Quick 'n' easy open baffles.

[alnewall]

Stuart.

The bass drivers are Eminence Beta 15a from Maplins. The same as Nick uses i think.

Next step is to try some horn midrange units from the depths of my shed and maybe some horn tweeters. Obviously these are sealed at the back, and may defeat the object of open baffles. But i might as well find out.

[Tony Moore]

There was just a huge flash and a bang that shook my house - it came from the direction of your house Al...Are you testing amps tonight? If not then I guess it may have been atmospheric....

[alnewall]

No, i've not been flashing or banging tonight.

Was a bit loud though. Set off next doors car alarm.

[alnewall]

Since i've been playing around with open baffles, i noticed that some midrange detail has been somewhat distant, sometimes backing vocals seemed to coming from behind the hedge at the bottom of the garden, while the band was playing on the patio.

I blamed this on the open baffle thing as it never happened when using cabinets. So i spent a few hours experimenting with horn midrange units and other drivers in an effort to correct this. The horns etc produced some interesting sounds, but nothing i'd want to listen to long term.

Back with the original configuration, i added some cheap caps to the full range drivers to bring them in at roughly the same frequency as the bass units cut off.

Bingo, everything sounded much better.
The backing singers returned to the patio and there seems to be an effortless feel to music that was missing before.

Presumably the two drivers were presenting an awkward load to the amp at the overlapping frequencies, because previously i was using a low pass filter
and running the Audio Nirvanas full range.
I'd been shying away from a crossover in the belief that the extra components might degrade the sound.

This is probably basic stuff for most of you but at least i've eventually learned something.


Now then, i want to try some horn tweeters from around 15/16kHz upwards.
The Motorola piezo ones seem to have a varying impedance dependant on frequency, so how do i work out the required cap value?