HB3 and Heybrook frequency specs in general...

[JwEs]

My manual says 35Hz to 20Khz. Is that +- 3db or 6db ? Was there a +- reference in Heybrook speaker specs in general or it depended on market info (competitors and what not...) ? I'm saying this because not mentioning the error makes it useless....
I found by ear and a frequency sweep that they respond very well until 40hz. I can hear 35hz but it's pretty lower in volume and after that it's a big steep. 30hz is almost not hearable at all, although the glass on the window vibrates a bit. I can definitely hear until 20hz with my Sony MDR 7506 so it's not my hearing...

[bob orbell]

Hmm, sounds like you need to fix the glass in the windows with putty.

[Richard]

That will be the room's resonance across it's width.

If you put your dimensions into a calc you'll see the fundamental and harmonic frequencies along the various axis and yours are well spread with few multiples, http://www.mcsquared.com/metricmodes.htm

If you then enter values for a 4m or 5m square room you'll see why many rooms have a boost at 40Hz especially if the listening seat is on the room boundary. Ironically if you're used to a room with that bass lift a room without it may seem bass light.

Here's a page with some interesting info about seating position, http://realtraps.com/art_room-setup.htm

Often, we can't change rooms or furniture easily but it helps to be aware when choosing speakers that will work in there. Our room is of similar dimensions to yours and has the speakers angled in with their front faces 0.7m from the front wall and the seat 1.7m from the back wall. Even then I've noticed that many folk who've had a listen instinctively lean forward and sure enough (as that article suggests) it is a little cleaner there but we make small changes elsewhere and adjust to it I suppose.