HD800? Another rumor?

[deepak]

Though I'm done with dynamics, I'm still excited to hear the HD800

[Dusty Chalk]

Their measurements don't have that same peak -- it only goes up to 310 on theirs. I just wrote John Atkinson and pointed it out and asked him to conjecture as to why the measurements would be different.

Here is John Atkinson's response:

>To what do you attribute the difference between your measurements and Headroom's?

I don’t know. I will recheck my measurement.

>I was also actually rather disappointed that you didn't post a frequency response curve. I realize they're supposed to be different with every headphone, but you could have at least measured the pair you had.<

As I explain in the measurements sidebar, measuring the frequency response of a pair of headphones is difficult and interpreting the result is not trivial. See the article at Stereophile: Between the Ears: the art and science of measuring headphones .

>There is some conjecture that the load the HD800 presents is more inductive than resistive, and is therefore not an easy-to-drive load, hence the difference in sound with different amplifiers.<

Those people don’t appear to know what they are talking about. The electrical phase angle of the HD800’s impedance is low, hence any inductive and capacitive effects are virtually non-existent.

Thank you for writing.

John Atkinson

Editor, Stereophile

Edited June 29, 2009 by Dusty Chalk

[luvdunhill]

Here is John Atkinson's response:

Dusty, can you post the two graphs in question, preferably including an impedance plot?

[atothex]

Damn, that's interesting stuff.

[Dusty Chalk]

No. I changed my post to show Headroom's plot, but the HD800 is in the current issue of Stereophile, so it's not online yet. It's on p. 89 of the orange-framed issue with a Boulder device on the cover. The phase is really mild -- I don't think it strays more than 15 degrees. I can attempt to describe the impedance plot verbally: there's a peak at 100 Hz, but the peak is at 310, the minimums appear to be at 210 (starting at 10 Hz, and another swale around 1.1kHz-1.4kHz), and then slowly going up again, to about 300 @ 50kHz. You can look around the Stereophile site, or check Audio Asylum -- I think he posts there, there might be some discussion, I don't know.

[n_maher]

I'd be curious to see how other headphones of known impedances measured on Stereophile's rig.

[Hopstretch]

Dusty, can you post the two graphs in question, preferably including an impedance plot?

Here you go.

Those people don’t appear to know what they are talking about. The electrical phase angle of the HD800’s impedance is low, hence any inductive and capacitive effects are virtually non-existent.

Be interested to hear KG's take on that assertion.

Edited June 29, 2009 by Hopstretch

[The Monkey]

Without knowing what I'm talking about, JA's response sounds like BS.

[deepak]

Yes, the DA11 and the Bidat using phones have similar tonal balances when using the CDP-X707SE as a transport. When the Bidat is fed from the CEC, there are some more notable differences, but not in tonal balance, are more in coherence, flow and other areas. However I haven't tried the CEC-Bidat combo using the HD800 yet, though I don't expect great improvements, using the O2 things remain as stated.

Hops, feel free to use as fine ale as needed to reset your perception, but don't make the listening tests during the process, which is commonly considered to make everything sounding gorgeous

Why aren't you using the CEC as a transport full time if it's a big improvement?

No. I changed my post to show Headroom's plot, but the HD800 is in the current issue of Stereophile, so it's not online yet. It's on p. 89 of the orange-framed issue with a Boulder device on the cover.

Hehe Stereophile loves their Boulder.

Edited June 29, 2009 by deepak

[Dusty Chalk]

Without knowing what I'm talking about, JA's response sounds like BS.

I disagree, it was refreshingly honest to hear him say, "I don't know".

Be interested to hear KG's take on that assertion.

Sure, like he's going to say anything other than that he knows what he's talking about.

Alright, maybe he'll say something to the effect of John Atkinson does not know what he's talking about...with more or less diplomacy, I'll not say which.

That said, the statement was based on his measured impedance phase -- if it turns out to be completely different, he may change his tune.

Hey, Dr. Gilmore -- do you have the capability to measure the impedance and impedance phase? It'd be nice to have a tiebreaker.

[kevin gilmore]

Hey, Dr. Gilmore -- do you have the capability to measure the impedance and impedance phase? It'd be nice to have a tiebreaker.

this is the correct way to do this.

Lock-in amplifier - Wikipedia, the free encyclopedia

I have a recent vintage SRS amp, now i just need some time to

set the thing up. Does not really measure impedance as such, but

is real good at measuring phase.

I think that increasingly stereophile is more and more full of shit.

