Headphones

Started by Bonehelm, June 10, 2007, 02:50:21 PM

Previous topic - Next topic

0 Members and 3 Guests are viewing this topic.

DavidRoss

I got yer raw transients right here:

"Maybe the problem most of you have ... is that you're not listening to Barbirolli." ~Sarge

"The problem with socialism is that sooner or later you run out of other people's money." ~Margaret Thatcher

Parsifal

Quote from: Todd on April 24, 2013, 04:54:38 PM


So the answer is no, you do not have any measurements to support your hypothesis, particularly as they pertain to "raw" transients, earbuds, and the impact on hearing.  You can suspect all sorts of things; you can prove nothing.

That is correct, I can prove nothing to someone who has no training in mathematics. 

To someone who is trained in mathematics I have given compelling evidence.  Impulse smearing will affect sound waves whose wavelength is smaller than the size of the room.  People are more accustomed to describing sound in terms of frequency, and this will affect frequencies above v/L, where v is the speed of sound and L is the size of the room.  Since the speed of sound is about 1000 m/s, and if we assume 10 m for the room, frequencies above 100 Hz would have their impulses smoothed out compared with headphones.  That is substantial.  For the headphone vs earbud comparison, we would set L to be the size of the earphone chamber, perhaps 10 cm at most.  Then we get (1000 m/s)/(0.1 m) = 10,000 Hz.  Only the very highest frequency transients would be smoothout out, which is probably not very significant.  So loudspeakers could provide substantial smoothing of transients, and headphones would probably provide very little smoothing of transients compared with earbuds.

Todd

Quote from: Parsifal on April 24, 2013, 05:20:09 PMFor the headphone vs earbud comparison, we would set L to be the size of the earphone chamber, perhaps 10 cm at most.


You can fancy yourself a scientist, or whatever, but the fact that you write about what you would do rather than what you have done tells me all I need to know.  You have no empirical evidence to support your claims, as I suspected.
The universe is change; life is opinion. - Marcus Aurelius, Meditations

People would rather believe than know - E.O. Wilson

Propaganda death ensemble - Tom Araya

Parsifal

Quote from: Todd on April 24, 2013, 06:43:09 PM

You can fancy yourself a scientist, or whatever, but the fact that you write about what you would do rather than what you have done tells me all I need to know.  You have no empirical evidence to support your claims, as I suspected.

I must admit your ability to defeat any argument by not understanding it is quite impressive.   :D

71 dB

#644
Quote from: Parsifal on April 24, 2013, 01:19:49 PM
Perhaps you should consider the fact that 71dB has formal education in the scientific discipline of acoustics and is more qualified to interpret the OSHA rules, since he has a detailed understanding of the concepts involved.  Of course, this would violate your life philosophy, which holds that anyone who disagrees with you obviously doesn't know anything.   ::)

A person with a formal education can be wrong too. I don't consider myself #1 expert on hearing protection field. It's been some 15 years since I actually studied these things in university. Anyway, I encourage people to follow the 3 dB exchange rate rule instead of the "weird" 5 dB exchange rate rule because it's much safer, logical (3dB = double power) and widely used.
Spatial distortion is a serious problem deteriorating headphone listening.
Crossfeeders reduce spatial distortion and make the sound more natural
and less tiresome in headphone listening.

My Sound Cloud page <-- NEW Jan. 2024 "Harpeggiator"

Todd

Quote from: Parsifal on April 24, 2013, 07:12:42 PMI must admit your ability to defeat any argument by not understanding it is quite impressive.



Will you be posting the results from your research here?
The universe is change; life is opinion. - Marcus Aurelius, Meditations

People would rather believe than know - E.O. Wilson

Propaganda death ensemble - Tom Araya

71 dB

Quote from: Todd on April 24, 2013, 01:20:12 PM

Hmm, "allowed" is an interesting word choice.  To be honest, I still place far more faith in the estimates of OSHA than in your opinion, but irrespective of whether one follows professional guidelines or amateur guidelines, listening to music at 115 dB (or 110, or 100 for that matter) is something only dunderheads do.

