Help me explain my experience - Macbook pro sounding 'better' than Chord Mojo - IE80 vs AK3003i IEM
Sep 10, 2018 at 4:11 PM Thread Starter Post #1 of 30

stretchneck

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Vice soundtrack on spotify, follow the link below, Track 4 'You made me breakfast' there is an Orchestral part of the music 39 seconds in that I will use as the basis for discussion.



Listening Impressions for the orchestra part:
  1. Macbook pro driving Sennheiser IE80 directly - sounds really 'rich', tonal and harmonic. Soundstage more intimate, less separation of instruments, darker than AK3003i. Really awesome, the music feels alive!

  2. Macbook pro driving AK3003i - very similar to above, but more clarity, brighter - but not as rich in colour and to me not as enjoyable as the IE80 (AK3003i has the edge in most other tracks though).

  3. Chord Mojo driving AK3003i - greater soundstage and imaging, but the richness of IE80 fed from the Macbook Pro is missing. I feel as though the quest for greater 'clarity' and 'separation' of instruments has meant that you loose the body of the music, it's become separated and less 'harmonic'... Can this be true?

  4. Chord Mojo driving IE80 - loss of 'richness' and 'enveloping' sound compared to playback via Macbook Pro - there is a gain in soundstage/imaging, but not as much as with the AK3003i (to be expected I guess as the IE80's are not as resolving as the AK3003i). Once again the AK3003i don't sound as dark as the IE80's.
So, I'm a bit baffled here - why does the apparent combination of a higher end outboard DAC in the form of a Chord Mojo and AK3003i sound 'worse' with this track? It's as if the quest of image separation means that the body of the music now exists as separate limbs. The more compressed presentation from the much cheaper DAC in the Macbook Pro, with less dynamic range, and poorer SNR, actually sounds better!?

By the way, actually tested this using an iPhone 7 with the external 3.5mm lightning adapter and it sounded dreadful - completely flat and devoid of almost all merit, which is not surprising for a £10 DAC. But I am surprised by how much better the Macbook Pro (A1502 - late 2013) sounds.

Help me explain, why and what I'm experiencing here as I'm at a bit of a loss as it goes against perceived wisdom of what is 'best' - SNR/Dynamic Range/Imaging etc... Trying to improve my kit so that I have a 'euphoric' and enveloping sound, whilst still retaining detail.
 
Sep 10, 2018 at 11:19 PM Post #2 of 30
Perhaps you upgrade your Mojo to Hugo 2 or even the original Hugo if you need that details. Mojo to me just sounds too polite with IEMs and details suffer because of that tuning. It shines as a pure DAC though feeding a desktop amp or power amps to speakers.
 
Sep 11, 2018 at 4:40 AM Post #3 of 30
Thanks - I might need some further help. So I am thinking that impedance/power affects more than just the volume it also affects the quality of the sound pretty significantly? What you suggest perhaps supports my experience, of the Mojo sounding 'thin' compared to the Macbook Pro which may be attributable to a weaker amp section in the Mojo compared to a standalone headphone amp.

However, technical side of it doesn't indicate that this should be issue?..

Impedance between these two headphones is not too different (IE80 16 ohms, 3003i 8 ohms), and they both have the same claimed sensitivity of 125 db/mW. The 3003i does require slightly more volume (watts, because of the lower impedance I presume) to achieve the same output.

But then look at the max outputs for each:

Macbook Pro max output is in the range of 2 Vrms, output impedance <24 Ohms

The output specs of the Chord Mojo and the original Hugo are pretty similar - 720mW into 8 ohms, which gives a maximum output of 2.4 Vrms i.e. slightly more than the Macbook Pro.

So whilst the Mojo has dramatically lower impedance, the amount of power supplied is pretty similar, in fact slightly higher than the Macbook pro.

So I'm still baffled based on this technical analysis, and don't know if switching to a Chord Hugo or other standalone headphone amp would solve the problem...

