I find it hard to attribute the sound difference (heard by the user on the Steve Hoffman forum) to a 22 ohm to 47 ohm output impedance difference. There's something else going on to cause that noticeable a performance gap between the two interfaces. Just merely tacking on another 47 ohm resistor on top of the (supposedly) existing Roland resistor would lower your output impedance to ~ 23 ohms; it would be easy to remove and I doubt it would negate any warranties.
Thanks, Mooly. Your assistance is invaluable!
It says here that the power range is ± 2.25 ~ ± 18V.
Is there any way to test that out with a voltmeter before plugging anything?
And then reverse it on the outside, ie. combine left & right grounds back into the headphone jack's ground contact?
Fair enough, though opening the enclosure means voiding the warranty. Can it be done externally?
You're welcome 🙂
So the acceptable voltage range is very wide and the quiescent current very low. Typically you would use either -/+12 or -/+15 volt rails (standard values). The low current consumption means you would probably would not need any heatsinks on the regulators.
You can easily check which pads are ground just by using a meter on its ohms range and checking for continuity.
The grounds are easy. You just take a lead from the headphone output and wire it like this. Or, you can run a four wire lead and combine the two grounds at the source instead.
The impedance of the HD600 is 300 ohms, as far as headphones go that's on the high end so a more forgiving condition for tolerating load series impedance. Putting 47 ohms in series with the headphones should not result in "unpredictable performance, boomy bass, distortion, etc". The increasing impedance in the bass has a peak at 500 ohms at 100 Hz. Driven by 47 ohms, this impedance peak will cause a -0.25 dB drop in the output SPL around 100 Hz. That's the sum total of it's influence.
Your problem is unlikely to be the 47 ohm output impedance, but instead lie with the fact that your amplifier cannot cleanly drive a 300 ohm load at the relatively high voltages required to power the HD600s.
While a unity gain buffer might coincidentally work, if it does its not because it converts 47 output impedance to <1 ohm, but because it converts the 300 ohm headphone load to look like >10 kohms, from the point of view of your existing output stage.
May I ask: what's this "problem" you're referring to? It sounds from your first post that you don't even have the headphones yet and are basing all this on the opinion of someone who, after comparing the headphones on an EMU interface and the Roland, reports the following (my comments in square brackets):
1. Much more bass on the Roland [there's no way to know if that's due to excessive bass on the Roland or lack of bass on the EMU] (I find this somewhat pleasing). [ok, it may be the latter?]
2. I have to crank the volume up to 50% on the Roland to get what 25% on the EMU gives me. [completely irrelevant: different sensitivities, pot taper, output levels, etc.]
3. I'm hearing lots of additional detail on the Roland that I had not previously heard. Nice. [but see point 5!]
4. While I enjoy (3), it seems to give me that detail at the expense of some distortion [not unusual to hear more detail along with more distortion if the new interface is merely more transparent than the old one, has a flatter FR, etc., and that distortion may well be in the source material or somewhere else in the system and it was being masked before] (could be my imagination). [yup, that too.]
5. The Roland has a very "full" sound, and not in a good way. [usually I understand "full" as more bassy, which in point 1 he said was pleasing] This is hard for me to describe, but it doesn't sound as "clear" as the EMU. [I'm not sure about "more detail" and "less clear", but he may mean something else...]
My point is, this is one subjective opinion from one person, and not a very consistent one at that. And by the way, he's not even saying that the reason is the difference in output impedances: he's asking if it could be.
I'm not saying an output buffer couldn't improve the sound IF for example the Roland isn't happy driving high impedance headphones, which could be the case, but you won't know until you get the phones and give them a try yourself.
Cheers,
Cabirio
1. Much more bass on the Roland [there's no way to know if that's due to excessive bass on the Roland or lack of bass on the EMU] (I find this somewhat pleasing). [ok, it may be the latter?]
2. I have to crank the volume up to 50% on the Roland to get what 25% on the EMU gives me. [completely irrelevant: different sensitivities, pot taper, output levels, etc.]
3. I'm hearing lots of additional detail on the Roland that I had not previously heard. Nice. [but see point 5!]
4. While I enjoy (3), it seems to give me that detail at the expense of some distortion [not unusual to hear more detail along with more distortion if the new interface is merely more transparent than the old one, has a flatter FR, etc., and that distortion may well be in the source material or somewhere else in the system and it was being masked before] (could be my imagination). [yup, that too.]
5. The Roland has a very "full" sound, and not in a good way. [usually I understand "full" as more bassy, which in point 1 he said was pleasing] This is hard for me to describe, but it doesn't sound as "clear" as the EMU. [I'm not sure about "more detail" and "less clear", but he may mean something else...]
