TR Forums

Frugal wrote:

I think the phase problem you speak of is diffraction caused by driver spacing.  That is a very real problem because an ideal line source has a maximum driver spacing and line length for every frequency.  

That's freq. combing related to interference at high freq.s due to the summing of wavelengths that are full developed (shorter in length and emitting the full wavelength).  As the freq.s go lower they get longer and don't cause this problem unless the physical distance between the two drivers/sources is to long. (..diffraction of sound is when sound moves around an object.)
It's not really much of a problem though, subjectively it gives that electrostatic sound - usually an increased level of clarity: mostly because the brain/ear hears the sound as higher than the average (ie. hears the freq. response near the top of those "spikes").
There are also modal problems with drivers when they are operating as bending-wave at higher freq.s because of the shape of the driver, damping of the surround, membrane profile, etc.. When displaying the freq. response of a single driver (like fullrange drivers) at higher freq.s you'll see something similar to combing effects as long as you don't display the freq. response with much (if any) smoothing applied. Similar effect though.

whm1974 wrote:

All I know now is that I brought a pair of Flips Audio Headphones from Walmart three years ago, and they sound great in speaker mode even with onboard audio.

Most headphones are minimum phase like fullrange drivers - just one driver, they have a better chance of sounding better.  They are also very near to your eardrum and don't need much power so non-linear distortion is usually a LOT lower.
You can also get far more accurate sound than any loudspeaker by utilizing a binaural recording.. or usually even "convolving" to binaural.  What you miss out on is tactile "impact", but you can pick that up with a tactile transducer (and amp to power it).

CScottG wrote:

What you miss out on is tactile "impact", but you can pick that up with a tactile transducer (and amp to power it).

When I'm feeling stupid, I watch movies with my headphones, but crank up the eight 15" IB subwoofers to get the feel of everything.

CScottG wrote:

whm1974 wrote:

All I know now is that I brought a pair of Flips Audio Headphones from Walmart three years ago, and they sound great in speaker mode even with onboard audio.

Most headphones are minimum phase like fullrange drivers - just one driver, they have a better chance of sounding better.  They are also very near to your eardrum and don't need much power so non-linear distortion is usually a LOT lower.
You can also get far more accurate sound than any loudspeaker by utilizing a binaural recording.. or usually even "convolving" to binaural.  What you miss out on is tactile "impact", but you can pick that up with a tactile transducer (and amp to power it).

Yeah but what is neat about these headphones is they can be turned into speakers by "flipping" the earpieces. That is the way I use them. And Like I said they sound great.

Waco wrote:

CScottG wrote:

What you miss out on is tactile "impact", but you can pick that up with a tactile transducer (and amp to power it).

When I'm feeling stupid, I watch movies with my headphones, but crank up the eight 15" IB subwoofers to get the feel of everything.

Ah, friendly with the neighbors! (..lol.)

CScottG wrote:

What you miss out on is tactile "impact", but you can pick that up with a tactile transducer (and amp to power it).

A past boss of mine took a 60's-vintage egg chair and put in a pair of good speakers at ear height and a butt kicker under the seat cushion for some oomph. Never had the chance to experience it, but his design looked sound.

Note: I originally went to post this yesterday afternoon. It got lost in a flurry of other stuff going on...

just brew it! wrote:

Seems to me that with today's sophisticated DSP tech, one could take the Bose approach a step further, and build a "good enough" driver/crossover/cabinet combo, with a signal processor to be inserted somewhere upstream which would precisely alter the signal to compensate for any peaks, dips, distortions, or phase shifts in the response. As an added bonus, with suitable on-site testing you could compensate for room acoustics as well.

Has anyone tried this approach?

At the speaker level, a crossover is just an analog signal processor. A complex one does way more than just route low frequencies to the woofers and highs to the tweeters. I would expect that its cheaper to just design decent cabinets and use well matched drivers with a proper crossover than it would be to put in the DSP horsepower. At the room level, its another story entirely.

There are entire book length threads on such stuff over on Home Theater Shack and other such boards. I'm actually going to be doing acoustic treatment on my theater room when I get some time (and money). One of the big problems with room level correction, especially if done electronically is you can only make one spot in the room sound really good. Its a classic optimization problem: make everywhere sound something between good and pretty good, or make one spot sound outstanding. I'm hoping that I can get to at least good everywhere with just diffusion, absorption, and bass traps, combined with careful speaker placement. As much as I'm a tech geek, I'd rather not have to get a DSP in the mix.

If you have the slightest bit of OCD tendency, audio can be a real rat hole, especially now that it is relatively easy to actually measure things and have a computer display all sorts of charts and graphs. Gotta know when to stop...

CScottG wrote:

Waco wrote:

CScottG wrote:

What you miss out on is tactile "impact", but you can pick that up with a tactile transducer (and amp to power it).

When I'm feeling stupid, I watch movies with my headphones, but crank up the eight 15" IB subwoofers to get the feel of everything.

