or Connect
Head-Fi.org › Forums › Equipment Forums › Portable Headphone Amps › JDS Labs C5/C5D (pg96) portable amp/amp+DAC
New Posts  All Forums:Forum Nav:

JDS Labs C5/C5D (pg96) portable amp/amp+DAC - Page 84

post #1246 of 3338
Quote:
Originally Posted by miceblue View Post
I repeated the above but with the O2's 2.5x gain and the C5's high-gain; I heard pretty much the same thing. A lot of pink noise kind of sound.



Amplifying the track in Audacity with a whopping 56.8 dB amplification, I get the following spectrogram:

That's...a lot of noise in the track.

 

I know, but I'm pretty sure I'm hearing more.  I'll listen again tomorrow.  I need to sleep! :-P  As I said though, it's pretty rare, but I have some classical and soundtrack stuff that's pretty darn quiet.  I suppose I could use audacity and normalize them....

post #1247 of 3338

Quote:
Originally Posted by miceblue View Post

.....what the hay? Such music exists? You can't even analyse the waveform in Audacity is how quiet that track is.

MacBook Pro -> Audirvana Plus (maximum volume) -> ODAC RCA out -> O2 (1.0x gain, maximum volume) -> V-MODA Crossfade M-100 (sensitive headphone) or K 701 (insensitive headphone)

Plenty of noise with this setup.


Clip Zip (maximum volume) -> FiiO L2 -> C5 (low-gain, maximum volume) -> headphone

Sounds pretty much the same to me....


I repeated the above but with the O2's 2.5x gain and the C5's high-gain; I heard pretty much the same thing. A lot of pink noise kind of sound.



Amplifying the track in Audacity with a whopping 56.3 dB amplification, I get the following spectrogram:

That's...a lot of noise in the track.

 

 

Thanks miceblue, that's what I suspected.

 

 

Quote:
Originally Posted by luisdent View Post

 

No that's good.  Thanks.  But I do hear the volume change noise with music and it gets louder as it gets louder.  That made sense trust me. :-P  So what happens when you have a song with a dead silent passage for two seconds?  Does the amp detect the silence and do something for that part of the song?  Let's say theoretically you had extremely quiet beeps of music with a second or two of dead silence between every beep.  Is the amp not rendering that continuously?  I guess I'm confused?

 

There is no signal rendering, as you might be thinking. The entire audio chain is real-time analog, and volume step changes are activated via digital control. The chip makes a calculated decision as to when it will enact your physical request to make a volume change. Because it's so fast, you perceive the volume change as instant.

 

There's always a small amount of noise when changing volume. With an analog potentiometer, you can measure and hear rustling from the physical changes at the potentiometer gangs (easier to notice with sensitive headphones at high gain). With digital stepped attenuation, rustling is replaced by a quick transient as gates toggle off at one resistance, and toggle on at another resistance. The transients are small, and when zero crossing detection is employed, they're effectively muted.

 

When you change volume during a silent passage, zero crossing normally doesn't matter because the signal is already close to 0, so the audible result is close enough to desired behavior. Instead of transitioning at exactly 0, volume changes take place near 0. The math works out to about 0.

 

As miceblue has pointed out, the example music you provided is full of pink noise. By raising volume to max, you're magnifying pink noise to random, non-0 values, and there's no predictable 0 crossing. So you're hearing the small transients multiplied by a gain of 6.5x.

 

Summary: If you listen to pink noise at or around max volume, yes, you may hear small noises while changing volume. If you listen to basically any music at any volume (besides pink noise), volume changes will be silent.


Edited by jseaber - 8/9/13 at 8:34am
Reply
post #1248 of 3338
I'm still confused. Lease tell me this... If i plug my ipod line out into my c5 and let's just say for volume testing i turn on my denon eq app. I boost some frequencies, and to avoid clipping i lower the overall eq gain...

Now my music is, let's just say for theoretical testing purposes -20db lower than it was. I turn my c5 up to compensate and hit max volume where the music is heard but relaxingly quiet...

Should i hear noise that isn't in the music file? Should i hear medium volume zappy type noises when pressing the volume up or down?
post #1249 of 3338
Quote:
Originally Posted by luisdent View Post

I'm still confused. Lease tell me this... If i plug my ipod line out into my c5 and let's just say for volume testing i turn on my denon eq app. I boost some frequencies, and to avoid clipping i lower the overall eq gain...

