Audio Tools on iOS

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Gold
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Audio Tools on iOS

Post by Gold » Sun Dec 23, 2018 12:54 pm

For the past month or so I’ve been using Audio Tools software on iOS with the iAudiointerface 2. The AP Portable One doesn’t have FFT capability. I’m working on building EQ’s and an FFT with a pink noise source will make that easier to see center frequency and bandwidth.

I’m becoming less enamoured with the setup. It’s really designed for acoustic measurement with a microphone input. It’s a bit touchy and confusing to me. Setting line levels and being sure of what you have is not straightforward. I’m going to keep with it and maybe I’ll get used to it. I have a feeling I’ll go to plan B eventually.

There is a Rigol 2 channel scope with FFT that I’m looking at. The 2000 series has a vertical resolution of 500uV/div. The 70MHz version with 2gig sample rate is $875. For general work and FFT I think that’s quiet enough. It’s big money to get something quieter.

I can use the iPad as a signal source with the interface I have. There is also an iOS DAW app for $10 and I have a MOTU USB interface that might work. If not I can get a cheap multichannel interface. It would be nice to have four channel output for lathe testing too. Then I can use an M/S board for balanced input to the scope.

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Re: Audio Tools on iOS

Post by mediatechnology » Sun Dec 23, 2018 3:21 pm

Paul - I don't have any iOS machines but I think emrr has used SpectraFoo.

In the Win space I use AudioTester which has gone awol from the web but is still available as Trial-ware as well as YMEC and Visual Analyzer.
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Re: Audio Tools on iOS

Post by Gold » Sun Dec 23, 2018 3:51 pm

I think Spectrafoo is only available for OS X. Choices for iOS are limited. I don't want a full size computer on the bench. There is no room and I know I would kill it within a few months by banging it, spilling something in it or otherwise abusing it. An iPad can stay out of the way.

I like the idea of an iPad on the bench and an iPhone on the go. I once tried to set up Right Mark on a PC laptop and failed miserably. I'm not comfortable with PC's for general use. I only use a PC for a DAW in the studio. It's a dedicated machine not connected to the outside world. The setup never changes and software changes are made with extreme caution. Trying to get a bunch of stuff working together on a PC that hasn't been extensively tested by someone other than me is a loosing proposition and a waste of time. I tried REW on a MacBook but wasn't into it. Like Audio Tools it is mostly designed for acoustic measurement. Free isn'y my number one concern. Ease of use and ergonomics I'm happy with are.

The scope would be useful as a scope and for FFT. Is relatively compact and is more like button per function which I like.

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Re: Audio Tools on iOS

Post by mediatechnology » Sun Dec 23, 2018 3:54 pm

I think a scope may lack the dynamic range you would want.
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Re: Audio Tools on iOS

Post by mediatechnology » Sun Dec 23, 2018 4:02 pm

BTW there are hacks for some Rigols to unlock features and bandwidth.
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Re: Audio Tools on iOS

Post by Gold » Sun Dec 23, 2018 4:35 pm

mediatechnology wrote:
Sun Dec 23, 2018 3:54 pm
I think a scope may lack the dynamic range you would want.
The scope I'm looking at has a vertical scale of 500uV/Div. Isn't 500uV about -65dBu? That seems pretty good to me. I have the AP for noise floor floor measurements below that. I'm not sure I need FFT measurements below that too often. I could always put an amplifier in front of the scope if I want better resolution at very low levels. No?

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Re: Audio Tools on iOS

Post by Gold » Sat Dec 29, 2018 2:20 pm

I’ve spent some quality time with AudioTools and the iAudioInterface2. I’m starting to get the hang of it. I think this might work out to be a great measurement system. I have a bunch of things to still work out. I’m actually enjoying working this out. This has the potential to be a scalable multi channel input system all connected via a wireless router like an Airport. You could check out a whole building audio system at multiple points as long as there is good WiFi. Then have all the plots appear on the master iPad with math functions available. You could then upload to Dropbox and import as a tab delineated graph into a spreadsheet.

If the $99 USB interface I ordered works then it will out cost about $50-$75 per channel assuming a used iPad costing around $100 is used.

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Re: Audio Tools on iOS

Post by mediatechnology » Sun Dec 30, 2018 8:51 am

Paul -

If you're interest is doing FFTs for EQ then you don't need the dynamic range you would for electrical measurement. I'm glad the iOS solution worked out.

For electrical measurements a good audio interface and PC or MAC software will almost rival what the AP can do. What you don't get that the AP or Prism offer is extended measurement bandwidth and flexible interfaces.

I've used a number of PC-based tools over the years and none were difficult to install. The machine itself is safely under the bench with the keyboard and mouse on a pull-out drawer.

The biggest problem with one of them (YMEC) is their licensing system which makes it difficult at times to replace a hard drive.

I sometimes use RMAA but generally default to AudioTester, Visual Analyzer and YMEC. (Audio Tester and YMEC were both about $40.)

SpectraPlus is nice but expensive.
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Re: Audio Tools on iOS

Post by Gold » Sun Dec 30, 2018 12:29 pm

mediatechnology wrote:
Sun Dec 30, 2018 8:51 am
I've used a number of PC-based tools over the years and none were difficult to install. The machine itself is safely under the bench with the keyboard and mouse on a pull-out drawer.

If I use a desktop PC then the rig isn’t portable. If I use a laptop, which I have, then it takes up too much bench space and I risk damage.

I tried RMAA on the PC laptop I have and was unable to get the gain structure right. REW on the Mac worked a bit better but didn’t seem worth the trouble of getting a new laptop for the bench. My Airbook is my studio office computer so I need it to be dedicated to that.

The iPad seems like a potentially perfect solution for me. The FFT module was $25 and the Smaart channel is $50. The Smaart has a nicer display and does 1/48 oct while the FFT module tops out at 1/24. You problay only need one or the other.

Unlike OSX or Windows, once you buy iOS software it is available on any device registered to the account. So setting up a multichannel system is inexpensive until you need a whole lot of channels. Small, portable, scalable, inexpensive and iOS is more like button per function. I feel iOS has a lot of potential in this area.

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Re: Audio Tools on iOS

Post by mediatechnology » Sun Dec 30, 2018 1:05 pm

I don't do portable but if I did I would want to use a tablet or a phone too.
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