Happy Posted June 30, 2016 Posted June 30, 2016 @@Keith_W thanks you learn something new everyday i guess. ive long thought the general position was that you deal with the room bass thing with DSP/EQ but not the above frequencies.
Keith_W Posted June 30, 2016 Author Posted June 30, 2016 Thanks for sharing, enjoying following your journey. Computer audio / hqp / accourate always seems a pita to get right. Then everyone seems to have trouble with drivers and pairing with dacs. Hope you get it sorted. Interesting the poster blizzard on that link who inspired this appears to be banned on that forum. Well that forum has recently gone through a bit of a "cleansing". They have booted out all the objectivists and everyone left are subjectivists to some degree. More or less what I was warning would happen on SNA years ago when I was a moderator. The objectivists have started their own forum. Result is - neither forum are particularly nice places to hang out. In one forum, everyone is demanding double blind tests for everything. In the other, they are talking about magic fuses. It's a real pity, because Whats Best Forum rose from the ashes of Audiogon (when Audiogon went to the dogs after it was sold to a new owner), and Audiogon was a nice place to hang out. There were some pretty smart people on Audiogon, including the designers for Ayre and Atma-sphere.
Keith_W Posted June 30, 2016 Author Posted June 30, 2016 @@Keith_W thanks you learn something new everyday i guess. ive long thought the general position was that you deal with the room bass thing with DSP/EQ but not the above frequencies. Well, for bass frequencies you chop the peaks and attempt to deal with the dips by moving the sub. There is plenty to learn, and I have a looong way to go. I recommend reading this as a good place to start: https://www.amazon.com/Accurate-Sound-Reproduction-Using-DSP-ebook/dp/B01FURPS40#navbar It is heavily focused on Acourate, and it runs through the features of Acourate pretty extensively. The author has a pro audio background and spent a lot of time designing studio listening rooms. He knows what he is talking about.
Happy Posted June 30, 2016 Posted June 30, 2016 Well, for bass frequencies you chop the peaks and attempt to deal with the dips by moving the sub. There is plenty to learn, and I have a looong way to go. I recommend reading this as a good place to start: https://www.amazon.com/Accurate-Sound-Reproduction-Using-DSP-ebook/dp/B01FURPS40#navbar It is heavily focused on Acourate, and it runs through the features of Acourate pretty extensively. The author has a pro audio background and spent a lot of time designing studio listening rooms. He knows what he is talking about. aw pls dont make my system even more complicated! so bass frequencies DSP is actually a big no-no eh? thought many ppl like DSP when it comes to bass management but not the upper frequencies. need to play with my DDRC again this wkend...
Volunteer sir sanders zingmore Posted June 30, 2016 Volunteer Posted June 30, 2016 aw pls dont make my system even more complicated! so bass frequencies DSP is actually a big no-no eh? thought many ppl like DSP when it comes to bass management but not the upper frequencies. need to play with my DDRC again this wkend... To be clear DSP is a no-no if you are trying to fill a null. It's perfectly fine to use it to reduce a peak
Happy Posted June 30, 2016 Posted June 30, 2016 To be clear DSP is a no-no if you are trying to fill a null. It's perfectly fine to use it to reduce a peak so if we have bass peaks on the graph it's ok to massage them with DSP? does this apply to higher frequencies too?