My point is, this is one subjective opinion from one person, and not a very consistent one at that. And by the way, he's not even saying that the reason is the difference in output impedances: he's asking if it could be.
I'm not saying an output buffer couldn't improve the sound IF for example the Roland isn't happy driving high impedance headphones, which could be the case, but you won't know until you get the phones and give them a try yourself.
I think so too... 😉
Cheers,
Cabirio
My ultimate goal is to get headphones which are good for mixing at a price I can afford. The HD600 are recommended headphones suitable for mixing. The mixes translate well to other sound systems and the price is reasonable.
I have chosen these headphones after days of research. The same research that also led me to the conclusion that the HD600, unfortunately, are not compatible with the audio interface I want to use.
From the world of guitar amplification, I have gained the experience with how the ratio between the guitar's pickup output impedance and the input impedance of the preamp it's plugged into greatly affect the quality of the signal, with a too low ratio making the signal muddy and diminished in tone. Through my research on headphones, I have learned that the same electrical concepts apply to headphones.
So while researching, and reading things like these:
From: http://nwavguy.blogspot.com/2011/05/fiio-e9-headphone-amp.html:
And this comment, from another article on the same website:
Here's more, from a technical article aimed at beginners, from John Siau of Benchmark Media:
Also here's a research whitepaper from the same author that proves the above claim.
Finally, discussions on threads like this one, helped solidify my conclusion that I would have to lower the Quad Capture's output impedance as lowest as possible to get the HD600 to sound the way they are supposed to.
Therefore, and I'm not trying to step on anyone's toes here (obviously you all are much more experienced than me), that's the direction that makes sense to me.
I have chosen these headphones after days of research. The same research that also led me to the conclusion that the HD600, unfortunately, are not compatible with the audio interface I want to use.
From the world of guitar amplification, I have gained the experience with how the ratio between the guitar's pickup output impedance and the input impedance of the preamp it's plugged into greatly affect the quality of the signal, with a too low ratio making the signal muddy and diminished in tone. Through my research on headphones, I have learned that the same electrical concepts apply to headphones.
So while researching, and reading things like these:
From: http://nwavguy.blogspot.com/2011/05/fiio-e9-headphone-amp.html:
(1/8th of 300ohm is 37.5, considerably lower than the Quad Capture's output impedance of 47ohm).
And this comment, from another article on the same website:
Here's more, from a technical article aimed at beginners, from John Siau of Benchmark Media:
Also here's a research whitepaper from the same author that proves the above claim.
Finally, discussions on threads like this one, helped solidify my conclusion that I would have to lower the Quad Capture's output impedance as lowest as possible to get the HD600 to sound the way they are supposed to.
Therefore, and I'm not trying to step on anyone's toes here (obviously you all are much more experienced than me), that's the direction that makes sense to me.
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The post editing timeout has expired, but I want to add this excerpt from the Benchmark Media whitepaper I linked to above. It pretty much sums up what a huge difference 0 ohm amps have on headphones performance:
Please send me the headphones with flat -96dB THD + N over the entire audio band. 🙄 You really need to measure the actual acoustic output THD.
😀
That excerpt is immediately followed by this paragraph:
This research paper seems to indefinitely support the complaint about boomy and out of control bass when using the HD600 with the 47Ohm Quad Capture quoted on the OP:
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HD600's are not monitor headphones they are hifi headphones. to monitor properly you need headphones that are 'neutral'. let me try and explain... if you mix something down using headphones that are bass heavy then your mix will be bass shy on other headphones or indeed loudspeakers. same goes for other areas of the audio spectrum.
yes HD600's are indeed nice HIFI headphones and people buy them for their sound signature but due to their signature they are not good for monitoring.
so when looking for headphones to monitor with you need 'Professional' headphones which sound rubbish on hifi's due to them being dry and sterile and a lot of people make the mistake of buying monitoring headphones for hifi use and then complain that they sound 'lifeless' and a classic example is the beyerdynamic range of headphones, people buy the pro version thinking that they are better... yes they are for monitoring but not for hifi.
you need a headphone that is going to make your music sound good on just about everything so low impedance and sensitivity are king here. if you can turn the sound up on low impedance headphones and it sounds good then its going to sound just as good if not better on high impedance ones but the same does not go the other way.
yes HD600's are indeed nice HIFI headphones and people buy them for their sound signature but due to their signature they are not good for monitoring.
so when looking for headphones to monitor with you need 'Professional' headphones which sound rubbish on hifi's due to them being dry and sterile and a lot of people make the mistake of buying monitoring headphones for hifi use and then complain that they sound 'lifeless' and a classic example is the beyerdynamic range of headphones, people buy the pro version thinking that they are better... yes they are for monitoring but not for hifi.
you need a headphone that is going to make your music sound good on just about everything so low impedance and sensitivity are king here. if you can turn the sound up on low impedance headphones and it sounds good then its going to sound just as good if not better on high impedance ones but the same does not go the other way.
