[Duck Hat]

I know that the iPod suffers from a large drop off in bass when driving very low impedance phones, so I was wondering about other DAP's. Have any of you noticed this problem in iRiver, Rio, Cowon, Sony, or any other company's mp3 players, or is this an iPod specific problem?

I have the iRiver h10, however the only low impedance earphones I could test it with are the stock earbuds, which aren't that bad (they're Sennheiser MX400's, which have and impedance of 32 ohms). I did notice that there was a less bass then when I used PX100's or grado SR80's, however I don't know whether this is the player or the earbuds, as the PX100's and SR80's both have pretty big bass. When I listened to the earbuds through a Cmoy hooked up to the headphone out (there is no line out on the h10, and the cradle hasn't come out for the 20gb model yet) of the player, the bass improved a bit, but not much. I also hooked up the earbuds to my computer (crappy soundblaster card ). I noticed a bit more low bass but not very much; I had to listen very hard to hear the missing bass. So, my conclusion is that when driving 32 ohm phones, the h10 is a tad bit deficient on bass, but not very much at all.

So what are your bass experiences with low impedance phones (I'm particularly interested in the E4c and the ER-4p) and non-iPod DAP's, iRiver or otherwise?

 

[necropimp]

my iriver flash player doesn't have such a problem

 

[Duck Hat]

Well, I have to admit, I wouldn't really have noticed it if I weren't looking for it hard; hell, I could even have made it up. I'm more interested in how they play with even lower impedance canalphones, like the e4c which everyone complains about with the iPod

 

[Silfer]

Heard two iRiver PCDPs and two different iriver flash players. They all didn't have bass drop off.
What you didn't hear was the mx400s fault. And yes, those buds do have better bass when amped.

 

[Duck Hat]

So this means there would be no problems using the e4c straight out of the player?

 

[Silfer]

Quote:

Originally Posted by Duck Hat So this means there would be no problems using the e4c straight out of the player?

Not because of their low impedance...Don't know how the e4c sounds unamped because I never listened to them but I would be VERY surprised if that iriver has a bass dropoff problem.

 

[Duck Hat]

Ok, thanks. So the dropoff is an iPod specific problem?

 

[sumguy_]

Just note: the SR-80, PX-100 and MX-400 are ALL 32ohms; so any variations in bass in your testing were most certainly due to the headphone itself

 

[bangraman]

Yes the H10 does have a similar problem to the iPod. And quite a few others have similar issues. And as you've noted, it's not a big deal in isolation. But the thing is that the iPod is quite severe in mid-bass (where most of the bass action takes place in pop music) fall-off when used with very low impedance phones so you're likely to notice it immediately. From the players I've looked at, it seems that the iPod falloff curve at 32 ohms load is what many others display at 16 ohms load.

 

[JaZZ]

Of the players tested in «Stereoplay» all have shown more or less bass drop-off, except for all iRiver models. Below the tests I've still found
(measurings done with a 25-ohm load, drop-off at 20 Hz):

Archos AV320: -2 dB
Archos Gmini 400: -3 dB
Apple iPod: -8.5 dB
Apple iPod mini: -9 dB
Cebop RunQ: -10 dB
Creative Muvo Square: -4.5 dB
Creative Muvo TX: -5.5 dB
Creative Zen Touch: -4.5 dB
D'Cube NMP 612T: -3 dB
iRiver H 320: -0 dB
iRiver iHP-100: -0 dB
Philips HDD 060: -4 dB
Samsung YP 55: -3.5 dB
Sony VGF AP1: -2.5 dB
Thomson PDP 2860: -10 dB
Trekstor iBeat 500: -4 dB
Trekstor USB Musicstick 250: -3.5 dB

 

[bangraman]

50hz ~ 80hz is a more realistic point to mention IMO for these things, but that may just be me.

 

[breez]

50-80Hz attenuation can be calculated from the 20Hz one.

 

[JaZZ]

Quote:

Originally Posted by breez 50-80Hz attenuation can be calculated from the 20Hz one.

Exactly. E.g. for the iPods it's -2 dB at 80 Hz and -3.5 dB at 50 Hz.

 

[bangraman]

Absolutely but the 20hz value is more of a spec thing than a real world thing.

 

[JaZZ]

Quote:

Originally Posted by bangraman Absolutely but the 20hz value is more of a spec thing than a real world thing.

Of course, but it's easier to read and display the drop-off at 20 Hz with (roughly) integer numbers than at 50 or 80 Hz with numbers such as -1.2, -1.75, -3.3. etc. In any event you can rely on the 20-Hz values for valuating the audible drop-off, because the -6-dB/oct slope characteristic is consistent with all concerned models.