Ah, friendly with the neighbors! (..lol.)

Lots of insulation, distant neighbors, and subsonics generally aren't localizable easily.

That is another reason for line arrays, if the sound wave is created floor to ceiling, it behaves like it is radiating in to a 2D space rather than a 3D space and as such the amplitude does not fall off as quickly with distance so you will get a bigger sweet area and the difference in volume from the front of the room to the rear will be less so you won't get that back seat of the car can't hear the radio effect.

This effect is frequently exploited in sound reinforcement because it can allow them to produce good audio far from the stage and possibly run "louder" without violating noise restrictions or totally blowing out the ears in the front row.

Waco wrote:

CScottG wrote:

Waco wrote:

When I'm feeling stupid, I watch movies with my headphones, but crank up the eight 15" IB subwoofers to get the feel of everything.

Ah, friendly with the neighbors! (..lol.)

Lots of insulation, distant neighbors, and subsonics generally aren't localizable easily.

Look at his location, he could have an earthquake machine and pass it off as underground testing.

Frugal wrote:

Look at his location, he could have an earthquake machine and pass it off as underground testing.

Thankfully, we're not allowed to do that any more.

I heard some information to the contrary from a researcher...

Well, the Comprehensive Nuclear Test Ban treaty was never officially ratified... so AFAIK anything with a yield under 150 kilotons is still technically legal under international law.

Well, let's just say there's a gentlemen's agreement to not test, and that there are lots of repercussions in store for any nation violating that agreement. We did sign it though: https://en.wikipedia.org/wiki/List_of_p ... Ban_Treaty

Now, back to insane audio gear!

See? Internet threads mutate !

Waco wrote:

Well, let's just say there's a gentlemen's agreement to not test, and that there are lots of repercussions in store for any nation violating that agreement.  We did sign it though: https://en.wikipedia.org/wiki/List_of_p ... Ban_Treaty

Now, back to insane audio gear!

Now I want a nuclear tactile transducer.

Sony's in on the act:
http://www.sony.com/electronics/walkman/nw-wm1z

"The NW-WM1Z is fully encased in a high-grade gold-plated oxygen-free copper chassis. Widely used in instrument manufacturing, the copper lends the player its unique natural, acoustic sound. Its conductivity and raw strength reinforce the Walkman® with unrivalled audio performance."

Yours for only $3200.

bthylafh wrote:

Sony's in on the act:
http://www.sony.com/electronics/walkman/nw-wm1z

"The NW-WM1Z is fully encased in a high-grade gold-plated oxygen-free copper chassis. Widely used in instrument manufacturing, the copper lends the player its unique natural, acoustic sound. Its conductivity and raw strength reinforce the Walkman® with unrivalled audio performance."

Yours for only $3200.

Ugh. Not that I generally ever buy Sony gear...but dammit. This is the crap that makes me angry.

Waco wrote:

bthylafh wrote:

Sony's in on the act:
http://www.sony.com/electronics/walkman/nw-wm1z

"The NW-WM1Z is fully encased in a high-grade gold-plated oxygen-free copper chassis. Widely used in instrument manufacturing, the copper lends the player its unique natural, acoustic sound. Its conductivity and raw strength reinforce the Walkman® with unrivalled audio performance."

Yours for only $3200.

Ugh. Not that I generally ever buy Sony gear...but dammit. This is the crap that makes me angry.

Sony wrote:

The surface mounted Fine Sound Register ensures even, effective distribution of power to the circuit components, for consistent sound quality.

The photo that caption appears under looks suspiciously like a surface-mount capacitor (with a stylized letter 'F' stenciled on it). And a power rail bypass capacitor would fit that description perfectly, as it indeed "ensures even, effective distribution of power".

The copper chassis though...

Take the concert feeling home and experience your music as the artist intended, in near High-Resolution Audio quality. DSEE HX upscaling technology uses an algorithm to analyze your music and replace any lost information, so that the quality is almost high-resolution level. Choose from 4 additional modes to the standard to bring out the best in your music.

Waco wrote:

The copper chassis though...

Is going to be a bitch to keep polished and not turn green.

Captain Ned wrote:

Waco wrote:

The copper chassis though...

Is going to be a bitch to keep polished and not turn green.

"Gold plated".

CScottG wrote:

whm1974 wrote:

All I know now is that I brought a pair of Flips Audio Headphones from Walmart three years ago, and they sound great in speaker mode even with onboard audio.

Most headphones are minimum phase like fullrange drivers - just one driver, they have a better chance of sounding better.  They are also very near to your eardrum and don't need much power so non-linear distortion is usually a LOT lower.
You can also get far more accurate sound than any loudspeaker by utilizing a binaural recording.. or usually even "convolving" to binaural.  What you miss out on is tactile "impact", but you can pick that up with a tactile transducer (and amp to power it).