Volunteer sir sanders zingmore Posted June 30, 2016 Volunteer Posted June 30, 2016 so if we have bass peaks on the graph it's ok to massage them with DSP? does this apply to higher frequencies too? Yes to your first question. Conventional wisdom says 'no' to the second. I say try it and see 1
andyr Posted June 30, 2016 Posted June 30, 2016 I switched off the computer and fired up the CD player and preamp. Now I have complete silence. It's the PC power supply which is introducing noise into the system. Most puzzling. And I thought that my Cary monoblocks had a decent power supply which should be immune to interference like this. As I suggested to you in a recent PM, Keith, you could try a hash filter on your PC, to see if this stops this interference (which the SMPS in the PC is injecting back into the mains). Regards, Andy
Keith_W Posted June 30, 2016 Author Posted June 30, 2016 thought many ppl like DSP when it comes to bass management but not the upper frequencies. If you are going to use DSP, it should be applied to all frequencies. It's not just the frequency response you need to worry about. For a few years, I was running the DEQX for the bass and an analog active crossover for the top (see my first diagram). This corrected the frequency response nicely, but played havoc with time alignment. Remember, the Haas effect says that any sound arriving at your ears 20ms after the first signal is perceived as separate to the first signal. Using any form of DSP, especially DSP that requires analog to digital conversion, will introduce more latency into the signal - usually in the order of 15-20ms. Latency is not an issue if the entire signal from 20Hz - 20kHz goes through the DSP. However, it IS an issue if only part of the frequency response is going through DSP. As I suggested to you in a recent PM, Keith, you could try a hash filter on your PC, to see if this stops this interference (which the SMPS in the PC is injecting back into the mains). I had forgotten about this Andy, thanks for reminding me. Would I be able to borrow yours for a weekend? Ticks and pops, you may as well go back to vinyl. I might, one day. But I found I was too lazy to play my vinyl. I would have to sit on the floor just to look at my collection. And those labels ... on those thin jackets ... make it very hard to read. Yes, I still think vinyl sounds better. But digital is tolerable if you happen to own a very nice CD player For a couple of years, despite owning a turntable, I listened to digital alone. And I was quite happy listening to digital. So, I decided to give up the turntable ... for now. 1
andyr Posted June 30, 2016 Posted June 30, 2016 (edited) I had forgotten about this Andy, thanks for reminding me. Would I be able to borrow yours for a weekend? Sure, Keith. I can bring it over on Saturday, sometime, if you are going to be home. I'll send you another PM to sort out an appropriate time. If you are going to use DSP, it should be applied to all frequencies. It's not just the frequency response you need to worry about. For a few years, I was running the DEQX for the bass and an analog active crossover for the top (see my first diagram). This corrected the frequency response nicely, but played havoc with time alignment. Remember, the Haas effect says that any sound arriving at your ears 20ms after the first signal is perceived as separate to the first signal. Using any form of DSP, especially DSP that requires analog to digital conversion, will introduce more latency into the signal - usually in the order of 15-20ms. Latency is not an issue if the entire signal from 20Hz - 20kHz goes through the DSP. However, it IS an issue if only part of the frequency response is going through DSP. Very interesting! I am just about to move from the 3-way analogue active XO that I've been using for the last 15 years to a 4-way miniDSP active XO (/ room corrector! ). With my upcoming Paul Spencer subs, I needed to delay the Maggie bass panels to compensate for: a. the extra distance of the subs from my ears, and b. the delay introduced on the subs by the LP/HP XO between them and the bass panels. Given that, it seemed to be to be obvious to replace the Maggies' internal analogue active XO with the miniDSP unit! So I'm glad that I am heading down the right track. And I'm hoping that my SQ will be improved by the fact that the miniDSP unit will allow delays to be implemented on the bass panel- mid panel XO and the mid panel-ribbon XO ... something an analogue active XO cannot do. Regards, Andy Edited June 30, 2016 by andyr