Thanks
 
Sep 11, 2018 at 6:51 AM Post #4 of 30
there is no single answer. the very fact that your issue is about specific tracks clearly makes it a case by case matter. then there is taste. in audio forums you have the fake objectivism of HiFi, where people pretend like they'll never be happy unless they get the identical copy of the original recorded sound. they for the most part never heard it, they don't have a clue if they would actually prefer that, but oh man do they want it as a principle.
then you also see a all lot of people defining actual fidelity with terms that clearly don't suggest love of it. like how "analytical" it sounds, or how neutral can be "boring".
the mirage of fidelity always sounding better is born from a very rational idea, but as music can be anything, sometimes that anything is just more enjoyable when altered.
I can only strongly suggest to you not to fall for the oldest trick in the book which is to assume that if you prefer something, then it's of higher fidelity and it must measure better. that's not how we, humans, work. we like what we like and all we can do is try to find clues as to which objective event makes it so. but ti's hard as our senses mix everything together. we can focus on some specific aspect of sound, but in reality what we focus on is already a blend of all the information our brain got to use(including non audio senses, and previous knowledge or ideas). so it's really hard to always pin an objective cause to a feeling. in this case I'd say it's one of those really not easy or simple correlations.



about the general idea of music feeling like an homogeneous thing, as opposed to clearly independent and separated instruments(in details and in space), I believe it's yet again a matter of circumstances and personal taste. sometimes I will wish to get the finest details so I can focus on that one instrument and feel like I'm getting all of it in details. other times I wish for the music to be "glued" together, so that it's music and not an assemblage of independent instruments(something the IE80 does well IMO with the enveloping subs and lack of mids).

as to why you feel that way with different gears, you're not getting an answer to that. or maybe you'd get a partial or plain false one, because somebody will pretend to master to conversion from electrical signal to subjective impressions. but things are usually too complicated and interconnected. I could tell you with high confidence that your low impedance IEMs generate higher crosstalk and distortions into the macbook. without any clue about the magnitude of that claim, we could extrapolate on the idea that crosstalk at very massive levels, does give that sense of the music being glued together, in fact it's a process used by sound engineers sometimes. I could also say that higher distortions(again if we completely ignore the actual magnitudes) may "blur" the details with extra tones. then you can jump on that apparently reasonable correlation and decide that now you know. but here is the thing:
-crosstalk below -40dB start to become unnoticeable to people. and it's rather rare that a device will have such a high crosstalk even into really low impedance IEM which will indeed increase crosstalk compared to what's written in the specs of the gear. so yes crosstalk will increase, but we can't know if it's high enough to be audible unless we measure the macbook into those loads. until then it's all conjectures without a shred of evidence.
- same idea with distortions. it is likely that the levels are probably higher than on the mojo. it is also factual that they are going to increase when using such low impedance IEMs. but distortion is a world that defines a lot of things. some distortions if high enough could indeed blur the details and all that. but then again some distortions could just as well create a feeling of "texture" and make us feel like there are more details(they just weren't on the original signal). and of course there is also the very likely possibility that most of those distortions are too low and we don't actually notice any of them.

so here we are, I made what is IMO a fair educated guess. and anybody can take that and run with it as a convincing argument and "fact". but I for one don't have a clue if any of it is relevant to your situation. (sorry :sweat_smile: )
the low impedance load presented by such IEMs is certainly taking its toll any amplifier. and some amplifier have a really hard time dealing with it(after all we're only 8 or 16ohm away from a short circuit). I assume that the macbook is going to suffer more, but TBH I don't know, the Mojo could be great with headphones and offer great power into a small form, but not be suited for low impedance(I remember reading some measurements into IEMs but the interpretations were all over the place and using an er4 as example of low impedance when the upper range is all but low impedance. so I really don't know and have never measured the Mojo or a macbook myself). we can play the guessing game all day, but without actual measurements I don't advise to take any of those ideas too seriously. even less so if your feelings are only about a few songs sometimes.
 
