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[Matt]

During v15 development, Mojave turned me onto a neat VST called 'SPAN'.  It's a DSP plugin that lets you see the frequencies you're playing per channel.  But as opposed to a spectrum analyzer visualization, the focus is on accurate measurement instead of fancy looks.  It has labeled axises, accurate representation of the frequency curve, a consistent logarithmic frequency axis, etc.

SPAN was really valuable as we built the Room Correction, because we could see exactly what was happening.

I think it'd be neat to build something like this into DSP Studio.  I've spent some time playing with a high-quality 64-bit FFT (the thing that breaks sound into frequencies) and using the tools we already have, it doesn't seem like this would be a big project.

Maybe the DSP could be called 'Analyzer' and always be locked as the last item in the DSP Studio so that it's always showing the final mix.

There's also an ulterior motive to the project, in that the ability to analyze a waveform and make accurate (and pretty) frequency displays is important both for a parametric equalizer and later a microphone calibration engine.

How interesting would you find this addition?  Thanks for any advice.

[fitbrit]

These would be neat additions. However, I - like most people, I dare say - use AV receivers throughout my home. All of mine use the latest Audyssey calibration systems and I find they do a great job. I do realise that many JRiver fans would like to use the PC as a pre-amp. I'd welcome these features, just in case I ever needed them in the future, but I doubt I'd ever use them myself. It's also cool for bragging rights when trying to convert friends to MC.

[mojave]

I love this idea! Of course I already like SPAN (and its companion parametric EQ program called GlissEQ). I use these all the time for double checking my Room Correction settings. Its a great first step towards implementing a parametric EQ. I like the name "Analyzer."

It would be cool if one could use "Analyzer" to analyze a movie, or a portion of a movie, and record peak output levels at the various frequencies and then produce charts. Bossobass, at AVSForum, posts a lot of Speclab comparisons between the digital levels of a movie and the actual playback levels in the room. It seems to me like this is a good way of determining if you are accurately playing back the Blu-ray as it was recorded.

Also, people with a receiver can still send HDMI audio as decoded PCM and use all the features of MC's DSP plugins, JRSS, Reclock, ffdshow, etc. There are many that don't like what Audyssey does, especially to the bass. Having manual control with a built in parametric EQ would be a nice alternative.

Sort of off topic, but dealing with the results of measurements, I keep wondering if the distance settings in Room Correction need more granularity. I also wish that the subwoofer tab in Room Correction could have the option for global crossover settings or per speaker crossover settings. With global, changing for one speaker would change it for all. It is rather tedious to have to go through the speakers and set high\low pass slopes and crossover frequency for each speaker when testing for which measures or sounds best. 

[bytestar]

I would love this Feature.. 

[Matt]

We added a first cut to 16.0.16.

After thinking about it more, I think it might be better as a visualization instead of a DSP.

A visualization is designed to show just what is being heard now, which is kind of tricky from a DSP.

Also, the concept of on and off doesn't really make much sense.

Thoughts?

[ThoBar]

It's Nerdy, so I love it.

We added a first cut to 16.0.16.

After thinking about it more, I think it might be better as a visualization instead of a DSP.

A visualization is designed to show just what is being heard now, which is kind of tricky from a DSP.

Also, the concept of on and off doesn't really make much sense.

Thoughts?

Makes sense to me

[fitbrit]

We added a first cut to 16.0.16.

After thinking about it more, I think it might be better as a visualization instead of a DSP.

Agreed.

[Matt]

After saying it might make sense as a visualization, I remembered you can't look at a visualization during video playback.  But calibration for video playback is really important.

So we'll have to think about the placement a little.

[fitbrit]

A detached or PiP window perhaps?

[jmone]

If your keen on "calibration for video playback" how about the adding the reclock ability to resample audio to keep in sync with video?  That we we can use the JR DSP.

[mojave]

Version 16.0.17 - Analyzer won't remember its frequency range. You have to reenter it every time you select Analyzer. Also, with stereo output I am getting three lines showing and with 2.1 I get four lines. Is one of the lines a sum of the others?

I wish Analyzer was a side flyout of Room Correction. For testing, it is nice to be able to see what is going on while making changes in Room Correction.

This doesn't relate to Analyzer, but every time I go to Room Correction it defaults to the left speaker. I wish it would stay on the last speaker I had selected. I'll make a channel mute or solo, view something with GlissEQ (or SPAN) or now Analyzer, then go back and have to reselect the channel to unmute or turn off solo.

[mojave]

Here is a picture of Analyzer as a flyout from Room Correction.

[mojave]

I don't use this plugin, but it has a graph that appears after you click the Graphs button near the bottom right. If a Graph (or Analyzer) button was integrated in the DSP studio, you could see the Analyzer regardless of what other plugin you had showing.

[mojave]

The full release of Room Equalization Wizard V5 was made on January 30. Maybe now that the official release is done John Mulcahy might have time to help port REW as a VST plugin (or another method) for MC. I don't know anything about programming, but maybe jvstwrapper could be used to convert REW into a VST plugin. This cooperation with JohnM could be similar to madshi helping integrate madVR. REW could generate all the sweeps and measurements that are used by the new Analyzer/Parametric EQ. REW would need to be at the beginning of the DSP chain so that its sweeps could go through all of MC's active DSP's. It would then generate and automatically load the filters for the EQ.

Having the ability to use REW internally could help generate more publicity for MC. I think many would buy or upgrade to V16 (or V17, V18, V19 . . .  ) just for this feature.

[mark_h]

Maybe the DSP could be called 'Analyzer' and always be locked as the last item in the DSP Studio so that it's always showing the final mix.

