Having now read a bit about the behaviour of passive radiators I am suitably put off the idea. They require tuning like a bass reflex and have a high mass which can be altered by adding more mass to change the Fs or Fp to be more precise :grin: You generally choose a diameter a bit wider than the ac...

Yesterday I cobbled together a speaker using my spare pair of 17 litre cubes. I put in my pair of B&W 6.5" mid bass from my P4 transmission lines and plonked the tweeter spheres just behind the up firing mid bass. I borrowed the inductor from the P4's for the low pass and for the high pass ...

Is that 42-0-42V with taps at 21V ? I expect once rectified it will be enough to launch those amp boards into space

Hope you are having fun.

Glad you got it going eventually. Attenuators can really make a difference - switch quality, type of resistors. Nothing beats no switch at all, just two resistors per channel soldered together. Can't change the volume though without doing a bit of soldering :lol: If you only have one source then you...

Here is a sketch of what it will look like. You may notice I have ditched the up firing tweeter. I think it sounds better without it. https://i.imgur.com/hhK4VRp.jpg I expect there to be more improvements to come as these are still a cobbled together affair. The chipboard cabs were vastly improved w...

I removed the crappy wooden legs on each speaker in case I had to backtrack and made some more out of lengths of 19 x 6 mm solid aluminum bar. The down firing driver is now only 17cm from the floor with a 30cm diameter steel hemisphere below it. https://i.imgur.com/f3Wlu51.jpg Speaker is only 61cm (...

Now I get to thinking do I actually need a full sphere at the bottom ? I could try just a hemisphere with the flat side on the ground. Not sure what effect that would have on things. The bass with a wavelength longer than 30cm probably won't care as it just wraps around it anyway. What will be chang...

Don't know about you but I'm getting sick of this thread :roll: And the possibility that I am chasing something that can't be achieved. Anyway, further messing about. I replaced the HDPE balls with the steel spheres. I did not put the foam back as I thought it was choking the openness of the speaker...

I replaced my crappy tweeter sphere support with three 35mm bolts hot glued at the edge of the cut out. That has dropped it much closer to the up firing mid bass. Not listened enough to form an opinion on this tweak. Latest picture with lowered tweeter sphere, shortened legs and foam around the down...

It does seem a waste of space to have a 30cm sphere at the bottom doing nothing. I could just fill it with sand to try and "mop up " the vibrations. Other idea was to put another driver in it but then I will have two drivers almost kissing. Would have to be a low passed bass driver of cour...