SpectrumView Plus

It saves every setting I put in place through even restarts but it turns the grid lines on SPECIFICALLY, and CONSTANTLY, to a point where I’m wondering if it’s my phone glitching or the app, cause it’s not me, I would have accidentally pressed any other button in settings by now, but it’s just always the grid lines and I always find myself turning them off- BUT, that’s my only issue with the app, so if you like grid lines this may be a five star review for you.

Worthless. Settings keep resetting on their own —set sample rate and maximum frequency and they reset when I uploaded a couple tracks I wanted to analyze. Go change it again and play the track and guess what, reset! After doing this a countless number of times I gave up! Not too mention I have settings set to display spectrogram when using playback or record but no it just stays in playback! Also when I do switch to spectrogram view while playing a track I can’t pause or pan! I want my money back!!! I can’t deal with worthless waste of time!

The app crashes when I try to play an iTunes song.

This is my favorite frequency analysis app. Incredibly useful and insightful. You can plug your music in or use the mic. A total pleasure to use on drugs. Sometimes it clips when I run my own tracks on it though that’s pretty minor.

The original, free SpectrumView was an eye-opener about the way a device like the iPhone could change the landscape of tools: quite unexpectedly, and without spending a cent, I suddenly had in my hand a fair equivalent of a kilo-buck spectrum analyzer; a tool I’d needed from time-to-time over the years, but “knew” I’d never own, or even have access to. It’s been great that the author(s) have continued to support the tool over the years, and, at some stage, even began extending it. I’m glad to have a number of those extensions, and, in this “Plus” version, to obtain them without the hassle of in-app purchases. Also, after so many years, I’m happy to put some money in the author’s pocket for all that work. (As to the reviewer who stated that the app has an 8 kHz frequency limit: go to settings and pick an audio sampling rate twice that of the maximum frequency of interest; even my iPhone 5s has no problem reaching 24 kHz. Whether the iPhone microphone is responsive to such frequencies, and equally responsive across whatever frequency range it does handle, is another matter, but that’s what external mics are for.)

Seriously

The free version is very cool. Pretty amazing for a free app. The plus version, not so much. In the time-domain view, you can't zoom in or out in the time domain (left/right); only up/down (frequency). Also, in both versions, the time scale (x axis) has horrible increments and tick marks. Like, 2.8 seconds, 5.7 seconds, 8.5 seconds (!!!). It's almost impossible to read the duration of any event, especially since you can't move the waveform left/right. Another enhancement I'd like to see would be the ability to put a marker on multiple peaks in the spectrum analyzer and maybe even a peak finder. In the time domain, the ability to put multiple markers and record the time between markets/events would be great.

When I bought this using my 4S it worked great one of my fav apps. On my 5S the colormaps are all wrong. I reported the bug got no feedback and no new version since 2013.

If you have an iPad mini retina (and perhaps other devices as well?) the screen color on this app will be red, not as the blue pictured in all the screen shots. This makes it very difficult to discern the spectrum readout as the colors are too similar to the background. When I contacted the makers of the app they said they were aware of the problem and working on it. That was 8 months ago. No fix yet. Frustrating. 2 stars from me until this changes.

As a long-time practitioner in the field of signal processing, I’d say Spectrum View+ is a nicely implemented and useful tool. It does many things well, and deserves to be on a solid path of continued updates. In that spirit, here are my suggestions for upgrades (I focus here only on the spectrogram mode ) * On my iPad2/iOS7, the major tick marks on the TIME axis always come up with non-integer values (e.g. 0, 11.0, 21.9,…). This varies depending on the sample rate, #samples selected for the FFT length, etc. Please change this so the major time ticks are *always* Integers. This would make reading the display much easier. It would also be very useful to make the major time ticks multiples of say 1, 10 , 20, 60… seconds, that sort of thing. * We need a way to expand the TIME axis. This could be done via a ‘speed’ control that would set how fast the display scrolls in time. I realize this will interact with the FFT update rate and other parameters but that can be dealt with internally. Time stretch could also be implemented via a pinch function that would stretch the axis. * Please add options for different spectrogram color mapping pallets. For example, grayscale, inverted grayscale, etc. There are many other standards in the ‘industry’. * Please add a ‘brightness’ and ‘contrast’ slider for adjusting the display. I’m sure I speak for others out there who like to tweak knobs and adjust the display properties for spectrum viewing. Offset and gain are typical ways of providing this control. * It would be very useful to have an alternate method of expanding the frequency axis. I would like to see an option to enter the frequency axis major increment *directly* via a manual entry. For example if I enter “100 Hz”, then that is what the major ticks will be. I realize this would require the horizontal reference lines to be automatically adjusted, but this approach would be very helpful. All for now, Cheers - PLM