DSP and room correction

[insider9]

regarding mic and measuring equipment would the below comment by Alan Shaw be of any concern?

http://www.harbeth.co.uk/usergroup/forum/the-science-of-audio/getting-the-best-sound-in-your-room-using-damping-materials/113-testing-room-speaker-acoustics 

No, to most extent.

Here's why. Umik-1 is USB a calibrated mic. Most will output the signal to an external DAC which even if it's not completely flat will process sweeps exactly the same as music hence will react in a same way.

I've started with Behringer ECM 8000 and was far from pleased with the process.

In the 9 months I've taken thousands of measurements of many different speakers, amps and dacs. I can safely say that results are not only reliable and repeatable but also accurate.

 

[Gazzip]

regarding mic and measuring equipment would the below comment by Alan Shaw be of any concern?

http://www.harbeth.co.uk/usergroup/forum/the-science-of-audio/getting-the-best-sound-in-your-room-using-damping-materials/113-testing-room-speaker-acoustics

Nope. The Umik-1 I recommended is a calibrated microphone, and the DAC is sent a digital signal which is converted to the sine-wave so the soundcard of the PC isn't involved.

Of course you can do all of this with a cheap mic in the analogue domain, but as Mr Shaw identifies do not expect to get flat and true results.

 

[lpv]

the beauty of minidsp in a box is once you’ve done with the set up you dont need pc in your audio chain.. same with more expensive dirac live boxes.. cheapest dirac live option is run a software on a computer but then you need it on all the time you listen music

 

[Gazzip]

I don’t think you can do this:

Streamer Out > Dirac In > Dirac Out > DAC In

with minidsp 2x4HD as this unit does not have digital out. it does have optical and usb in and audio out, no digital so you can manipulate sound to your liking but you have to rely on minidsp dac but you can’t output processed signal to your own dac.

I didn't suggest for a second that minidsp was the answer. I would use a small form factor PC for the job as described above (Dirac In > Dirac Out), which also opens up DDC's world to virtualy any client server/streamer option he can imagine.

 

[lpv]

cheers guys..

I’m thinking to get minidsp 2x4 HD to run only for sub and leave monitors untouched

 

[lpv]

I don’t think you can do this:

Streamer Out > Dirac In > Dirac Out > DAC In

with minidsp 2x4HD as this unit does not have digital out. it does have optical and usb in and audio out, no digital so you can manipulate sound to your liking but you have to rely on minidsp dac but you can’t output processed signal to your own dac.

I didn't suggest for a second that minidsp was the answer. I would use a small form factor PC for the job as described above (Dirac In > Dirac Out), which also opens up DDC's world to virtualy any client server/streamer option he can imagine.

oh, ok..

yeah, this approach got much more sense

small pc ( nuc?) with dirac live

 

[insider9]

If you use a PC as a source with Dirac Live. I'd suggest looking at Roon with its DSP options. It does require manual setup which is harder than running Dirac Live however is far more powerful than Dirac Live and provides a multi room player for a very similar cost to a single Dirac Live licence.

 

[Gazzip]

I don’t think you can do this:

Streamer Out > Dirac In > Dirac Out > DAC In

with minidsp 2x4HD as this unit does not have digital out. it does have optical and usb in and audio out, no digital so you can manipulate sound to your liking but you have to rely on minidsp dac but you can’t output processed signal to your own dac.

I didn't suggest for a second that minidsp was the answer. I would use a small form factor PC for the job as described above (Dirac In > Dirac Out), which also opens up DDC's world to virtualy any client server/streamer option he can imagine.

oh, ok..

yeah, this approach got much more sense

small pc ( nuc?) with dirac live

Yep, that's what I'm saying, I just couldn't remember the acronym, NUC. *smile* I also use mine to run LMS and SqueezeLite so that I can control it with iPeng from my iPAD...

 

[Pedro2]

Which what DSP essentially is, just in the digital domain, without any potentiometers and sliders messing with the signal purity.

Well done boys. Spread the word.

I believe that this is how Linn (DS/DSM) streamers operate. You download software on to your computer which then controls all basic settings (configurable inputs, max volume etc) on your streamer. In addition, this software also provides DSP in the digital domain. No microphones or decibel readings are then required. The software asks you to input various parameters (e.g. room dimensions in mm, material construction of floor and walls as well as the make and model of your speakers). Some clever (I believe) algorithms are then applied that show your various room 'nodes' (problem frequencies). You then have the choice of switching a correction on or leaving it off. I have found it extremely good at removing some problem bass boom in our listening room although recent choice of speakers have helped aleviate major issues as well.

The Linn approach is called Space and it has much written about it on Linn's website and even more on their forum. There is one 'Linnie' who appears to travel the world staying at peoples' homes and optimising their Space settings. Sounds like the best job in the world to me!

