Rockbox Technical Forums

Rockbox General => Rockbox General Discussion => Topic started by: Jamalarm on February 14, 2007, 05:08:38 AM

Title: Quick question (Bass)
Post by: Jamalarm on February 14, 2007, 05:08:38 AM
I recently bought a 60gb iPod with the intention of Rockboxing it immediately (My H340 finally died) but i have encountered a problem.

The bass seems to be absurdly weak, compared to the iRiver. Is this just be having the settings wrong (I have the bass setting up full, software EQ on - bass high, hardware EQ on - bass high).

I am yet to actually play anything in the stock firmware, so i don't know whether this is just a dodgy rockbox setting thing, or just terrible hardware.

I'd rather it was the first, to be honest.

Any ideas?
Title: Re: Quick question (Bass)
Post by: AlexP on February 14, 2007, 06:57:47 AM
I haven't got an iPod, but I would have thought the obvious thing would be to try it in the OF - annoying I know give itunes etc, but it is the only way to tell for sure.  That being said, I can't recall any other mention of this, so it may well be iPod vs H3x0 difference.
Title: Re: Quick question (Bass)
Post by: Ararat on February 14, 2007, 06:59:30 AM
Have you tried to set the software EQ off, and adjust the bass levels manually?
Also, the bass depends a lot in which earphone you are using...
Title: Re: Quick question (Bass)
Post by: soap on February 14, 2007, 07:35:54 AM
iPod hardware has horrible bass response on sub 32 ohm loads.  What is the impedance of your headphones?
Title: Re: Quick question (Bass)
Post by: Jamalarm on February 14, 2007, 08:41:00 AM
According to the faithful internets, 32 ohms. They're AKG K81DJs.

Does this mean that i'm never going to get lovely purring/punchy bass?

If so, does anyone want to buy a day-old 60gig video ipod?
Title: Re: Quick question (Bass)
Post by: soap on February 14, 2007, 08:46:51 AM
With a 32ohm load Rockbox on the iPod should sound almost identical to Rockbox on the H340.
Title: Re: Quick question (Bass)
Post by: Jamalarm on February 14, 2007, 08:49:47 AM
Hmmm... so i'm looking at dodgy settings somewhere.

Something i did notice is that, when turning the bass up (not in the EQ), it didn't actually add any bass that i could notice. It seemed to raise the mids more than anything.

Maybe i'll give the stock firmware a try, see if it sounds alright.

Also, what is this impedance malarky? Could you give me a quick explanation as to what it means/does?
Title: Re: Quick question (Bass)
Post by: soap on February 14, 2007, 08:55:16 AM
Also, what is this impedance malarky? Could you give me a quick explanation as to what it means/does?
That's really a question for another forum, or Wikipedia.
Title: Re: Quick question (Bass)
Post by: Jamalarm on February 14, 2007, 09:14:11 AM
Also, what is this impedance malarky? Could you give me a quick explanation as to what it means/does?
That's really a question for another forum, or Wikipedia.


Fair enough.

One further thing. Is there anything in the fact that rockbox on the ipod only allows a bass setting of 9, while on the iriver it goes up to 22?
Title: Re: Quick question (Bass)
Post by: LinusN on February 14, 2007, 09:20:32 AM
One further thing. Is there anything in the fact that rockbox on the ipod only allows a bass setting of 9, while on the iriver it goes up to 22?
It's because the two players have different hardware for the audio processing.
Title: Re: Quick question (Bass)
Post by: saratoga on February 14, 2007, 11:46:01 AM
Hmmm... so i'm looking at dodgy settings somewhere.

Something i did notice is that, when turning the bass up (not in the EQ), it didn't actually add any bass that i could notice. It seemed to raise the mids more than anything.

Maybe i'll give the stock firmware a try, see if it sounds alright.

You could try a different pair of headphones.  If you've got a high impedance pair, or an amplifier sitting around (AUX in on a stereo or whatever), that'd be worth trying to see how much of an issue it still is.

FWIW, the RMAA test results show that 32 Ohms should only be a few dB below flat, hardly noticeable.  

Also, what is this impedance malarky? Could you give me a quick explanation as to what it means/does?

Briefly, its the extent to which an electrical circuit resists current when a voltage is applied to it.  In this case, pulling a lot of current (low impedance) makes it harder for some DAPs to drive headphones properly.  Longer explanation:  see wikipedia.
Title: Re: Quick question (Bass)
Post by: Jamalarm on February 14, 2007, 01:24:04 PM
Well, tried music through normal software. Even worse. Truly appalling bass levels and reponse.

