Does anyone really listen to movies with bass peaks at 115-118db? (1 Viewer)

[Lee-c]

steve nn: Yeah, but could you possibly run your sub so hot that the bass would be at ref. level, but the
rest of the frequencies be so much lower than ref. that it would be completely safe to listen to them
without totally throwing the balance of the audio in the movie out of whack? You might have to
run your sub +15 db or something to get to that point, wouldn't that overwhelm the higher
frequency stuff (like voices) in many situations?

 

[Pete Saunders]

Great dicussion everyone! I think the best point made is that it probably isn't safe for your ears to listen Dolby reference levels for prolonged periods because not just low frequencies but the mids and highs are included also.

And you are correct. Maybe I should have titled this thread "listening to movies at 115-118dbs" and not bass only levels.

My comfortable zone, however, in my house for my ears is 100-103dbs. Others like that wall thumping bass.

Regards all!

 

[Tom Vodhanel]

Clean dynamic peaks of 105dBs from the mains aren't going to hurt anyone either. We aren't talking about a speaker playing a sinewave (or any steady state signal) for "9 minutes"(or whatever osha is worried about). We are talking about brief peaks...a second here, 2-3 seconds there in an action oriented DVD. I guess in theory, if you ran an endless loop of EVENT HORIZON for 60 years (ages 18-78?) and listened to it 16 hours a day...something would probably be amiss with you at the end of the task...

Tom V.
SVS

 

[Pete Saunders]

I understand your point, Tom, and it is in your best interest to promote your theory, but exposure to high dbs is cumulative.

100-105dbs for a few seconds might be okay (I generally listen to 100-103 peaks), but there may be several of those peaks throughout a two hour movie. Who knows what we are really doing to our hearing. I'll let you know in twenty years or so .

I just don't think I would want to listen to many peaks in the 115-118db range since it only takes less than 30 seconds to damage your hearing according to most of the charts. And in a perfect world, all HT systems would have the lowest amount of distortion or the lowest noise floor possible (that's what I strive for), but we know that doesn't happen in reality. High dbs combined with any level of distortion would be assumed to be a bad mix for your ears.

But we all want impact in our movies ( hey, I don't mind a little wall rattle) and ideally without ear damage. So what to do. I guess for me it is to limit damage to my ears (it's the health professional in me) and maintain a moderate degree of impact by listening to what I hope are reasonable levels of high db movie soundtrack and/or high db bass.

Pesrsonally I think at times the subtlety or details of a soundtrack can be lost with bass set too high, but that is just my preference. I guess it just all depends on what you want to experience in the movie.

Regards again.

 

[Tom Vodhanel]

>>>I just don't think I would want to listen to many peaks in the 115-118db range since it only takes less than 30 seconds to damage your hearing according to most of the charts.

 

[Ned]

This thread was an excercise in futility. At the start Pete didn't want to listen above 103 peaks, and nothing we've said made any impact on that. Hurray for timewasting!

 

[Greg Conti]

"Duration of 120 dBA before damage to hearing is 9 seconds."

Hmmm...I wonder what all those raves I went to with 36 18" Cerwin Vega subs in a room half the size of a basketball court did to my hearing? :frowning: Never felt any pain. Only when they were pushing the higher frequency cabs would I feel pain. I was always amazed at how loud music could be played with the right gear and not be harsh or feel pain.

 

[Vaughan Odendaal]

This thread hasn't been futile.If anything, its shown the misconceptions that are running around.

Since reference levels are peak figures, they only last for a few seconds.Since hearing is relatively insensitive to low frequencies, I doubt that 130db down to 20hz would do any damage.But its definitely frequency related.It depends not only on the duration of exposure, but also for the duration of the peaks.

It also depends on the individual.Some have a greater threshhold for sustaining a given amount of sound pressure.IMO, those db charts are a guideline, and not univerally held facts.

Regards

 

[steve nn]

Lee-c I have been thinking of your question and I think you must know that a +15db sub calibration is going to sound like #$%^. I have maybe egsagerated my calibration or calibration intent? +6db would/might be fine with my preferences at -15 to -20 listening level with a (20 Hz tuned) sub minus allot of mid bass freqs. Now if you are running a sub tuned to 25-28, then I would cut that calibration back.



The LFE will not hurt you but it's those darn speakers that will. You will need to find what works for you. Some times 90 db is plenty for me and then at other times 125 db or a tad more is what is called for.......

