A few thoughts (and questions) after diking around with Dirac Stereo

[tineared]

I could not follow this thread because of the Milan Hi Fi show where a new player featuring Dirac Live has been shown:

Milano hi-fidelity 2013 autunno: index

 

And dare I ask what the name of that new player would be ?

 

(couldn't find it on the page...)

[tympathique]

Hi arjan

 

I can't recall making any claims about the hi-end status of your or anybody else's system so i don't see why you are bringing that up.

Regards, Arjan

 

I'm the one to blame about this "hi-end" confusion.

 

It was a mistake, but it's the only part of the post that I regret not to have developed enough. It was not the goal of the reply and I was more thinking of myself 3 years ago with my old system and from many experiences with my friend's evolving systems. However, I have specified that I was talking about MY equipment and MY difficulty with filters DR effects, not specific to DIRAC which I never tried but with all correction filters whatever their gender.

 

That said, it is a fact that there is a blurry line to be traced to establish comparisons between system sensibilities, based on personnal taste, acoustics, hardware characteristics, speakers type and positioning ect.... How can someone be able to refute this?

 

I still think that all systems will be affected by correction filter. Digital signal modification could not be without effects as an senior HST told me recently

"eventually you enter the analog world, and that’s where the headroom penalty will show up, in the form of clipping in the amplifier at the boosted frequency. Or of not there, in the speaker itself" This is just a quoted reply and just one aspect of the discussion.

 

I respect software developers, including DIRAC 's new approaches with mixes phases filtering. Filter for filter, it sounds very much like an improvement to me. We have the right for questions, trying to be honest doing so.

 

arjan said something that I shared and tried to support his effort.

 

regards

jacques

[flak]

 

Digital signal modification could not be without effects as an senior HST told me recently

"eventually you enter the analog world, and that’s where the headroom penalty will show up, in the form of clipping in the amplifier at the boosted frequency. Or of not there, in the speaker itself"

 

Hi Jaques,

 

you, and the senior HST that you are mentioning, are talking about aspects that are real and that certainly have to be taken into account.

(they are not news for Dirac Research either )

 

In order to clarify these aspects I'm quoting a few sentences from the new unreleased 1.0.4 manual:

 

"There is a possibility (as of version 1.0.4 of the DAP) to adjust the DSP Gain (headroom) applied to the signal before it is passed from the DAP to the selected Output device.

The purpose of the DSPGain is to reduce the level of the processed signal in order to avoid clipping at or before the DAC (Digital-to-Analog Converter).

 

This clipping would otherwise sometimes occur as a consequence of the processing that may increase the level range of the digital audio signal.

By adjusting the DSP Gain, you can choose between louder playback level with increased risk for clipping, and lower playback level with reduced risk for clipping.

 

When a digital signal exceeds the range of the digital-to-analog converter (DAC), then digital clipping occurs. Depending on the amount of clipping, and what information is lost in the clipping, different artifacts result but generally the clipped waveform causes non-linear distortion.

Digital audio sources, such as DVD or CD, are recorded with the DAC limitation in mind, so that the signal stays within the DAC range. However, any boosting of the digital signal increases the risk of clipping.

 

If digital clipping is detected in the Dirac Audio Processor (DAP), then the Clip indicator in the DAP Controller™ is lit for a short moment (the Clip indicator is only available in the Windows version of the DAP, not in the Mac OSX version).

 

In case of digital clipping reduce the playback volume in the media player (the input to the DAP) and compensate this by increasing the volume in the amplifier.

An alternative fix is to adjust the DSP Gain of the DAP"

 

mmm... after posting this I think that most forumers will be satisfied but for the fact that it has not been possible to feature the clip indicator in the Mac version.

In that case we will have to rely on hearing as we also most often do with power amplifiers that do not feature a clipping indicator either... :-( :-(

(I hope that they will anyhow be pleased by the addition of the new alternative gain control feature)

 

Ciao, Flavio

[jkenton]

Hi Jaques,

 

you, and the senior HST that you are mentioning, are talking about aspects that are real and that certainly have to be taken into account.

(they are not news for Dirac Research either )

 

In order to clarify these aspects I'm quoting a few sentences from the new unreleased 1.0.4 manual:

 

"There is a possibility (as of version 1.0.4 of the DAP) to adjust the DSP Gain (headroom) applied to the signal before it is passed from the DAP to the selected Output device.

The purpose of the DSPGain is to reduce the level of the processed signal in order to avoid clipping at or before the DAC (Digital-to-Analog Converter).

 

This clipping would otherwise sometimes occur as a consequence of the processing that may increase the level range of the digital audio signal.