 

[Gazzip]

If you use a PC as a source with Dirac Live. I'd suggest looking at Roon with its DSP options. It does require manual setup which is harder than running Dirac Live however is far more powerful than Dirac Live and provides a multi room player for a very similar cost to a single Dirac Live licence.

Roon is one of those things that has never really been properly explained to me. I have tried to read around it but jusat cannot get my head around what it actually is. Is it like Logitech Media Server with its suite of powerful plugins or am I way off piste?

What makes it so much better than everything else? It seems to be he buzz word at the mo with no real discussion as to what it does and why it is so good. Did I miss the memo or something?

 

[insider9]

If you use a PC as a source with Dirac Live. I'd suggest looking at Roon with its DSP options. It does require manual setup which is harder than running Dirac Live however is far more powerful than Dirac Live and provides a multi room player for a very similar cost to a single Dirac Live licence.

Roon is one of those things that has never really been properly explained to me. I have tried to read around it but jusat cannot get my head around what it actually is. Is it like Logitech Media Server with its suite of powerful plugins or am I way off piste?

What makes it so much better than everything else? It seems to be he buzz word at the mo with no real discussion as to what it does and why it is so good. Did I miss the memo or something?

I'll do my best to explain but it might take a while to type it up

 

[Gazzip]

Which what DSP essentially is, just in the digital domain, without any potentiometers and sliders messing with the signal purity.

Well done boys. Spread the word.

I believe that this is how Linn (DS/DSM) streamers operate. You download software on to your computer which then controls all basic settings (configurable inputs, max volume etc) on your streamer. In addition, this software also provides DSP in the digital domain. No microphones or decibel readings are then required. The software asks you to input various parameters (e.g. room dimensions in mm, material construction of floor and walls as well as the make and model of your speakers). Some clever (I believe) algorithms are then applied that show your various room 'nodes' (problem frequencies). You then have the choice of switching a correction on or leaving it off. I have found it extremely good at removing some problem bass boom in our listening room although recent choice of speakers have helped aleviate major issues as well.

The Linn approach is called Space and it has much written about it on Linn's website and even more on their forum. There is one 'Linnie' who appears to travel the world staying at peoples' homes and optimising their Space settings. Sounds like the best job in the world to me!

I cannot see how a system that doesn't measure the FR of the room could be in any way accurate. Sure it could guess whether there will be LF or HF issues based upon the parameters you mention, but over correction and/or under correction could make the situatiion worse, not better. What you describe is at best a blunt tool and amounts to some kind of automated digital bass and treble control. However any opportunity offered to correct LF and HF of the output signal is a bonus, so if these can also be manually adjusted (as with the Devialet system) then no bad thing...

 

[insider9]

Think of it as a concept more of an environment and not just a piece of software. All has their RAAT protocol at heart which is as far as I know the most thought out protocol to transport sound in current day and age.

To run Roon you need a couple of elements

Server + Endpoint (s) + Remote

Now all can be different bits of hardware or one. Basic setup would be a PC running Roon connected to a DAC. All operated from a phone or a tablet. More interesting setup would be a server with a number of different endpoints (zones). Endpoints can be other PCs or streamers that the server sends music over home network. They can use external DACs or not it really doesn't matter. It's a whole multi-room solution with excellent UI.

What's more Roon catalogues your music library, adds missing artwork, lyrics, all the metadata. Integrates fully with Tidal. Has many DSP options with a convolver that can do up to £131k taps (for comparison Chord DAVE uses £161k taps any many Minidsp units around 10k). Best part is that you can roon various DSP settings to different endpoints. Downside is you'd need to rely on other software to come up with filters (either free or paid). That means with one software solution you correct many zones with their specific DSP settings. You can do much, much more.

Main downside is that it requires a decent hardware to run on but it depends on the size of library and the operations you intend to do e.g. if you want to upsample everything to DSD256 than you'll need an i7 for a server. However endpoints can be very basic. Roon has managed to get many hardware partners who are certified Roon Ready.

They offer a two week free trial. However HB channel offers a free 2 months trial. Use this code NL1601HBPROJECT. Just a simple sign up and no payment info necessary.

 

[newlash09]

As insider9 correctly mentioned, there are a lot of ways to implement room correction. Would be helpful to know which streamer you have. And do you also have external dac ?

We are discussing two different options here :
1. Minidsp + REW - only frequency correction. Completely manual. Cna be done both in the analogue or digital domain. Can be run on a computer which is acting as your music source or you can add a external minidsp device if you are using a streamer and no computer.

