Fane 12-250TC Retro Speaker.

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Cressy Snr
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Re: Fane 12-250TC Retro Speaker

Post by Cressy Snr » Sun Nov 03, 2019 12:14 pm

Did a bit more work on the ‘eyes’ in the speaker grilles yesterday.
8CD72FF0-ECCC-421E-AC12-F4324D58576E.jpeg
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I further closed down the ‘pupils’ by stitching a piece of 25 holes-per-square-inch, ‘binca’ cotton cross-stitch fabric to the back of the grille, along with the other two, previously existing mechanical filters.

Through the grille can be seen two of the elliptical apertures. The centre is clear, through to the cone dustcap at the centre of the treble whizzer.

The second eye, surrounding the centre hole, attenuates the outer edges of the treble whizzer itself, and there is a third, larger eye, invisible, behind the second one, that attenuates the radiation from the edge of the larger midrange whizzer.

The overall effect is (as we travel outwards from the driver centre) a progressive attenuation of the lower treble to upper midrange region, as all the ‘eyed’ panels are the same 4 inch outer diameter, so that the effective thickness of the material decreases, as we approach the centre of the driver. The highest treble tones pass unimpeded through the grille centre aperture.

After playing a few torture tracks, I can reliably say that, all traces of screech have been banished from the presentation and the rising response trend of this driver is effectively tamed.

The result is a rather nice improvement over the previous grilles, with clearer highs, a more detailed, midband, and the bass has come out from behind the rest of the frequency range.

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Re: Fane 12-250TC Retro Speaker.

Post by ed » Sun Nov 03, 2019 2:18 pm

Steve if you could measure this(with some precision) and get repeatable results then you might possibly have the basis of a patent....just think about it......'the Cresswell eye" or somesuch
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Re: Fane 12-250TC Retro Speaker.

Post by IslandPink » Sun Nov 03, 2019 2:40 pm

Nice ! Good work, Steve.
"The bass is the king of the instruments - it has no known natural predator" (Wobble)

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Re: Fane 12-250TC Retro Speaker.

Post by Cressy Snr » Sun Nov 03, 2019 5:07 pm

Problem with all this stuff is that I’m not a scientist. I’m fine with the creative stuff and the lateral thinking that resulted in the ‘eye’ grilles but try and quantify the process and get involved with the maths and I tend to give up because of inability in that department.

Anyway, having said all that; here is a third octave RTA of the speaker in-room, taken at 1m, level with the driver centre and about 10deg off axis.
986BFDD8-309F-43C7-B998-E98C4D0CB6C3.png
Very high treble is down above 13KHz (assuming the OTL isn’t to blame) so wouldn’t be good enough for the bat-eared contingent, but the mids to lower treble content looks and sounds nice and even. There is a bit of a shelf lowering of the bass end, but the upside to this is that the bottom end is completely free from boom. The upper bass dip starting at 125Hz and continuing to 250Hz is probably responsible for the lack of subjective boom frequencies. Nothing nasty in room is being excited.

I think the performance of the speaker system with response correcting grille allows the big wideband driver to show off its best bits, and its very wide range. Purists would want a supertweeter to prop up the last half octave of treble, but as my ears drop off a cliff at 10KHz I couldn’t care less. :lol:

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Re: Fane 12-250TC Retro Speaker.

Post by Cressy Snr » Sun Nov 03, 2019 8:12 pm

ed wrote:
Sun Nov 03, 2019 2:18 pm
Steve if you could measure this(with some precision) and get repeatable results then you might possibly have the basis of a patent....just think about it......'the Cresswell eye" or somesuch
IslandPink wrote:
Sun Nov 03, 2019 2:40 pm
Nice ! Good work, Steve.
Oh, and thanks chaps :)
Sure there must be prior art somewhere to do with all this grille manipulation. Using it to play around with the FR of a full range driver? It’s too obvious isn’t it?

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Re: Fane 12-250TC Retro Speaker.

Post by IslandPink » Sun Nov 03, 2019 9:59 pm

Probably ... but it may have been in the 1930's !
Just started reading Bjorn's book and the history section, lots of peripheral stuff about the development of undersea transmission lines, how valves were created , phonograph horns etc, just amazing how diverse the ideas were and how many clever people there were experimenting with all this stuff.
"The bass is the king of the instruments - it has no known natural predator" (Wobble)

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Re: Fane 12-250TC Retro Speaker.

Post by pre65 » Fri Nov 08, 2019 6:44 am

Steve, does Ants 15" version of the driver "suffer" the same issues that you had with the 12" verson ?
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Re: Fane 12-250TC Retro Speaker.

Post by izzy wizzy » Fri Nov 08, 2019 7:52 am

Cressy Snr wrote:
Sun Nov 03, 2019 5:07 pm
I think the performance of the speaker system with response correcting grille allows the big wideband driver to show off its best bits, and its very wide range. Purists would want a supertweeter to prop up the last half octave of treble, but as my ears drop off a cliff at 10KHz I couldn’t care less. :lol:
Not doubting you know your own ears but I've read we can get pleasure from high frequencies through our eyes which may explain the preoccupation with super tweeters. This audio game is not only just about ears but a whole body experience.

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Re: Fane 12-250TC Retro Speaker.

Post by Cressy Snr » Fri Nov 08, 2019 9:08 am

pre65 wrote:
Fri Nov 08, 2019 6:44 am
Steve, does Ants 15" version of the driver "suffer" the same issues that you had with the 12" verson ?
Yes, but not to the same degree. IMO it’d still need correcting.

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Re: Fane 12-250TC Retro Speaker.

Post by Cressy Snr » Fri Nov 08, 2019 9:20 am

izzy wizzy wrote:
Fri Nov 08, 2019 7:52 am

Not doubting you know your own ears but I've read we can get pleasure from high frequencies through our eyes which may explain the preoccupation with super tweeters. This audio game is not only just about ears but a whole body experience.
I’ve read that too, so if you wear glasses, you must be missing out big time. Also listening with eyes closed ought to be a no-no. Most commercial high end speakers have raised treble, which makes me wonder if they know that only old gits buy hi-fi. :lol:

For me, I like the Fanes as I’ve got them now. Smoooth.

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Re: Fane 12-250TC Retro Speaker.

Post by izzy wizzy » Fri Nov 08, 2019 9:35 am

Cressy Snr wrote:
Fri Nov 08, 2019 9:20 am
I’ve read that too, so if you wear glasses, you must be missing out big time. Also listening with eyes closed ought to be a no-no. Most commercial high end speakers have raised treble, which makes me wonder if they know that only old gits buy hi-fi. :lol:

For me, I like the Fanes as I’ve got them now. Smoooth.
IME raised treble enhances "imaging" but don't sound right to me i.e. not natural whatever that is. The "fad" for unloaded MCs does something similar as they have rising top end when unloaded.

I reckon that HF gets round the edges of yer glasses and through yer eyelids ;)

I had my Tannoys too hot at Owsters due to new crossover caps. Knocking them back a bit gives you a bit more ,aaaahhh and relax. Smooth is the way forward :)

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