By adjusting the DSP Gain, you can choose between louder playback level with increased risk for clipping, and lower playback level with reduced risk for clipping.

 

When a digital signal exceeds the range of the digital-to-analog converter (DAC), then digital clipping occurs. Depending on the amount of clipping, and what information is lost in the clipping, different artifacts result but generally the clipped waveform causes non-linear distortion.

Digital audio sources, such as DVD or CD, are recorded with the DAC limitation in mind, so that the signal stays within the DAC range. However, any boosting of the digital signal increases the risk of clipping.

 

If digital clipping is detected in the Dirac Audio Processor (DAP), then the Clip indicator in the DAP Controller™ is lit for a short moment (the Clip indicator is only available in the Windows version of the DAP, not in the Mac OSX version).

 

In case of digital clipping reduce the playback volume in the media player (the input to the DAP) and compensate this by increasing the volume in the amplifier.

An alternative fix is to adjust the DSP Gain of the DAP"

 

mmm... after posting this I think that most forumers will be satisfied but for the fact that it has not been possible to feature the clip indicator in the Mac version.

In that case we will have to rely on hearing as we also most often do with power amplifiers that do not feature a clipping indicator either... :-( :-(

(I hope that they will anyhow be pleased by the addition of the new alternative gain control feature)

 

Ciao, Flavio

 

Mainly with non-classical music. When I play at higher volume levels I hear clipping. This corresponds to Amarra meters going into red zone. I would like to download version 1.0.4 of DAP in order to adjust DSP gain to see if it corrects problem. Changing gains in the user selectable filters I created makes no difference.

Cheers

[flak]

Mainly with non-classical music. When I play at higher volume levels I hear clipping. This corresponds to Amarra meters going into red zone. I would like to download version 1.0.4 of DAP in order to adjust DSP gain to see if it corrects problem. Changing gains in the user selectable filters I created makes no difference.

Cheers

 

Hi Jkenton,

 

sure, but you should send me a PM letting me know if you use a Mac or a PC, a Stereo or a Full version, a Trial or a Paid license... I'll let you have the new manual also with additional instructions

 

Ciao, Flavio

[arjan2856]

Hi Flavio,

 

Thanks for letting me try the new 1.04 version. This morning i've tried the new DAP compared to playing direct via Audirvana+ and Jriver MC19. By setting the DSP gain to 0dB the sound is quality is closer to playing direct via the other players so the volume reduction was definitely part of the issue. Can you share some information about what kind of volume control is used by DAP, is it a Dithered volume reduction? From the dithered volume controls i've heard i think the iZotope MBIT+ dither used by Audirvana+ is the least decremental.

 

Still playing direct via both Audirvana and Jriver sounds a little more open, more detailed and more dynamic then playing through the DAP without any filter or volume reduction selected. So there is still some room for improvement there on the MAC platform compared to these players. So a VST or AU plugin would still be a nice option i think if this is technically possible.

 

This afternoon i will do a full new measurement of my room and use the volume reduction within Audirvana and see how i like the overall sound with room correction filter in place and will compare with the Amarra symphony iRC as i think Amarra should probably sound closer to the performance of Audirvana then the DAP.

 

You mentioned the introduction of a new player using the Dirac technology, any information which player this is? Is it a software or hardware player?

 

Regards, Arjan

[flak]

Hi Arjan,

 

let me express my point of view which is strictly personal and does not necessarily reflect Dirac Research's opinion.

 

I'm personally using Foobar on a Pc so I cannot comment about sound quality differences between different Mac players like Audirvana and Amarra, even less about differences between Audirvana 1.5.8 and Audirvana 1.5.9, and if possible even much less when the differences are the ones between two different options of Direct modes as available in the same Audirvana 1.5.9 fractional release...

but there seems to be a never ending room for improvement.

 

So let's take for good that players can sound better every other day... still I think it's undeniable that, no matter if you will use Amarra with iRC or Audirvana (or Jriver) with Dirac Live, you will anyhow have a much larger improvement over your present situation both in the frequency response, and in the almost always overlooked impulse response, as I see them in your graphs:

 

 

 

Finally there could be some other aspects to take into account when you talk about dynamic range and best possible sound quality, i.e. in your case you are using a high quality 80 watts per channel Naim amplifier and 88dB for 2.83Vrms sensitivity Naim speakers.

 

It's a perfect match but you may incur into a short blanket situation... if you wanna reproduce a recording with a wide dynamic range (i.e. you may find some with 60 dBs) at let's say 5 dBs over ambient noise, which can even reach 50 dBs, you can see that the system may not be able to play the peaks without sometimes clipping (which is often perceived as slightly harsh, edgy and compressed sound because it only happens for milliseconds)

Now I'm mentioning a short blanket because there is a way out... reducing the volume,

but in this case you will hide the "pianissimos" under the noise carpet reducing the dynamic range.