Now my music is, let's just say for theoretical testing purposes -20db lower than it was. I turn my c5 up to compensate and hit max volume where the music is heard but relaxingly quiet...

Should i hear noise that isn't in the music file? Should i hear medium volume zappy type noises when pressing the volume up or down?

 

Yes, I suppose the above theory isn't helping. You're describing atypical listening conditions.

 

You'll never hear transition noises under normal conditions (strong source level and moderate to low amp volume).

Reply
post #1250 of 3338
Quote:
Originally Posted by jseaber View Post

 

Yes, I suppose the above theory isn't helping. You're describing atypical listening conditions.

 

You'll never hear transition noises under normal conditions (strong source level and moderate to low amp volume).

 

Exactly john!  I never said otherwise! :-P  I didn't say it was a problem.  I just said I wish I had that small bit more power so that those situations wouldn't have noise.  That's all.  But I know it's a balance of battery life, functionality, price, etc.  But just because it's atypical doesn't mean it never happens. ;)  Especially with EQ.  Unfortunately, a lof of earphones including the er4s require EQ to be neutral.  The er4s is already quiet.  Add a low bass boost and you need to compensate with lowering the EQ gain.  Then throw quiet soundtrack music at it and it's not super rare that this happens, but it isn't really "common" either.  But don't get me wrong, I'm not any less happy with the c5 because of those rare situations.  In fact, I practically won't listen to music without it. :-P  But using my apogee duet it's nice to be able to use any EQ setting I want and never worry about lack of power.  But alas, that is a desktop (although small) amp.

 

For what it's worth, I think you nailed the portable amp with the c5.  No complaints at all.  I was "just sayin'g"  :-p


Edited by luisdent - 8/9/13 at 3:31pm
post #1251 of 3338

Oh man. I'm using the C5 (low-gain) while riding in a bus and the instrument separation is definitely better than through the iPhone 4S's headphone out. Electric guitars are clear and well-defined, cymbal crashes are detailed and well-defined, the soundstage is noticeably wider and instruments sound more spaced-out in my head. Turn on the bass boost and the deeper sounds of pedal drums become audible over the bus noise.

 

Just pure awesomeness, hahaha.

post #1252 of 3338

Why does the ER4S require EQ to be neutral?  I bought my ER4S years ago because it was the most neutral, flat, and accurate earphones available.  Love the C5 on high gain setting with bass boost on feeding music into my ER4S.  I never had to raise the C5 volume setting more than 50%.

post #1253 of 3338
N
Quote:
Originally Posted by thx1000 View Post

Why does the ER4S require EQ to be neutral?  I bought my ER4S years ago because it was the most neutral, flat, and accurate earphones available.  Love the C5 on high gain setting with bass boost on feeding music into my ER4S.  I never had to raise the C5 volume setting more than 50%.
Then you don't listen to the same music i do. :-P. and the irony is that i listen to music quieter than most people i know.

First, you're asking why i need eq for the er4s when you are using the bass boost? The bass boost adds a decent amount of bass and affects frequencies beyond the bass. As good as it sounds it is bassier than neutral. Therefore, i eq the low bass only, because the er4s IS the flattest iem around in my opinion, but it still isn't perfect. It drops off around 50hz and lower. I eq those frequencies only a few db higher. However, the 20-30hz range gets even lower, and although it doesn't make a massive difference at that low frequencies, it definitely makes it better and almost perfectly neutral, so i eq those to around +8db. This is backed up by listening as well as graphs.

So with eq i have what i find to be a nearly perfectly flat iem. This us what a lot of audiophiles desire. But that requires at least -8db of eq gain to prevent clipping. Sometimes more. I don't understand why, but even my pro audio eq's clip despite a precut gain of the equivalent boost amount. Perhaps frequencies are handled in an additive way, i'm not sure... Now you have a beautiful sounding earphone that is quiet to begin with and now at least -8db quieter.

I've compared my er4s to fitear, shure, pfe, sony, tdk, westone, etc. and it is the quietest jem i've heard so far, by a decent amount usually. In fact most require at least 10-15 db less volume to sound the same. Therefore if you are using a different iem with no eq, you are using at least 10db less volume and 8db less gain from eq. That's 18db difference. Add to that the fact that the type of music most people listen to is modern highly compressed (dynamically), poorly mastered music and you could easily be talking about another 10-20db less volume needed.

