[me7]

Is the "phase shifted impulse response" (whatever that means

) audible? Can anyone who owns a 6G actually hear it when listening to music?

 

[Buckster]

my classic here is sat in its box unopened - undecided whether to keep it and not worry about these "audio" problems - or send it back for £20 and get a 5.5G ..

I had my fingers burnt with a IPOD Photo - which never sounded quite right - and was never corrected by Apple

 

[WittyzTH]

SQ is not the problem on my 80Gb Classic, but the lag of interface is a bit make me annoy. Sometimes when I switched the menu quite fast, my Classic screen became freeze.

maybe it's only MY Classic problem. I'll see the technician soon about this.

 

[Superpredator]

I'm waiting for technically knowledgeable Head-Fiers to descend on Apple's Satisfaction page. It would be nice if Apple heard enough complaints that they started taking SQ more seriously.

From what I've heard though, the Classic sounds good. No experience myself.

 

[lustaficko]

Could someone explain what phase responce does to the music? I don't really know.

 

[viper32]

Quote:

Originally Posted by Buckster /img/forum/go_quote.gif my classic here is sat in its box unopened - undecided whether to keep it and not worry about these "audio" problems - or send it back for £20 and get a 5.5G .. I had my fingers burnt with a IPOD Photo - which never sounded quite right - and was never corrected by Apple

I felt the same way at first too. But I took the plunge so to speak and for me it was a very good choice. I love the classic and still say that it is the best sounding ipod from the HO. I also think its the best player I have tried so far with the UE-5C's, very good synergy with them. I dont think you will be unhappy. But I do understand your reluctance.

 

[Bob Mahoy]

Again, phase response is a measure of how long it takes a certain frequency to reach the HO/LO in relation to the others. In the classic's case, bass is actually arriving after treble (or so I remember). Have another look at the first link I posted, it explains it pretty well.

Also...I suspect that there must be some inconsistency in manufacturing both because of the different graphs and because people are rating it all over the place (from worst to middle of the road to exactly the same as 5.5g to best ever). Granted, this is usually because of personal taste, but there isn't any consistency whatsoever.

 

[kipman725]

Quote:

Originally Posted by Bob Mahoy /img/forum/go_quote.gif the main issue is uneven phase response; some frequencies arriving "late."

depends on how bad it is.. fortuatly by doing some very hard maths it should be posible to construct a allpass filter to correct this

(if your all still worried about it in a few years time I will do it for you as I plan on becoming an eeeng). (my maths currently isn't good enough to construct said filter - I have been trying for my own ADC design as Im using a filter which has phase distortion problems but its just so far beyond anything I can do at the moment.)

 

[mirumu]

Quote:

Originally Posted by ozz /img/forum/go_quote.gif is there a bass increase that can be heard or is noticeable between it and the 5.5.

Looking at the graph rhymesgalore showed comparing the two the 5.5G is outputting a 30Hz sound at at half the volume it should be whereas the Classic plays it very close to the correct volume. This difference should be noticeable with very good headphones.

 

[Prozakk]

Double post via 'site glitch I guess.

 

[Prozakk]

Quote:

Originally Posted by mirumu /img/forum/go_quote.gif I tried to reproduce the graphs linked in the original post since I have an almost identical computer setup to the person that measured them. The difference is that my Powermac G5 has a M-Audio Revolution 7.1 soundcard which I thought would be a bit more accurate than the inbuilt sound hardware of the Powermac G5 that he was using. I followed the method described measuring from the headphone output and my graphs look pretty much the same with a few exceptions. Note that my iPod is not one of the European volume limited ones so I can get higher output power from the headphone out. I still had room to up the volume but if I put it any higher than I used to measure these graphs with it started clipping and chopped off the tops and bottoms of the waveforms. First, the bass response I am seeing for the 6G iPod looks much better, this makes me think that the guy's speculation that his measurement hardware (i.e. Powermac G5 onboard sound) was causing the roll off is correct since my M-Audio card shows good bass response all the way down even below 20Hz. Also, my card doesn't roll off quite as quickly on the top end and it looks like 20Khz is achieved reasonably comfortably. I am still seeing a treble spike at the top end of about 0.1db but I'm sure that is just not big enough to be audible. Overall I think the frequency response looks pretty respectable. For the impulse response graph, I get the following which looks very similar to the graph he posted except it's spiking in the other direction. I don't know how to read this so can't really draw any conclusions from it but it certainly looks more like the graph he showed for the 6G than the one he showed for the 5.5G so I'm assuming that this is showing the phase problems. I do see that the amplitude of the spikes on my graph are bigger too although I don't know if that means anything important or not. Someone who knows how to read these will hopefully be able to summarise it better than me. Hopefully someone with Rightmark or some other measurement software can generate some graphs too just to rule out it being a problem with this FuzzMeasure software. My Windows computer's sound card is far too poor to give any remotely accurate graphs.

Thanks for the info. But now I don't know if I should get an iMod or a 6g...ARGH!

 

[mirumu]

Quote:

Originally Posted by me7 /img/forum/go_quote.gif Is the "phase shifted impulse response" (whatever that means ) audible? Can anyone who owns a 6G actually hear it when listening to music?

I can't hear it, but the headphones I'm using (Shure E500s) may not be good for spotting the difference. It may also be more obvious when directly compared with a device that does not have this phase shift. When I get the time, I am planning to compare the Classic with a CD player using some high resolution and quite analytical headphones like my Stax to see if I can pick it under those conditions. Oh, and I'm using lossless files on my iPod so I'm happy if it is noticeable I'll be able to spot it.

I think it's also worth me adding that none of what I do find is going to make me consider selling or returning my iPod Classic. I still think it sounds very good, especially for use with IEMs as I will be generally using it. It certainly sounds better than my 4G iPod Photo and 2G iPod Nano. In the week I've owned it so far I've used it for hours a day at work and found it to sound consistently good and it hasn't been at all fatiguing.

 

[mirumu]

Quote:

Originally Posted by Prozakk /img/forum/go_quote.gif Thanks for the info. But now I don't know if I should get an iMod or a 6g...ARGH!

Vinnie's post here might help you out on that.

 

[Skylab]

I spent some time listening to the iPod Classic's line out today, through my Meier Opera headphone amp. I thought it sounded quite good. The Classic certainly does not have what anyone could really call "major sonic problems", at least in terms of their having any practical consequence when listening. I was listening in a VERY high resolution system, and while the sound might be just a shade less warm than the 5G I very briefly compared it to, the Classic certainly sounds GOOD, IMO. I switched then to my 5.5G iMod iPod, and it sounds audibly better, but it sounds audibly better than the stock 5G as well.

This is a tempest in a teapot, IMO.

 

[Prozakk]

Thanks Miru!