 

[Sebastian]

I will see some of you guys in line for a miracle ear in a few years.

Anytime, I run freq sweeps on by sub (Just long enough to chart my subs response), my left ear hurts a little and that is SPL's

 

[Pete Saunders]

Ned, Ned, Ned! Don't ruin a good thread!

I never said that listening to peaks above 103db is wrong for others, just not right for me as I find it fatiguing--even with my fairly high end, low distortion system. I also want to protect my ears a little, because who knows what years of exposure to all of the loudness of home theater will do to our ears. It doesn't mean I'm listening to home theater at low total volume or low bass volume; I'm just listening to it in reasonable levels for me. My walls can rattle a little; I just don't need the neighbor's walls to rattle too.

I also admitted that there must be a mix of mid and high frequencies when listening to high dbs in movies and that the name of the thread should have not just included bass only frequencies. Let's admit it, impact in movies comes from the midrange, and rumble and rattle ( that you can sometimes feel very well) comes from bass.

But I still believe, however, that long term listening to home theater in the high db ranges may well do some hearing damage. By long term I mean a few years.

And to each his own. Some people are bass fanatics and like to be blown off their seats when listening to movies. That is fine. I like impact too but believe bass should be integrated so that it disappears into the movie and doesn't overwhelm the soundtrack.

I thought there were good discussions here, but unfortunately your statement was a little juvenile.

 

[Pete Saunders]

Tom, I would really like to believe your statement that high db bass doesn't damage hearing because our ears are insensitive to those low frequences and that we are only being exposed for a few seconds ( although there are a few high bass scenes in Vertical Limit that seem to go on for a long time). Hopefully this is true, but I have not read anything to find support in this.

While it may be true that humans can't detect hearing in the low 20s or be able to localize those frequencies, most subs are producing at least 80hz which is detectable. The cilia in your ears are still receiving bass sound in the form of pressure waves. And I bet I'm not the only one who has listened to movies with high bass who has developed headaches. But I will admit, mid and high frequencies probably would do damage quicker due to the shorter wavelengths.

Again, to each his own, but I just want to be reasonable when it comes to listening to high db bass or high db movies.

Regards and best success with SVS

 

[Pete Saunders]

www.engineeringharmonics.com/papers/hearing1.htm

Everyone, here is a good article on hearing damage and low versus high frequencies. It essentially says we hear mid and high frequencies first and better, so we perceive them as louder. Yet, you are still hearing bass from 35hz and above and can get just as significant hearing damage from high db bass. The article goes on to say the jury is still out on what frequencies do the damage the fastest.

And there might just be something to Tom's opinion that we really need to be exposed to low bass for long periods at a time before any damage happens. Of course the article mainly talks about exposure to music, but I'm sure we could apply much of this to home theater.

Hope this helps to clarify things a bit.

Regards all

 

[steve nn]

I myself am willing to conceed that high SPL's can't be good for my hearing. My general listening level is -15 for HT and a + 3 to 4 sub calibration. I do bench race at times but not very often so I hope I fair out ok? Some do and will call me a bass head with my multiple SVS's and AV15 but after time in this obsesion/hoby I don't run my LFE as hot as some would think.

IMO low Hz bass is very interesting at higher spls but I do try to be carfull. I hope I am corect knowing what it takes to make my ears sore.

Pete you make a good point and hats off to you for bringing your question forth. Let me ask you a question now.

At -15 with 107-115 db peakes corected in the LFE dept. would you consider me a bass freak for HT purposise? In stating your opinion I ask you to consiter how well a svs sub does in the lower Hz material as oposed to some other oferings.

 

[Robb Roy]

By doing the '+3db hot' thing, you are deviating from the intended mix - you might as well not calibrate the sub and just set it by ear.

If the goal is to not deviate from the intended mix, then you should get rid of the volume control on the receiver (could that be the next THX spec.?). The mix was designed to be listened to at reference level, which, as this thread points out very well, most of us never do. This thread also points out over and over again that human hearing is less sensitive to low frequencies. Not only is it perfectly acceptable to have a difference of opinion with a sound technician, but setting your sub a tad hot might actually create a perceived impression of the movie's soundtrack that is closer to what the technician/director intended while playing the movie at lower volumes (by causing some of the tactile low frequency stuff that would only normally be felt/heard at closer to reference volume). In the end, people create movies for the impression they make on people, not measurements (ticket sales excluded).