Do to the shape of the ear canal (IIRC) headphones exhibit wild peaks and valleys in the high frequency region, so while the midrange and below may well be much flatter than speakers because of either crappy speakers, or untreated rooms the highs are wildly colored on headphones, although I believe there's some 3d printed headphones that solve that problem.
Example of typical headphone frequency response:

Mikael33 wrote:

Do to the shape of the ear canal (IIRC) headphones exhibit wild peaks and valleys in the high frequency region, so while the midrange and below may well be much flatter than speakers because of either crappy speakers, or untreated rooms the highs are wildly colored on headphones, although I believe there's some 3d printed headphones that solve that problem.
Example of typical headphone frequency response:

It's always a guess.  Because of the very close proximity to your eardrums, it's a larger guess with respect to linear response.  Still, it can be equalized digitally.  (..perhaps the worst aspect results from increased channel separation, particularly from closed-back headphones, and different linear responses from left and right ear.  This can create localization problems be it "in head" or if binaural "externalized". This really isn't a problem with loudspeakers, even in the relative nearfield (.5 to 1 meter) because you tend to hear enough of each channel summed for each ear.)
There are also problems with linearity and loudspeakers as well though.  It's just that we tend to "shoot for" a linear response between 1 and 2 meters at a single fixed point (and usually done so to remove room effects at higher freq.s), and we measure in the extreme near-field to try and get a reasonable representative response of the loudspeaker's low freq. linearity. (..even most anechoic chambers for measurement don't extend much lower in freq. than 75 Hz.)

A headphone that sent a perfectly flat frequency distribution into your outer ear would not be received by the eardrum as a perfectly flat frequency response. Better yet, since everyone's ear canal is different, there;s no way to guarantee a perfectly flat frequency response at the eardrum. That's why headphone auditioning is a requirement before purchasing. Headphone X will sound slightly different to everyone who listens with it.

Captain Ned wrote:

Headphone X will sound slightly different to everyone who listens with it.

This right here is the core of Audiophilia nervosa. It's an inherently unreproducible claim: "this sounds different." "How?" "I can't quantify, it's just different" and you basically have to take it on faith. There's a kernel of truth to the notion that everyone's auditory equipment is slightly different, but again, we don't have any reproducible way to cancel that out, and even if we did you've got nerves and neurons further in that can't be accounted for.

bthylafh wrote:

Captain Ned wrote:

Headphone X will sound slightly different to everyone who listens with it.

This right here is the core of Audiophilia nervosa

However, the idiosyncrasies of inner-ear response curves will have much less effect on loudspeakers in a room compared to headphones on (or in) the ears.

Is there science to prove or disprove that?

CScottG wrote:

Mikael33 wrote:

Do to the shape of the ear canal (IIRC) headphones exhibit wild peaks and valleys in the high frequency region, so while the midrange and below may well be much flatter than speakers because of either crappy speakers, or untreated rooms the highs are wildly colored on headphones, although I believe there's some 3d printed headphones that solve that problem.
Example of typical headphone frequency response:

It's always a guess.  Because of the very close proximity to your eardrums, it's a larger guess with respect to linear response.  Still, it can be equalized digitally.  (..perhaps the worst aspect results from increased channel separation, particularly from closed-back headphones, and different linear responses from left and right ear.  This can create localization problems be it "in head" or if binaural "externalized". This really isn't a problem with loudspeakers, even in the relative nearfield (.5 to 1 meter) because you tend to hear enough of each channel summed for each ear.)
There are also problems with linearity and loudspeakers as well though.  It's just that we tend to "shoot for" a linear response between 1 and 2 meters at a single fixed point (and usually done so to remove room effects at higher freq.s), and we measure in the extreme near-field to try and get a reasonable representative response of the loudspeaker's low freq. linearity. (..even most anechoic chambers for measurement don't extend much lower in freq. than 75 Hz.)

I play music with Foobar2000 and use the Bauer stereophonic-to-binaural plugin when I use my Beyerdynamic DT-990 Pro headphones. Btw those are some bright ass headphones, took me about a week to not find them super bright, particularly guitars and cymbals in rock/metal. I also use foobar to convert music for use on my iPod shuffle at work and use that DSP, kinda a pain to have to convert music to get it to sound "right" but it's worth it.
On the subject of speakers though I have a pair of JBL studio monitors (LSR 308s) and have spent a considerable amount of time researching optimal placement, breaking out my tape measure and trying out different spots in my monitors and chair to help get the low end under control, my "office" is in a pretty small rectangular room so the acoustics are bit **** but by applying the 38% rule I've vastly improved the frequency response, when I had my speakers much closer to the wall as well as my desk there was a pretty big valley in the 100-200hz range and a big peak around 45hz, didn't sound horrible without something to compare to but when I would swap to my headphones I would notice all the missing frequencies. I record music and I struggled with the mix on my bass guitar as certain notes would be much louder so I'd have to use my headphones to check how the bass mix was.