sorry but what measurements do you need to take? you mean for DRC?

 

Yes, that's right. DSP can do a lot more than just room correction. Once fully implemented, it will time align the drivers, perform driver correction, room correction, apply ISO 226 equalization curves, calculate the IACC (inter aural coherence coefficient), correct the phase, upsample the signal up to PCM384 or DSD512, and so on. All these calculations are done in 64 bit floating point. There are so many functions available in Acourate that it is bewildering for me. I have the book, and I have read the book a couple of times, but my brain is a little too small to understand much of what it can do. 

 

I have scoured audio forums around the world looking for other people who have done what I am proposing to do. So far I have only found a handful of people. 

 

OK, getting rid of analog sources is something I agree with but that means your reason for ditching DEQX in the first place no longer applies

 

There are other reasons for not using the DEQX, and preferring Acourate, that i'm not going to go into. There are too many fanboys on SNA and I don't want to turn this thread into a pissing contest. 

Edited June 28, 20169 yr by Keith_W

There are other reasons for not using the DEQX, and preferring Acourate, that i'm not going to go into. There are too many fanboys on SNA and I don't want to turn this thread into a pissing contest.

Yeah I assumed so, but you didn't actually say that until now. All good, continue on.

Interesting, Keith! I have been contemplating a similar path, so I am watching with great interest!

I have scoured audio forums around the world looking for other people who have done what I am proposing to do. So far I have only found a handful of people. 

 

 

Acourate is certainly designed to be powerful and flexible .... rather than "user-friendly".

 

 

I'm considering moving to Uli's convolver  (I've just been talking to him recently too) ....   my system architecture is still a bit enigmatic  (as you appreciate going by your story, there are compromises with every decision).   I've just been too busy designing my speakers (procrastinating perfectionist warning) .....   which isn't helped by me having a "B" system that I"m happy with.

 

I am also battling with 4x 4-way speakers (ie.  4.0 surround), which muddies the waters.    Especially with the Acourate workflow (which is a bit stereo-centric).

 

I haven't posted much about mine.... but intend to as soon as the architecture is pinned down  (it basically is, but).

I will have to one day bite the bullet and admit i do need a computer in my system maybe. Thanks

Sent from my iPhone using Tapatalk

 

Acourate is certainly designed to be powerful and flexible .... rather than "user-friendly".

 

 

I'm considering moving to Uli's convolver  (I've just been talking to him recently too) ....   my system architecture is still a bit enigmatic  (as you appreciate going by your story, there are compromises with every decision).   I've just been too busy designing my speakers (procrastinating perfectionist warning) .....   which isn't helped by me having a "B" system that I"m happy with.

 

I am also battling with 4x 4-way speakers (ie.  4.0 surround), which muddies the waters.    Especially with the Acourate workflow (which is a bit stereo-centric).

 

I haven't posted much about mine.... but intend to as soon as the architecture is pinned down  (it basically is, but).

 

And I would be very interested to read about your experience. I am not sure how well Acourate would work with a 4.0 setup, given that the time alignment "clicks" only pan from the left to the right speaker. 

 

FWIW I have a pair of borrowed power amps connected in my system right now. It is taking longer than anticipated for my power amps to be repaired, so I might go do some sweeps when I get back tonight. 

 

I will have to one day bite the bullet and admit i do need a computer in my system maybe. Thanks

 

Oh, you would love my PC. Apart from the optical drive, there are no moving parts. Not even a cooling fan. Even the power supply is passively cooled. It is completely silent. When you turn on the PC, the BIOS briefly spins up the optical drive as part of the POST. Then the rest of the boot takes place without a sound. 

Oh, you would love my PC. Apart from the optical drive, there are no moving parts. Not even a cooling fan. Even the power supply is passively cooled. It is completely silent. When you turn on the PC, the BIOS briefly spins up the optical drive as part of the POST. Then the rest of the boot takes place without a sound. 

 

wow so you can turn it on/off like a CDP or something? no need to type in stuff (apart from the set ups)?

 

did you make/build it custom?

I will have to one day bite the bullet and admit i do need a computer in my system maybe. Thanks

 

Don't get despondent too early, David! 

 

Like me you play vinyl - unlike me, you appear to have some fancy "digital stuff" as well.     If you follow what I will be posting here over the next few weeks:

http://www.stereo.net.au/forums/index.php/topic/87451-the-new-listening-room/page-4#entry1653604

 

. . . you will see how a miniDSP unit similar to yours will (with Paul Spencer's expertise) be providing:

1. delays of the main speaker's woofers, to line up with the subs' positioning and the time difference generated by the sub-woofer filter slopes
2. 3-way active XOs in the Maggies (replacing the 3-way analogue active XO I've been using for 15 years)
3. delays on the ribbon and mid outputs, to compensate for the time differences generated by the woofer-mid & mid-ribbon filters, and the delay required by the woofers (as per #1), plus
4. room correction. 

