Equalizer bands control the wrong frequencies

[yellowantphil]

Poweramp version 2.0.9-build-554-play (Full Version)

My phone: Alcatel One Touch Evolve

Android version 4.1.2

Stock ROM

I also submitted this on the bug reporting document on Google Docs

 

I was trying to equalize my car stereo using a pink noise track played through Poweramp, analyzing the spectrum using a microphone and a ten-band hardware frequency analyzer (built into my home stereo equalizer). The sliders in the Poweramp EQ all control the frequency band one octave lower than they’re supposed to.

 

To demonstrate this, I set Poweramp's equalizer this way:
Preamp -10 dB
One slider set to +10 dB
All other sliders 0 dB
Tone control off, limiter off, EQ control on

I played pink noise through Poweramp and recorded it onto my computer. I then analyzed the frequency spectrum in Audacity. Setting the 16 kHz slider to +10 dB shows a peak at 8 kHz and another one 16 kHz in the recorded audio. The sliders from 62 Hz to 8 kHz all give peak output at half of their labeled frequencies. I think that the 31 Hz slider was trying to output a peak at 15 Hz, but my phone can't seem to output such deep frequencies.

The equalizer works fine if you always move the slider that is one higher than the frequency band you are trying to control, but I can't control the 16 kHz band individually. This also makes it difficult to use my hardware frequency analyzer, because I have to remember to always move the slider one higher than the band I am looking at on the analyzer display.

[maxmp]

In short: there is certainly an issue with your setup. You (and probably anyone) can hear difference between 1k / 2k or 8k / 16k pretty easily just by ear, even without analyzers)) So that error would be too obvious.

 

Longer: There is a difference between DVC and non DVC modes, and non-DVC equalizer is a bit tricky, but nothing like octave (2x) errors. There is also small round errors in lower frequency bands due to fixed point arithmetics, but it's only a few hz (e.g. really there is 34hz vs 32hz band). As it strictly by 2 for you, this can be some sort of aliasing, or lack of freq. resolution.

 

Thanks!

[yellowantphil]

Hmm... I tried it with and without direct volume control, and have the same problem either way. The built-in equalizer accessible from the MusicFX button appears to work correctly, but I don’t want to use that one. I guess I will just blame my phone, and keep moving the sliders one above the frequency band that I want to change.

 

Thanks for your reply.

[site]

Phone: Samsung Galaxy S3
Android: 4.3.1
CyanogenMod 10.2

I finally upgraded to 2.0.9 build 554-play two days ago and had been having trouble with the audio on my phone while playing music through Poweramp. I had previously saved a custom EQ setting with the Preamp decreased by two notches (so -2.8db I think) and bass boosted by two notches (+2.8) at both the 62Hz and 125Hz frequencies. I combined this with never setting the phone's volume up to 100%, because that would cause clipping no matter what. After upgrading, when playing through the phone speaker, sound would clip even with volume not at maximum.

Even more interesting, when playing on my car stereo through a radio transmitter, bass would be audiably farting/clipping and the transmitter would occasionally shut off while playing. A "feature" of the transmitter I use is that if it does not detect sound at a certian db level for a certain amount of time, the device powers off. After fiddling with the EQ settings for a while It turns out that not only are the Hz sliders off (I had to knock back the 62Hz slider to 0 [flat] and 125Hz to +1 notch [+1.4db] to prevent clipping/farting), as the OP states, but so is the Preamp. I had to pump it back up to 0 (flat) and turn the phone's volume up to 100% just for the transmitter to stay on while in use.

Everything was fine until upgrading to build 554, and I have not messed with the Android OS in any way since I did so. It's definitely a Poweramp issue.

[pwampusr]

I can confirm this on:

 

Motorola Droid 4 (XT894)

Android 4.1.2

Poweramp 2.0.9-build-554-play (Full version)

 

 

I noticed that the high frequencies are not as clear as before. And basses are blurred. I thought my ears or my earphones went wrong. But I could not belive it. I started to looking for a bug reports about Poweramp EQ and found this topic.

 

I generated pink noise, played it on Poweramp while 500Hz EQ band pushed up, digitized and did a spectrum analysis with Sound Forge and I see peak around 248Hz. I repeated the process with 1kHz EQ pushed up on Poweramp. Then I see peaks around 442Hz in the spectrum analysis.

 

I hear high frequencies as bad because 8kHz band highlighted now instead of 16kHz. I'm happy to know my ears are healthy :-) Please corret this bug.

As a workaround, now I use the treble knob instead of the EQ to create a clear sound. The two channel tone control works as before.

 

Until you fix the bug, where can I download an older version of Poweamp?

 

Independently from the above, Poweramp is awesome, thank you!

 

 

(sorry for my bad english)

[pwampusr]

I found old versions here:

http://www.papktop.com/tag/Poweramp

(I don't know if this site is a safe or not. Use it on your own risk.)

 

I experienced the bug in version 2.0.8 and 2.0.7 too. This is interesting, because my sound quality problems started since just 1-2 months before.

I checked it with Sound Forge's spectrum analizer and with my desktop equalizer with spectrum analyzer built in too.

[Rhiannon]

I found old versions here:

http://www.papktop.com/tag/Poweramp

(I don't know if this site is a safe or not. Use it on your own risk.)

 

I experienced the bug in version 2.0.8 and 2.0.7 too. This is interesting, because my sound quality problems started since just 1-2 months before.

I checked it with Sound Forge's spectrum analizer and with my desktop equalizer with spectrum analyzer built in too.

Thank you for the link. I´ve downloaded an old version and it sounds like the Poweramp player should sound.