You couldn't be farther from the truth 🙄I'm not seeing very much information from their descriptions though, not sure that this, after all, is anything interesting.
I suspect what they are talking about is actually baffle step (2pi to 4pi transition) dressed up in BS ?
Just try harder in your search. This should give you more information about their unique flow resistive damping of the rear openings.
I thought you were trying to reduce box colorations, not to enhance them. 😉As for box colourations, this link looks more interesting... 6moons.com - industry features: Will the original please stand up?
Rudolf
I'm not seeing very much information from their descriptions though, not sure that this, after all, is anything interesting. There are no photos of the rear side, but the text says it is try-amped active and the electronics are on the backside. With this much electronics, it would be surprising if it wasn't a flat FR.
I suspect what they are talking about is actually baffle step (2pi to 4pi transition) dressed up in BS ?
If you click on downloads there is a technical drawing which shows two vertical slots in the back whose dimensions are 435mm x 84mm either side of the amp pack.
I don't see how baffle step correction would in itself lead to a cardioid bass response.
It works for me so you might have to google 'ME Geithain' to get there.
hmmm... works for me now too. Some intermediate router myst have been down.
dave
Member
Joined 2009
Paid Member
This should give you more information about their unique flow resistive damping of the rear openings.
Rudolf - thanks ! - yes, this is much much better. Now it looks much more like I was thinking with the big ports behind the driver. I'm liking what I see here more and more. The only thing I noticed that I was a bit unsure of, the designer talks about slowing down the speed of sound with stuffing by special materials - something I thought MJK had already debunked. But then it also says there are some chambers inside to delay the back wave. Looks really interesting. Is it a kind of TL
I thought you were trying to reduce box colorations, not to enhance them. 😉
It was a kind of counter example 😉
If you click on downloads there is a technical drawing which shows two vertical slots in the back whose dimensions are 435mm x 84mm either side of the amp pack.
got it!
Attachments
Last edited:
Member
Joined 2009
Paid Member
Member
Joined 2009
Paid Member
Pardon? When reading through the current scientific literature there is very broad agreement that 1/3 resolution below the Schröder frequency was a very bad mistake. 1/3 wasn't chosen because of its perceptual validity but because of technical limitations.
Who agrees ? References of the current scientific literature !
Everyone knows ear low freq loudness bandwidth is even more coarse than 1/3 oct.
- Elias
Also what is the likelihood of glass fibres or dust escaping through a bass reflex port into the room ?
100 %
Who agrees ? References of the current scientific literature !
Everyone knows ear low freq loudness bandwidth is even more coarse than 1/3 oct.
- Elias
Excatly, loudness but unfortunately that's not what I was talking about.
I thought that would be obvious. But the problem to solve is more tricky. Read what Siegfried Linkwitz is writing about it.It's a U-frame -
Some more to read about the innards of a cardioid U frame from John Kreskovsky.
Rudolf
Member
Joined 2009
Paid Member
I thought that would be obvious.
always dangerous to make assumptions 😱
Seems to me the design is unnecessarily complicated in order that they could accommodate an integrated amplifier into what is essentially a U-frame. What would have been more interesting was if it was an attempt to remove boxiness from the mids. They created a 'cavity' behind their dipole mids, between the back of the mid-hi baffle and woofer. Time to move on....
I'm revisiting the Boffle, looking at it as a dipole with 'built in' room treatment behind it which looks as if would address colourations from box/room. There's not a lot of DIY examples about.
And I found something over on audio karma under the title baffle that looks like an attempt to create a structure to absorb the back wave - and it looks remarkably like the Zu speaker technology. I think I found this before but wasn't thinking about box colourations much at the time.
Attachments
Last edited:
Gareth,
I believe that Gary Pimm's speakers are essentially Boffles.
There are no images behing the icons you posted, can you point us to something we can read?
dave
I believe that Gary Pimm's speakers are essentially Boffles.
There are no images behing the icons you posted, can you point us to something we can read?
dave
Member
Joined 2009
Paid Member
ooops !
go here: The Boffle - AudioKarma.org Home Audio Stereo Discussion Forums
post 9.
Didn't see anything at Gary's website that looked like a baffle ?
the closest I could find was "The basic test setup is a large infinite baffle (wall in my basement)"
go here: The Boffle - AudioKarma.org Home Audio Stereo Discussion Forums
post 9.
Didn't see anything at Gary's website that looked like a baffle ?
the closest I could find was "The basic test setup is a large infinite baffle (wall in my basement)"
I don't see anything at the AK thread that looks like a boffle (even the thing called the boffle)
http://p10hifi.net/tlinespeakers/forum/boffle-RadioElectronics.pdf
http://p10hifi.net/tlinespeakers/forum/Boffle-patent.pdf
Basically a U-frame with a heavily damped back-side
Gary doesn't seem to have any narrative on his speakers (my info is from Bud's & Chris' personal exposure)
dave
http://p10hifi.net/tlinespeakers/forum/boffle-RadioElectronics.pdf
http://p10hifi.net/tlinespeakers/forum/Boffle-patent.pdf
Basically a U-frame with a heavily damped back-side
Gary doesn't seem to have any narrative on his speakers (my info is from Bud's & Chris' personal exposure)
dave
Member
Joined 2009
Paid Member
I don't see anything at the AK thread that looks like a boffle (even the thing called the baffle)
I wasn't saying there was, but the post in that thread, with the images that you couldn't see in my post, were claimed to be designed to reduce back wave coloration.
You must have tried this Boffle approach, seeing as you've probably tried most things in speaker kingdom! - what are your thoughts ?
I've only faked it up as yet. Appropriately damping the back of a regular box with the back removed. In most cases an improvemtn in quality with a reduction in quanity of bass.
Many things i haven't tried yet.
dave
Many things i haven't tried yet.
dave
Reading John Kreskovsky (Bless him...) is harder than reading Quantum Field Theory. Just my measley brain no doubt. 😀
A review of where we have got to is in order I think. A BOFFLE is a box with lots of felt pads with holes in them stacked along it seems. That looks rather good if the pads are held in place somehow.
Sorry, no open baffles there. We are talking box colouration, after all.
Do continue. 🙂
A review of where we have got to is in order I think. A BOFFLE is a box with lots of felt pads with holes in them stacked along it seems. That looks rather good if the pads are held in place somehow.
Sorry, no open baffles there. We are talking box colouration, after all.
Do continue. 🙂
Attachments
Note that what looks like a panel on the back should be another piece of damping and th ehole is not required.
Pimm is using Ultratouch witj good effect in his.
dave
Pimm is using Ultratouch witj good effect in his.
dave
Good Grief, a boffle works much like the Cochlear Canal in your ear. I didn't realise the canal has an output window as well as an input! 😎
How The Ear Works - With Pictures
I'd trust nature to evolve an efficient structure, albeit this is a microphone, but then that is the same principle. Next thing I'll figure out the vocal chords are a ribbon tweeter. 😀
How The Ear Works - With Pictures
I'd trust nature to evolve an efficient structure, albeit this is a microphone, but then that is the same principle. Next thing I'll figure out the vocal chords are a ribbon tweeter. 😀
Attachments
- Home
- Loudspeakers
- Multi-Way
- Box colourations - really ?