Marc

DEQX Owners Thread

598 posts in this topic

25 minutes ago, Sir Sanders Zingmore said:

 

I just reckon as more and more people have more and more music on DSD, they may well want it to stay in DSD all though the signal path. 

 

Whether or not that is any better than converting to PCM for convolution is almost irrelevant 

 

 

 

Until you need to implement an IIR filter or do a simple volume control on the raw data then it becomes impractical.

 

cheers

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1 hour ago, aab said:

 

Oh I see what you mean. Why do you think it can do convolution natively in DSD? I have only looked at this page http://www.signalyst.com/consumer.html and it does not seem to claim that. It mentions this:

"Selectable convolution algorithm (FIR) for equalization, such as digital room correction (2 options), for PCM/DSD content"

 

 

I asked the author of HQPlayer this very question on another forum. I can't find the post right now, but his answer was: HQPlayer performs DSD convolution natively, in DSD, with no conversion to PCM at all. 

 

Davewantsmoore made a point earlier about the high processing power required for native DSD convolution. He is right. I have an intel i7-6700K. If I convolve 8 channels in PCM 192kHz, it uses 5% CPU. If I convolve 8 channels in DSD256 (quad DSD), it uses 80% CPU. And this is with native FLAC 44.1kHz files. If I attempted to play a single DSD recording (DSD64), then CPU usage goes above 100% and the file plays, but stutters like mad. In short, you need even more computing power than my i7-6700K, which is already an order of magnitude more computing power than found in a DEQX. 

 

For the DEQX to support DSD convolution, they would therefore need (1) to increase the computing power in the unit, and (2) to rewrite their software to perform native DSD convolution. It ain't going to happen. 

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I wonder if anyone has tried to istall the Roon version of the DEQX software. Everything was fine until the very last point: when i tried to play to the DEQX on my MacBook pro, Roon gave the message: "Transport: Failed to open the device"
 
It is frustrating because I can see the track information on the screen of the DEQX! Is this something to do with using a mac? 

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48 minutes ago, ArhurS said:
I wonder if anyone has tried to istall the Roon version of the DEQX software. Everything was fine until the very last point: when i tried to play to the DEQX on my MacBook pro, Roon gave the message: "Transport: Failed to open the device"
 
It is frustrating because I can see the track information on the screen of the DEQX! Is this something to do with using a mac? 

 

Get onto DEQX. I am sure they will point you in the right direction.

My HDP-5 is currently en-route from DEQX with the latest firmware + Roon implemented. Looking forward to giving it a go!

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44 minutes ago, Marc said:

 

Get onto DEQX. I am sure they will point you in the right direction.

My HDP-5 is currently en-route from DEQX with the latest firmware + Roon implemented. Looking forward to giving it a go!

 

 

thanks Marc, will do.

 

By the way the new software sounds great! A noticeable improvement.

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Arthur, their customer support is second to none. Best I have experienced.

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Can we please try and stay on topic in relation to a DEQX owners thread. :)

Starting to head in another direction now that may warrant its own thread perhaps?

 

EDIT: DSD/PCM Conversion Discussion Split to:

 

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By the way I never recieved a response from DEQX or Roon re why the Roon version of the DEQX software is not working. 

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5 hours ago, ArhurS said:

What do you think of this:

 

http://www.digitalaudioreview.net/2017/01/between-ad-and-da-the-power-of-pragmatism/

 

i was told that it was pointless to have a high quality DAC before a DEQX but this writer suggests otherwise.  Would that apply to HQPlayer as well? 

 

I think the major point Mr. Darko was making was that AD/DA situations are essentially transparent and hardly the boggeyman that they are often made out to be.  If one has several AD/DA processes in the chain and those processes are well engineered then it probably doesn't matter in which order they are done.  Insert a crook AD/DA, then that is what you get; the old weakest link in the chain scenario.

 

A friend had his PS-Audio Directstream DAC in front of his DEQX and was very happy with that configuration.  I thought about trying it but there are insufficient digital inputs on the PSA (and of the wrong type) for my digital sources, and source selection would be split across 2 boxes, so it would only have been an experiment.  In which case, I haven't ever bothered. The way my system is configured there is only one DA step and the 'control'  is all in the DEQX, so that works quite well.  Other family members can operate the system when it is relatively simple like that.

 

Sorry, don't know anything about a Roon implementation nor HQPlayer.  I have seen Roon running on Alan's Mac but it was not 'connected' to a DEQX box.  As far as I know "Roon endpoint" is still in development since there has been no official announcement that I have heard.  Moot point, I think, for me since I have a HDP4 [I suspect Roon can only work on a HDP5 'cos it should need an ethernet port??].  They will release it in time.  I much prefer a release of a tested, reliable and stable product than the incremental bug fix approach that we have seen from PSA and their Directstream DAC firmware.

 

Regarding digital manipulation of the PCM before it gets to the DEQX (eg. sample rate changes in the source device etc.) , I have noticed no difference at all if my MSB memory spinner upsamples or not.  If HQPlayer (however it works, and whatever it does) brings something to the table then it's worth a try.  One never knows.

 

 

 

 

 

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Aechmea, many thanks for a beautifully written response.

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I have just purchased some horn speakers. I assume that I can measure them for DEQX just like any other speakers?

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I have just purchased some horn speakers. I assume that I can measure them for DEQX just like any other speakers?