I posted that in a hurry. I should have put my words better. If I have time I may study OSHA's reasoning (I already read something but that didn't really explain anything). Placing faith in something (OSHA) is kind of religious. Use your own reasoning man.

When listening to music one has to keep in mind that music is dynamic. The highest peaks can be even 115 dB but the equivalent sound pressure level is much lower. I mention this just in case so everyone understands we are talking about equivalent levels.
Spatial distortion is a serious problem deteriorating headphone listening.
Crossfeeders reduce spatial distortion and make the sound more natural
and less tiresome in headphone listening.

My Sound Cloud page <-- NEW Jan. 2024 "Harpeggiator"

71 dB

#647
Quote from: Parsifal on April 24, 2013, 05:20:09 PM
That is correct, I can prove nothing to someone who has no training in mathematics. 

To someone who is trained in mathematics I have given compelling evidence.  Impulse smearing will affect sound waves whose wavelength is smaller than the size of the room.  People are more accustomed to describing sound in terms of frequency, and this will affect frequencies above v/L, where v is the speed of sound and L is the size of the room.  Since the speed of sound is about 1000 m/s, and if we assume 10 m for the room, frequencies above 100 Hz would have their impulses smoothed out compared with headphones.  That is substantial.  For the headphone vs earbud comparison, we would set L to be the size of the earphone chamber, perhaps 10 cm at most.  Then we get (1000 m/s)/(0.1 m) = 10,000 Hz.  Only the very highest frequency transients would be smoothout out, which is probably not very significant.  So loudspeakers could provide substantial smoothing of transients, and headphones would probably provide very little smoothing of transients compared with earbuds.

The speed of sound in normal pressure and room temperature is about 345 m/s. You must be confucing feets and meters. Your theory about transient smoothing is more or less valid but told in laymans terms. At low frequencies the things get complex as we have standing waves. Also, the room affects also when the wavelenght is larger than the room.
Spatial distortion is a serious problem deteriorating headphone listening.
Crossfeeders reduce spatial distortion and make the sound more natural
and less tiresome in headphone listening.

My Sound Cloud page <-- NEW Jan. 2024 "Harpeggiator"

Todd

Quote from: 71 dB on April 25, 2013, 08:48:24 AMUse your own reasoning man.



I don't use my own reasoning when it comes to setting listening levels.  I use my own preferences.  As it turns out, I generally don't listen very loud.  I knew about the 85 dB being a baseline for hearing damage, so first thing I did when I finally bought a cheap SPL meter was measure how loud I listen to music.  Turns out most of the time I listen at around a 70-75 dB average volume, with peaks hitting 80-90 dB, depending on the recording.  I then did a rudimentary test using headphones, and it's roughly the same.  When I feel like listening loud, I almost never go above 90 dB average, and then usually for only short periods.  A better SPL meter and sophisticated software would yield more precise results, of course, but I have no reason to spend the dough.
The universe is change; life is opinion. - Marcus Aurelius, Meditations

People would rather believe than know - E.O. Wilson

Propaganda death ensemble - Tom Araya

Parsifal

Quote from: 71 dB on April 25, 2013, 08:58:24 AM
The speed of sound in normal pressure and room temperature is about 345 m/s. You must be confucing feets and meters. Your theory about transient smoothing is more or less valid but told in laymans terms.

You are correct, of course, so using the correct number the frequency cutoffs would be about 3 times lower.

71 dB

Quote from: Todd on April 25, 2013, 09:00:55 AM
I don't use my own reasoning when it comes to setting listening levels.  I use my own preferences.

Yes, when listening to music, one can set the levels accordings to comfortable (often safe) preferencies.

Quote from: Todd on April 25, 2013, 09:00:55 AMAs it turns out, I generally don't listen very loud.

Loud is a subjective term.

