Digital EQ

A place for software, hardware and DSP-based audio gizmos. All things code and the hardware that runs it. Time and amplitude are described in bits and pieces here. Links to interesting gizmos and software.
billshurv
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Digital EQ

Post by billshurv »

For a while now (and yet another thing I blame Wayne for) I've been considering EQ options for when listening to music, particularly vinyl. The problem is that, until you try something you can't be sure if it's worth having, and in the analog domain that could end up as a lot of soldering for disappointment at the end of the day. But given I have a miniDSP active cross-over it would be churlish to to accept that digital EQ has its place in my system.

So I've been looking around at the various options for digital eq with a focus on
1. usability
2. features (must be able to do M-S filtering)
3. WAF.

So far everything I have seen failed on one or more of those as they are focussed towards a fit and forget type of use, but, being sure that pro-audio has seen and fixed this problem already furtled around and finally found something that seems to tick the boxes in Calf studio https://calf-studio-gear.org/. This is a set of plugins for linux that work with JACK audio. The neat bit for me is that the 5 ,8 and 12 band parametric plugin allows each filter to set to either stereo, L, R, M or S so I have an easy way of messing around to try and find out what actually makes a positive difference for me and then decide on next steps.
Calf - Equalizer 12 Band.jpg
The bonus is that this is also midi compatible so I have a controller hooked up, so I can sit on the sofa and twiddle knobs which was the biggest usability stumbling block that I had with other options. poking a laptop whilst listening for changes is a bit fraught!

Hooked up to a focusrite Scarlett 6i6 I get SPDIF out to go into the miniDSP saving a DA/AD stage. The 6i6 may not be the greatest IO box in the world but second hand they are £100-120 so will fill the gap and work with old laptops I have lying around. In terms of a rapid prototyping capability I think it should work well, and may be good enough to be the permanent solution.

Sure those of you more studio biased will be rolling your eyes over my ignorance on this at this point :). And any other methods I could try for this would be appreciated. I do worry about how I check for processing delays...
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mediatechnology
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Re: Digital EQ

Post by mediatechnology »

I need to try their plug-ins on my Ubuntu box.
billshurv
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Re: Digital EQ

Post by billshurv »

well got ubuntu loaded on an old laptop, so phase 1 done. Been looking at controllers and the novation launch control XL looks like it will fit the bill. You can program the pots for a limited range, which is what I need to ensure I don't put stupid levels of gain in. The stereo tools plugin has a width control and a full set of mono options, so when I am series strapping it can duplicate left to both outputs. Short term saves me a bit of soldering. This could actually work and get me running :)
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launchxl.jpg
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mediatechnology
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Re: Digital EQ

Post by mediatechnology »

I like Stereo Tools a lot. What version of Ubuntu are you running?
billshurv
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Re: Digital EQ

Post by billshurv »

I'm using ubuntu studio 18.10 mainly because that comes with calf studio pre-installed and should just work (for a given value of just).
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mediatechnology
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Re: Digital EQ

Post by mediatechnology »

I'm running Ubuntu Studio 16.04 and need to upgrade to the 18.04 LTS version. I understood 18.10 to be a dead development fork so I was concerned about its upgrade path from 18.10 to 19.X.

Ubuntu has been doing a very annoying thing which is thrashing the hard drive at the most inconvenient times. It's either indexing or checking for updates. It starts this process right in the middle of work. By the time I get System Monitor to start to see what's hogging resources the process has ended. Would be curious to see if your machine has this problem. If I run process monitor continuously it doesn't want to seem to start it.
billshurv
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Re: Digital EQ

Post by billshurv »

I will monitor as I move forwards, but TBH will be sticking an SSD in this machine as soon as possible. The HDD in this is a slow laptop one and didn't work well on windows in its old life. But I will monitor that. As this will be for a very few use cases I wasn't too worried about version and grabbed the top one on the list as a proof of concept. This may of course come back and bite me in 6 months :)
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mediatechnology
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Re: Digital EQ

Post by mediatechnology »

Under Ubuntu Studio 16.04 LTS about the only browser I've been able to get to work reliably is Firefox.

Chrome, Chromium, Vivaldi and Opera (all Chrome-based) crash when handling video streams.
I may have an odd video chipset causing this.

FWIW website statistics still show Win 7 dominates with 27.21% of visits. Linux is 6th at 5.86%.

With Apple, Google, Microsoft and their ilk continually taking positions that are hostile to liberty Linux is looking better and better all the time.
I live-booted the Zorin OS https://zorinos.com/ and its lovely.
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mediatechnology
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Ubuntu Studio 16.04 Disk Thrashing At Inconvenient Times

Post by mediatechnology »

mediatechnology wrote: Wed Dec 05, 2018 6:41 am I'm running Ubuntu Studio 16.04 and need to upgrade to the 18.04 LTS version. I understood 18.10 to be a dead development fork so I was concerned about its upgrade path from 18.10 to 19.X.

Ubuntu has been doing a very annoying thing which is thrashing the hard drive at the most inconvenient times. It's either indexing or checking for updates. It starts this process right in the middle of work. By the time I get System Monitor to start to see what's hogging resources the process has ended. Would be curious to see if your machine has this problem. If I run process monitor continuously it doesn't want to seem to start it.
I think I found that problem.

Started using iotop to monitor disk activity.
It took awhile as it begin to thrash really hard iotop would lock-up so it took awhile to catch it.

Something is running updatedb.mlocate

mlocate scheduled in /etc/cron.daily but it seems to try to run and thrash more than once a day.

chron.hourly is empty.

I tried this to prevent its execution:

Code: Select all

sudo chmod -x /etc/cron.daily/mlocate
billshurv
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Re: Digital EQ

Post by billshurv »

Ah yes, that will do it. I tend to run locate updates manually when I know I'm not doing anything. Very 20th century I know :)
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