Log in

View Full Version : Pocket RTA for Real Time Spectrum Analysis

Jon Westfall
12-02-2005, 12:00 PM
<div class='os_post_top_link'><a href='http://www.4pockets.com/software_info.php?par=PocketRTAPro&pro=&pid=55' target='_blank'>http://www.4pockets.com/software_in...Pro&pro=&pid=55</a><br /><br /></div><i>"Pocket RTA Pro is a highly portable real-time spectrum analyser for your PC and Pocket PC. PocketRTA Pro has many advanced features which are normally only found in much more expensive sound analysis software, providing fast and accurate spectrum analysis suitable for both amateur hi-fi enthusiasts and professional A/V engineers. Uses include system calibration, monitoring of noise levels and testing of audio equipment. "</i><br /><br /><img src="http://www.pocketpcthoughts.com/images/web/2003/westfall-20051202-pocketrta.jpg" /><br /><br />While this software isn't new, one of our readers was very impressed with it and decided to share it with us. If you're a sound engineer, this looks like some software you may want to take a peek at. Then crank it up and enjoy :wink:

12-02-2005, 12:34 PM
RTA Pro is very good as a spectrum analyser (particularly if your PDA has additional, decent analogue sound input so that you don't need to rely on the, in general, crappy frequency response and not very good signal-to-noise ratio of the built-in microphone), but its synthesizer capabilities are far from perfect (if you want to generate sounds - noise, sine wave(s) or anything).

See for example http://www.pocketpcmag.com/blogs/index.php?blog=3&amp;p=303&amp;more=1 on two, much better PPC-based alternatives in this respect: the free Pocket Oscillator and the commercial iPlay.

12-02-2005, 02:30 PM
I guess this will not work so well with the Axim x50v built in mic ro SPL usage? This would be a nice setup for being able to adjust the speaker levels in HT systems.


12-02-2005, 02:57 PM
I guess this will not work so well with the Axim x50v built in mic ro SPL usage? This would be a nice setup for being able to adjust the speaker levels in HT systems.


The x50v has a mic-in ring, so, you can directly connect an external mike with a decent frequency response to it.

12-02-2005, 03:01 PM
I did not know that! Thanks for the tip!


12-02-2005, 07:02 PM
Remember that the PPC / PocketRTA combination needs to be callibrated: The software can only assign an arbitrary number to the difference between the quietest sound and the loudest sound your PPC can detect, it can't relate that directly to 'real' SPL (for our non-initiated readers SPL = Sound Pressure Level). However, as long as you can get access to another callibrated SPL meter sometime, then setting up PocketRTA is really easy. The exact method varies with the PPC model, but the manual is pretty clear.

Actually PocketRTA Pro is new as far as I am aware. PocketRTA has been around for a while and I use it a lot. The Pro version is new and has some neat extras (but not neat enough for me to want to pay to upgrade!). Despite the poor frequency response of the built-in mic, I find it does a pretty good job of identifying frequencies of squeals and rings in a live PA environment, enabling me to EQ them out a lot faster than I can by using my ears and guessing.

And I don't think I have ever needed to use the sound generation facilities which Werner says are poor, so I'm not bothered by that failing.

12-03-2007, 04:30 AM
Can anyone help?

First - how do you close the program? I can't figure out how to get out of it without doing a soft reset.

Second - how do you callibrate?

Third - where do you get a manual for this? I have looked all over and cannot find anything. Maybe if I could find the manual, I could figure out how to close the program and how to callibrate it.

I am using this on a Cingular 8125, but may also try it on my Dell Axim X51v. My goal is mainly to test dB levels. We are testing a new siren/loud speaker system at work next week that is for Emergency Evacuations and need to know how loud the siren/loudspeaker is. Would like to record the sound as well.


12-03-2007, 05:25 PM
The exit button depends on your device but it's usually one the front of the PPC, at the top, on the right. On my Vario II it's the internet browser button. On my Xda2s it was in a similar position. On that device the same button also was used to adjust the sound pressure meter callibration up which was a pain, because it upset the callibrateion every time I exited the program. On my vario II the callibration is done with the softkeys.

It's a LONG time since I read the manual. But I recall there used to be one, or at least a FAQ on the website... try this link (http://www.4pockets.com/support/manuals.php)

I've never used it to record. I'm not even sure it can. There are other apps to do that, and, indeed, there are some on the 4Pockets web site.

Much as I like (and use) this software, for callibrated sound pressure measurements, you really need a dedicated unit. There are some pretty inexpensive ones available. What PocketRTA will be good for is to help you work on the sound EQ so the announcements are clear. I regularly find that if I'm struggling with clarity, then I'll get 'it's too loud' complaints above 85dBA, but if I've got the EQ right and the clarity is there, I can push the sound pressure above 94dBA (that's eight times louder) without getting any complaints.