Dont worry about the DEQX just yet. We need to know more about these horn speakers. We will also need photos!

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What do you think of this:
 
http://www.digitalaudioreview.net/2017/01/between-ad-and-da-the-power-of-pragmatism/
 
i was told that it was pointless to have a high quality DAC before a DEQX but this writer suggests otherwise.  Would that apply to HQPlayer as well? 

I got told that too, in fact that was what stalled my purchasing one.

Sent from my SM-T113 using Tapatalk

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If you are using HQPlayer you can mimic most of the dsp/convolution and crossover functions of deqx using other software. For multichannel you still need capabe dac/s. Roon also hasthis functionality now as well.

The advantage of the software based solutions being you can use whatever dac and pre you choose and also whatever sample rate, now including dsd1024!. Having said that deqx can be simpler and is an all in one solution.

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On 5/16/2017 at 3:42 PM, ArhurS said:

I have just purchased some horn speakers. I assume that I can measure them for DEQX just like any other speakers?

you can measure horn speakers the same as any other speaker with DEQX and create a "speaker correction" filter to apply to the speaker/driver.

 

That said, the "speaker correction" is only as good as the speaker measurement.

If reflections are present in the speaker/driver measurement (and at low frequencies they always are) you need to decide if want to include these reflections in the "correction" filter applied by DEQX.

 

DEQX and other similar products, have the ability to "window out" the first and subsequent reflections in the measurement, but you lose detail (specifically low frequency information) depending on the window length.

This is why speaker manufacturers pay lots of money to test speakers in anechoic chambers, and speaker DIYers measure speakers outdoors, and preferably waaay off the ground - to maximise the time difference between the direct sound hitting the mike, and the first reflection hitting the mike (you "window" just prior to the 1st reflection to ignore the data from the 1st reflection and beyond) .

 

Horn speakers may require the mike further away for a proper measurement - and "close miked in room" measurements may not work well - depending on the horn setup.

 

This is not a limitation of DEQX, but a limitation of capturing a speakers' response without reflections.

To get "reflection free" measurements with data below about 500Hz or so requires a serious outdoor measurement rig (no boundaries for a long way, including the ground).

 

cheers

Mike

 

PS I run PSE144 horns and DEQX and changed my amp setup to leverage measurements of the PSE144 done on a better measurement rig than I could ever replicate

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thanks Mike for a great response. Approximately how far away would you recommend for the measurement? My speakers are Volti Rivals.

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1 hour ago, ArhurS said:

thanks Mike for a great response. Approximately how far away would you recommend for the measurement? My speakers are Volti Rivals.

 

Does the DEQX procedure provide guidance on this?     I'd be very surprised if the answer is not yes.

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On 5/18/2017 at 6:11 PM, davewantsmoore said:

 

Does the DEQX procedure provide guidance on this?     I'd be very surprised if the answer is not yes.

The DEQX doco does provide this info - examples below

 

"The microphone should be mounted about 3 feet (or 1 metre) from the speaker and lined up with the tweeter axis. Best results will be obtained if you use a microphone stand with a boom to support the microphone.
If larger speakers are used it may be necessary to mount the microphone further from the speaker, in order to reduce the angle between the drivers and the microphone (and any associated off-axis effects). However, moving the microphone further from the speaker will potentially increase measured room effects and /or reduce the period of the measurement before the first room reflection, hence the reason for the suggested distance of 3 feet."

 

and 

 

"Better results may be obtained by measuring the speaker outside, provided that a quiet location is used. One method, particularly useful for large speakers, is to rest the speaker on the ground, pointing up at a 45 degree angle. The microphone should still be lined up with the speaker's driver axis, i.e. it will be pointing down at the speaker at a 45 degree angle. When measured with this method, the speaker measurement can be similar to that obtainable in an anechoic chamber."

 

and the DEQX Technical Support Advisory Paper on "Dealing with speaker measurement reflections" and a similar paper on "Calibration Hints".

 

DEQX doesn't provide measurement guidelines for specific speakers - too hard

 

On 5/18/2017 at 5:04 PM, ArhurS said:

thanks Mike for a great response. Approximately how far away would you recommend for the measurement? My speakers are Volti Rivals.

You could regard the Volti's as a "large" speaker and use the DEQX guidance accordingly.

 

In some cases I choose to ignore DEQX' advice, and do an "in room close miked" measurement (like 10mm from the driver) on my 18's (which are way too heavy and unsafe to get off the ground far enough to provide a useful measurement down low), do a DEQX speaker correction based on the close miked measurement, then do a DEQX room correction to fix room response (or just measure room response and apply my own EQ).

 

Mike

 

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12 hours ago, almikel said:

DEQX doesn't provide measurement guidelines for specific speakers - too hard

 

No I didn't expect specific. .... more just the guidance in general  (eg. whether they say, it MUST be a certain distance ... or whether you can do what ever you want as long as it is more than X from boundaries, etc.)

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I just read the review of the Volti Rivals in Stereophile magazine and they measured the horn midrange arriving at the microphone 0.55 milliseconds after the woofer and 0.75 milliseconds after the tweeter. So Mike is right, looks like I will need to have the microphone much further away- maybe 2 m. For my current ATC drivers I have the microphone about 60 cm away.

 

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@ArhurS

 

although (IMHO) better implemented actively, DEQX can correct timing errors like that even with the passive crossovers remaining in place

 

Mike

Edited by almikel
added ArthurS

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