-Robb

 

[Pete Saunders]

Hi Steve,

Again, I think to each his own. 115-117 bass peaks might be fine for you or your house setup. If I played bass that loud in my HT room, I know the pictures might fall off or my wife might pound my head against the walls!

If I wasn't worried about my ears, I might be tempted to play bass that loud. I still feel in my HT room that my bass peaks offer me plenty of impact. Also, I have my HT room extensively tweaked for sound (flat traps, canvas pictures, tube traps) and have lowered the noise level of my system by applying various electronic tweaks, which actually lowered my high listening levels from 105-107db to 100-103 dbs. Much easier on my ears.

There is a theory that states that some high dbs may be attributed to higher distortion levels. I guess one example of that is when I had to replace my 6 y.o. sub. Well that particular sub sounded very loud and rattled the walls fairly well. I replaced it with the same brand, but this brand has 6 years of improvements and a more powerful amp. When I now listen to movies at the same db levels, the walls don't rattle quite as much, and the bass doesn't seem as loud. Much easier on the ears, but the bass output from both was calibrated to exactly the same db levels. So what was happening: lower distortion levels with much better control, blending and transparency of movie bass.

But hey, when I was younger and first started out in HT, I pushed the bass up very high. When I got into higher end equipment, I realized I was missing a lot of the soundtrack and overwhelming the midrange and treble by doing that.

Everyone does their own thing, however. From what I have seen on this forum, SVS seem to be able to put out high db bass very well and satisfies those who want to REALLY FEEL IT in home theater. Nothing wrong with that (as long as it's done in measured doses for your ears), but not quite preferable for my ears. I want a convential explosion in my home theater and not a nuclear bomb

Regards!

 

[Tom Vodhanel]

Hi Pete,

Never saw Vertical, so I can't comment on that observation. Except perhaps to note that the "more than a few seconds at a time" scenes do seem rare enough that we would pick it out like this when it happens.

I read the link, but really didn't see anything specific regarding frequency vs. volume vs. time.

Tom V.
SVS

 

[Eric Eash]

i know running a sine wave at around 15khz-20khz would probably damage my hearing at very low dbs. i can't stand that ringing sound. also, working around fighter jets and very large aircraft like the C-5 can also really hurt your hearing. I probably will be deaf in 20 years, but i'm going to enjoy my HT in the meantime.

eric

 

[Marti D.]

A few words here:
As a guy who mixes sound for Film and TV,I am both shocked and amused at what I have been reading. We mix at 85spl "C" weighted , each speaker calibrated individually. I won't get into subwoofer calibration right now. That gives you 20 db of headroom for peaks in level etc. That is 105spl and summed together is VERY LOUD! Now I'm sitting back at a min of 20 feet from the screen with 3 3632T JBL Triamped speakers (Left, Center and Right)in front of me, 2 18" JBL Subwoofers and 6 JBL Surround speakers. Now the Mains are getting 750 watts through each element in each speaker ( low, mid, highs) and 1200 watts through the subs. It's clean and loud, however I don't abuse my ears with anything like a few of you are suggesting. Add to that level your amps which are clipping and distorting. Not a good thing!! Once you've heard a good sounding mix you'll realize that the type of level (118 in the subs!) is not clean,and not good for you. Go to a good sounding Theater or Stereo Store and find a benchmark for you to try and replicate, not just a Radio Shack meter pinned to the right!!!
Take Care,

 

[steve nn]

I think something to consider here is the higher spl levels we are talking about are not a every day practic and with most movies/material would not be enjoyibl imo. Robb Roy sums up my thoughts to the T. It's the (Tactile low frequency material) that interests me the most. I like reference LFE at a -15 listining level or there about. It depends on the material. I do not like reference output on all channels. I remember watching U-571 in the theater and quit frankly I had to put my fingers over my ears. In a movie like that I tone things back myself with all the shrill sound afects coupled with the LFE. I think my meager B&W speakers along with SVS and QSC acheive this very well for me.

The higher spl moments in our house are reserved for when the wife is gone or I just want a quick heavy dose bass fix. It would not surprise me in the least if they came out in a few years after more study and suggested that higher doses of LFE are good for our health and list all the benifits?? Of course this would be at a -15 give or take listening level though.