We are hopefully going to do a bit of a revamp to the site in the next 6 months or so and we have a lot of ideas.
One new comparison chart that I want to add is an SPL per cubic liter of cabinet metric. This would be based at the same 12, 1/3rd octave center frequencies as currently used for the burst testing. The burst SPL would be considered for each system at each bandwidth and a value assigned based on the SPL and the total external volume of the system. This way it would give a relative value of power density at each bandwidth. Should be interesting to see small systems compared to huge horns and the like in this manner. I haven't quite worked out the exact comparative formula yet. Since SPL is a log function it will likely require converting to Pa and back. Shouldn't be too bad though. Anyone want to take a stab at a normalized formula?
Below is an idea for a different type of distortion graph that was suggested by Nathan Funk at Funk Audio.
Not exactly easy to put together right now and it's just kludged together in excel at the moment but something could be automated to make it faster I'm sure. Basically the distortion captured during the long term sweep measurements from each system are charted at a single frequency as it increases with the increased output of the device during the sweeps rather than over the whole bandwidth during a single sweep. The sweeps themselves are only measured at increases of 5dB typically so a few data points will be used to extrapolate the rest of the data between to fill the curves in. Judging from the rough results here it looks like this is not an issue. It does make comparison easier but also only represents a very tiny slice of the bandwidth. Still I think it is worth adding something like this possibly though.
Here are a few charts showing a collection of drivers tested in the standard sealed cabs with the data shown in the manner detailed above at 10, 12.5, 16 and 20Hz.
10Hz Sealed Distortion.png 102.14KB 0 downloads
12.5Hz Sealed Distortion.png 111.74KB 0 downloads
16Hz Sealed Distortion.png 105.79KB 0 downloads
20Hz Sealed Distortion.png 88.29KB 0 downloads