Keith_W Posted June 30, 2016 Author Posted June 30, 2016 (edited) A friend came over last night and we did more listening tests in various different configurations. The outcome is pretty disappointing. Bear in mind that ALL the comparisons were done with the same DAC, with volume matching via an SPL meter. The only difference was the digital source! Files on the computer were ripped using Exact Audio Copy and stored in FLAC. This was compared against the original CD. 1. CD Player --> Preamp. Easily sounds the best. As I mentioned earlier, notes sound "whole". You can easily tell the start and stop of a note, whereas on the computer it sounds as if the edges are rounded off. When instruments are massed, it is easy to pick out individual instruments. The computer tends to smear them. 2. Computer optical drive --> HQPlayer with NO convolution --> USB --> DAC --> Preamp The purpose of this configuration is to test the adequacy of the optical drive on the PC to the CD player transport. No contest, CD Player wins hands down. So much for "bits is bits" and the marketing of Playback Designs which claims to "completely eliminate" jitter. 3. HQPlayer with Acourate convolved filters @44.1kHz --> USB --> DAC --> Preamp (Note, I have to use 44.1kHz because the DAC only accepts a maximum of 48kHz via USB input) Improves on the CD player in some ways - the system sounds more coherent, bass in particular is very good. However - notes are smeared, and in some passages I can hear some kind of digital noise. Hard to describe. Notes are smeared, and the tone sounds off and unnatural. I can accept that this is only my third attempt at using Acourate, and I may not have done the measurements or filters correctly. So let's remove the convolution and see what happens: 4. HQPlayer with NO convolution @ 44.1kHz --> USB --> DAC --> Preamp Sounds worse than HQPlayer with convolution! Some of the faults of the system are back (poor integration of bass, poor coherence). On top of that, digital noise is STILL there, notes are STILL smeared, and the tone still sounds off. Since I have an RME sound card, capable of 192kHz PCM output via AES/EBU, let's try this: 5. HQPlayer with Acourate convolved filters @44.1kHz --> AES/EBU --> DAC --> Preamp Note that this is exactly the same configuration as (3), the only difference is that I am using the RME card and outputting via AES/EBU. Surprisingly, this configuration drops the volume by about 3dB when compared to USB. I looked carefully at the RME driver and the manual of the DAC and could find no reason why the volume should drop. Anyway, the overall presentation seemed more "polite". Dynamics weren't quite as good - transients didn't have the same attack. And this was after level matching. Very disappointing considering the cost of the RME card - I would have hoped for better. But, since it is capable of passing through 192kHz PCM, let's try this: 6. HQPlayer with Acourate convolved filters @192kHz --> AES/EBU --> DAC --> Preamp By this stage we were getting a little tired, but we could hear very little difference between this configuration and (4). We have to go back and listen again. To round off the night, we went back to listening to the CD player direct. We both agreed that it is much superior to ANY of the computer configurations. CONCLUSIONS 1. CD Player is superior to the computer in any configuration. Not sure why, or whether this can be addressed by tweaking the computer more (e.g. linear power supply, etc). 2. HQPlayer with Acourate convolved filters sounds better than no convolution. Even my early attempts at generating filters with Acourate results in a better sounding system than without. 3. AES/EBU sounds worse than USB in my system with a 3dB volume drop. I am not sure why, might be a setting in the RME card. I will have to look closer. 4. Upsampling to 192kHz made relatively little difference compared to all the above. Further listening may reveal more differences. Edited June 30, 2016 by Keith_W 2
Happy Posted June 30, 2016 Posted June 30, 2016 Interesting. I guess at the level of your gear every little glitch matters. Not the first time I heard CDPs trounce computers. I love optical connection because it enables me overcome the ground loop and associated noises. BTW I've spent about an hour reconfiguring the XO settings and reapplied the Dirac Live with a view to maximise the horn output as opposed to bass bins. Love the outcome. Sent from my iPhone using Tapatalk
Keith_W Posted July 23, 2016 Author Posted July 23, 2016 I have spent quite a bit this month. In a few weeks, I will hopefully have: - my new Merging NADAC 8 channel DAC, - a pair of subwoofers - a linear PSU for the computer I will evaluate the changes and then decide what to do next. Hopefully this is the end of the road for upgrades. 3
joz Posted July 23, 2016 Posted July 23, 2016 I will evaluate the changes and then decide what to do next. Hopefully this is the end of the road for upgrades. LOL!!!!