Bugger. I don't know what to do now. This is going to annoy the hell out of me.
Title: Re: Quick question (Bass)
Post by: soap on February 14, 2007, 02:43:47 PM
I don't know what you are, or think you are, hearing (much less used to) but the frequency response of the iPods with a >=32 ohm load is pretty flat, and compares very well with most other DAPs out there.
Have you tried the hardware EQ?
Title: Re: Quick question (Bass)
Post by: Jamalarm on February 14, 2007, 04:03:23 PM
The settings i'm using at the moment are:

Bass: +9

SW EQ: Rock settings, tweaked with bass higher
precut of -10dB

HW EQ: low pass filter? (can't remember name) +12dB

It's still disappointingly weak. When i had my Iriver, the bass used to be able to make my head vibrate on some tracks and was wonderfully punchy. I had the bass on +20dB and the EQ on rock then.

Maybe i read the impedance of my headphones wrong?
Title: Re: Quick question (Bass)
Post by: saratoga on February 14, 2007, 04:18:56 PM
Your headphones may just have very poor bass.
Title: Re: Quick question (Bass)
Post by: xlarge on February 14, 2007, 04:21:40 PM
+20db? Thats not sane... But every one to his on taste.

Why don't you lower all highs and mids and pump the volume?
Title: Re: Quick question (Bass)
Post by: bk on February 14, 2007, 04:28:14 PM
Maybe you destroyed the drivers in your headphones with such amplified low end. Or your eardrums.

If you really care, connect the ipod to the line input on your soundcard and record some sample audio. Then you can load it into a sound editor and see if the bass is as low as you think it is.
Title: Re: Quick question (Bass)
Post by: soap on February 14, 2007, 04:37:11 PM
Let us bring the topic of discussion back to Rockbox.
Title: Re: Quick question (Bass)
Post by: Jamalarm on February 14, 2007, 04:41:18 PM
Your headphones may just have very poor bass.

Nah, they have absolutely fantastic bass. That's one of the main reasons i bought them.

Edit:

Yeah, sorry. This is rapidly veering into irrelevance. I'll stop complaining here and move to an ipod specific complaining portal. Thanks everyone!
Title: Re: Quick question (Bass)
Post by: PHK Brasil on February 14, 2007, 05:58:43 PM
The settings i'm using at the moment are:

Bass: +9
This adjust not works on iPods. Just works as a "second" volume, increasing volume without changing bass response.

I don't know, but if this adjusts works on iRiver and you're using the same settings, you got minus 9dB of bass on your iPod, comparing to iRiver.

Maybe is what happening.




[Off Topic]
iPod hardware has horrible bass response on sub 32 ohm loads.  What is the impedance of your headphones?
Soap, I knew that this was a problem on 3rd gen iPods. This remains on 5gen iPods, with the Wolfson audio chips?

♪
Title: Re: Quick question (Bass)
Post by: saratoga on February 14, 2007, 06:21:07 PM
Its on all ipods, but is worse on the older ones.
Title: Re: Quick question (Bass)
Post by: PHK Brasil on February 16, 2007, 11:57:30 AM
Its on all ipods, but is worse on the older ones.
Could you send me a link to this article, please? I just know the dutch Stereoplay Magazine one, but is a iPod 3rd generation test.

♪
Title: Re: Quick question (Bass)
Post by: saratoga on February 16, 2007, 12:21:20 PM
I did these tests myself using a crappy onboard sound card.  The noise level figures are worthless (sound card had strong hiss), but the frequency response graphs should be accurate.

http://www.duke.edu/~mgg6/rmaa/Ipod3G.htm
http://www.duke.edu/~mgg6/rmaa/IpodNano1G.htm
http://www.duke.edu/~mgg6/rmaa/Ipod5G.htm

Had a Nano 2G and a Zen Vision:M handy, but ran out of time to test them.
Title: Re: Quick question (Bass)
Post by: PHK Brasil on February 16, 2007, 12:35:51 PM
♪
Thanks a lot, saratoga.

♪
Title: Re: Quick question (Bass)
Post by: kamisamanou on February 18, 2007, 11:20:24 PM
I have a 60gb iPod that's been Rockboxed and the bass on it is phenomenally powerful. I have a pair of Grado Labs SR60's and the original iPod earbuds and the bass comes through great on both.