Sep 11, 2018 at 7:17 AM Post #5 of 30
Don’t have any of your same equipment to listen along, though I get your point.

You’re experiencing synergy with the specific IEMs and MacBook Pro. The cherry on top is a specific tone of a track that seems to work for you. In fact it sounds so good it emotionally triggered you to make a thread about the phenomenon.

One answer could be your still discovering the sound signature you like. There is nothing wrong with finding the signature with a lesser piece of equipment. The sad truth is though that it is a one off situation where the planets all lined up. In daily practice you will probably find the system ends up as nice for some songs, but lacks the transparency for most of your collection.

Your most likely experiencing color with the song. At times color can actually add a euphonic factor to the listening experience. It’s hard to judge as in most cases it’s simply added harmonics/distortions due to a spike in the response of the system that coincides with the song.

Many of these so-called accidents are actually sign posts to help you with your journey. There could be a new signature you can create which adds whatever character you found you love in your daily listening experience. Even the best of audiophile equipment has personality. We tend to think the high dollar purchases are pristine and void of color; though nothing is farther from the truth.

I’m not going to make a short list of my favorite and most expensive gear here, but I can promise you it adds harmonics and warm color to most of my files. High end manufacturers put the color in as it adds character. But it’s all about mixing and matching, synergy.

You can match a flat dull and laid-back IEM with a forward and robust V shape DAC/Amp and end up winning. You most likely found that the combination you stumbled upon added a color missing but wanted from your future happiness Head-Fi End-Game rig!
 
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Sep 11, 2018 at 8:29 AM Post #6 of 30
Thanks for all of the useful feedback - looks like the best approach is to try out combinations to get the synergy. I'm going to try and ipod gen. 5.5 - apparently the older iPods offer a slightly warmer, richer mid-range, with noticeable positive effects on vocals, stringed instruments, pianos and acoustic drum kits (according to this article). Plus its a cheap way to try out different sound signatures.
 
Sep 11, 2018 at 9:42 AM Post #7 of 30
391A6610-93D9-449A-B2A2-A43F56878D5E.png
Thanks for all of the useful feedback - looks like the best approach is to try out combinations to get the synergy. I'm going to try and ipod gen. 5.5 - apparently the older iPods offer a slightly warmer, richer mid-range, with noticeable positive effects on vocals, stringed instruments, pianos and acoustic drum kits (according to this article). Plus its a cheap way to try out different sound signatures.

Don’t know if this is your signature, but the ZX300 thread has a bunch of members who purchased the Joybuy 16 GB Sony edition.

I have heard the ZX300 and it’s both warm and highly detailed.
https://m.joybuy.com/600198203.html
 
Sep 12, 2018 at 12:28 PM Post #8 of 30
  1. Macbook pro driving Sennheiser IE80 directly - sounds really 'rich', tonal and harmonic. Soundstage more intimate, less separation of instruments, darker than AK3003i. Really awesome, the music feels alive!

  2. Macbook pro driving AK3003i - very similar to above, but more clarity, brighter - but not as rich in colour and to me not as enjoyable as the IE80 (AK3003i has the edge in most other tracks though).

  3. Chord Mojo driving AK3003i - greater soundstage and imaging, but the richness of IE80 fed from the Macbook Pro is missing. I feel as though the quest for greater 'clarity' and 'separation' of instruments has meant that you loose the body of the music, it's become separated and less 'harmonic'... Can this be true?

  4. Chord Mojo driving IE80 - loss of 'richness' and 'enveloping' sound compared to playback via Macbook Pro - there is a gain in soundstage/imaging, but not as much as with the AK3003i (to be expected I guess as the IE80's are not as resolving as the AK3003i). Once again the AK3003i don't sound as dark as the IE80's.
So, I'm a bit baffled here - why does the apparent combination of a higher end outboard DAC in the form of a Chord Mojo and AK3003i sound 'worse' with this track? It's as if the quest of image separation means that the body of the music now exists as separate limbs. The more compressed presentation from the much cheaper DAC in the Macbook Pro, with less dynamic range, and poorer SNR, actually sounds better!?

