Headphone speed and its effect

[linnite]

Quote:

Originally Posted by Catharsis /img/forum/go_quote.gif So does this mean that a 10,000 hz signal would become a 9,800hz signal because it any given frame of "real" time, there are a few milliseconds where the driver is warming up and a few milliseonds of cooling down (attack and decay)?

No, the driver still makes as many (attempts at) rises and falls, it just doesn't get the time to complete the fall before it's time to rise again.

So, taking a guess here, a square waveform would tend to get rounded off so it looks like a sinewave but with shallower peaks and troughs...

 

[Catharsis]

Quote:

Originally Posted by b0dhi /img/forum/go_quote.gif A faster transient response implies a higher maximum relative frequency response. Since that isn't the case with armatures, it would mean they have a slower transient response. That is especially true considering the fact that armatures need to displace less total air to get the same dBSPL at the eardrum, due to the fact that they have a tighter and closer coupling to it.

I agree b0dhi. Could it be that IEMs (some of them), sound fast because they have tight bass, and also form a direct route to our brain. The bypassing of the outer-ear / lack of diffuse field equalizaiton etc could increase perception of speed.

Tight bass (not to be confused with crappy bass), has always been associated with "fastness" in general. The Ety's certainly have tight bass.

 

[leeperry]

so is it beyer only, or is high impedance where the money is?

from Peter Groof(beyer headphones PM) :

Quote:

I expect the 32Ω version to sound less transparent than the 600Ω version. Headphone systems with lower impedances usually have a slightly heavier diaphragm + coil causing it to react slower to impulses…systems with higher impedances do the opposite.

when I swapped the 250Ω drivers for 600Ω, the 600Ω were definitely lighter...and they appear more transparent/cleaner/faster

 

[Catharsis]

Quote:

Originally Posted by linnite /img/forum/go_quote.gif No, the driver still makes as many (attempts at) rises and falls, it just doesn't get the time to complete the fall before it's time to rise again. So, taking a guess here, a square waveform would tend to get rounded off so it looks like a sinewave but with shallower peaks and troughs...

Wouldn't this be less driver excursion? I've been keeping an eye on the squre wave graphs over at headroom, and headphones such as the DT880 (not routinely regarded as fast), has incredible bass extension, and maintains a 50hz waveform very well - better than the HD800 in fact.

The Etymotics on the other hand are REALLY square, but seem to have less driver excursion as it's clear that the bass extension doesn't compare.

Someone earlier on this thread discussed the fact that some stats might be able to maintain this square wave better, but at the expense of driver excrusion which results in a thinner bass.

All of the above examples would ALSO show up on a FQ response graph.

 

[Catharsis]

Quote:

Originally Posted by leeperry /img/forum/go_quote.gif so is it beyer only, or is high impedance where the money is? from Peter Groof(beyer headphones PM) : when I swapped the 250Ω drivers for 600Ω, the 600Ω were definitely lighter...and they appear more transparent/cleaner/faster

This makes perfect sense to me. In the case of Senns 6xx (with 300ohm cans), I think they're plenty fast. It's just a matter of the laid-back and diffuse field presentation that makes people THINK they're slow. Or it's a result of improper amplification.

 

[leeperry]

I mean, if you want speed...you want high impedance basically? apparently 32Ω can't be "fast" in dynamic coil based drivers?

 

[charlie0904]

I will work hard to buy myself a pair of electrostat setup..... *sob*

 

[paulb09]

I fail to see how lower impedance would necessarily relate to higher weight. Unless having heavier materials cuts costs that much, I seriously doubt these little 16 ohm ear-buds next to me have a heavier combined weight of diaphragm, magnet and coil than my K601. For a start, the driver diameter is 40mm compared to at least 15mm or less for the ear-buds (that's the diameter of the enclosure).

Technically, if you had the exactly the same diaphragm and magnet for two drivers, yet one was 32 ohm and one was 600 ohm, unless you had added a resistor into the circuit elsewhere, the 600 ohm would be heavier because it would have more turns and/or thicker wire in the coil to produce the extra impedance.

Also remember that driver construction is different for different models, so just because one is 600 ohms and the other is 600 ohms doesn't mean that one can't have a heavier diaphragm. I'd also be willing to bet that the circuit could have resistors added just to increase impedance. Of course, ear-buds need to run off portable sources with low voltage, therefore a lower impedance is imperative to allow kids to kill off their ears with ear splitting volume, but if you've ever tried them in a dedicated headphone amplifier you'll realise you don't have to turn the volume knob up that far from 0 to get a lot of volume. If you take that ear-bud and add impedance, then you'll be able to turn the volume control higher to get the same volume. Of course, sensitivity also plays a role here too, but I think you'll have gotten my point already.