I know that. However, the HD600 are recommended as an entry level mixing headphones and they are a pair I can afford and have the flattest frequency response in their price range. Believe me, I have done my research. Also with software such as Sonarworks Reference, it is possible to achieve an absolutely flat frequency response with a limited set oh headphones, HD600 included.
Can you please explain that?
low impedance headphones are easy to drive into distortion due to them needing less power to drive them. think small speaker big amp, there comes a point when the amp is driving the cones far to hard which results in the cones distorting same goes for headphone diaphragm's. but this is normally preferable to small amp big speakers where the amp goes into clipping trying to drive the cones. so using low impedance headphones lets you go louder with less watts but then lets you hear that the levels are too high where as if you use high impedance headphones with a small amp then you are driving into clipping of the amp more easily so you turn the levels down when there is no need to.
who recommended HD600's as monitor headphones? if they were any good for monitoring then studios would be full of them...
do you honestly think that professional studios use expensive headphones..
who recommended HD600's as monitor headphones? if they were any good for monitoring then studios would be full of them...
do you honestly think that professional studios use expensive headphones..
Thanks for the thorough explanation 🙂
Read again–I said "entry level mixing headphones", not "absolute professional studio-level mixing headphones". There are many good reviews of the HD600 headphones around the web specifically concerning monitoring and mixing.
Are you aware of better alternatives for mixing of this price range or cheaper? I couldn't find any with as much substantial acclaim as the HD600.
Read again–I said "entry level mixing headphones", not "absolute professional studio-level mixing headphones". There are many good reviews of the HD600 headphones around the web specifically concerning monitoring and mixing.
Are you aware of better alternatives for mixing of this price range or cheaper? I couldn't find any with as much substantial acclaim as the HD600.
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You should wait until you get the headphones and then try them out for yourself, comparing to your reference loudspeakers. Don't try to fix something until you know that it's broken. You can't evaluate objectively from other people's opinions.
Of course if you have 0 series resistance the non-linear current develops no voltage that plot shows nothing useful. The acoustic output is what you hear the only valid comparison is the actual acoustic THD, a series resistor can actually lower the real THD. Some cell phone manu's pad the output resistance to boost bass. I use HD650's BTW.
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best advice by murrays...
but since you asked then i would recommend the Byerdynamic DT-770 pro 80ohm, you will find these and their brothers in arms in almost every studio on the planet. they take a gooood while to bed in but once they are they are a good all-rounder. dont ask them to sound good plugged into a hifi as they are sterile/dry.
comfort... robustness... sound... isolation... price... spare parts availability.
but since you asked then i would recommend the Byerdynamic DT-770 pro 80ohm, you will find these and their brothers in arms in almost every studio on the planet. they take a gooood while to bed in but once they are they are a good all-rounder. dont ask them to sound good plugged into a hifi as they are sterile/dry.
comfort... robustness... sound... isolation... price... spare parts availability.
The post showing the increased distortion with a 30 ohm source was measured with headphones (Sony MDR-V6) that have an input impedance of 63 ohms . That is WAY different than the Sennheiser's 300 ohms. The difference between 37 and 47 is NOT "considerably lower " but 63 vs 300 most definitely is!
Well, the signal was measured at the headphones input and the headphones are a series resistor by themselves... I recommend reading the whole paper (it's quite concise).
While I agree that I should compare them to my monitors and that should be the final verdict, I am acting based on research, not based on other people's opinions (see my posts from the previous page).
True, I did go down the rabbit hole of technicalities after I had read the complaint I quoted in the first post. But, obviously, the subjective observations described in that complaint have eventually turned out to be rooted in real electrical, mechanical and acoustical principals as exemplified by actual research and experience from multiple 3rd party sources (again, plenty of examples in my post from page 3).
And I have learned all that before posting here...
Thanks. However, first of all, the HD600 are open-back headphones and the DT-770 are closed-back. Open-back headphones are preferred for mixing as they contribute to a more natural stereo image as experienced with speakers.
But even if we compare the HD600 to the semi-open DT-880 or their fully open-back brother, the DT-990, the DT trio are all widely dismissed for colored sound expressed as a V-shaped frequency response, or harsh highs and loud (though tight) bass. Or to quote a comment from one of the many threads I have scoured over the past week, that sums up the bulk of reviews, comments and comparisons I have read:
I appreciate your input, but I digress. Please, let's not turn this helpful discussion into a headphones comparison thread–already so many out there the web 🙂 I know why I'm going for the HD600. Now I want to make sure I can use it in the way it was designed to be used.
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