2. Dirac - gives frequency + time correction also. Supposed to give better sound staging and imaging than mini-dsp if speakers are not setup at optimal distances. Is automatic. Can be done both in analogue or digital domain. Can be run on a computer being used as music source or an external minidsp ddrc series component can be included in the existing audio chain. Is more expensive than mini-dsp.

Depending on the resolution of the existing system, online articles are advising to use these systems in digital domain, as the analogue stage might ingest a little noise in comparison to the overall system. However this might not be applicable to most systems.

So once we know your system , may be others can suggest more accurately.

 

[insider9]

As insider9 correctly mentioned, there are a lot of ways to implement room correction. Would be helpful to know which streamer you have. And do you also have external dac ?

We are discussing two different options here :

1. Minidsp + REW - only frequency correction. Completely manual. Cna be done both in the analogue or digital domain. Can be run on a computer which is acting as your music source or you can add a external minidsp device if you are using a streamer and no computer.

2. Dirac - gives frequency + time correction also. Supposed to give better sound staging and imaging than mini-dsp if speakers are not setup at optimal distances. Is automatic. Can be done both in analogue or digital domain. Can be run on a computer being used as music source or an external minidsp ddrc series component can be included in the existing audio chain. Is more expensive than mini-dsp.

Depending on the resolution of the existing system, online articles are advising to use these systems in digital domain, as the analogue stage might ingest a little noise in comparison to the overall system. However this might not be applicable to most systems.

So once we know your system , may be others can suggest more accurately.

Bit in bold is incorrect. Minidsp does only some units (2x4) that only do frequency. Vast majority do both phase and amplitude. Minidsp can be more powerful in capable hand than Dirac Live. It does however need someone who's willing to learn and has time to do so.

 

[newlash09]

As insider9 correctly mentioned, there are a lot of ways to implement room correction. Would be helpful to know which streamer you have. And do you also have external dac ?

We are discussing two different options here :

1. Minidsp + REW - only frequency correction. Completely manual. Cna be done both in the analogue or digital domain. Can be run on a computer which is acting as your music source or you can add a external minidsp device if you are using a streamer and no computer.

2. Dirac - gives frequency + time correction also. Supposed to give better sound staging and imaging than mini-dsp if speakers are not setup at optimal distances. Is automatic. Can be done both in analogue or digital domain. Can be run on a computer being used as music source or an external minidsp ddrc series component can be included in the existing audio chain. Is more expensive than mini-dsp.

Depending on the resolution of the existing system, online articles are advising to use these systems in digital domain, as the analogue stage might ingest a little noise in comparison to the overall system. However this might not be applicable to most systems.

So once we know your system , may be others can suggest more accurately.

Bit in bold is incorrect. Minidsp does only some units (2x4) that only do frequency. Vast majority do both phase and amplitude. Minidsp can be more powerful in capable hand than Dirac Live. It does however need someone who's willing to learn and has time to do so.

Well noted that phase and amplitude correction are also included. I read somewhere , that Dirac also has time delay to align sound coming from the speakers to arrive at the exact same time . Helpful if both speakers are not the exact same distance from listening position. Was referring to this actually. Don't know if mini DSP has this time correction also .

 

[insider9]

Yes, it does. Like I said in majority of the hardware they do. I've used Minidsp 2x4 HD and now use Minidsp OpenDRC-DA8. They both very good sounding units and very flexible.

For your PMCs if you ever want to go active OpenDRC-DA8 would be a good starting point. It can do up to 4-way. DAC is really good. That's on top of it's abilities to room correct.

 

[newlash09]

That was helpful. Though I can't hear small differences iam trying to make things as pure as possible. Was considering using the chord dac ( just paid good money for it ). So want to use Dirac in digital domain and go into the chord dac. Then want to split the output analogue signal in a active crossover. Then split things into 4 bands. 80 Hz down to a sub. 350 to 80 Hz to the PMC's bass driver, 350 to 2.4 khz to mid range dome, 2.4 khz and upwards to tweeter. Will need to add two more Amps to the parasound to achieve this. I was thinking of using pro crown amp for the bass driver. Parasound for the mid range. And an yet undecided amp for tweeter.

How does all this sound. Worth attempting is it , or is it better to just stick with minidsp and one amp.

 

[insider9]

That was helpful. Though I can't hear small differences iam trying to make things as pure as possible. Was considering using the chord dac ( just paid good money for it ). So want to use Dirac in digital domain and go into the chord dac. Then want to split the output analogue signal in a active crossover. Then split things into 4 bands. 80 Hz down to a sub. 350 to 80 Hz to the PMC's bass driver, 350 to 2.4 khz to mid range dome, 2.4 khz and upwards to tweeter. Will need to add two more Amps to the parasound to achieve this. I was thinking of using pro crown amp for the bass driver. Parasound for the mid range. And an yet undecided amp for tweeter.

