Do any of the spl guys out there reframe from burping thier subs/ systems and just play loud music?
On a side note I don't get this new way of spl which has been around for a while.
does anyone know when burping took over the IASCA spl song that used to be used back in the late 80's early to mid 90's?

 

playing music is too much of a constant current draw.

 

Thats what bass race is for .

 

burping is playing the track for a couple seconds, ei, play 35 hertz for a second or 2, then switch to say 40 hertz, or play the 35 again. You could also play one freq for a second, pause, then play again, pause, play.......so on. this way your power source doesn't drain.

maybe someone else could explain better if this makes no sense.

 

Bass race is essentially trying to play a song as loud as possible in your class (I think they range like 120-129.9, 130-139.9, etc) Over 30 seconds and taking your average score. Burping is playing a test tone for usually like 3 seconds at peak frequency. This allows for way more power than most woofers are rated for, however will defintely reduce the life span of the woofer.

 

Okay I will explain why we "burp" now instead of playing music.

In the 80's and early to mid 90's you had either a sealed enclosure or infinite baffle.

When I first got into car audio the ported enclosure was in its infancy, this was back around 1995 or so.

With a sealed or infinite baffle type install the response of the woofer(s) is fairly flat.

With a ported enclosure we are able to tune it to a certain frequency that works best for the woofer(s) and the vehicles fs to give us a big gain at that frequency.

Also we burp one frequency because with the amounts of power that woofers see now a days, playing a frequency that is below the tuning of the enclosure (which in most cases for SPL is high say 50hz plus) will cause the woofer to lose control, and losing control with 5k plus is no good. Also playing one frequency is a lot more efficent then music.

I hope this all makes sense.