 

[CDBacklash]

Quote:

Originally Posted by paulb09 /img/forum/go_quote.gif I fail to see how lower impedance would necessarily relate to higher weight. Unless having heavier materials cuts costs that much, I seriously doubt these little 16 ohm ear-buds next to me have a heavier combined weight of diaphragm, magnet and coil than my K601. For a start, the driver diameter is 40mm compared to at least 15mm or less for the ear-buds (that's the diameter of the enclosure).

Its not nearly as simple as higher ohmage. In fact, adding a higher resistance to any given can will not necessarily give a better performance on the headphone at all (typical symptoms FWIR are rolled off highs and reduced bass) which would suit the 770 i _guess_, but in a way also ruin what makes the can fun in my opinion. All resistance really does is reduce the amount of current required to generate the power to run the phone. As a side effect, the sound is altered.

If ohmage was the key to a transient response, you'd never see low ohmage headphones and sennheisers would be quite speedy in my opinion.
An ER-4x is SPEED incarnate, yet will drive well from just about anything (if you are talking about the P model).

as for the remark about lower ohmage cans having a slightly heavier diaphragm, i think that has to do with beyers construction to put as little material possible into the can. Im not entirely sure about this, but a can with more current running through it will "run hotter" and a lighter diaphragm may melt or become damaged from the current running through it (sort of like lighter cpus melting at higher speeds, as well as some metals melting at higher speeds)

 

[Catharsis]

Quote:

Originally Posted by linnite /img/forum/go_quote.gif No, the driver still makes as many (attempts at) rises and falls, it just doesn't get the time to complete the fall before it's time to rise again. So, taking a guess here, a square waveform would tend to get rounded off so it looks like a sinewave but with shallower peaks and troughs...

Slight thread revival....

If you were to plot this example on an x/y axis, you would see that your descriptions results in a decrease in amplitude of the signal which would translate to a loss of volume in a specific frequency.

With this example you have stated, high frequency roll-off would be the outcome (a decrease in amplitude), and as b0dhi has stated (and other audio professionals), transient response is directly related to high frequency performance. If a driver can produce 20,000+hz without attenuation of the original signal relative to the other frequencies, the driver IS NOT forced to rise and fall at any other times other than that which is dictated by value of the input frequency.

 

[Young Spade]

Nice post man. I didn't know what the fast/slow meant either (only barely).

 

[oqvist]

Quote:

Originally Posted by leeperry /img/forum/go_quote.gif I mean, if you want speed...you want high impedance basically? apparently 32Ω can't be "fast" in dynamic coil based drivers?

There is many ultra fast low impedance headphones out there like Ultrasones and others so I doubt you can make such a generalisation

 

[Catharsis]

Quote:

Originally Posted by oqvist /img/forum/go_quote.gif There is many ultra fast low impedance headphones out there like Ultrasones and others so I doubt you can make such a generalisation

Agreed, the highly regarded "fast" Sony SA5000 clock in at 70ohm and the highly regarded "slow" headphones the HD650 clock in at 300ohm. That theory might not hold any water.

I thoroughly disagree with these highly regarded opinions however and feel that impedance has little if anything to do with "speed". Both the SA5000 and the HD650 have exemplary transient response.

Personally I'm convinced that a flat FQ response and extension in both high and low frequencies is the RESULT of a good transient response.

 

[kool bubba ice]

The DT48/SA5000/900/W5000 are all very fast and range between 5-70 ohms... Am curious. The DT48a was purposely made to have a severe high roll off, according to the graph. Does that mean they are 'slower.'? I can't read German, so have no idea how they were measured.

 

[Catharsis]

Quote:

Originally Posted by kool bubba ice /img/forum/go_quote.gif The DT48/SA5000/900/W5000 are all very fast and range between 5-70 ohms... Am curious. The DT48a was purposely made to have a severe high roll off, according to the graph. Does that mean they are 'slower.'? I can't read German, so have no idea how they were measured.

My mind must be drawing blanks. What is the "900"?

According to technical data I have read on loudspeaker design, a flat FQ response is the greatest indicator of transient response, or to put it correctly, a flat FQ response is the RESULT of good transient response (among other things). The DT48 has a FQ response of 16-20000hz with a deviation of +/- 1db (according to beyerdynamic) which according to audio engineers would yield a fantastic transient response. Considering that CD audio tops out at 22.05khz I think you're golden with the DT48.

The SA5000 (thank you for the recommendation btw - I love it), has a spike at 2.5khz, and as such frequencies within that band come through loud and clear and many instruments sound snappy with a fast attack at this FQ. To be honest, the DT880 has a treble spike further up the FQ spectrum and I find is actually MORE revealing than the SA5000 ONLY within that region of the FQ spectrum.