Jump to content
IGNORED

HQPlayer Convolution Questions


Recommended Posts

1 hour ago, dm68 said:

Thanks @Miska. One other question, I am using an NAA but could not work out how to include it while taking the measurments with REW so ended up plugging my DAC into the control PC. Does this change in signal path make much difference to the measurements and if so is there a way to route REW test signals through HQPlayer in order to keep the NAA in the signal path?

 

It doesn't change the result in a way that would matter. For my measurements I just use Toslink cable from the measurement computer to the DAC and use a measurement microphone. The only case where this could matter is if you use rePhase or Acourate or similar that does also phase corrections AND the DAC is using minimum-phase filter.

 

You should always try to make sure you are using linear phase digital filter when doing room correction measurements.

 

Signalyst - Developer of HQPlayer

Pulse & Fidelity - Software Defined Amplifiers

Link to post
Share on other sites
2 hours ago, Miska said:

For example direct conversion from DSD64 to DSD256 with volume

In this specific case you are listing, the "volume" implies DSD64 is converted to PCM (volume DSP applied) then that PCM to DSD256 correct? the word "DIRECT" to me means usually "no PCM" but it was my understanding volume and DSP must be done under PCM.

 

EDIT01: And of course this comment you posted

"PCM engine for PCM outputs and SDM engine for SDM outputs. Both have all the same DSP functionality"

kind of tells me the SDM engine has "no PCM" at all so even convolution and DSP are done under SDM "direct"

Link to post
Share on other sites
3 minutes ago, luisma said:

In this specific case you are listing, the "volume" implies DSD64 is converted to PCM (volume DSP applied) then that PCM to DSD256 correct?

 

No, it is 2.8M -> 11.2M with specified gain.

 

Signalyst - Developer of HQPlayer

Pulse & Fidelity - Software Defined Amplifiers

Link to post
Share on other sites
53 minutes ago, Miska said:

 

It doesn't change the result in a way that would matter. For my measurements I just use Toslink cable from the measurement computer to the DAC and use a measurement microphone. The only case where this could matter is if you use rePhase or Acourate or similar that does also phase corrections AND the DAC is using minimum-phase filter.

 

You should always try to make sure you are using linear phase digital filter when doing room correction measurements.

 

Hi Miska, Focus Fidelity does do phase corrections. So referrring back to my previous question is it at all possible to carry out measurements with REW via HQPlayer and the NAA and keep the signal path the same as during music playback.

Link to post
Share on other sites
4 minutes ago, dm68 said:

Hi Miska, Focus Fidelity does do phase corrections. So referrring back to my previous question is it at all possible to carry out measurements with REW via HQPlayer and the NAA and keep the signal path the same as during music playback.

 

I think you could export the test signal, play & record it and then import it afterwards. But I don't think it is usually worth the effort if you know/can choose the DAC's digital filters.

 

Signalyst - Developer of HQPlayer

Pulse & Fidelity - Software Defined Amplifiers

Link to post
Share on other sites
15 minutes ago, Miska said:

 

I think you could export the test signal, play & record it and then import it afterwards. But I don't think it is usually worth the effort if you know/can choose the DAC's digital filters.

 

OK many thanks.

Link to post
Share on other sites

Note that I've got accidentally "funny" results from phase corrections because the ADC used for microphone was using a minimum phase filter. So also pay attention into what kind of gear is used for the microphone side.

 

Signalyst - Developer of HQPlayer

Pulse & Fidelity - Software Defined Amplifiers

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×
×
  • Create New...