Visual Analyzer (Spectrum Analyzer, Scope, Function Gen)

I came across this piece of excellent free software, that I have found to be quite useful in working on my ST-70. It is called Visual Analyzer, and runs on a PC. I am running it through a USB DAC, and into my ST-70. I am using a calibrated microphone connected to the PC microphone input. The function generator is quite nice, and can generate just about anything, including full sweeps. The spectrum analyzer is quite capable, and includes a "hold" function that stores/displays the average spectral content over time. I have tried a variety of microphones, and most seem to do a decent job of representing what I am hearing. I can place the microphone in front of either speaker, or my listening position to make A/B speaker/tube comparisons. This is certainly not the same as a $50,000 lab bench, but for free, I find it very helpful. Here is a link to the software. I recommend the beta 4.2 version, which is found on the forum. You can simply enter as a "guest". I have no affiliation with this company!

http://www.sillanumsoft.org/prod01.htm

Thanks for the info.....................have  fun







long live  Acoustat ESLs...........



Thank for the site Bob.............

While using the function generator, I was able to uncover a major right side speaker rattle that occurred right at 590hz. Found several loose screws, and the problem is gone. I also used it to give myself a hearing test! 50-12,400hz is the best that I could do. The microphone went to 22Khz, but the ears gave out at 12,400.

Most people are happy with just listening, but some of us anal retentive types just can't resist making things overly complicated. Been playing with that kind of stuff for while now, using the following:



- REW (Room EQ Wizard) on a laptop
- Outboard USB audio breakout box ((Behringer UCA202))
- Mixer (Behringer ZENYX502))
- Calibrated mike (Dayton EMM-6)
- jRiver Media Center ($40) Not just a media player. Call it a digital Swiss Army Knife.
- BSR decibel meter used to initially calibrate the software.

A bit of a learning curve and a lot of head scratching, but I got it all figured out. First results were quite spectacular, just transferring the suggested adjustments to my analog parametric EQ. I thought it sounded right nice before, but you'd be surprised how much of a difference fairly minor changes can make.

REW interfaces directly with the MiniDSP if you want to bypass an analog eq completely. I got decent enough results with that option, but not enough to float my boat. Sounded a bit thin, but mostly I figure that was me trying stuff I shouldn't have, trying to combine two different readings into one set of eq filters.

Next up ... took the same readings and used those to build a "convolution" file that imports directly into jRiver Media Center. REW has the option to either do that with standard text filters OR a WAV file that acts as an overlay on the actual music. I went with the WAV, and ... wOw ... just wOw. Took a few attempts to get it right, but well worth the effort. That was a while back, and my analog PEQ is now bypassed and collecting dust for all my digital music. Not saying the manual PEQ isn't good, just that the digital eq is better, mostly on the bottom as you'd expect. Just way better definition. I still use the PEQ for spinning vinyl, but I'm working on a system to route that thru jRiver also.

One last tweak? One of the gurus on jRiver's forum came up with a unique approach using some additional software:

- Holm Impulse(freeware)
- REW (freeware)
- RePhase (also freeware - optional)
- Basic technical info on your speakers from the manual to set crossover points

Quite complicated, but should be a day's work once you get the hang of it. Basically doing the same thing that REW does all by itself, but each software package does each step just that much better. The goal is to create a set of complex filters that account for more parameters, including time delay and reflections. These are then typed directly into jRiver's DSP studio. These are much more accurate than the "easy" approach.

Not to bore yall with the nitty gritty ... too late? Here's a link for anyone interested ...

http://yabb.jriver.com/interact/index.php?topic=87538.0

PS ... you can see what I'm currently working with below. This is a pic of the left channel up to 2500hz using REW.



The top line is the raw signal (scale +/- 5db), bottom after the filters are applied (+/- 2db), gray lines are reference to mike calibration. These filters also employ a "house curve" to boost the midrange - optional, but fairly standard practice for room voicing to give the music a bit more pOp. Still a few minor blips, but I should be able to smooth that even further with the next approach ...

I'm sure some of you are thinking about now that some of us have waaaaaay too much time to kill. I'm thinking you're probably right.  

My goodness! The cold winters here in Michigan, give us both a lot of free time. That is an impressive setup!

Keeps the walls from closing in ...   

