[Audio Jester]

I hope this is in the right section, I mainly wanted to keep this as "scientific" as possible.

I got into a heated discussion with a friend of mine about the term "clarity" when it comes to the use of separate drivers. This topic came about when discussing my use of headphones for gaming and how it offers an inferior audio "atmosphere" compared to his 5.1 system. I conceded that his system was able to create more accurate localization of sounds (e.g. a bullet being shot in front of you, wizzing past and impacting on something behind you), but then he made the inference that my headphones could not offer the "clarity" of his system due to the use of separate drivers (e.g. Tweeter/mid/woofer). I can understand that having bass,mid and treble coming out of the same speaker may cause some interference due to the movement of the driver, but I recall someone telling me that this is not exactly true because the frequencies are produced by different sections of the driver.

So, who can shed light on this? Unfortuately these kinds of debates require more than subjective assumptions.

 

[wnmnkh]

It is all about physics again.

Basically, it is very hard to make a driver to cover the whole frequency (usually resulted in limited freq response and higher distortions such as IM) due to physical limitation. Not to mention being a single driver means directionality is way too severe (it means sound will change rather drastically based on speaker/listener positions compared to multi-drivers).

But, the problem of multi-driver speakers is crossover. Yes, it is on signal path and usually degrade/eliminate/color/alter/change the original sound. Also being more than one driver, they are less efficient than single-driver. For dual-drivers, there is a thing called "bi-amping" but it still does not completely eliminate "crossover" process.

Headphones do not suffer the problems of typical full-range (a.k.a single-driver) speakers; because drivers hardly move/very lightweight, no need of powerful output and 'room' is very small or nonexistent. I'd say headphones are 'ideal' full-range speaker design.

 

[anetode]

Directional queues come from specific frequency ranges and temporal queues in the form of reverberations, which in turn change based on the directivity of the original sound and the subsequent reflections of the soundwave. This is why DSPs like the Dolby Headphone system work: they add a slight echo to specific frequencies. But before soundwaves reach your inner ear they are modified by a set of reflections caused by the shape of your ear, otherwise known as the head-related transfer function. Since ears come in different shapes and sizes, there are many individual HRTFs. A human being gets used to his/her HRTF at an early age, but since certain sounds (like music) don't occur in nature, opinions vary on exactly how directional information should be encoded in audio reproduction. This is why people who are used to listening to music in, say, orchestra halls, expect their speakers/headphones to recreate the sound variations caused by those environments. Coupled with the variations of HRTFs, this is why no one can agree on the best headphone

To get back to the point, it doesn't matter how many drivers you have or how close they are to your head, all that matters is that your brain is fooled into hearing a specific frequency at a specific time. So accuracy in speakers/headphones is what counts because it allows designers of DSPs like EAX to have a consistent reference point. In fact, having more than one driver per ear in a headphone complicates the problem, since there are now many sound sources releasing soundwaves that interfere with each other and fudge up the original sound. Some of these reflections might cause reverberations or attenuation that provide unique sound queues. Then again, these weren't present in the original and so the directional information they contain is random - not useful. Quite the opposite is true for speakers, where multi-channel audio is the only way to consistently get across any directional information. The difference is that with speakers you don't have to worry so much about differences in HRTF caused by ear topology.

The challenge in any system for providing directional queues with headphones is in providing for interactivity. That is, you hear something in the left ear, turn left to face it, but it's still to your left. You're like a dog chasing its own tail. There are now head-tracking systems, by the likes of beyerdynamic and akg, that allow for a dynamic and interactive soundfield. Take the technology used in the wii and combine it with headphones and you get the state-of-the-art in 3d positional audio

 

[Audio Jester]

Thanks for the responses wnmnkh and anetode.
With regards to the comments from wnmnkh, am I correct in interpreting what you have said that both multidriver and single drivers lose clarity but in different ways? So would it be fair to say that headphones have the ability to have better "clarity" than speakers?

Anetode: Sort of heading off topic, but accuracy of 3D positioning is something that I was not confident that headphones could achieve as well as a 5.1 setup. With relation to gaming, it would seem more likely that the audio is created with the assumption that most people would aspire to run it through a 5.1 system and therefore it would be produced to sound best with that system...(if only games could be created with a binaural mix

) Wouldn't 5.1 be better simply because it has drivers dedicated to physical "positions"?

 

[anetode]

A proper implementation of a head-tracking system is superior. In fact, Harman engineers test their 5.1 (& other) systems by modeling their output using software and then feeding the output to a pair of K701s that work in conjunction with head tracking. Unfortunately these systems aren't widely known/marketed and many are still in development. The few that are available are prohibitively expensive (2k$+) and require specialized software which has compatibility limitations. It might stay this way for the foreseeable future as it's easier and more profitable to sell a consumer a bunch of speakers than a system that only one person can use at a time.

Without head-tracking, 5.1 & higher multi-channel audio is the next best thing. To get the best results you have to satisfy a whole mess of setup criteria, everything from speaker type (direct radiator for the front, dipoles for the surrounds) to speaker placement, to receiver implementation, room-correction equalizer, etc.. Of course most of the benefits can be had by non-professionals going by intuition and trial and error. Go to a demo room at a high-end installer and you'll be blown away by what's possible. HTIB need not apply, you're talking at least a few grand to ensure the best performance.

