Frugel horn. Would somebody care to explain the design?

[hifinutt]

Chris,
I went for the copper coloured Alpair drivers.

Should be thread on her somewhere with photos-lovely looking speakers finished to a really high standard.

now i do love the look of the pearl acoustics sibelius and its made of 33mm french oak and has drivers made by mark fenlon and is not braced as the wood is very rigid. if these were not 5k then i would be very tempted . paul messenger wrote a brilliant review in hi fi critic in sept 2017 . apparently takes 12 weeks to make the sibelius .

in his review he mentions that they come with copper coloured drivers [95mm mark fenlon design] silver grey or paper . he states only 5% of the panal preferred the paper which has higher sensitivity and is more suited to valve amps , he says

so leaning towards making a frugalhorn or the similar pensil , i will also be thinking about the copper alpair driver or the pluvia

http://pearlacoustics.com/the-sibelius.php

[Macca]

Electrostatic panels have to be large to get any bass out of them. So if it was small it wouldn't cover the full frequency range.

[walpurgis]

Smaller, non full range electrostatic speakers (mids & tweeters) have been made. However, full range eletrostatic speakers need to be large in order to displace enough air to produce the volume/scale required. The tensioned film diaphragms, simply can't manage the excursion that moving coil cone types can, so need to have a greater surface area to shift as much air. Same applies to ribbon and isodynamic speakers.

[Stratmangler]

Why? Moving coil drivers don't have any bass either until you put them in a cabinet to prevent bass cancellation from front to back.

I was sat in front of some open baffle speakers yesterday, and there was no shortage of low end grunt.

[walpurgis]

Moving coil drivers don't have any bass either until you put them in a cabinet to prevent bass cancellation from front to back.

A suitable moving coil driver mounted on a baffle (panel) the same size as an electrostatic speaker will produce bass, but have a similar low end cut-off as the electrostatic speaker. Both being subject to LF cancellation below a certain point determined by the distance between the front and back of the radiating area of the transducer.

[Macca]

I was sat in front of some open baffle speakers yesterday, and there was no shortage of low end grunt.

Try playing something with really low bass (below 40hz) and see how well they manage. You can't just get rid of the cabinet and have no downsides.

[walpurgis]

I was sat in front of some open baffle speakers yesterday, and there was no shortage of low end grunt.

Some OB speakers employ equalisation to compensate for cancellation effects. This requires more power though.

[Stratmangler]

But how big was the baffle? Would there be the same low end grunt if the took the drivers off the baffle? The baffle is there to prevent low end cancellation.

They were a variation on these

[Stratmangler]

Some OB speakers employ equalisation to compensate for cancellation effects. This requires more power though.

These are passive, and a very benign load (and by that I mean the variant is a very benign load - the ones pictured require a fair bit more grunt) - a pair of 300B SET monoblocs was powering things, and with a downhill run and a strong following wind you're only talking about 7 watt output.

[walpurgis]

A great many years ago, there was a speaker design called the Hartley 'Boffle'. A cross between a box and a baffle!

Basically an open back enclosure with sheets of damping material between the rear of the driver and the open back of the cabinet.



I believe this was quite successful, but can't quite see how.