Hifiman HM-801 RMAA Tests - Page 26  

I know I said I was out of this thread (twice now!) but I just want to come to defend the Hifiman on one important point.  I'm copying my post from ABI.

There is one more important point to add, just so we don't all stick our foot in our mouths and make any faulty claims.

For the devices with crossovers, you are measuring the FR deviation BEFORE the crossover. You do not know what is going on after the crossover. So a measured (at the amp output) gain of X db at Y frequency is not automatically equivalent to a similar gain from the transducers or what you are hearing. You would have to measure the sound with a microphone for that.

Hope that makes sense. If is very possible that the actual audible change in the FR is less than what is measured at the amp output.

Just wanted to state that so people keep that in mind before cursing the Hifiman to #$*$.

those picasso-like graphs prove that hifiman is a piece of art

Quote:

Originally Posted by odigg 

...

For the devices with crossovers, you are measuring the FR deviation BEFORE the crossover. You do not know what is going on after the crossover. So a measured (at the amp output) gain of X db at Y frequency is not automatically equivalent to a similar gain from the transducers or what you are hearing. You would have to measure the sound with a microphone for that.

Hope that makes sense. If is very possible that the actual audible change in the FR is less than what is measured at the amp output.

Just wanted to state that so people keep that in mind before cursing the Hifiman to #$*$.

Yes, that makes sense. But let's look at it this way:

source ---> crossover ---> driver

If the source is putting out a 100mV, 500 Hz tone, then some portion of the signal arrives at the driver. It'll be at the same level regardless of the source, i.e., it doesn't matter if it's the HM-801 or the Clip+ that plays that tone. Now stop both players and play a 2.5 kHz tone. The Clip+ is still at 100mV, but the HM-801 output is now at 168mV, which is 4.5 dB higher than before. If you compare what actually reaches the driver, it'll also be 4.5 dB higher than the signal that was there when the Clip+ was playing. Ditto for the other drivers, even if the frequency doesn't fall within the crossover's passband.

Maybe the math for the voltage divider between the crossover and driver changes when you increase level, but I don't think that's what you were saying.

Quote:

Originally Posted by odigg 

...

For the devices with crossovers, you are measuring the FR deviation BEFORE the crossover. You do not know what is going on after the crossover. So a measured (at the amp output) gain of X db at Y frequency is not automatically equivalent to a similar gain from the transducers or what you are hearing. You would have to measure the sound with a microphone for that.

Hope that makes sense. If is very possible that the actual audible change in the FR is less than what is measured at the amp output.

Just wanted to state that so people keep that in mind before cursing the Hifiman to #$*$.

Yes, that makes sense. But let's look at it this way:

source ---> crossover ---> driver

If the source is putting out a 100mV, 500 Hz tone, then some portion of the signal arrives at the driver. It'll be at the same level regardless of the source, i.e., it doesn't matter if it's the HM-801 or the Clip+ that plays that tone. Now stop both players and play a 2.5 kHz tone. The Clip+ is still at 100mV, but the HM-801 output is now at 168mV, which is 4.5 dB higher than before. If you compare what actually reaches the driver, it'll also be 4.5 dB higher than the signal that was there when the Clip+ was playing. Ditto for the other drivers, even if the frequency doesn't fall within the crossover's passband.

Maybe the math for the voltage divider between the crossover and driver changes when you increase level, but I don't think that's what you were saying.

Quote:

Originally Posted by Galatian 

The other thing I'm just so confused about is, if the Hifiman really has an inferior sound quality as the graphs suggest, how can so many people - including well-recognized reviewers - be so wrong on their reviews. How can so many people become part of a big fraud (that is of course if this truly is one)?

Also if test seems to be so easy why has nobody done that with cables or other alleged HiFi equipment so far? There is something really odd going on here and I'd like to get to the ground of things instead of circling around the same point over and over again as most of the contributors of this thread are doing. There has been no substantial "evidence" for either side for probably 20 pages (with exceptions that is).

Do you know what the graphs mean?  There's a hell of a lot of cheap gear out there that measures very well but sounds like crap.  While the stereo crosstalk graph matches dfkt's impressions of the perceived soundstage, nobody seems to be interested in learning about digital filters, why they are there and why they can have either a sharp roll-off (which gives a flatter looking graph) or a slow roll-off to counter distortion which comes as a result of digital to analogue conversion.  This roll-off occurs at a rate at frequencies which should be essentially inaudible.
 

Quote:

Originally Posted by yuriv 

Aha, I should have checked the thread on the ABI forum before posting these graphs. They have frequency response plots of the HM-801 driving UE11, SE530, and SM3. The response is anything but flat.