Those multidriver "5.1" headsets are an overpriced underperforming gimmick.

 

[Audio Jester]

Thanks anetode,
This whole discussion with my friend actually came about due to my dislike of 5.1 for watching movies... call me crazy but I like the sound to come from what I am looking at.

Do you feel that headphones have better/worse/similar clarity of a 5.1 setup?

(i think part of this is that my friend cannot believe that my headphones could possibly be as good as his $6K home theatre system.)

 

[anetode]

Yes, clarity as in smooth & detailed sound, not cut off at either end of the frequency response. Perhaps not as effective at conveying directional information, but also not victim to linear distortions due to room reflection.

Just an opinion, I don't presume to know what sort of setup your friend has or how it sounds. I doubt there's an absolute scientific answer to your question.

 

[Audio Jester]

Quote:

Originally Posted by anetode /img/forum/go_quote.gif I doubt there's an absolute scientific answer to your question.

Yeah, that was what I was afraid of. I guess there is some much "research" done by fans/businesses into why one speaker setup is better than another that you could find evidence for just about anything... All I know is that when I slip my cans on I am damn happy.
Thanks for your input.

 

[Ham Sandwich]

Beyerdnamic makes the Headzone which does head tracking for surround sound style sound in headphones. It's in the $2K range. I've not heard it.

Then there is the Smyth Realiser A-8. $lots

I'm sure there are others. It's not a product family that I follow.

It would be interesting to try those systems out. In general the HRTF computed types of headphone processing don't work well with me, at least the ones I've tried so far haven't worked well with me. Might be due to my "unique" hearing.

 

[Audio Jester]

Heading back to the original topic... Wnmnkh said
Quote:

Originally Posted by wnmnkh /img/forum/go_quote.gif Headphones do not suffer the problems of typical full-range (a.k.a single-driver) speakers; because drivers hardly move/very lightweight, no need of powerful output...

Does this imply that if you had a system (e.g. Orbs) which have single drivers that do have to move more etc, are they less clear than having separate tweeter/mid/woofer?

 

[Impossible]

i really want a headphone designed with a multi-driver layout. Just like many IEM's. Each driver is doing way less work. A driver designed specifically to do only high frequency is going to be better then one designed to do everything and so on for the lows and mids. This design works very well with speakers and IEM's (large form factor and very small form factor). I really don't see why it cant be done well with headphones.

 

[dunring]

i really want a headphone designed with a multi-driver layout. Just like many IEM's. Each driver is doing way less work. A driver designed specifically to do only high frequency is going to be better then one designed to do everything and so on for the lows and mids. This design works very well with speakers and IEM's (large form factor and very small form factor). I really don't see why it cant be done well with headphones.

It has been done, the Asus Centurion has separate 7.1 drivers in them, and Turtle Beach made one with 5.1 array of drivers on each side. Quality wasn't as good as two really accurate matched drivers though so they never took off.
The best gaming I've ever heard is the hd800s, audio Technica adh1000x, and Grado 325.
The 1000x especially is uncanny how well you can hear behind you. On a sound blaster ae-7 or ae-9 I could hear behind me, turn and fire without even aiming. It also has the best female vocals I've heard.

 

[Impossible]

Yes but I think in these cases its 7 or 5 identical drivers for surround duties where the entire frequency range is sent to them, not what I'm talking about. What I'm saying is seperat drivers for seperat parts of the frequency range.

Like a speaker or iem

 

[castleofargh]

i really want a headphone designed with a multi-driver layout. Just like many IEM's. Each driver is doing way less work. A driver designed specifically to do only high frequency is going to be better then one designed to do everything and so on for the lows and mids. This design works very well with speakers and IEM's (large form factor and very small form factor). I really don't see why it cant be done well with headphones.

Multidriver being better for IEM is not a concensus. It’s beneficial in limited capacity like to try and mitigate some issues of balanced armatures. The lowest distortion, best phase, biggest frequency extension, are usually found in a single relatively large dynamic driver(but of course those work best with vented designs=poorer isolation).

Attempts at multidriver headphones have been few and bad. In a world were each brand is constantly trying to look different and reinvent the wheel, you can be confident that if things were as good and straightforward as you imagine for multidriver headphones, we'd have it everywhere by now in as many forms as possible. It not happening is information enough.
The multichannel approach is something different and it's got some small success stories in gaming, but IMO multidriver headphone is also not the right solution for that(as mentioned long ago in previous posts, calibrated DSP and headtracking can do a lot more than a few drivers around the ear).

 

[Impossible]

I wouldn't agree with this. There are many iem's now that have been implemented well. There is definitely concensus on the matter. The best regarded iem's are mostly multidriver. There is a huge community and plenty of reviews to support this.

Just because something hasn't been done yet doesn't mean it can't be done well. Maybe the first few multidriver iem's were not so great but things have moved on so much.