Hardware EQ for Ipod 5th gen.

[torne]

I suggest you use whichever settings make the audio sound pleasing to your ear; that's what they're for. I told you which was more efficient, but that's not a suggestion

The bug you linked there sounds like perhaps the tone controls and equaliser interfere when it's deciding whether to precut the audio and by how much...

[h.finn]

ok
I'll experiment
 

[saratoga]

Ok,
Here's my setup:

Graph. Eq:
2.5   60         6.4
5.5   450       6.0
1.5   4000     2.1
2.5   15530   2.2

Bass:   +8
Treble: +12
Volume:-76dB

The bass preset also includes a precut to avoid distortion.  Did you remove the precut? 

[h.finn]

" Did you remove the precut?"
You mean the cutoff?
The cutoff is at 1

[Chronon]

Settings > Sound Settings > Equalizer > Precut

It only takes non-positive gain settings (mine is -3.0 dB, for example).

[soap]

Are you using pre-cut equal to the amount of software EQ being applied?

[h.finn]

OOOOOOOOPPPPPPPPPSS
Sorry, I didn't understand
 
I actually have precut at 0
!!
Could that be part of the problem?
Because yesterday evening I switched off the equalizer all together and moved the bass to 0 value and (the bass) was still distorted.
...
P.S. i noticed that on the RB instructions, when the graphical eq is shown, there is always, at bottom of the screen, the text: "Edit mode: Gain".
As in:
http://download.rockbox.org/daily/manual/rockbox-iriverh300/configure_rockbox/images/ss-equalizer-220x176x16.png
..........
Well: I actually don't have that little footnote!
??

[soap]

If you don't apply precut any software EQ gain is likely to exceed the headroom in your audio files and clip (distort.)

Modern mastering techniques leave almost no headroom, and older-style mastering techniques never, in my experience, left the (at least) 12 dB of headroom you need to prevent your EQ settings from clipping.


*I said (at least) because I didn't study the Q values of your software EQ settings and for all I know your bands are overlapping, meaning that some frequencies may be boosted more that the highest gain value (12 dB) I saw.

So, in summary.

1 - negative pre gain in the software EQ equal to the maximum applied EQ gain.
2 - "Sane" volume level set to prevent Rockbox from applying any volume control in the digital domain.
3 - Line-out or volume set to 0 and then use headphone out as a line-out.
4 - Distortion still?
 

[h.finn]

Hi Soap,
I'm taking notice of your suggestions.
And will try them out tonight!
But: "use headphone out as a line-out"
??
The sound quality is inferior to the dock!
Isn't it?

H.

[torne]

Why should it be? Line out and headphone out are the same thing, except the latter has a volume control on it. They're both driven by the same DAC. If you set the volume to 0dB then headphone out will be at the exact same level as line out.

[h.finn]

Rrrightt!
That's a kind of revelation to me
 
'cause I thought that the audio going through the headphone output undergoes an additional step of amplification, potentially coloring the sound or adding noise.
I read somewhere:
"The line out is a line level signal, meaning it doesn't go through the iPods headphone amp circuitry.
If you are going to another source you will get better results with the line level"
?
Also I found this NOT to be true:
"...you basically have control over the volume of a headphone plug, but a line out is at a constant volume" : well, how come I can change the volume in line out?

[torne]

If you don't know what precut is then you probably shouldn't be worrying about the impact of an amplifier on the sound..

soap suggested you use line out, or headphone output at 0dB; you are already using line out, so that's fine. The difference between the two is not something you will notice.

I already explained to you what Rockbox does with the volume control: in order to support playing audio very quietly (quieter than the lowest setting the hardware supports, but not actually muted) Rockbox scales the digital audio's amplitude down in software if you decrease the volume extremely far. Since this is done in the digital domain it also affects line out, but if you were using the headphone output you would find the volume at those levels is already so quiet as to be basically inaudible

[h.finn]

ok
point taken
 
 :'(
I'll study all the info a bit
 

H.
P.S.: just a little point: having a "good ear" for music, doesn't necessarily mean knowing the technical details, right?
 
H.

[torne]

No, but the sound quality differences between minor variations in the analogue path, on a portable MP3 player, are something that generally only "audiophiles" would care about; they're not something that people actually *hear* unless the hardware is crappy. There's a difference between having a good ear for sound and being concerned about entirely hypothetical differences