Quote from: Todd on April 25, 2013, 09:00:55 AMI knew about the 85 dB being a baseline for hearing damage, so first thing I did when I finally bought a cheap SPL meter was measure how loud I listen to music.  Turns out most of the time I listen at around a 70-75 dB average volume, with peaks hitting 80-90 dB, depending on the recording.

My listening happens at similar levels. This kind of listening doesn't damage hearing even if one listen to music all day long.

Cheap SPL meters aren't very accurate. What weighting did you use? A? C? Linear? How about time-weighting? S, F or I? These choices affect a lot for what the dB value means.

Quote from: Todd on April 25, 2013, 09:00:55 AMI then did a rudimentary test using headphones, and it's roughly the same.  When I feel like listening loud, I almost never go above 90 dB average, and then usually for only short periods.  A better SPL meter and sophisticated software would yield more precise results, of course, but I have no reason to spend the dough.

Measuring headphones isn't that easy. People tend to use higher sound pressure levels when using headphones because:

- Distortion makes the sound appear louder. Since headphones can produce very high levels without significant distortion, headphone sound seems quieter compared to loudspeakers.

- Reverberation makes the sound appear louder. Since headphohes lack reverberation, people compensate turning volume up. This is the "transient mearing effect told by Parsifal".

- Headphone listening doesn't disturb others as much as loudspeakers do. So, headphone people turn the volume up!

Spatial distortion is a serious problem deteriorating headphone listening.
Crossfeeders reduce spatial distortion and make the sound more natural
and less tiresome in headphone listening.

My Sound Cloud page <-- NEW Jan. 2024 "Harpeggiator"

Todd

Quote from: 71 dB on April 25, 2013, 10:02:18 AMCheap SPL meters aren't very accurate. What weighting did you use? A? C? Linear? How about time-weighting? S, F or I?


I know they aren't accurate, but they are accurate enough for my purposes.  I used A weighting and F time weighting last time I measured.



Quote from: 71 dB on April 25, 2013, 10:02:18 AMMeasuring headphones isn't that easy. People tend to use higher sound pressure levels when using headphones because:


I didn't claim I performed sophisticated measurements.  What I did was set the volume to what I normally listen at and then place the SPL meter mic right up to the earpiece.  It was about 1 dB higher than my speakers from what I recall, at least using my Beyers.  If memory serves, I actually prefer listening to Grados at a lower volume due to the additional energy in the 1-3 KHz region.  (I very rarely listen to Grados anymore as I find the sound too aggressive.)  In general I tend to prefer about the same volume in domestic settings.  When I drive, that's a different story.
The universe is change; life is opinion. - Marcus Aurelius, Meditations

People would rather believe than know - E.O. Wilson

Propaganda death ensemble - Tom Araya

Mirror Image

Just bought these Beyerdynamic DT 770 250 Ω closed-back headphones -



Specs -

TECHNICAL SPECIFICATIONS
Transducer type . . . . . . . . . . . . . . . . . . . Dynamic
Operating principle . . . . . . . . . . . . . . . . Closed
Nominal frequency response . . . . . . . . . 5 - 35,000 Hz
Nominal impedance. . . . . . . . . . . . . . . . 80 Ω / 250 Ω
Nominal SPL . . . . . . . . . . . . . . . . . . . . . 96 dB SPL
Nominal T.H.D . . . . . . . . . . . . . . . . . . . . < 0.2%
Power handling capacity . . . . . . . . . . . . 100 mW
Sound coupling to ear . . . . . . . . . . . . . . Circumaural
Ambient noise isolation . . . . . . . . . . . . . approx. 18 dB(A)
Nominal headband pressure . . . . . . . . . approx. 3.5 N
Weight (without cable) . . . . . . . . . . . . . 270 g
Length and type of cable
80 Ω version . . . . . . . . . . . . . . . . . . . . . 3 m / straight cable
250 Ω version . . . . . . . . . . . . . . . . . . . . 3 m / coiled cable
Connection . . . . . . . . . . . . . . . . . . . . . . Gold plated stereo
jack plug (3.5 mm) and
1/4" adapter (6.35 mm)

71 dB

#653
I Studied things. OSHA requires hearing conservation program. That's why it allows higher levels. The difference between 3 dB and 5 dB exchange rates is due to different ways of predicting the noise levels outside that highest exposure. OSHA claims that in typical occupational environments the 5 dB rule gives almost the same results as the 3 dB rule.

