Full range unbaffled ?

[MartinJones]

Anyone ever had a go at playing with a full range driver (eg. Fostex F120A) as an unbaffled loudspeaker?

Yes, yes, the bass will be hopeless; but consider valve amp connected to non-x/overed driver with no 'boxy' effect.

Martin

[James D]

Seems a bit perverse...

Surely even a small baffle is worth doing and any open baffle has no boxy or horn effect by definition...

Running adriver without a baffle results in a strange tonality as all the lower midrange and upper bass is missing as well as the nether regions - and Yes I have tried it and still do occasionally but it really isn't worth anything other than a quick test

James

[The Shadow]

Martin,

If I had used my Fostex FE108 Sigma drivers baffleless for any reason other than to see if they were working or not, I would have junked them straight away.

The midrange was sucked out giving a terrible hollowness to voices and there was searing quality to the treble that was quite frankly offensive.

Cone drivers are meant to be used on a baffle or in a cabinet. They are a disaster unmounted I'm afraid.

Steve

[Paul Barker]

otoh I have heard that Lowthers are improved by open baffle placement, particularly with one driver in front of another to reinforce it.

Not tried it though.

Talking to Vry he has removed the whizzer on one, so I'm going to borrow it and try it dipole (OB) for midrange, hopefully without the horrible forward sounding resonating whizz bang.

[Paul Barker]

otoh I have heard that Lowthers are improved by open baffle placement, clearly high pass frequency is quite high, might be 300hz or so I don't quite remember.

Talking to Vry he has removed the whizzer on one, so I'm going to borrow it and try it dipole (OB) for midrange, hopefully without the horrible forward top end....

[petercom]

But, Paul, the man asked about no baffle not open baffle.

A baffle will alter the dispersion characteristics through two factors, the baffle 'step' where the dispersion changes abruptly from 2pi radiation and the baffle edge diffraction where the edges of the baffle act as secondary sources.

A baffle may also add its own coloration through resonance of the panel/material used.

So if you could find some resonant free method of holding the drive unit firmly in space you might think you were gaining some advantage.

However operating without a baffle reduces the path length between front and rear of cone and causes cancellation at low and lower mid frequencies dependant on the driver dimensions. There are also odd effects throughout the midband as cancellations occur at different path lengths dependant on cone breakup modes.

All-in-all you are better off using a well designed baffle. Refer to Gilbert Briggs Sand Filled Baffle for more info.

[Paul Barker]

But, Paul, the man asked about no baffle not open baffle.

I know I digress.