 

This is without a computer in the mix (computer only used, as you know, for programming the miniDSP).

 

 

Andy

I am not sure how well Acourate would work with a 4.0 setup, given that the time alignment "clicks" only pan from the left to the right speaker.

 

It works (although complicated)... it's quite a swiss army knife    

Don't get despondent too early, David! 

 

Like me you play vinyl - unlike me, you appear to have some fancy "digital stuff" as well.     If you follow what I will be posting here over the next few weeks:

http://www.stereo.net.au/forums/index.php/topic/87451-the-new-listening-room/page-4#entry1653604

 

. . . you will see how a miniDSP unit similar to yours will (with Paul Spencer's expertise) be providing:

1. delays of the main speaker's woofers, to line up with the subs' positioning and the time difference generated by the sub-woofer filter slopes
2. 3-way active XOs in the Maggies (replacing the 3-way analogue active XO I've been using for 15 years)
3. delays on the ribbon and mid outputs, to compensate for the time differences generated by the woofer-mid & mid-ribbon filters, and the delay required by the woofers (as per #1), plus
4. room correction. 

 

This is without a computer in the mix (computer only used, as you know, for programming the miniDSP).

 

 

Andy

 

Sounds interesting! Mine is more like 4.1 way active.

Sounds interesting! Mine is more like 4.1 way active.

 

Aaah, OK - so more complex.   Then maybe you will need a mainframe - not just a PC!!??    

 

Andy

Aaah, OK - so more complex.   Then maybe you will need a mainframe - not just a PC!!??  

 

Andy

 

Not entirely sure what you mean by a mainframe but let's not further go OT...I'll be more than happy to discuss further on your future thread

wow so you can turn it on/off like a CDP or something? no need to type in stuff (apart from the set ups)?

 

did you make/build it custom?

 

I built it myself. Albeit with some help from Tricka / Andrew S or whatever he calls himself on SNA these days. He pointed me towards the case, and I selected all the components to put in it. 

 

No need to type anything in at all. I have customized my Windows startup so that a push of a button turns on the system, it boots by itself, bypasses the login screen, and automatically launches all the applications which I need I also have a touch screen monitor, mounted on an arm that reaches out to the listening position. I can also control the PC from my Android tablet. And I have a Logitech K830 wireless keyboard, which has its own trackpad, to type in stuff if I need to. 

 

I bought the i7-6700K because it is way overpowered for my needs. I can therefore underclock it and improve heat dissipation and reliability. Or, if I need the processing power, I can just run it at normal clock speeds. The fanless case I am using is rated to dissipate up to 100W CPU TDP, and the i7-6700K comes in at 95W. 

oh wow knowing Andrew I'm sure the computer is meticulously set up (and probably super expensive!). Well done!

I am a Windows guy, and I have built my own computers since I was a teenager. I have been chatting with Andrew quite a lot, he is a Mac guy and he found Windows a bit hard to use. I would be the same if I was forced to use a Mac. This kind of hardware flexibility would be impossible to achieve with a Mac, unless you have a Hackintosh. 

Well, it's up and running. There are a few problems, however. 

 

1. Computer is connected to the DAC via USB, and not via AES/EBU. This is because the pro sound card I am using (RME HDSPe AES) uses a D25 sub output for AES/EBU, whereas the Playback Designs MPS-5 SACD player (being used as a DAC) uses the conventional AES/EBU (XLR) socket. I will need to get a breakout cable for the above. 

 

2. With no convolution, the PC as a source sounds awful, compared to playing a CD in the MPS-5. On the MPS-5, notes have a nice, clear, defined edge. On the PC, it sounds rounded off. And this is with using HQPlayer. 

 

3. For some reason, the Playback MPS-5's USB input maxes out at PCM 48kHz. It should be capable of much higher than this. I need to read the manual or update the firmware - something to do later. 

 

4. It's noisy! There is a background hiss going through the system, and doing things on the computer, even switching windows, sends a click through the system. 

 

5. The aesthetics of the playback software (HQPlayer) on the PC leave much to be desired. I know I can use either Roon or Muso as the front end instead, but I hate both of them! 

