Related to this I did a little experiment with some cheap headphones I bought recently. The Thieaudio Ghost, I probably bought them the same time as
@solderdude as
Linsoul do sell them cheap whenever they have a sale on (typically for $49.99).
At the normal price they are not worth it but at $49.99 they are good for a project like this but I would agree with Solderdude review findings, that they have too much bass distortion at higher volumes so mostly only good for normal listening volumes (also see my measurements in a bit).
At the same time, I bought FiiO new usb-c dongle (with 5 band PEQ) the
JA11 from Aliexpress (for something like $9), my original idea was to 'permanently' fix the Frequency response of the Ghost with the JA11 cable so that when using the Ghost on my iPhone or with my MacBook Pro, i.e. always use the JA11 with the Ghost and not worry about different PEQ Applications.
Note: I have a KB501X soft ear pinna and a 711 clone coupler - which is good, in my opinion, for 'relative' measurements (I have measured a bunch of my other headphones already with this gear e.g. the HD600 which the Ghost was being compared with originally) so comparing different headphones that I have measured with the Ghost is a reasonable exercise (and certainly a fun exercise).
But then I didn't like the comfort and general flexibility of the Ghost so I thought sure buy some more comfortable earpads, I had a few already but since I was going to measure and hopefully fix the FR using the JA11, that I would try some 'deep foam' earpads (and keeping inline with my doing this on the cheap i.e. < $10 ) - again I decided to buy from Aliexpress specifically this
largest 120mm x 100mm here ).
FYI: This is what they look like on the Ghost:
I understood it would change the frequency response but I was probably not prepared for how much it would change with these pads.
So, onto my measurements.
First - here is a comparison of the Stock earpads on the Ghost compared to my HD600:
So I can see how it was mentioned as a HD600 competitor as far as the bass FR but the upper midrange and treble are far away from the Harman Target curve.
Here is the distortion I was getting with the stock pads, so some bass distortion even at relatively normal listening volumes:
So, I thought 'fixing' the Bass to Harman with the stock pads would actually only cause more distortion.
Now with the Aliexpress 'deep plush' earpads I got the following change to FR:
Obviously, both the bass and treble have change significantly for the worse but given I would be 'fixing' this with the PEQ on the JA11 I wasn't too concerned.
One funny thing I noticed this change made the FR similar in some respects to the Eris (i.e Zeos Pantera's new collab with Harmonicdyne) - which has similar deep ( though I imagine much higher quality ) earpads:
Though the Ghost with these Aliexpress earpads is arguable easier to EQ.
So, now with the JA11 - you can apply 5 PEQ filters using either their FiiO Android Application or using their website
https://fiiocontrol.fiio.com (only on a Chrome based browser like Chrome, Chromium, Arc, Edge etc).
So I came up with the following simple filters - actually just 4 of them so I have some wiggle room in the treble:
Then remeasuring the Ghost + new Earpads + JA11 with PEQ:
So the reason I left one of the PEQ filters was to remove that 13K/14K peak but since this area is badly measured on these KB501x - I think that area should be done manually to preference.
Then finally I thought he distortion measurements with these changes were slightly more promising i.e. playing 'harman OE' bass at 86dB (rather than 80dB for the roughly the same distortion with the original pads):
Obviously still not perfect but good enough for me to decide this fun exercise was a success, e.g. for roughly $70 I have a reasonable well tuned and now very comfortable headphone.
Here are some more pictures.
The new earpads compared to the originals:
And finally with the JA11 attached:
Anyway, I hope people found this interesting.