 

http://anythingbutipod.com/forum/showthread.php?t=54879&page=5

 

Maybe you can get the Clip+ to sound just like the HM-801 if you stick a 16-ohm resistor between it and the headphones. A simple inline volume control might do the trick.

Now I think we're getting somewhere.  I wonder how the graphs would look at medium or high volumes.  That low-volume performance DOES look terrible.  I hope dfkt takes the time to measure the results from other DAPs as well, as it would be interesting.

 

Quote:

Originally Posted by odigg 

I know I said I was out of this thread (twice now!) but I just want to come to defend the Hifiman on one important point.  I'm copying my post from ABI.

 

There is one more important point to add, just so we don't all stick our foot in our mouths and make any faulty claims.

For the devices with crossovers, you are measuring the FR deviation BEFORE the crossover. You do not know what is going on after the crossover. So a measured (at the amp output) gain of X db at Y frequency is not automatically equivalent to a similar gain from the transducers or what you are hearing. You would have to measure the sound with a microphone for that.

Hope that makes sense. If is very possible that the actual audible change in the FR is less than what is measured at the amp output.

Just wanted to state that so people keep that in mind before cursing the Hifiman to #$*$.

odigg: It's people such as you whom are most needed in this thread, to provide actual science and not nonsense. 
 

Quote:

Originally Posted by Currawong 

1: See my previous posts where I talked about how dfkt's conclusions from the graphs were wrong based on what appears to be a lack of knowledge on digital filters.

 

2: Read the whole thread on dfkt's forum.  There is a clear disdain towards the Hifiman and portable amps in general.  From what I can see, he, and his friend Walkgood wanted an excuse to have a go at it, so have used their misunderstanding of what they are seeing in the graphs, especially with regards to the treble roll-off, to justify their opinion.  While I believe it's fair enough to feel all these things are "way too expensive toys" (dfkt from one of his posts on his site) I don't believe it's reasonable post falsehoods as fact, especially when one's motivation is to attack people rather than discover and understand the truth about something. Unfortunately, audio and electronics are complex things, the more of which you learn about, the more you realise you don't know.  It's very easy for people say "Here! Look! This graph is flat so it's best!" or "These numbers are lower, so they are better!" without understanding the limitations of those measurements, most importantly what they DO measure, and what they DON'T. 

 

3: There are too many examples of blatant trolling in this thread.  I don't need to list them.

 

4. All the information about digital to analogue conversion is readily available online and is supported by mathematics.  It's not my job to educate anyone.  People can google "soft roll off digital filter" and get all the information on why it's used themselves.  

 

5. This thread isn't obscure.  It's equally public and equally shows up on the front page when a post has just been made. Considering the outright disgusting behaviour of many people in this thread, I'm surprised it hasn't been closed.  Anyway, who says that a topic should or shouldn't have particular presence somewhere?  What's special about this one?  If anything, because of its subject nature, it is now in the correct forum.

1)  Cool, the FR isn't the only issue.  There's various other poor measurements.

2) Whether he feels the players cost is justified or not has nothing to do with his findings.  For example the crosstalk measurements are extremely poor for this player.  There wasn't swipe anywhere in the original post.  His tone didn't even begin to change until he started coming under fire from those quick to defend the player without any explanation besides they "liking how it sounds".

3) Yes, you do.

4)  It's a NOS player using a slow roll off filter rather than a steep filter.  Filters prevent aliasing, and a slow roll off rather than a steep filter prevents ringing.  It doesn't mean we have to like the implementation (it's a general complaint regarding NOS design when you get down to it).

This coming from someone that owns both types of DACs mind you.

5)  Agree to disagree, this is like a death sentence.  I also disagree that the conduct is "disgusting", at least not from those criticizing the player.  I see more swipes taken from those in the defense camp.

Quite a few of us understand it just fine.  Use of oversampling and a cheap digital filter would have worked better though in terms of measurements.  The "slow roll-off" is only useful is NOS designs to prevent aliasing.  The sharp filter works just fine with OS designs.

Once again, when we get down to this the FR is just an example of the old NOS vs. OS debates ages ago.  The other poor measurements, however, aren't as easily explained.

PS:

Subjective.  If it measures well in all categories it's reproducing the signal as intended.  It's your own prerogative if you dislike what's being reproduced.

so where are the test results Dfkt?:)

Sigh. Except everyone who has reviewed it has said its miles above competition. 

So conclusions?

1) Dfkt's test on recording these is flawed

2) None of you have a good enough ear to distinguish cheap from quality

If its 2, consider yourself lucky in a way, since it saves you a lot of money. But its not the player, its you.
 