 

Anyway, I fired up Acourate. This is the result of my very first measurement sweep: 

 

 

You can see that the high frequencies are -10dB down compared to the midrange. Also a downward curve in the upper bass, above 100Hz. 

 

I then designed a target curve. Since it's my first, I decided to make it flat. I told Acourate to invert the frequency response with respect to the target curve, and used it to generate a convolution filter. I then redid the measurement: 

 

 

WOW! It's almost flat, apart from the dip in the bass which is a room issue (I decided not to touch this). 

 

I loaded the convolution filter into the HQPlayer convolver engine and started playing music. Jaw dropping. Close to the best I have ever heard my system. 

 

Right now, only the frequency response and room correction has been fixed. I will not be able to perform any of the advanced functions of Acourate (time alignment of the drivers, individual driver correction) until I obtain more DAC channels and thus be able to individually measure each driver. 

 

I will have to slowly work through all the issues above. But for now, it all bodes well. 

Here are a few updated system pics. 

 

 

Overview of the system. 

 

 

View from the listening chair. 

 

 

The whole system with a borrowed subwoofer - a Genelec monster pro sub. This thing is so powerful it makes the house vibrate. 

 

 

Dell S2240T touch screen monitor mounted on an Atdec Systema arm: http://www.atdec.com.au/tv-monitor-mounts/desk-mounts

 

 

Equipment stack. From top to bottom: Playback Designs MPS-5, Audio PC, Cary SLP-05 preamp, Cary SLP-05 power supply

nice system. especially the acapellas. 

 

 

4. It's noisy! There is a background hiss going through the system, and doing things on the computer, even switching windows, sends a click through the system.

 

You have some type of driver or interrupt issue  (that may also explain the 44.1/48khz limitation, if it is supposed to be capable of higher)

 

You should not be able to hear any types of noises (buzzes, clicks, hiss, etc.) which are modulated by activity in the computer (eg.  like moving the mouse, switching what is on the screen, etc.)

it all bodes well. 

 

Frequency response dominates.  

 

PS - Love the ship.

I decided not to touch this

 

why not?

why not?

 

EQ isn't usually a good tool to correct room issues with

EQ isn't usually a good tool to correct room issues with

 

Really? So DRC is not a kind of EQ?

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.

You have some type of driver or interrupt issue  (that may also explain the 44.1/48khz limitation, if it is supposed to be capable of higher)

 

You should not be able to hear any types of noises (buzzes, clicks, hiss, etc.) which are modulated by activity in the computer (eg.  like moving the mouse, switching what is on the screen, etc.)

 

Well, it's even more confusing now. I suspected it might be the USB interface making the noise, so I bought a cable at lunch time which converts the D25 Tascam output of the RME HDSPe AES sound card into AES/EBU XLR and plugged that in. The low background hiss is gone, but I still get ticks and pops whenever I do something on the PC, like launch a program. 

 

Then I noticed that I was STILL getting ticks and pops through the system even though my preamp was selected for a different input! 

 

So I switched off the DAC. STILL get ticks and pops. 

 

Switched off the preamp. STILL get ticks and pops!! This means that the interference must be travelling through the power supply! Either that, or I am somehow still getting signal transmission through the low level cables even with equipment switched off! 

 

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. 

 

 

Frequency response dominates.  

 

PS - Love the ship.

 

Thank you! HMS Bounty, built from an Artesania Latina kit. Took me 18 months, completed in 2008. I am working on a new one - HMS Royal William. Two years now, and still haven't finished the deck. 

 

 

why not?

 

Why shouldn't bass be corrected via DSP - davewantsmore gave you the correct answer. The dip in the frequency response is caused by a room issue. The correct solution would be to reposition the sub, or install acoustic treatment. Throwing more energy at the frequency dip will not flatten out the response, rather it will exacerbate problems elsewhere in the room. 

 

I was chatting on the phone to an American the other day, who is helping me set up Acourate. He said something quite amusing - "many people on audio forums are stuck in the 1970's way of thinking - they want a flat frequency response. Modern thinking takes into account the effect of psychoacoustics". One such example is that the ear/brain is more sensitive to amplitude peaks than amplitude dips. 

 

Another example is that the frequency response should roll off from 1kHz so that it is between -4dB to -6dB at 20kHz, according to several papers published recently in the AES by Dr. Sean Olive (2009), and Dr. Floyd Toole (2015). As you can see, I left mine flat because it was my first attempt. I will redo the measurements tonight with a few brand spanking new tools that I bought today and see if I can improve it further. 

 

Quite enjoying this Acourate journey so far! I still need to sort out some PC issues though. 

Edited June 30, 20169 yr by Keith_W