[Ilkka]

SteveCallas wrote:

Aren't that large? It's up to ~10db at some points.

Sorry about the bad wording, I meant that the difference in SPL at different frequencies isn't as large as your simulations show when both systems are properly optimized. For example your simulation shows around 7.5 dB difference at 20 Hz when the correct value is 3.5 dB. At 50 Hz you show 5 dB when the correct value is 1 dB. So in other words you tried to inflate the difference in favor of SLLT. As I have said many times, I just want to keep things fair.

Though different drivers are in play, porting is the main reason why a 12hz tuned SVS Plus can provide as much distortion limited output in the low teens as Velo DD18.

I've never claimed that porting wouldn't help to boost the output around the tuning frequency. Are you forgetting who you are talking to?

And although pretty much OT, but since I have heard both subs in question (even owned the other), I can tell that there is no question which sub sounds subjectively cleaner and more powerful at any frequency, at any output level. SVS' port noise becomes very audible at those output levels (THD test doesn't pick that up). Plus if you look at AV Talk's measurements, you'll notice that when pushed any higher than 95 dB average (90 dB absolute SPL) below ~17 Hz, SVS' THD will shoot sky high, while Velo maintains its composure much better. Also AV Talk's measurements don't show what happens below 15 Hz, but based on my own measurements, I'd predict that SVS' "blue line/90 dB" THD will grow extremely rapidly below 15 Hz (already before the small signal level tuning frequency at ~11 Hz due the fact that the port will start to compress heavily).