There's also an ulterior motive to the project, in that the ability to analyze a waveform and make accurate (and pretty) frequency displays is important both for a parametric equalizer and later a microphone calibration engine.

How interesting would you find this addition?  Thanks for any advice.

It must be understood that the frequency display is actually pretty meaningless unless the room has been measured with a microphone.  The room has by far the largest effect on what we hear and will "distort" those lovely frequency displays quite grossly by the time the signal gets to our ears.

I've been using (TacT) room correction in all my music rooms and Meridian (861) correction in my cinema for the past decade and couldn't now live without room correction. One HAS to measure the signal in the room to be able to correct it.  Room Correction without such measurement is worthless.

Fortunately it's getting a lot easier to do quick corrections, eg parametric EQ, using things like the iPhone and any of it's many RTA apps.  This will allow you to do quick and dirty (but also quite nice) corrections.  I've already done this with MC's Equalizer and some pink noise tracks.

But if you want to do full correction you'll need a microphone, test tones and a decent parametric equalizer as a minimum.

It would be really very cool to get live feedback via the analyzer while allowing us to tweak parameters and see the results in real time.

[mojave]

It must be understood that the frequency display is actually pretty meaningless unless the room has been measured with a microphone.

You are correct when talking about room correction. However, a spectrum analyzer is invaluable in determining what is happening electronically to the signal before it is ever heard through the speakers. This is done by using 2.0, 5.1, and 7.1 pink noise and viewing the DSP changes by watching the spectrum analyzer. Here are a few of the things that I use it for:

Understanding High and Low pass Crossover slopes:  I have some subwoofer drivers with an Le of 2.07. This means that without a crossover, the driver starts to roll off on the upper end at around 100 Hz. By using pink noise and analyzing the effect of a 24 db/octave or 48 db/octave crossover at various frequencies, I can determine which is best for my system. For example, too high of a crossover with too shallow of a rolloff will coincide with the drivers natural rolloff. This will cause a reduction in output through a certain frequency range.

Understanding the subwoofer settings in Output Format:  How does checking or unchecking "Something outside the Media Center will make the subwoofer +10" effect the output on the LFE channel?

Verifying channel mapping:  My surround left channel is going to the surround back channel. Is this an error on the source, with the soundcard drivers, or with MC's settings? It turns out it is with the soundcard driver and MC provided an option in the Audio setting to swap channels.

What is JRSS doing?:  Using a spectrum analyzer allows one to see the affect JRSS has on surround and LFE channels.

What frequencies are below 20 Hz in this song or movie?:  Play a portion of music/movie while watching the spectrum (with it set to max) will enable you to see the max peak output levels.

Are my surround levels too quiet because of a setting or because of the source?:  A quick check with the analyzer lets you see that the source has the surrounds mastered at a lower level than the mains and center.

Knowing that your settings are correct and you are capable of accurately representing the original signal with your equipment/speakers is just as important as measuring the room response later. This is more important when using MC and an HTPC as your only source (i.e. no receiver), but can still be of benefit even if you are outputting to a receiver.

Most people don't know what their system is doing. For example, the Oppo BDP-83 has its low pass filter set at 143 Hz with an 18 dB/Octave slope and its high pass filter set at 90 Hz with a 13 dB/octave slope. If using the analog outs and bass management on the Oppo, you will not get an even frequency response of the electronic signal before the room even comes into play. Using a spectrum analyzer provided that info. Measuring the room might also show a problem, but you wouldn't be able to correct it because the problem lies with signal.

[mark_h]

Most people don't know what their system is doing. For example, the Oppo BDP-83 has its low pass filter set at 143 Hz with an 18 dB/Octave slope and its high pass filter set at 90 Hz with a 13 dB/octave slope. If using the analog outs and bass management on the Oppo, you will not get an even frequency response of the electronic signal before the room even comes into play. Using a spectrum analyzer provided that info. Measuring the room might also show a problem, but you wouldn't be able to correct it because the problem lies with signal.

With room correction you are looking to achieve a target curve AT YOUR EARS, so it doesn't really matter what the signal is doing (assuming no gross errors such as clipping) as long as what reaches you ears hits your target.  Using pink noise through the subs and mains independently will reveal their contribution to the overall sound, including any crossovers, and the signal can then be tweaked as required.

My comments regarding the usefulness of the analyzer are related to room correction only.  I agree with what you say about the other uses for it.

[tunetyme]

I think any and all tools that can improve one's listening experience will be helpful to me and a great selling point.

[Jasonpctech]

up REW brought me here and use of that will get my $49.
Thanks for the heads up Mojave!

[mojave]

Thanks, Jasonpctech. I hope this solution works well for you. I hope MC will soon allow us to import REW settings, but they don't take that long to set up manually.

[Vincent Kars]

Playing Bach’s Harpsichord Concert 1 BWV 1052
This is acoustical with the double bass as the lowest register
I do understand seeing nothing in the analyzer above 20 kHz (Redbook)
But where does the spectrum < 20 Hz comes from?
Artefact from the analyzer?

[newsposter]

The audio-feelies (and some legit users) of the world would love to be able to set up a series of 100% accurate and real-time meters (using assured APIs that take to MC internal datapaths) in our visualizations/skins.

That kind of access would go a long ways towards being able to use MC as the calibration and adjustment source for some serious DTS-quality (DTS certified??!!) setup of audio and video.

[flac.rules]

I like the new analyzer, although, as i am sure you are aware, it would be nice with some more polish (labeling the axis and graphs and so on), it also would be nice to be able to show the mic input in  the analyzer with the electronic output. I don't now how far you plan to go ahead in the future with calibration and so on, i guess there is potential for a lot of features, however there is a bit of work involved (reverberation time, frequency analyzer and so on)