andyr Posted July 23, 2016 Posted July 23, 2016 I had forgotten about this Andy, thanks for reminding me. Would I be able to borrow yours for a weekend? I have spent quite a bit this month. In a few weeks, I will hopefully have: . . . a linear PSU for the computer Are you still interested in seeing whether a hash filter between your computer and the wall socket, stops the 'clicks' you are getting when your mouse moves? Please PM me if so, so we can arrange a time. Regards, Andy
Keith_W Posted July 23, 2016 Author Posted July 23, 2016 Thanks Andy, I will get in touch with you to try out that hash filter. And Joz, you may LOL ... but I do change my equipment much slower than most people on SNA
Keith_W Posted July 24, 2016 Author Posted July 24, 2016 (edited) Yes, now that I think about it. In more than 20 years in this hobby, I have only ever owned: - 4 pairs of main speakers (each sold to fund upgrades) - five pairs of amps (3 of which I still own, and are in service) - 4 CD players (each sold to fund upgrades) - one preamp (still own) - two turntables (both sold) - one pair of subwoofers (another pair on the way) ... and I have never owned a standalone DAC. The NADAC will be my first one. I know people who have that much gear kicking about simultaneously in listening rooms smaller than mine! Edited July 24, 2016 by Keith_W 1
davewantsmoore Posted July 24, 2016 Posted July 24, 2016 4. Upsampling to 192kHz made relatively little difference compared to all the above. The only reason a difference could be expected, is in the situation where the DAC (or other processing) attains different levels of performance when fed different sampling rates. For example, most DACs use internal upsampling filters and will use different filters for each rate .... and in the extreme, use no filters for high input rates. As a dangerously gross generalisation, professional equipment is less likely to do this (attain different levels of performance given different input rates) 'clicks' you are getting when your mouse moves? Hmmm.... If there are audible noises caused by activity on the computer (something changing on the screen, or moving the mouse, etc.) .... then there is typically a problem with the drivers/configuration for the audio device. You should not hear these noises. They not normally caused or fixed by things like cables, or power conditioners, etc. 1
andyr Posted July 24, 2016 Posted July 24, 2016 (edited) Hmmm.... If there are audible noises caused by activity on the computer (something changing on the screen, or moving the mouse, etc.) .... then there is typically a problem with the drivers/configuration for the audio device. I certainly agree, dwm. It is not logical that moving a mouse on a computer should cause a noise through the speakers. So there may well be a configuration problem with Keith's computer. Whether he can find the right configuration setting to remove the noise ... is the $64,000 question! You should not hear these noises. I absolutely agree. But Keith has (heard the noise) - so the issue is ... how to stop the noise from happening? Given it should not be possible to hear a noise when a mouse moves ... this is where we have to move outside the boundaries of 'conventional' thinking. They not normally caused or fixed by things like cables, or power conditioners, etc. I would agree they would not be caused by cables or power conditioners ... but maybe they can be solved by such devices? My thinking is as follows: when Keith moves his mouse, he hears a noise through the speakers. there is no logical reason why he should be hearing this. the only way this noise can be happening is either: there is some RFI happening when he moves the mouse - and this is getting into the preamp or amp (via cables?). I suggest this is highly unlikely. or the mouse movement generates a pulse which is going back out through the PC's power cord, into the mains and so into the amp or preamp. the latter is also very 'left field' - but if it is happening, then a hash filter between the computer and the wall should stop the pulse from getting into the mains (and infecting his other components). Regards, Andy Edited July 24, 2016 by andyr
ENIGMA Posted July 24, 2016 Posted July 24, 2016 Hi Keith, Looks Like you need to get turntable No. 3 1
Super Mustud Posted July 24, 2016 Posted July 24, 2016 Very interesting, Keith. In a way surprised you are still on the journey. Thought you were pretty much set some time ago.
davewantsmoore Posted July 24, 2016 Posted July 24, 2016 (edited) It is not logical that moving a mouse on a computer should cause a noise through the speakers. I absolutely agree. But Keith has (heard the noise) - so the issue is ... how to stop the noise from happening? Given it should not be possible to hear a noise when a mouse moves ... this is where we have to move outside the boundaries of 'conventional' thinking. there is no logical reason why he should be hearing this. I didn't mean to imply the underlined parts. It is totally possible. It's actually not an uncommon problem. Having the wrong drivers installed. Having an IRQ or resource conflict between the interface the audio device uses, and some other thing in the computer. If you google, it there are many people suffering from the same issue (and much discussion of the troubleshooting and solutions). the only way this noise can be happening is either: there is some RFI happening when he moves the mouse - and this is getting into the preamp or amp (via cables?). I suggest this is highly unlikely. or the mouse movement generates a pulse which is going back out through the PC's power cord, into the mains and so into the amp or preamp. It isn't getting out of the computer, and into another component.... but rather the computer "getting interrupted and taken off task" when it should be doing the music, resulting in glitchy ticks and pops, or worse.... the solution is in the computer software / configuration. Edited July 24, 2016 by davewantsmoore
Happy Posted July 24, 2016 Posted July 24, 2016 Get rid of the computer Sent from my iPhone using Tapatalk 1
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