How does all this sound. Worth attempting is it , or is it better to just stick with minidsp and one amp.

Not good I'm afraid

Been there myself. Any processing that includes crossovers needs to be in digital domain to give you maximum benefit. That means you'd need 3 Chord DACs and obviously 3 amps. Should you got active your Chord Dac will not have much use.

That's also why I said to start with. OpenDRC-DA8 and it's AKM4440 competes on sound vs Chord Mojo rather well. That's unfiltered just DAC vs DAC. But you can suit the sound to your liking and not just correct for the room.

Edit
If you want to keep it passive get an all digital Minidsp with Dirac Live. The cleanest solution with the least messing about.

 

[QuestForThe13thNote]

As insider9 correctly mentioned, there are a lot of ways to implement room correction. Would be helpful to know which streamer you have. And do you also have external dac ?

We are discussing two different options here : 1. Minidsp + REW - only frequency correction. Completely manual. Cna be done both in the analogue or digital domain. Can be run on a computer which is acting as your music source or you can add a external minidsp device if you are using a streamer and no computer.

2. Dirac - gives frequency + time correction also. Supposed to give better sound staging and imaging than mini-dsp if speakers are not setup at optimal distances. Is automatic. Can be done both in analogue or digital domain. Can be run on a computer being used as music source or an external minidsp ddrc series component can be included in the existing audio chain. Is more expensive than mini-dsp.

Depending on the resolution of the existing system, online articles are advising to use these systems in digital domain, as the analogue stage might ingest a little noise in comparison to the overall system. However this might not be applicable to most systems.

So once we know your system , may be others can suggest more accurately.

i think if I tried it, it would be using the digital minidsp device unit as I can put it between my cyrus streamer and dac/pre, and use just digital connections.

I am tempted to borrow one and it doesn’t look too expensive, but this I think might be my problem with it taking a pessimist standpoint: If the Dirac system changes the frequency response in digital domain, will this be enough to bring sq improvements to the system as opposed to other upgrades like amps and speakers or sources, mains conditioning, etc. Will getting used to your system in your room environment to then hear changes in responses, akin to changing things on a graphic equaliser, be a real improvement. Might it just be different, but not necessarily better. There is an element in hi Fi that when you start getting used to something and then you change it, if it’s not a huge change for the better, it’s something that upsets the status quo.

im of course playing devils advocate and if it did really work I’d stand corrected.

 

[newlash09]

Understand I have to do all processing in digital domain. In which case, I will plonk for the open drc da-8 next summer. I can always use the chord some where else. Especially ever since I heard the Yamaha hsr 12's, been itching for a small late night setup in my guest bedroom

 

[insider9]

i think if I tried it, it would be using the digital minidsp device unit as I can put it between my cyrus streamer and dac/pre, and use just digital connections.

I am tempted to borrow one and it doesn’t look too expensive, but this I think might be my problem with it taking a pessimist standpoint: If the Dirac system changes the frequency response in digital domain, will this be enough to bring sq improvements to the system as opposed to other upgrades like amps and speakers or sources, mains conditioning, etc. Will getting used to your system in your room environment to then hear changes in responses, akin to changing things on a graphic equaliser, be a real improvement. Might it just be different, but not necessarily better. There is an element in hi Fi that when you start getting used to something and then you change it, if it’s not a huge change for the better, it’s something that upsets the status quo.

im of course playing devils advocate and if it did really work I’d stand corrected.

You advocate tuning with cables but playing devils advocate on DSP thread?

On a serious note, I know where you're coming from. I use DSP in a very limited way to what I've used in the past. I belive that acoustic room treatment brought better improvements in my listening space.

Forget graphic equalisers... it's like comparing horse drawn carriages and cars. FIR based DSP does not have to touch frequency response one bit and can still improve clarity.

 

[insider9]

Understand I have to do all processing in digital domain. In which case, I will plonk for the open drc da-8 next summer. I can always use the chord some where else. Especially ever since I heard the Yamaha hsr 12's, been itching for a small late night setup in my guest bedroom

Yep, use my Yamaha with Coax out to OpenDRC-DA8 and the combination is great. Before you spend any money with Minidsp do have a look as they refresh their range on a regular basis.

 

[newlash09]

You are not playing devil's advocate

As I mentioned before, I cannot spend a huge amount of money in superior amplification that does the whole audio spectrum from 20hz to 20 khz. So been trying to break it into bits and pieces, and choose a amp that does one part very well. All your opinions formed over a lot listening experience are what I don't have. So just voicing myself aloud .

 

[newlash09]

Will do. The best part is that I can do one thing at a time as budget permits. And my wife will never come to know