If we talk about safe levels in music listening, we must take this into count. OSHA is taylored in noisy factories etc. were hearing conservation devices are used if needed. In music listening I would recommend the Criterion Level = 85 dB(A), Exchange Rate = 3 dB rule.

Spatial distortion is a serious problem deteriorating headphone listening.
Crossfeeders reduce spatial distortion and make the sound more natural
and less tiresome in headphone listening.

My Sound Cloud page <-- NEW Jan. 2024 "Harpeggiator"

Mirror Image

Received the Beyerdynamic DT 770 250 Ω closed-back headphones earlier today and tested them out. They're going back to Amazon for a full refund. Way too tight on my head. Great sound quality, but comfort is so important to me. I know I didn't give these headphones anywhere near enough time to 'break in,' but I listen for long periods of time, so comfort is just as important as the sound quality.

Holden

Have you considered IEMs?
Cheers

Holden

71 dB

Quote from: Mirror Image on May 03, 2013, 08:00:49 PMWay too tight on my head.

Brand new headphones tend to be tight. Also, your head needs to get used to the pressure pattern caused by the phones. When I bought Sennheiser PX-200 for my iPod (outdoor use) years back, at first they felt uncomfortable but then something happened and I can "forget" I am wearing them.
Spatial distortion is a serious problem deteriorating headphone listening.
Crossfeeders reduce spatial distortion and make the sound more natural
and less tiresome in headphone listening.

My Sound Cloud page <-- NEW Jan. 2024 "Harpeggiator"

Brian

USB headphone amp in production.
http://www.kickstarter.com/projects/gavn8r/geek-a-new-usb-awesomifier-for-headphones

I'm considering jumping in while it's $140, but honestly, I don't know the first thing about headphone amps or what else is out there. The USB aspect sounds pretty useful since my laptop is my "sound system".

Pat B

Quote from: Brian on August 15, 2013, 08:28:30 AM
I'm considering jumping in while it's $140, but honestly, I don't know the first thing about headphone amps or what else is out there. The USB aspect sounds pretty useful since my laptop is my "sound system".

I don't see any indication that they're in production yet. Their delivery estimate is in January. Claiming to "support" mp3, flac, and aiff (!) is a bit of a turn-off for me since all of that is handled before it gets to their product. As far as what else is out there, here's a start:
http://www.headphone.com/headphone-amps/amplifiers.php

I have a Total BitHead which apparently is now OOP. :(

The first question is probably whether you need one at all. I bought mine to go with ER-4S phones since they are moderately difficult to drive. I don't always use it. My other phones are Grado SR-60's and I rarely use the amp with them.

DavidW

Quote from: Brian on August 15, 2013, 08:28:30 AM
USB headphone amp in production.
http://www.kickstarter.com/projects/gavn8r/geek-a-new-usb-awesomifier-for-headphones

I'm considering jumping in while it's $140, but honestly, I don't know the first thing about headphone amps or what else is out there. The USB aspect sounds pretty useful since my laptop is my "sound system".

That is stupid.  Sorry but kickstarter is for helping fund something innovate that doesn't currently exist.  USB headphone amps exist from several brands and are not that expensive.

I'm sure Brian you know and understand how kickstarter works, but for everyone else... don't consider it an investment.  Alot of kickstarters don't pan out and the money is just gone.  You have to be willing to put money towards a project with no expectation of seeing that money back, in hopes of seeing a product make it to market that otherwise would not exist.  It is as simple as that.