What you can do is put a 300 ohm pot in series with the headphones and turn it

up and down, simulating a low impedance and high impedance amplifier. Sound

is hugely different. Grado's and hd600's don't exhibit the same kind of behaviour.

If stereophile would do the same thing with different damping factors, things would

come out very different.

Edited June 29, 2009 by kevin gilmore

[Hopstretch]

Hehe Stereophile loves their Boulder.

Truth. I cannot for the life of me think who wants a $24,000 player that supports WAV, AIFF, FLAC and OGG -- but only if they're burned to disc.

[The Monkey]

I disagree, it was refreshingly honest to hear him say, "I don't know".Sure, like he's going to say anything other than that he knows what he's talking about.

I meant this part:

The electrical phase angle of the HD800

[Currawong]

Truth. I cannot for the life of me think who wants a $24,000 player that supports WAV, AIFF, FLAC and OGG -- but only if they're burned to disc.

If I had $24k to spend on a player, it would be a Mac Pro with a 30" screen, which would come to the same thing.

I don't understand the description of those Stereophile graphs. At certain frequencies I have a high resistance to technical jargon.

[pabbi1]

Where do we get stock HD800 cables?

Senn USA - though, they charged me the $163, but, never sent the cable. I got an invoice, but after 3 weeks, canceled the order. The part number is buried somewhere in the thread.

I'm selling a stock reterminated with dual XLR in the fs forum since I have the APS.

[Dusty Chalk]

I meant this part:

The electrical phase angle of the HD800

[The Monkey]

Fair enough. Moar measurements!

[luvdunhill]

Heck, they might have had a completely different pair of phones in there while making the measurement, though out of HD650/HD600/K701, I didn't find any that corresponded. Which is why he responded with, "I'll measure them again".

Is it possible that the free air impedance could be different from the impedance when loaded with the dummy head, or whatever Headroom uses? Did he measure them while they were on his head?

[Dusty Chalk]

John Atkinson did, indeed, specifically say that they were on his head when he measured them. Which is fair. Whether or not that corresponds to free air is left as a judgment on the part of the reader. I suspect it would be closer to a dummy head than to free air (and vice versa [i suspect Headroom's dummy head would more closely reflect normal real-world listening situations than free air]), myself.

Whether or not actual impedance was measured while on the dummy head in Headroom's measurements can only be ascertained by Headroom.

[n_maher]

Given that Headroom's measurements match up pretty well with other man'f impedance claims it seems reasonable to think that they are measuring "actual impedance".

I'll shoot Tyll a message pointing him to this thread to see if he can clear the (free) air.

[Dusty Chalk]

Yeah, go ahead, I just emailed Ivy (hey, it was her email that's on the measurements page).

And yes, since headphones are their specialty, I tend to expect Headroom's measurements are the more accurate, but I didn't expect Stereophile's to be wrong.

But luvdunhill's thought on head-vs.-no-head might be a legitimate one. I'd be curious if there's anything to that.

[Elephas]

Elephas, what amps did you use with the PS-1?

I also use the Zana Deux.

I don't have a lot of experience with amps, certainly a lot less than most people here. I've never heard a balanced amp. Besides the ZD, I only have the Lehmann BCL and a AT-HA5000.

I've been more interested in electrostatics than dynamics for a while, but maybe the HD800 will kick-start my interest in a better dynamic amp. I'm thinking about how to acquire a balanced Beta22.

[justin]

Anyone else notice the graphic symbol on the HD800 that says not to put them in the trash?

[postjack]

Anyone else notice the graphic symbol on the HD800 that says not to put them in the trash?

ha. isn't that on the box though? as in don't throw away the box?

[Torpedo]

Why aren't you using the CEC as a transport full time if it's a big improvement?

I use it full time when listening to the Bidat, that's my best digital. However since the DA11 is pretty new and I'm giving it some burn-in before deciding if it will remain in the main rig, or will just have a role in the secondary PC rig to play HD files, I'm using the Sony. I've noticed the Lavry is quite immune to the transport or the link used between transport and DAC. Then I prefer wearing out the Sony than the CEC, which moreover is giving some aging signs and from time to time refuses to play some CDs. The Sony plays about everything, that's why it's sitting in the main rig, so the discs that won't play on the CEC, play on the Sony.

I know that sooner or later the CEC will die, and I'll need a replacement, but new CECs are very expensive and other transports I've tried unfortunately don't sound as good with the Bidat. The only one coming close is an even older Theta Data II, which I keep just in case the CEC died, so I'd have decent sound while finding a suitable one that I can afford.