back to times when it was hard to achieve even that. Their rotary woofer is rated to 1 Hz.
Eminent Technology, Inc. Planar Magnetic Loudspeakers and Audio Technology
Wikipedia says 12 Hz and links to this article:
http://asa.scitation.org/doi/full/10.1121/1.2761883
As you go lower, the sound (which needs to be louder) gets sensed more and more as pressure. It would seem that such sensing could be done to at least 3 Hz if not 1 Hz.
So classical music never needed such a bass instrument, but the sound within a large concert hall (or church, etc) will naturally resonate at very low frequencies related to the size of the building.
A big problem with any kind of cone woofer is the need for size goes up too quickly to be practical, and what the LF range needs is large acoustic power to work at all. So just have 1Hz response at low power only does little if nothing.
I personally would love to have a rotary woofer. I'm tired of coffin sized subwoofers (such as I have) running out of steam around 16 Hz.
Eminent-tech claims that 20 Hz was merely a "generally accepted" low frequency limit, dating back to times when it was hard to achieve even that. Their rotary woofer is rated to 1 Hz.
Eminent Technology, Inc. Planar Magnetic Loudspeakers and Audio Technology
Wikipedia says 12 Hz and links to this article:
http://asa.scitation.org/doi/full/10.1121/1.2761883
As you go lower, the sound (which needs to be louder) gets sensed more and more as pressure. It would seem that such sensing could be done to at least 3 Hz if not 1 Hz.
So classical music never needed such a bass instrument, but the sound within a large concert hall (or church, etc) will naturally resonate at very low frequencies related to the size of the building.
A big problem with any kind of cone woofer is the need for size goes up too quickly to be practical, and what the LF range needs is large acoustic power to work at all. So just have 1Hz response at low power only does little if nothing.
I personally would love to have a rotary woofer. I'm tired of coffin sized subwoofers (such as I have) running out of steam around 16 Hz.
''professionally calibrated'' HOW ?
More details please. Please feel free to explain in great great details how a transducer is CALIBRATED PROFESSIONALLY ?
can't wait for the answer, dude.
Cross·Spectrum - Calibrated MiniDSP UMIK-1 Microphones for Sale
It's calibrated by a firm specializing in acoustics, noise and vibration control. One of the guys there does it in his spare time. He's a professional. He calibrates against a professional mic that is itself calibrated annually and costs several thousand dollars. That's how, dude.
Just a guy, and what about ISO226:2003 (or back to F&M if you wish) ?
everything is an average. Nobody's know what your earing perceptions are, nobody is feeling the same way, or maybe everybody is feeling the same way (unlikely) and nobody is sure about that, either way.
Basically it's all about pain threshold. You might find 10hz @ 130db very pleasing while my sister can find it unbearable, even at 100db. Who knows.
Bottom line is: we have sound systems that are designed for certain bandwith, more or less flat, for a pleasant experience (accuracy? based on what?) and to achieve certain output.... That's about it.
Frequency response + amplitude.
far behind, Rt and spatial positionning for acoustic effects, sense of grandeur, ambiance... But basically it's about FR and SPL.
I'm extremely confident you'd make a survey, actual in-room testing, and you'd end up with something like 150hz-8khz @ 80db at listening position as being acceptable by 90%+ people.
95-105db as being loud (audible bandwith), 110-115db as being very loud (loudness contoured) and 120-125db as being unbearable.
and 35hz-18khz flat as being ''very hi-fi''...
I'm sure studies were already made on those things anyway.
everything is an average. Nobody's know what your earing perceptions are, nobody is feeling the same way, or maybe everybody is feeling the same way (unlikely) and nobody is sure about that, either way.
Basically it's all about pain threshold. You might find 10hz @ 130db very pleasing while my sister can find it unbearable, even at 100db. Who knows.
Bottom line is: we have sound systems that are designed for certain bandwith, more or less flat, for a pleasant experience (accuracy? based on what?) and to achieve certain output.... That's about it.
Frequency response + amplitude.
far behind, Rt and spatial positionning for acoustic effects, sense of grandeur, ambiance... But basically it's about FR and SPL.
I'm extremely confident you'd make a survey, actual in-room testing, and you'd end up with something like 150hz-8khz @ 80db at listening position as being acceptable by 90%+ people.
95-105db as being loud (audible bandwith), 110-115db as being very loud (loudness contoured) and 120-125db as being unbearable.
and 35hz-18khz flat as being ''very hi-fi''...
I'm sure studies were already made on those things anyway.
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The rotary woofer needs a CLOSET sized damped tunnel to kill off the high frequency noises it creates. And it costs $18000.
You can buy fifty 18s for $8000 and mount them all on ten 18x18x18 inch manifolds.
The conventional woofer boxes can be MUCH smaller, the drivers are MUCH less expensive and the conventional system would be MUCH louder.
Rotary woofers are incredibly dangerous too. If you have kids or pets that you don't want splattered all over your walls there are definitely better choices. Witness the potential for death here -
YouTube
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10 hz and below is not in the audible spectrum. How are you going to hurt your cochlea with tones you can't even hear? Have your wife or kid or friend blow in your ear as hard as they can. Does it hurt?
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