Any help with these would be appreciated 1. Using a tempest in a approx 200 vented enclosure, what Fb would you use which would give really good sound quality (ignoring SPL) and which would give you really high SPL (igoring sound quality and a very low Fb) 2. Is there any physical way of measuring the air speed in a port. I would have use of any equipment in my engineering college (doubt they'ld have anything useful though) 3. And I'll ask this question again (just for hope), does anyone have a idea of the pressure build up in a vented enclosure (just say for example, a 200L vented tempest with a Fb of approx 17Hz) Cheers Just have to say, I have a RS SPL meter on the way, can't wait to find out what SPL I can produce in my room with the Tempest. Hopefully about 115dB or more!!! Only for people like us, hearing aid companies would go out of bussiness.