Filtering higher listenable frequencies or not?

[Decee1]

Hello out there

Currently i am building a Class A Headphone amplifier and i have a bit of a problem. I got young ears so i am really sensitive to higher frequency and i feel like sometimes when audio is not filtered aka having a nice and clean frequency response my ears are bleeding. Currently i managed to get the current respons

Is audio normally filtered around 16-20KHz or am i just using too high volume? I don't feel like the volume is too high myself which is why i'm confused. Headphones i'm using are Beyerdynamics DT990 32 OHM


---Update---

Apparently Spotify has a distortion problem so you should not use it at 100% volume...

 

[Conrad Hoffman]

'Phones are usually louder than you think. So many places to have a problem. Digital will be filtered by the nature of the beast. If it's low rate MP3, it might sound pretty awful; it does to me. Above 256 it's not so bad. IMO, the amp should be flat as a board because there's no reason why not. Somewhere ahead of that you can apply some correction, if needed. We'd have to know a lot more about the source and even what type of music you listen to. IMO, there's this belief that flat response sounds best, but it doesn't seem true in practice. When everything is right you shouldn't be bleeding and there shouldn't be listening fatigue even over a long session. It may take a bit of a downward tilt to achieve that.

 

[scottjoplin]

Headphones are for listening at very low volume, that is the whole point of them, not many people are aware of this, and you are young so the chances are you are listening too loud. Turn them down, give yourself time to adjust and see how it sounds

 

[Decee1]

Yeah they are, but the goal for me with the project is trying to amplify the audio signal with high impedance so it won't affect the frequency response so it sounds weird and it does indeed work and it does make it sound much better imo when listening to it

 

[Decee1]

Listening at low volume does also make the sound less filling in the sound, when turning it up it does sound better but getting too loud is just making it sound awful. Anyways let's stay at the topic please...

 

[adason]

Audio signal from FM tuner and CD player are filtered above 19-20 kHz, there should be no signal in ultrasound.
LP and good reel to reel are not.

However, its possible that you may have something oscillating in your headphone amplifier in ultrasound frequencies and you do not know about it, just sense it. Check it with oscilloscope if you have chance.

 

[Decee1]

When i am not playing any audio i cannot hear anything, it is just when listening at higher volume i can hear the audio makes a kind of peak which is not in the amplifier part, i wonder if it is because i am using spotify at 100% volume, a few times i turned down Spotify to around 80-90% and that solved it

----UPDATE----
Apperently it is... Spotify has a problem with it clipping at 100% volume... How embarrassing for a big company like Spotify..

 

[scottjoplin]

Is that really how the volume control on the site works? How are you connecting your headphones at the moment? The amp building is work in progress?

 

[Decee1]

If you Google "Spotify Distortion" you will get many results, apparently it is a common issue. Currently i am connecting the audio source though a USB Streamer to a PCM5102 module and then to the AMP itself, had a few people look the amp though and they are impressed by the design and also a few people have listened to it at full blast with the result they couldn't hear it clipping. So it has to be Spotify. :/

 

[joztom]

If you like to amplify audio signals inside all over declaring 20Hz-20 kHz, you will get about nothing in pure sinusoidal form. Every sinusoidal has implemented aliquots in triangle, saw or quadratic grass signals in it. You can imagine in 1 kHz tone with ten to hundred aliquots inside, you measure really 100kHz tone. If you once more close frequency with filters, yes, you will get frequencies, but nothing from real speech or music. Limited bandwidth is one of the biggest lie in audio dialogues. Imagine, you seat in auditorium, full of listeners and listen applause of ten thousand people, maybe the last are 200m from you. You can clear listen everybody in front of limited bandwidth your ears. This much more complicate to answer, why is this so. The fast amplifier with minimum 100V/microsec and 1MHz bandwidth are the law for good reproduction.

 

[adason]

If you like to amplify audio signals inside all over declaring 20Hz-20 kHz, you will get about nothing in pure sinusoidal form. Every sinusoidal has implemented aliquots in triangle, saw or quadratic grass signals in it. You can imagine in 1 kHz tone with ten to hundred aliquots inside, you measure really 100kHz tone. If you once more close frequency with filters, yes, you will get frequencies, but nothing from real speech or music. Limited bandwidth is one of the biggest lie in audio dialogues. Imagine, you seat in auditorium, full of listeners and listen applause of ten thousand people, maybe the last are 200m from you. You can clear listen everybody in front of limited bandwidth your ears. This much more complicate to answer, why is this so. The fast amplifier with minimum 100V/microsec and 1MHz bandwidth are the law for good reproduction.

what a load of BS!

 

[scottjoplin]

Every sinusoidal has implemented aliquots in triangle, saw or quadratic grass signals in it.

This bit makes a kind of sense if you turn it the other way round, ie, it is completely wrong

 

[joztom]

I have to apologize to all of you; I am old and also bad in English. In term of this I am not able to express all my knowledge and mileage after 45 years in this hobby. The best judge is anytime your own ears; never you hearing any suggestions from outside.