Quote:

Originally Posted by JxK 

Agreed. I just tried the files and the differences were tiny. I think I know which is the original CD since it sounds just a bit better, and which is the 801 thanks to the rolled off treble...but the other two are a toss up.  And in a portable set up (out and about) I don't think anyone would hear a difference. Which means that for all practical purposes the 801 doesn't sound worse, but is ~$750 more expensive than it should be.

Quote:

Originally Posted by Bojamijams 

Sigh. Except everyone who has reviewed it has said its miles above competition. 

 

So conclusions?

 

1) Dfkt's test on recording these is flawed

2) None of you have a good enough ear to distinguish cheap from quality

 

If its 2, consider yourself lucky in a way, since it saves you a lot of money. But its not the player, its you.
 

We can just make random accusations without evidence now?

dftk's tests aren't flawed.  His recording interface is perfectly fine for the job.  If you're going to make such accusations maybe you should do RMAA and prove he performed it wrong.  Until then, libeling him isn't very becoming.

You either can't tell the difference apart in players, or you can - but one still doesn't measure up to snuff.  It's fine if you subjectively like the player, but it surely isn't accurately reproducing a signal.

Those are the facts as they stand.

Its selling to audiophiles.  Just because you're on this forum doesn't mean you're an audiophile. Just because you REALLY love music and you have a lot of expensive toys doesn't mean you're an audiophile.  You have to have the ear to be able to tell these differences, otherwise you're just a sucker whose paying for way too much when you can't take advantage of it.

And when I say you, I don't mean YOU personally.

A LOT of people here think their ears are same as everyone's, or as good as the greatest ear.  They think because they can't hear a difference between this and that that there ISN'T a difference and thats a fact.  But not all ears are created equal. Not all brain audio receptors are created equal.  There are people who can name the note by hearing it.  There are conductors that can detect one violin out of 35 thats out of tune.  I do not have those ears and I bet 99.99999% people here don't either.  But there are varying degrees of sensitivity and acuity. 

I'm quite surprised that people don't see the parallelism between people saying there's no difference between a Clip and Hifiman and all those teenagers claiming that Skullcandy is as good as it gets and there's no point paying for more. 

Sorry I should have phrased it

1) OR 2)
 

Quote:

Originally Posted by Shike 

Quote:

Originally Posted by Bojamijams 

Sigh. Except everyone who has reviewed it has said its miles above competition. 

 

So conclusions?

 

1) Dfkt's test on recording these is flawed

2) None of you have a good enough ear to distinguish cheap from quality

 

If its 2, consider yourself lucky in a way, since it saves you a lot of money. But its not the player, its you.
 

 

 

We can just make random accusations without evidence now?

 

 

dftk's tests aren't flawed.  His recording interface is perfectly fine for the job.  If you're going to make such accusations maybe you should do RMAA and prove he performed it wrong.  Until then, libeling him isn't very becoming.

 

 

You either can't tell the difference apart in players, or you can - but one still doesn't measure up to snuff.  It's fine if you subjectively like the player, but it surely isn't accurately reproducing a signal.

 

Those are the facts as they stand.

Quote:

Originally Posted by Bojamijams 

Its selling to audiophiles.

So what?  Are we saying audiophiles have NEVER been suckered, ever?

Same applies to you.

You really love these strawman arguments don't you?

Cool, do a DBT.  If you don't succeed then there was no reason to buy the player.  If you do succeed you admit the player isn't properly reproducing the signal.  You may like the subjective sound produced, but guess what?  It's still wrong.

Once again, these are the current facts. If you're saying the player IS reproducing the signal properly and you can DBT it, show contradictory evidence for RMAA.  You're saying dfkt did something wrong, SO PROVE IT.

You really enjoy these strawman arguments don't you?

I see a parallelism, but you're not wanting to hear it.  It's more like the Beats crowd justifying the high cost and poor performance of their equipment when there's much better performing equipment at a lower price - empirically (not counting for subjective taste).

Or it could be placebo, or the player could really measure off like shown which allows people to identify it.

Once again, show contradictory measurements if you're going to accuse people of doing improper measurements or being incapable of hearing.  We really don't appreciate libelous claims here.

Quote:

Originally Posted by dfkt 

The RAR password is sfjkw48uhsdgr8.

Hey, I was right!

Originally Posted by JaZZ 

I'm venturing a guess:

 

1: Cowon V5

2: original Flac

3: HM-801

4: Clip+

Originally Posted by JaZZ 

Additionally my ranking in terms of sonic preference:

 

1:   . Track 2

2:   . Track 3

3a: - Track 4

3b: - Track 1

The HiFiMan sample sounded second best to me behind the original recording.

(listened through Corda Symphony [DAC and amp] – Silver Dragon – HD 800)

.