It's entirely possible that the Macbook has a high enough output impedance that introduces an EQ effect to some IEMs it drives (ie being of very low load impedance), which makes the sound richer at the expense of imaging. You can deliberately EQ things that way too - boost too much between 50hz to ~800hz you can make instruments sound richer but in the case of non-orchestra music the penalty for that is less depth as it enhances the drums mostly (except in most non-classical/jazz recordings, chances are they don't have a lot of depth as recorded/mastered anyway, though you could end up hearing the bass drum in front of the vocalist).

Note that output impedance does not have uniform interactions and depends on certain driver and amp circuit specs, so your iPhone or any other device like a 150ohm jack on an HT receiver isn't necessarily going to have the exact same effect even if they had the same output impedance.
 
Sep 12, 2018 at 12:51 PM Post #9 of 30
And that’s the thing here. It’s always a great learning experience if you have a friend with different sound signature tastes around. If your friend has a complete opposite signature taste you can get an idea of just how extremely different everyone is.

Now I’m not saying the original poster is still learning his signature style; but if he is then finding a tone even if it’s part of a song on a secondary system is simply an aspect of the Head-Fi learning curve. It’s very much like stopping in at a party and learning about a new food you never tried, but now love.

Most of us who have known other audiophiles in life can mentally jot down their sound signature taste. Much of the time too; we can learn of new products which may not be right for us but perfect for them. I actually know more flat and treble heads than bass heads. Still as a whole products I have purchased but never liked seemed to always filter out some of the low end and bring up the treble to seem to enhance clarity. At one point I was asked to demo a DAC and sat back listening to the possibly new DAC demonstration then a return to the current system DAC.

My option to the guy was that he was about to trade musicality for treble detail, and he went right along with my view and kept his old DAC. But bass heads have the same but opposite issue; where they will gravitate in the direction of bass to overwhelm detail.

The above is the perfect example of how flat gets closer to transparency and the reason why audiophile perceptions of flat audio have validity here. Still in the last few years, more than ever before we are finding more headphones which present a bass response along with clarity. This new signature somehow presents all the detail with added warmth.

Of course many of us bass heads fell in love with cheap bass heavy headphones only to be let down as after 6 months when we found the bass messed up too much of the detail. And in reality that’s the test; which is finding a headphone signature which stays interesting year in and year out. Obviously staying closer to transparency and flatness is a more trusted and safer goal.
 
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Sep 12, 2018 at 1:15 PM Post #10 of 30
A short feedback to your observations:

I do own the Mojo and some other DACs, also a MacBook Pro, but never used it as a serious source.

I have some Pinnacle P1 IEMS but my main headphones are Audioquest NightHawk and Nightowl. I also used the Mojo as source in my 10k stereo.

Observation 1: the Audioquest HPs reveal WAY more of the Mojo qualities than the P1 IEMS and the stereo system reveals more again than the headphones.

Observation 2: my other DACs may sound appealing in the short run, bold, brash, impressive and the Mojo may sound almost too smooth when switching. But after just a little while with the Mojo I just want to keep listening and exploring. Again, much more pronounced with the headphones and speaker system than with IEMS.

But I also found that Mojo sounds best with acoustic recordings, studio engineered music benefits less.

In the end, if you like it it’s good for you! :/)
 
Sep 12, 2018 at 2:32 PM Post #11 of 30
Vice soundtrack on spotify, follow the link below, Track 4 'You made me breakfast' there is an Orchestral part of the music 39 seconds in that I will use as the basis for discussion.
Listening Impressions for the orchestra part:
  1. Macbook pro driving Sennheiser IE80 directly - sounds really 'rich', tonal and harmonic. Soundstage more intimate, less separation of instruments, darker than AK3003i. Really awesome, the music feels alive!

  2. Macbook pro driving AK3003i - very similar to above, but more clarity, brighter - but not as rich in colour and to me not as enjoyable as the IE80 (AK3003i has the edge in most other tracks though).

