Colin Posted February 10, 2003 Share Posted February 10, 2003 I would think as low as 40 for ppp harp or similar. In my listening environment, anything below 55dB on the C weighted, slow response Rat Shack meter is below the audible threshold. "Fer shure... Pun intended? At 15db absolute, I'd hear nothing... Are we talking measured SP levels with a separate meter? Or are you using your receiver indicated levels? "So, at the mid-70dBs, which I typically listen at home, when the orchestra crescendo hits a brief peak 55dB higher, the CD only gives me a 90bd peak big difference. " I've been able to obtain the full dynamic range without compression...even at 16/44.1. I assure you the total range is at LEAST 60db. Yes, that was my point. The live range is huge. How do you know you captured the entire dynamic range? What did you use to measure it? Not the simple VU level meters on the recording device, I hope. Besides, I was talking about conventionally recorded CDs, not ones burned live with no compression. Quote Link to comment Share on other sites More sharing options...
Mallette Posted February 10, 2003 Share Posted February 10, 2003 >I would think as low as 40 for ppp harp or similar. In my listening environment, anything below 55dB on the C weighted, slow response Rat Shack meter is below the audible threshold. >Now we are getting somewhere... C weighting is for very high sound levels. I have only used it (another previous life) while doing film sound 100 yards from an Air Force jet test stand. Measured 140db at one point... Thank god for hearing protection, but I still think I lost a bit in my left ear. "Fer shure... Pun intended? >Yes >At 15db absolute, I'd hear nothing... Are we talking measured SP levels with a separate meter? Or are you using your receiver indicated levels? Mostly field experience. After many years in several careers involving audio, I can generally estimate pretty close. Anyway, 15 db A-weighted is less than most studio noise levels. "So, at the mid-70dBs, which I typically listen at home, when the orchestra crescendo hits a brief peak 55dB higher, the CD only gives me a 90bd peak big difference. " >I've been able to obtain the full dynamic range without compression...even at 16/44.1. I assure you the total range is at LEAST 60db. Yes, that was my point. The live range is huge. How do you know you captured the entire dynamic range? What did you use to measure it? Not the simple VU level meters on the recording device, I hope. >Yes. However, they are really highly accurate software meters on Sound Forge 6. If they were not accurate, I'd get digital clipping. I've yet to see a red clip indicater light up that didn't turn out to be audible, or hear audible digital clipping when the meter didn't catch it. That's my definition of accurate. Perhaps higher accuracy is possible, but I don't need it. AAMOF, I bust takes on red without even bothering to check anymore. Besides, I was talking about conventionally recorded CDs, not ones burned live with no compression. >Oh yeah. Yuk. There is no excuse for compressing a CD. None. LP's, in spite of that wonderful analogue sound, are compressed quite a bit. If you get half the dynamic range of a CD, you are doing good. That's why I've been using DBX dynamic range enhancers for over 30 years. With a bit of practise, they can be set with one twist to add between 10 and 40 percent dynamic range without audible side effect. Nice to have that CD silence between tracks, as well as reall "omph" in the tympani and such. Dave Quote Link to comment Share on other sites More sharing options...
Colin Posted February 10, 2003 Share Posted February 10, 2003 Kick Drum: Produces a broad span of frequencies with very high energy between 30 and 80Hz. (Live levels can reach 127dB, equivalent to 25 acoustic watts, or a typical box loudspeaker being driven by a 3kW amplifier!) Rock and jazz bass-drum output tends to have a higher frequency range than the orchestral bass drum. Quote Link to comment Share on other sites More sharing options...
Mallette Posted February 10, 2003 Share Posted February 10, 2003 Take a look at this drum. I shot this in central Thailand at an umbrella festival. Wish I had had a recording device. WAY into the subsonics. It juggled my gets at this range. The sound started subsonice, then would "wow" into the sonic range. Completely unique sound. Lots of great sounds there...big bronze temple bells, Thai classical orchestras. Wish I had the bucks to go back and record an audio tour... Dave Quote Link to comment Share on other sites More sharing options...
Terry N. Cruse Posted February 10, 2003 Share Posted February 10, 2003 WHAT? Quote Link to comment Share on other sites More sharing options...
prodj101 Posted February 10, 2003 Share Posted February 10, 2003 whats "comfortable" also depends alot on the music you listen to, or at least for me. I can listen to rap and techno very loud, without my ears feeling stressed, but throw in the cd "Headhunters" by Herbie Hancock, and the guitar riffs just peirce my ear drums, even thought they are the same level according to the SPL meter. Quote Link to comment Share on other sites More sharing options...
