The curious case of my new "Boffle" speakers

[w1jim]

Don't ask me why, but I picked these up from an estate sale the other day.
They are the Hartley boffle design - a combination of a box and a baffle. The idea was to accoustically isolate the backwave.
The ones I got have Norelco drivers. I've yet to hook them up - and have no idea what I'll do with them either.

Internally they have stacks of carpet padding with a decreasing diameter hole cut in them - the rear has a sheet of padding.

 

[w1jim]

Some pictures of my new speakers.

 

[fips152]

Have you listened to them? If so, how do they sound?

 

[w1jim]

Not yet - they're in the garage and it's too hot out there.
Hopefully in a few days - apparently they're supposed to be smooth, coherent but light on the bass.
The cones have a whizzer cone to them.

 

[nexus]

i imagine if they sounded great then the concept would have caught on...

 

[valvenator]

i imagine if they sounded great then the concept would have caught on...

:headscrat...but then it seems like a lot of work to put into a crappy design

 

[Gang-Twanger]

:headscrat...but then it seems like a lot of work to put into a crappy design

Yeah, I can't wait to hear about the sound. Do you have a tube rig to try them? Cool design, if it works.

 

[evsentry3]

i imagine if they sounded great then the concept would have caught on...

Now days it's called an Open Baffle design. Often done for the low end with sides to do much the same thing. The heavy padding just changes the driver Q to better mate in this design and allow the more normal lower Q driver.

And it has caught on...in slightly different form, cause it does have the potential to sound so good!

EV3

 

[Gang-Twanger]

What's Q? The resonance frequency? Oh, that's fs. So, what is Q? I forgot (Shoulda' written it down). I know Qts is the total driver Q or something like that, but I can't remember what Q represents.

"The Curious Case Of Benjamin Boffle"...

 

[Oblivion321]

This post really Boffles me. Someone put a bit of work into them and am curious how they sound.

 

[w1jim]

The guy who built them was an interesting character. He worked as a physicist and built these back in the fifties. He said that they had a triaxial driver in them and changed it to the current driver around 1970. He was under the impression it still had the triax but clearly that's not the case.
All this thought that went into this and he was running it with a Realistic STA-65C receiver; I would have thought he'd have something more intriguing.

He apparently was a real Radio Shack fan.

 

[w1jim]

Sound is "eh", but that might be on account of the Grundig "Cassceiver" I'm using.
Will make for an adequate and strange garage system though.
I should put some tweeters in the system and see how that brightens them up.

 

[toxcrusadr]

You might have some placement issues there.

 

[darg]

Yeah, I would also guess they might need more space to the wall with that kind of opening in them.

 

[valvenator]

If they're a take on open baffle then they are too crowded in. Now that I take a better look they look a lot like U-frame open baffles, don't they?

 

[w1jim]

The original owner had them mounted up high on a wall.
Hard to believe but this isn't my critical listening room!
So I'm probably not going to invest in sound treatments.

 

[MartinV56]

The History Of Hartley Loudspeakers​

the model 215 full-range driver and an ingenious cabinet design called the Boffle. The Boffle (a cross between box and baffle) was the world's first attempt at acoustically eliminating the driver's rear wave.

The History Of Hartley Loudspeakers

Founded in 1927, by H.A. Hartley in London, England, Hartley coined the phrase "high fidelity". This was a noteworthy beginning for a company who would innovate and change the face of the loudspeaker industry forever. Hartley, with engineer P.K. Turner and ideas from Barker, Voigt, and Olson set...

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