  3. Chord Mojo driving AK3003i - greater soundstage and imaging, but the richness of IE80 fed from the Macbook Pro is missing. I feel as though the quest for greater 'clarity' and 'separation' of instruments has meant that you loose the body of the music, it's become separated and less 'harmonic'... Can this be true?

  4. Chord Mojo driving IE80 - loss of 'richness' and 'enveloping' sound compared to playback via Macbook Pro - there is a gain in soundstage/imaging, but not as much as with the AK3003i (to be expected I guess as the IE80's are not as resolving as the AK3003i). Once again the AK3003i don't sound as dark as the IE80's.
So, I'm a bit baffled here - why does the apparent combination of a higher end outboard DAC in the form of a Chord Mojo and AK3003i sound 'worse' with this track? It's as if the quest of image separation means that the body of the music now exists as separate limbs. The more compressed presentation from the much cheaper DAC in the Macbook Pro, with less dynamic range, and poorer SNR, actually sounds better!?

By the way, actually tested this using an iPhone 7 with the external 3.5mm lightning adapter and it sounded dreadful - completely flat and devoid of almost all merit, which is not surprising for a £10 DAC. But I am surprised by how much better the Macbook Pro (A1502 - late 2013) sounds.

Help me explain, why and what I'm experiencing here as I'm at a bit of a loss as it goes against perceived wisdom of what is 'best' - SNR/Dynamic Range/Imaging etc... Trying to improve my kit so that I have a 'euphoric' and enveloping sound, whilst still retaining detail.

My two cents (& best guess).
Voltage is normally talked about for driving headphone, but from my understanding lower impedance (Ohm) IEMs require less voltage, but might need more current.
So it could be the Macbook Pro is providing more current, then the Chord Mojo.
(or maybe the correct balance of voltage/current?)
The Mojo might be designed for driving headphones that are more voltage demanding and not in need for as much current.
How do your IEMs sound plugged into a phone, or portable mp3/DAP player?
 
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Sep 12, 2018 at 3:40 PM Post #12 of 30
My two cents (& best guess).
Voltage is normally talked about for driving headphone, but from my under standing lower impedance (Ohm) IEMs require less voltage, but might need more current.
So it could be the Macbook Pro is providing more current, then the Chord Mojo.y
(or maybe the correct balance of voltage/current?)
The Mojo might be designed for driving headphones that are more voltage demanding and not in need for as much current.
How do your IEMs sound plugged into a phone, or portable mp3/DAP player?

Cheers - purpleangel

I thought this as well, as the sound could be interpreted like a deficiency in current, and the AK3003i could response better to more current... however nobody publishes these figures! But looking at the maths I gave earlier:

Macbook Pro = 2v output at 24 ohms gives 0.3 amps
Mojo = 720mW into 8 ohms, which gives a maximum output of 2.4 Vrms = 0.3 amps

So they're both similar in terms of Vrms, but perhaps peak current delivery and the reserves in the Macbook pro are much greater. But will probably never known the true answer as there's never enough information without your own test rig.

In terms of comparisons, ipod 5.5 has been ordered so will see how that compares - I have also taken onboard Redcarmooses idea of a Sony DAP - does seem to meet my requirements as well, so I may also pick up a used nw-zx2 and compare them all.

Either way, no rush decisions as I know that different music will very well sound different depending upon what it's played on.
 
Sep 12, 2018 at 3:52 PM Post #13 of 30
Cheers - purpleangel
I thought this as well, as the sound could be interpreted like a deficiency in current, and the AK3003i could response better to more current... however nobody publishes these figures! But looking at the maths I gave earlier:
Macbook Pro = 2v output at 24 ohms gives 0.3 amps
Mojo = 720mW into 8 ohms, which gives a maximum output of 2.4 Vrms = 0.3 amps
So they're both similar in terms of Vrms, but perhaps peak current delivery and the reserves in the Macbook pro are much greater. But will probably never known the true answer as there's never enough information without your own test rig.
In terms of comparisons, ipod 5.5 has been ordered so will see how that compares - I have also taken onboard Redcarmooses idea of a Sony DAP - does seem to meet my requirements as well, so I may also pick up a used nw-zx2 and compare them all.
Either way, no rush decisions as I know that different music will very well sound different depending upon what it's played on.
As a long shot, try connecting the Mojo, to the Macbook Pro using optical (if the Mac has optical output), see if it makes a difference.
 