That's 28-38db.

So whether one person hears it or not, doesn't mean it doesn't happen.
Edited by luisdent - 8/9/13 at 4:57pm
post #1254 of 3338

Thanks luisdent for the reply.  The ER4S was my first big money purchase.  I got it based on reviews in Stereophile and The Absolute Sound magazines.  I fancied myself an audiophile so I got the ER4S.  I never EQ'd because according to those audiophile magazines, it was a no-no because you are altering what the artists intended.  The ER4S detail retrieval was awesome but the bass was so weak.  When I got the Shure SE530, I was amazed by the improved mids and bass over the ER4S.  Then the JDS Labs C5 came along and I enjoyed my SE530 and ER4S even more with that bass boost feature.  Now I want to try some basshead stuff L3000.gif

 

Lessons learned:  1) I must not be a true audiophile because I want a U shape sound vs. flat.  2) I listen to ALL kinds of music played in shuffle mode on my iPod and I'm too lazy to play around with EQ.  3) The JDS Labs C5 is the best money spent in my portable audio setup.

post #1255 of 3338
The c5 is the best money i've spent on any amplifier type device. The cost vs quality ratio is extremely good.

Just because you don't like a perfeclfy flat response doesn't mean you're not an audiophile. There are high quality and low quality earphones of all different response shapes. And while flat is usually considered to be more "accurate", that doesn't mean It's better. It's a matter of preference.

Ipod eq sucks. Period. There's no real customization. The touch has better eq apps available though. If someone says the er4s is perfect they're wrong. It is the flattest thing out there in my opinion, but it still lacks low bass. This lack of sub bass can give the impression that they're not bassy, although they have excellent bass overall. But even by graphing standards they are low in the sub bass region. Some graphing standards suggest a +6 boost to low bass as a means of making it sound more natural. Whether that's the case or not, the er4s is lower than any graphing standard's perfect reference bass level. But overall it is very linear from bottom to top. Once eq is applied it is practically perfectly flat. So you aren't hearing what the artist intended if you use the er4s with no eq. Heck, the artist probably never intended you to even hear their music in headphones at all. They mix and master on speakers 9/10 times. But bringing any earphone closer to a studio monitor speaker means bringing it closer to a flat frequency response. Those magazines were giving opinions, not facts. So you're view of the bass wasn't wrong. I don't know "how" much bass you prefer, but there were low to some degree.

I haven't heard the 530, but the shure 535 is very flat up to the treble. It's almost the exact opposite of the er4s. Perfectly flat up to the rolling off treble. The er4s is perfectly flat down the the rolling off bass. Not that either are "perfectly" flat, but very linear and smooth responses. Anyhow, there are other differences that come into play besides frequency response too. Luckily the C5 is "perfectly" flat. :-) So whatever earphone you use will be rendered at its best.
Edited by luisdent - 8/9/13 at 6:38pm
post #1256 of 3338
"Then you don't listen to the same music i do. :-P. and the irony is that i listen to music quieter than most people i know."

Luisdent,if you dont mind,would you be able to give an example of a track that you find particularly problematic?
I would like to download it and see.
I'm asking because I make a fair bit of quiet ambient music on logic,and that can be pretty quiet in the early mixing stage,butI still can't imagine having to max out the volume on the c5!
It would be great to hear what you are listening to for comparison..
Edited by musicbased - 8/10/13 at 8:54am
post #1257 of 3338

luisdent thanks for your help.  I would like to try EQ with my ER4S.  What app are you using and what are the settings?  

post #1258 of 3338
Quote:
Originally Posted by thx1000 View Post

luisdent thanks for your help.  I would like to try EQ with my ER4S.  What app are you using and what are the settings?  

 

I'm currently using a clip zip and fuze, so I use the rockbox EQ settings for those.  If you want an ipod app, I was using accudio at first, but switched to denon eq.  My early denon eq settings are in the er4s thread:

 

post #1967

 

I've been tinkering with different settings and frequency graph comparisons.  Pretty much every graph shows a drop in sub bass around 50hz and lower:

 

9c2102168653320daa17f21df2c0764a.png

 

http://www.headphone.com/buildAGraph.php?graphType=0&graphID%5B%5D=743 (this graph looks like it was made with the glider tips... yuck.  look at the goldenears with the glider tip:

8b2cfe57aa0bdb8810e566a9ccf115f6.png the treble is more erratic like the headroom graph.  I don't hear this with the triple flange.  But they don't say what they used as far as I can tell.  Anyway...)