 

In conclusion I personally think that if you are looking for real improvements you could benefit more from a state of the art digital room correction (and eventually from more power if you have a high ambient noise) than from any player.

 

In my biased opinion of course

Flavio

[arjan2856]

Hi Flavio,

 

Thanks for your point of view, all very valid points. Of course i will take the overall benefit of the Dirac package into consideration and not only base it on the performance of the Dirac Audio Processor. I was merely giving some feedback about the relative performance of the DAP compared to other OSX players on my system and i've seen the same being noticed by others as well on different forums. Maybe it's as well my curiosity about why there is such a difference between software players, when i started a year ago with computer based audio i laughed at stories that different software can sound different as i was convinced that as long as all the bits arrive at the DAC it should not matter. I still cannot get my head around why different players that all claim to transmit bit perfect output sound different on my Naim Dac that completely buffers and re-clocks the incoming data. Yet is does and Audirvana definitely stands out compared to others i've tried, and we're really not talking about subtle changes.

 

Maybe my description about the difference in sound quality is not accurately called dynamic range. Maybe transients or leading edge definition and detail is more appropriate. In Audirvana the keystroke of a piano has more body, the plucking of a guitar string is more noticeable, voices are more detailed. DAP sounds more flat in comparison. I'm pretty sure i don't play near loud enough that clipping is a factor here, my Naim amp can handle 400VA transient power and dynamics is one of Naim's key qualities. Maybe Audirvana is not playing fair and they are doing signal processing as well to create a sound that makes their player stand out. According to the developer it only has to do with optimising the audio path what ever that means.

 

Any way i take your overall point of view into account and listen for a few days to Dirac and see if the improved bass response in the room makes up for a bit of loss in detail that i hear. I will also listen to the Amarra implementation of the Dirac filter and see which one i prefer.

 

Thanks for all your replies, it's much appreciated!

Regards, Arjan

[tineared]

For the curious, here are two overlaid measurements. The dark one is from a denon calibration puck (DMS-305), the light one is from a UMIK with calibration file. The filter (and correction) from the UMIK measurements is better, especially in the highs.

 

So, word of advice to everyone else : listen to what Flavio says, and make sure you've got a calibrated mic before you download the trial.

 

[supra]

I also think the Dirac "processor" cuts dynamics, in truth I think it's rubbish. I heard some genuine improvements in sound but at too high a price in terms of overall sound quality.

But recognizing that there was something good in there I tried Amarra Symphony with Dirac's IRC.

This doesn't use Dirac processor, and is in a different league, i think it is a quantam shift in computer audio, it is so good.

If you want the ultimate in speaker/room "correction" (wrong word, but will do) you have to bite the bullet and get Symphony.

[flak]

..... I tried Amarra Symphony with Dirac's IRC.

This doesn't use Dirac processor, and is in a different league, i think it is a quantam shift in computer audio, it is so good.

If you want the ultimate in speaker/room "correction" (wrong word, but will do) you have to bite the bullet and get Symphony.

 

Well... I'm quite glad to read that you have found Amarra iRC a quantum shift in computer audio and that it is the ultimate in speaker/room correction

Only you should be aware that if you listen to the same file with Amarra iRC, or Amarra with Dirac Live, you are practically listening to the same thing as the DSP code itself is the same as the DAP and it has been written by us at Dirac.

 

Now which could be the reason for a difference you have found?

It could be that Amarra iRC features a DSP gain control that was not still available in Dirac Live and it is probably especially useful in your setup.

Dirac Live with DSP gain control (version 1.0.4) will be released pretty soon and I'm pleased to make the beta available now to all forumers who are testing Dirac Live.

Please send me a PM with your email letting me know if you are using a Mac or a PC.

 

Ciao, Flavio

[Nusa]

Well... I'm quite glad to read that you have found Amarra iRC a quantum shift in computer audio and that it is the ultimate in speaker/room correction

Only you should be aware that if you listen to the same file with Amarra iRC, or Amarra with Dirac Live, you are practically listening to the same thing as the DSP code itself is the same as the DAP and it has been written by us at Dirac.

 

Now which could be the reason for a difference you have found?

It could be that Amarra iRC features a DSP gain control that was not still available in Dirac Live and it is probably especially useful in your setup.

Dirac Live with DSP gain control (version 1.0.4) will be released pretty soon and I'm pleased to make the beta available now to all forumers who are testing Dirac Live.