Really though ... the difference is well worth the effort. I figure I got a couple hundred into the setup, including some long RCA cables to get the signal to the speakers. You really don't want to be in the room when running the tests as that can screw ... er ... skew the results dramatically.

It's not all software though ... you DO have to pay attention to hardscaping to get rid of the big lumps first. Anybody else tack carpets to their ceiling to tame primary reflections?



I have fun telling people to wipe their feet when they come in, and pointing up ...  

PS ... if you get REALLY bored, start playing with waterfalls ... haven't really gotten into that yet. That's all about reflections and sound wave decay as it travels your way. The basic information is automatically calculated into the output filters, but I understand you can do some amazing things getting down and dirty with those ...



PPS ... I've got a bit of a rattle at around 26hz, but I think that's my sternum ...

I am looking at JRiver right now. I have been using Foobar2000 with a ASIO driver to my Nuforce DAC. Will JRiver run bit perfect on a Windows7 system?

Yup ... I run native WASAPI using my Maverick D1+ at it's maximum bitrate and resolution. No additional drivers required. That's using either USB or S/PDIF (optical), but I prefer the sound of the USB, even though it's lower resolution. Just sounds way sweeter to my ears.

jRiver has a 30 day "try before you buy" plan that makes it nice ... don't like it, don't buy it.

Windows 8 is even better - the Microsofties put a lot of work into the audio engine, and the current generation WASAPI is rumored to be the next best thing to bit perfect.

PS ... You said a dirty word ... ASIO! Hope you're not using ASIO4ALL - The driver works well, but it can be a real PITA to kill. Uninstall, and it comes back to life first time you hit the internet and tries to take over, creating all sorts of random playback issues. You almost need to pound a digital stake thru it's black heart to make it go away permanently - as in tweaking the registry with extreme prejudice. Luck with that - it drove me somewhat bonkers when I first tried to get rid of it.

I am using the Nuforce supplied ASIO driver for Foobar, and the WASAPI driver in XBMC. I download JRiver, and the WASAPI driver is working fine. I play Pandora one quite a bit in XBMC. I do not see a Pandora interface in JRiver.

Never really noticed the Pandora thing as I don't do that. Limited bandwidth and a 5gb a month limit here. Way I understand it, jRiver development would be more than happy to integrate that, but the legal types at Pandora want too much money for the feature.

Ever try Last FM? That's available in MC ... give it a listen ...

BULLETIN
Just ripped this from the jRiver forum:

I would love native support for some online services but in the meantime I came up with something which works well.  

1) Log in to your Pandora through the web.
2) Click Share this Station and send yourself an email
3) Copy the URL from the button
4) Open Theater View and set up a New Category named Pandora
5) Inside that category add an External Page and give it the name of your station and URL from your email

I threw in about 10 stations now and works pretty well.

~~~~~~~~

No idea what that all means, as I've never seen Pandora except on my "smart" tv, and then only to see if it worked. Give it a shot - we'll be expecting a report back!  

Thanks sKiZo. I was able to get Pandora to work, but encountered a problem. Since JRiver is using the url to stream Pandora, it uses the default Windows7 audio drivers. These are not WASAPI in Windows7! As a result the sound from Pandora is very poor. Pandora in XBMC does not use a url interface, and therefore, I get a WASAPI output.

I like your idea on room EQ. When I was sweeping freq, I found a few narrow spikes that I would like to remove. One is at 530hz, and very narrow. From what I have read from the links you provided, this should be easy to do!


Update:

I found this for Foobar2000;

http://mathaudio.com/howto-speakers.htm

This does not seem to have all the features of REW, but it seems to do quite well. I just ran my room, and the resulting impact is indeed astonishing to say the least! Mathaudio allows you to change the EQ while listening to music, and the differences are very apparent. It removed all of my spikes.

Maybe post back in the jRiver forum thread I linked and see if there's a fix for the driver issue using Pandora. They're very helpful and knowledgeable there, and I wouldn't doubt the question's already been answered somewhere.

Took a look at Mathaudio ... one more tool to play with. I'll play around with the trial version - I should be able to run it as a plugin from jRiver - but it'd have to be REAL good at $100 to get rid of the beeps, now that I know what I can do for free.

Mathaudio is free for Foobar2000! Give it a try!