Terry N. Cruse Posted February 10, 2003 Share Posted February 10, 2003 As a child of the 60s.......... I don't remember ever listening to Khorns and not thinking "could we turn it up a little". (if you can remember the 60s....you were not there..) In the early 70s a Marantz TV commercial stated "Don't turn down the volume..turn down the distortion". I can't remember sound that was too loud if it was CLEAN. But then again...the 60s I.B. Slammin Quote Link to comment Share on other sites More sharing options...
WMcD Posted February 10, 2003 Share Posted February 10, 2003 Have I been to the Meyerson? No. I assume that is the hall in downtown Dallas. Maybe some day. Gil Quote Link to comment Share on other sites More sharing options...
BryanJ Posted February 10, 2003 Share Posted February 10, 2003 Thought this was a little informative. It was one of the wifes training outlines. Has some general info on db. Bryan Hearing Conservation Program Syllabus.txt Quote Link to comment Share on other sites More sharing options...
jnorv Posted February 11, 2003 Share Posted February 11, 2003 How do I check the calibration on my RS SPL meter? At listening levels at which I used to blow out my Thiel's, I only read 90-95 db. Jim N Quote Link to comment Share on other sites More sharing options...
WMcD Posted February 11, 2003 Share Posted February 11, 2003 I hope to get together with Dave Mallet again. I believe his experience with live recording using extended bit systems, plus his love of vinyl gives him some unique insights to dymanic range. It is my suspicion that we're not quite appreciating the "noise floor" in any ordinary setting. I find that, per the OSHA publication, we're sitting in 50 dB in an ordinary living room. Isn't that the bottom of the RS meter sensitvity? When I start with the LMS system in a living room, a garage, or outdoors, without sending a signal to the speaker the digits are bouncing around 50 to 55 dB. Some day I'll have to start carrying the RS around to determine what the "quiet" level is any given setting. That will have to include urban settings like the CTA bus and the Starbucks. I'll agree that a lot of pop music is compressed. But that may be one of the jokers in the pack as compared to classical music or natural sounds. I.e., 80 dB of pop music means, pretty much, 80 dB all the time. So we may not quite be appreciating the higher levels of music either. Gil Quote Link to comment Share on other sites More sharing options...
Mallette Posted February 11, 2003 Share Posted February 11, 2003 >How do I check the calibration on my RS SPL meter? At listening levels at which I used to blow out my Thiel's, I only read 90-95 db. It would help in this discusssion and similar to declare what weighting your meter is set to. It you are using C weighting, your readings are probably accurate. >I hope to get together with Dave Mallet again. You are always welcome, Gil. You will find the system quite different than last time. >It is my suspicion that we're not quite appreciating the "noise floor" in any ordinary setting. I find that, per the OSHA publication, we're sitting in 50 dB in an ordinary living room. Isn't that the bottom of the RS meter sensitvity? I've not used that meter, but I'd be surprised if it could read no lower than that A or B weighting. Again, C weighting is not very useful at low ambient noise levels. 50db background B weighting is probably about right for the "average" urban LR. Again, being where I am, I can be as low as the 30's with everything shut down. Unfortunately, due to Mssrs. Fletcher and Munson, there is diminishing returns as it gets quieter. If you've ever been in an anechoic chamber, you know what a horrendous roar your blood makes rushing through your body!! >I'll agree that a lot of pop music is compressed. But that may be one of the jokers in the pack as compared to classical music or natural sounds. I.e., 80 dB of pop music means, pretty much, 80 dB all the time. So we may not quite be appreciating the higher levels of music either. It's my theory that pop started out compressed because if you can't hear it clearly on an AM car radio, it don't make number one. Other reason, for sure, but I am convinced that is one of them. It still holds. Chamber music is a bit hard to listen to on a heavy freeway. Dave Quote Link to comment Share on other sites More sharing options...
Invidiosulus Posted February 11, 2003 Share Posted February 11, 2003 ---------------- On 2/11/2003 8:47:18 AM Mallett wrote: If you've ever been in an anechoic chamber, you know what a horrendous roar your blood makes rushing through your body!! --------------- I've heard it stated that if our ears were any more sensitive that in a truly quiet room we would be able to hear the movement of air molecules bumping on each other due to tempature changes and whatnot. Peace, Josh Quote Link to comment Share on other sites More sharing options...
