[romanrex]

Hello, I would like to know what what is best filter (short, fast, slow) and best setting (narrow, wide, normal) to use for iem with low impedance

Features of the XDP-300R. The audio stream on the DAC always arrives at a sampling frequency of a multiple of 48 kHz. Probably, the XDP-300R was designed as a customised smartphone. It differs from smartphones on Android by a good resampling algorithm.There are no specific distortions.

This conclusion from the graphs

In Sharp modes a very strange graph of the impulse envelope

Slow mode is not better

It is well seen that the impulse envelope is not symmetrical. This asymmetry is not similar to the typical variants with the names "Minimal" or "Short".

And the Short mode itself is "curve".

The aliasing charts show unnecessary distortion in the form of harmonics (16k, 17.8k, 20k Hz). They "wrapped" inside the audible range at high frequencies.

Sharp mode

Slow mode

Short mode

The aliasing and pulse graphs differ from each other in the digital filter of the DAC. (Sharp, Slow and Short). Thus, that resampling is produced at a close frequency to 44.1 kHz. This will be 48 kHz.

If we look at the graphs with 192 kHz resampling, then all the impulse characteristics hardly differ.

Upsampling Mode 192 kHz Slow

Upsampling Mode 192 kHz Sharp

Upsampling Mode 192 kHz Short

In general, we see the Linear Slow mode for SRC.

The main difference between resampling in 192 versus "supposedly without it" is the non-availability of distortions in the field of high frequencies (16k, 17.8k and 20k Hz).



In the settings there is the option Lock Range Adjust. Somewhere, it is described as a jitter setting. For jitter, this setting is not affected in fact, but affects the resemming algorithm.



In Wide modes, you can see not the best suppression of aliasing

in narrow modes it is the best.

By indirect evidence, than "narrow", the more resource-intensive and high-quality algorithm. At the maximum there are clicks.

Для оценки работы Lock Range Adjust был выбран режим Slow.

In addition, it can be seen that the spectrum "mirrors" is not a multiple of 44 kHz (the boundaries are marked with a dashed line). The mirror boundaries are multiples of 48 kHz, which indicates a different final sampling frequency.

Maybe this is a feature of a regular player? No. When using the foobar2000 player, we get a change in the impulse response when changing the filter modes. Impulse characteristics are similar to "curves".

Thus, the best option for the Pioneer XDP-300R, is a resampling of 192 kHz. In this mode, all the characteristics are quite normal.

 

[swesko]

Thank you Very much for the good explanation and recommendation. I only use it as a fun dap, my ibasso dx200 is my more serious dap.

 

[afico]

So the best would be : upsampling on and Slow and Narrow right?

 

[romanrex]

so i will have problems with Fiio f9 pro..sigh

Pro version was not tested. With Fiio f9 no Pro changes in frequency response are negligible.

Only delta with Fiio f9
Totla frequency response of Fiio f9

 

[romanrex]

So the best would be : upsampling on and Slow and Narrow right?

Slow was chosen to work with Lock Range Adjust without resampling. With resampling, Slow, Sharp and Short do not affect, because their function is performed by the resampling algorithm.

Narrow is best.

 

[afico]

@romanrex which is the best DAP you've measured so far?

 

[NickleCo]

I have the 300r but I noticed that at low 1 there's a faint hiss and thus I'm resorting to low 2 for all my iems, now my question is that is it safe for me to use low 2 on the daily. Sorry for sounding nooobish (which I am at amps...) I read that in the lowest gain settings im "chocking the amp" (is chocking a good thing or not?)

 

[LYuen]

I have the 300r but I noticed that at low 1 there's a faint hiss and thus I'm resorting to low 2 for all my iems, now my question is that is it safe for me to use low 2 on the daily. Sorry for sounding nooobish (which I am at amps...) I read that in the lowest gain settings im "chocking the amp" (is chocking a good thing or not?)

Are you using streaming apps?
If yes the hissing noise is pretty normal with sensitive IEMs
No harm to the gears, just annoys your ears

My suggestion is to play offline files with stock music player app, which has much lower noise level
Low 2 is safe, just that the sound signature is soft and less exciting (or less powerful)

 

[Lurk650]

From another DAP I had, the manufacturer said its actually better to use a higher volume number and a lower gain than a high gain and lower volume number. Which does make sense.

 

[LaRocK]

can the 300r use the sandisk 400gb micro sd card? reason i ask is that they're onsale at amazon and b&h today for $159.

/guy

Been using a sandisk 400GB in mine for several months now and it works flawlessly. It's even coped fine with multiple playlists imported from iTunes via iSyncr

 

[/guy]

Been using a sandisk 400GB in mine for several months now and it works flawlessly. It's even coped fine with multiple playlists imported from iTunes via iSyncr

thanks! i actually have an ak70mk2 and i've put the 400gb card in it and moved the 200gb card from it to the other slot on the 300r. i just wanted to know that i'd be able to use the 400gb card as a backup or substitute in the 300r if necessary.

tks to all who replied. glad i caught the sale. /guy

 

[NickleCo]

Are you using streaming apps?
If yes the hissing noise is pretty normal with sensitive IEMs
No harm to the gears, just annoys your ears

My suggestion is to play offline files with stock music player app, which has much lower noise level
Low 2 is safe, just that the sound signature is soft and less exciting (or less powerful)

Yep I use streaming apps, and thank you for replying! It made me realize that its the wireless connection that's making the noise

 

[Lurk650]

Yep I use streaming apps, and thank you for replying! It made me realize that its the wireless connection that's making the noise

My CA Lyra II would have background noise on Spotify but not the offline music apps (uapp/stock app). I never noticed it with my Meze though, have to test my N40's tonight.

 

[NickleCo]

My CA Lyra II would have background noise on Spotify but not the offline music apps (uapp/stock app). I never noticed it with my Meze though, have to test my N40's tonight.

In my case all my iems has that annoying hissing noise (CA nova, polaris and noble savanna).

 

[Lurk650]

In my case all my iems has that annoying hissing noise (CA nova, polaris and noble savanna).

Yeah I just sold off my Lyra II due to sibilance in vocals and lacking the midrange I prefer. I don't believe my CH9T had the hiss though. The N40 do require a higher volume than normal so I'm hoping they won't have it. If so it will be disappointing as I bought the 300R since it has streaming capabilities, I might as well revert back to a normal player with better battery life and listen to only offline music.

One thing I haven't tried is downloading songs from Spotify for Offline listening, wonder if that still has the hiss.

Never had Spotify hiss from my phone with any gear. I'm thinking maybe its the combo of sensitive IEMs and using balanced out (which apparently has a higher output impedance).