Please send me a PM with your email letting me know if you are using a Mac or a PC.

 

Ciao, Flavio

 

BTW Flavio, I happen to have both Amarra+iRC and Dirac Live as I have benefitted from the cross-grade discount offered recently.

I’ve obviously tested one against the other in playing along with Amarra, and couldn’t find any noticeable difference in SQ between them. However, one thing got my attention; with Dirac Live the sound level is much lower than with iRC, even if my iRC DSP gain control is set to -5db. As a matter of fact, when in iRC the DSP level control is set to 0db, the sound is as loud as when iRC is off. With Dirac Live, as soon as it is on, with or without a corrective curve loaded, the sound level is lower than without Dirac. Why such a different behaviour? Many thanks and keep up with the good work!

[flak]

Dear Nusa,

 

up to version 1.0.3 of Dirac Live the DSP Gain of the audio processor has been -8dB, so the Dirac audio processor sounds lower in level when compared to iRC.

From v 1.0.4, the DSP Gain is settable in the audio processor, allowing up to -0dB.

The beta as you know is out now and we expect to release 1.0.4 within the coming weeks.

 

Thanks for your interest :-)

Flavio

[arjan2856]

I also think the Dirac "processor" cuts dynamics, in truth I think it's rubbish. I heard some genuine improvements in sound but at too high a price in terms of overall sound quality.

But recognizing that there was something good in there I tried Amarra Symphony with Dirac's IRC.

This doesn't use Dirac processor, and is in a different league, i think it is a quantam shift in computer audio, it is so good.

If you want the ultimate in speaker/room "correction" (wrong word, but will do) you have to bite the bullet and get Symphony.

 

I've compared as well last week the difference between Amarra iRC and Amarra Dirac and find as well that the Amarra implementation sounds a lot better. The Dirac audio processor still makes the sound 'flat' on my system while Amarra maintains the original sound quality far better. I guess in Amarra iRC the Dirac filter is used as a DSP plugin while Amarra it self deals with the sound output where in my opinion a lot of difference can be made as it shows between different software players. The Dirac audio processor on the MAC is just behind what other players can do by now. I like of course that with Dirac i can use the correction filter for different sources but right now the sound quality is still too far behind Amarra iRC.

[Nusa]

Dear Nusa,

 

up to version 1.0.3 of Dirac Live the DSP Gain of the audio processor has been -8dB, so the Dirac audio processor sounds lower in level when compared to iRC.

From v 1.0.4, the DSP Gain is settable in the audio processor, allowing up to -0dB.

The beta as you know is out now and we expect to release 1.0.4 within the coming weeks.

 

Thanks for your interest :-)

Flavio

 

Thanks Flavio! I now understand!

Dare I ask you for something else?

 

Yesterday I've tried something just to get a rough idea if my favourite curve is really correcting the way it should. You know how we say here: fidarsi è bene non fidarsi….

 

For that I've opened the Dirac audio processor and loaded on the first slot with my favourite curve. Then, I've opened the Dirac Calibration tool and in the panel "Sound System" instead of selecting the XMOS of my DAC, I've selected "Dirac audio processor". Once this is done, theoretically, Dirac measurements should be done through the corrective curve and I should have a reading very close to the target curve. Shouldn't I?

And indeed, when performing the "Test" inside "Output and Levels", it is clear that the pink/white noise the test is generating is "corrected" (I can tell, since toggling on and off Dirac audio processor would change the sound).

But when performing the measurements (only sweet spot, just to have a quick look) I get a curve similar to the uncorrected one! Boh, Perché?

 

By the way, in doing all the process described, when performing the "test" and when generating the impulses for measurements, there is also quite a lot of background noise associated with it, but does not seems to affect greatly the measurements… after all it is just to get an idea.

Could you (or somebody else) please tell me why my assumptions are proven to be wrong?

[flak]

Hi Nusa,

the week-end is coming but I've been just in time to get an answer from Nilo as follows:

 

"The Filter will be switched off if trying to measure through DAP (This should by the way not be allowed by the software, so it's a bug; thanks!). This is to avoid mistakes when designing filters, because you will only be able to apply one filter"

 

Ciao, Flavio

[Nightmare]

Unfortunately another ´sudden death´ of an interesting discussion not having further feedbacks of those who had issues with earlier versions of Dirac Live Room Correction Suite. So what´s about your review findings with the 1.0.4? Still ´dynamik´ problems or missing sound quality? Will test the 1.0.4 soon, also. Just got my XTZ micro for the trial. Curious how it works and if I will hear differences comparing it to Amarra Symphony iRC as well.