Sep 12, 2018 at 4:02 PM Post #14 of 30
It's entirely possible that the Macbook has a high enough output impedance that introduces an EQ effect to some IEMs it drives (ie being of very low load impedance), which makes the sound richer at the expense of imaging. You can deliberately EQ things that way too - boost too much between 50hz to ~800hz you can make instruments sound richer but in the case of non-orchestra music the penalty for that is less depth as it enhances the drums mostly (except in most non-classical/jazz recordings, chances are they don't have a lot of depth as recorded/mastered anyway, though you could end up hearing the bass drum in front of the vocalist).

Note that output impedance does not have uniform interactions and depends on certain driver and amp circuit specs, so your iPhone or any other device like a 150ohm jack on an HT receiver isn't necessarily going to have the exact same effect even if they had the same output impedance.

Very interested feedback. I have read this article on lifewire regarding the effect of output impedance and found the following, quote:

"Incidentally, almost all tube power amplifiers use output transformers, and because output transformers are just coils of wire wrapped around a metal frame, they have substantial impedance of their own, sometimes as much as 0.5 ohm or even more. In fact, to simulate the sound of a tube amp in his Sunfire solid-state (transistor) amplifiers, famed designer Bob Carver added a “current mode” switch that placed a 1-ohm resistor in series with the output devices. Of course, this violated the 1-to-10 minimum ratio of output impedance to expected input impedance that we discussed above, and thus had a substantial effect on the frequency response of the connected speaker, but that’s what you get with many tube amps and it’s exactly what Carver wanted to simulate."​

Once thing we do know is that the Macbook pro output impedance 'violates' the 1-to-10 (or 1-to-8 ratio depending upon your source), whereas the Mojo with it's dramatically lower output impedance (and associated higher damping factor) does not.

So perhaps this is one technical reason why I might be hearing what I do - the impedance mismatch (24 ohm output on the Macbook Pro, 16ohm input for the IE80) might actually sound rather good!?
 
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Sep 12, 2018 at 4:53 PM Post #15 of 30
Very interested feedback. I have read this article on lifewire regarding the effect of output impedance and found the following, quote:

"Incidentally, almost all tube power amplifiers use output transformers, and because output transformers are just coils of wire wrapped around a metal frame, they have substantial impedance of their own, sometimes as much as 0.5 ohm or even more. In fact, to simulate the sound of a tube amp in his Sunfire solid-state (transistor) amplifiers, famed designer Bob Carver added a “current mode” switch that placed a 1-ohm resistor in series with the output devices. Of course, this violated the 1-to-10 minimum ratio of output impedance to expected input impedance that we discussed above, and thus had a substantial effect on the frequency response of the connected speaker, but that’s what you get with many tube amps and it’s exactly what Carver wanted to simulate."​
Once thing we do know is that the Macbook pro output impedance 'violates' the 1-to-10 (or 1-to-8 ratio depending upon your source), whereas the Mojo with it's dramatically lower output impedance (and associated higher damping factor) does not.
So perhaps this is one technical reason why I might be hearing what I do - the impedance mismatch (24 ohm output on the Macbook Pro, 16ohm input for the IE80) might actually sound rather good!?
The 1 to 10 (or 1 to 8) impedance spread (source to headphone) is more like a good guild-line, if the spread was only 1 to 5, it does not really make much of a noticeable difference (if any noticeable difference).
If you did have an impedance issue, one thing you would notice is a bloated (louder, less detailed) bass.
 

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