 

Elsewhere they're not perfect either... however, with the red knowles filters in place the hump around 2-3khz is flattened out.  You can eq the 7-7.5khz are up just a bit, say 1.5-2db, to make the treble more flat up to the range where it becomes harder for most people to hear.  Basically, the eq I've settled on based on a lot of listening and graph comparisons is a few db of boost in the 50hz and a few more at 20 and 30hz.  Then a very small 7.5khz boost for air and flattening the treble.  Again, using red filters.  I I used stock green filters, I would eq the 2.5khz or so area down a few db as well.  Here are some screenshots of eq that gnarlsagan and I use and find to be excellent:

 

http://cdn.head-fi.org/4/4a/500x1000px-LL-4a6ae55d_ER4Seq.png

http://cdn.head-fi.org/1/17/500x1000px-LL-17faa18a_Screenshot2013-08-08at12.32.13AM.png

 

You can see from my eq (the darker one) that the er4s doesn't require much.  And what it does require is a very simple smooth bass boost.  The 7khz isn't really a big deal, but it helps so I do it.  Even without eq the bass is superb, but it's just not at reference levels.  You'll never feel it like a speaker without masking other frequencies, but it will give it more of the body it should have way down low.  Even with no eq though, the bass is very "capable".  Just listen to doin' it right by daft punk.  They can hit the lowest sub bass notes with no issue.  Again, not at the volume it should be at by a small amount, but you can hear the full sub bass quality.  So check that out.  I can give you my current rockbox settings if you want.  I think they're the best, most refine, but essentially almost identical to the screenshot above...

Quote:
Originally Posted by musicbased View Post

"Then you don't listen to the same music i do. :-P. and the irony is that i listen to music quieter than most people i know."

Luisdent,if you dont mind,would you be able to give an example of a track that you find particularly problematic?
I would like to download it and see.
I'm asking because I make a fair bit of quiet ambient music on logic,and that can be pretty quiet in the early mixing stage,butI still can't imagine having to max out the volume on the c5!
It would be great to hear what you are listening to for comparison..

 

I'll try to go through my library later with the c5 and find a few examples.

post #1259 of 3338
That would be great, thanks!
So what made you switch from the iPod touch to the clip?
post #1260 of 3338
Quote:
Originally Posted by musicbased View Post

That would be great, thanks!
So what made you switch from the iPod touch to the clip?
A few reasons. First, my 64gb ipod is always full. I had a lot of problems syncing due to no space left. I could't run apps as well with no free space, or camera or video, etc.

The touch is also not as good from the headphone output. It's driven me crazy since i got it. In the car using an aux cable and any earphones. There's always been a really slight but annouing lack of micro clarity. Or at least something weird about the clarity. I got my wife a zip and compared them. The zip sounded like my c5 with the ipod line out. Side by side i was able to easily hear where the flaw was in the ipod HO.

Now i have my ipod for apps, surfing, video, photos, games, etc. and a lot of storage. My zip (now a Fuze v2) is smaller, better HO quality, i get 64gb plus the 8gb in the zip or 2gb in the fuze, so i get almost 12gb more useable space than i had for music on the ipod. I could add another card or get a 128gb when they come out soon.

I also like the fully custom rockbox eq much better than any app or ipod eq except maybe accudio's parametric eq. Rockbox has other powerful audio features as well. The zip uses a standard micro usb cable too. I prefer the fuzes wheel control and physical buttons to the ipod any day. Faster scrolling, control within your pocket and "no vision" control. More minute volume adjustments than the ipod. Shorter and skinnier. More track info can be displayed using rockbox. No itunes required. The list goes on...

I'm actually a huge ipod advocate, but the 5g touch is inferior in headphone output than any other ipod i've ever tested. Every other ipod (i've owned and trued a bunch) has very close to identical quality. All are close to the c5 in linearity and whatnot, just not power and finesse. But the new touch isn't there for me.
Edited by luisdent - 8/11/13 at 11:13am
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Portable Headphone Amps
Head-Fi.org › Forums › Equipment Forums › Portable Headphone Amps › JDS Labs C5/C5D (pg96) portable amp/amp+DAC