Mallette Posted February 11, 2003 Share Posted February 11, 2003 http://www.e-2-s.com/kb-3.htm is a nice brief explanation of SPL weighting schemes. http://www.audiophilia.com/hardware/spl.htm is a good third party review and explanation of the RS meter, including some calibration info (not supposed to need to). 1. Objective-To understand the elements of the Hearing Conservation Program Bryan: Ouch. "To understand" is not an objective. "To be able to define..." is an objective. Sorry, but the Instructional Systems Technologist in me pops out from time to time. Back in your hole... :-> Otherwise, that is a nice little bit of info on hearing protection. One thing we've danced around in this thread without stating a "rule" is the effect of distortion on ultimate comfortable level. I'll propose a guideline: The maximum SPL which can be experienced comfortably and with pleasure is directly proportional to the distortion level of the source and signal chain and the conditon of the hearing of those listening. Something to chew on, anyway. Fun thread! Dave Quote Link to comment Share on other sites More sharing options...
BryanJ Posted February 11, 2003 Share Posted February 11, 2003 Mallet, you must understand, my wife is lecturing to NASA Flight/aircraft mechanics, not PHD's or Doctors. I am a DDS Doctor and that point you made came from left field I thought? We are not stringent Aerospace eng's with great skills in tech writing as my dad was for NASA. She has to make her "Objective" exactly what you said "Ouch" to. The way is it is there. They are most grateful for her visits since it puts the EL Paso hangar up to date with Houston's Johnson's, and Calif's JPL ect. I think when the class has not an inkling of what your are talking about, which is usually the case, Yes "To Understand" the basics is an objective I can "define" topics all day long but when you meld the information with the "REAL WORLD" and real time situations with the captive audience, then you have a teacher and not just defintions that go in one ear and out the other. The students now have neural traces that cross link to thier own experiences. Hope that comes through ok? I gave only an outline she had on my laptop, I'll ask her if she cares to "elaborate". Wife said my new RS digital was a "TOY"!! compared to her German made unit:( She said she could ck one out which I might have to compare the readings . I saw the same RS unit calibration sites on a search. Dr BMJANOS:) Quote Link to comment Share on other sites More sharing options...
Mallette Posted February 11, 2003 Share Posted February 11, 2003 Whoa...I had no intention of insulting your wife or anyone else. It's a well thought out paper that concisely lays out the issues. However, my graduate qualification is in Instructional Systems. The definition of an objective is the foundation stone of that field and all else proceeds from it. It is not a semantic issue. LIVES are on the line. Do you want your helicopter pilot to understand how to perform an autorotation landing, or be able to demonstrate one? One is entirely metaphysical and can not be proven, the other is entirely verifiable. My sincere apologies if I offended, and my instructional systems hat is back in the closet where it belongs in this forum... Best regards, Dave Quote Link to comment Share on other sites More sharing options...
Mallette Posted February 11, 2003 Share Posted February 11, 2003 You mentioned your wife's "German made unit" and the RS unit being a toy. Indeed, it is useful for gross measurement, but its very price tells you it does not have the extremely (I prefer ribbons) precise microphone, and highly calibrated weighting circuits for truly precise measurement. I had a vacuum tube SPL meter back in the 70's as Director of Sound Production for a company that produced educational film strips and such. It was AWESOME. Had the only Rochelle Salt microphone I've ever seen on it. Just like in our hobby, a vacuum tube SPL meter reads more accurately at clipping levels than SS ones. Sure wish I had stolen it... No doubt went to the trash after I left. Sometimes one can be too honest! Dave Quote Link to comment Share on other sites More sharing options...
BryanJ Posted February 11, 2003 Share Posted February 11, 2003 No apologies needed Mallet. I've come to enjoy this forum the most and will input the most since becoming a La Scala owner. We all come from all venues which is most interesting to myself. These Flight engineers/mechanics already have thier own "dogma" or "Objectives" My wife(industrial hygienist) is there to teach the best she can to people who only have a rudementry inkling of what is going to be said. So take it with those grains of proverbial salt and then put the salt on a nice ripe tomato and enjoy. I know I do:) Great forum and keep your hat on! I do!!! Bryan forgive all spelling and grammar, I'm a bad boy!!or was back then:)!! Quote Link to comment Share on other sites More sharing options...
BryanJ Posted February 11, 2003 Share Posted February 11, 2003 I still think our RS unit does what we need it to! I'll let you all know how it goes against the German unit if the wife indeed can check it out like she says. As far as calibration, they have thier own unit which produces decbel's of known value to calibrate to. Have a good evening all and a good dinner!! Bryan Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted February 12, 2003 Share Posted February 12, 2003 Uh...that was nice, but back to the subject at hand. Read my Signature below. It says it all! I can crank my Cornwalls to just over 100dB without ear strain or nose bleeds! I'm not deaf yet, but when I play my CD of J.S. Bach's "Toccata & Fugue in D Minor" by Virgil Fox at the Ruffatti Organ at the Garden Grove Community Church at "live" levels, it sounds like there's a huge pipe organ in my tiny music room! Breathtaking! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.