Delaytime vs. Temperature


…a needless undertaking in connecting a pro audio system to the Internet of Things (IoT)

I bet you know, that a change in temperature will affect the speed of sound an thereby your well adjusted delaytime of you speakers. I bet you also know that there is no need for a panic attack. But hey since I´m a perfectionist and there are more and more tools to adjust this issues I thought about „why not connecting a pro audio system to the fast growing Internet of Things. OK, in truth I just wanted a environment sensor to connect it to my SNMP setup to show in my „IT For AVs | media network for events“ workshops within the PRTG network monitoring software. …but at the end I´m just a child who needs to play 🙂

C A L C U L A T I O N 

– delay time – 

Workflow

Calculate the delay time offset over temperature change for a given [measured] delay time.

  1. Note the temperature during delay time measurements and fill in „Temperature 1“ *1
  2. Note the measured delay time in [ms] for each different delay position and fill in „delay time [measured]“
  3. Read out the new temperature from your sensor and fill in „Temperature 2“
  4. Use the calculated „Change delay time with“ setting and adjust your delay time
  5. Note the new temperature and delay time for the next offset calculation
  6. Repeat for each delay position *2

hint:
*1 Working indoor, you may average 2 sensors on different room levels within the „sound-line“
*2 Each delay line speaker need a separate calculation

Extreme subwoofer example

Extreme delay tower example

Link to google spreadsheet

Calculator

C A L C U L A T I O N 

– air absorption – 

Workflow

Paperwork only…

  1. Note the temperature and humidity during measurements
  2. Note the related distance in far field to the sound source
  3. Calculate the air absorption for frequencies of interest with parameters from 1.+2. and note them for later
  4. Repeat step 3. with updated temperature and humidity
  5. Calculate the level difference
  6. Adjust air-absorption EQs
  7. LISTEN
  8. CHECK LIMITERS!

Link to Sengpiel

Calculator

M E A S U R E M E N T 

– L I V E   D A T A – 

I thought „hey, you need to measure anyway, why not proper from the scratch? Setup my sensor, connect it to my mobile hotspot, go to my webpage, calculate, change delay time when necessary. 

Well OK, it is a bit nerdy. This graphs will show my live sensor data when it is connected to the internet of things. I can also monitor it in a local IP network with PRTG and recieve alarms for custom delaytime thresholds. …I am working on a non internet based LPWAN version talking direct to a speaker management processor.

Temperature

now

past hours

past 48h

Humidity

now

past hours

past 48h

…DO YOU WANT TO PLAY WITH ME?

I need someone who can create online calculation in mathlab or take over the data from thingspeak to a java calculation with custom forms.

The next goal ist to enter the start temperature and measured delay time into a web based form and the calculator should pick up the actual temperature from a given thinkspeak channel.

Please contact me!