909-8A: 400Hz tractrix horn?

[adam_ecofan]

hi all,

went to see if there were woofers to
match the 299 stash - indeed there
are - 411-8A's; not sure how many
but hopefully enough to see a few
sets of altec speakers built - don't
hold your breath though - may take
some time to manifest results...

cheers,

a

[GM]

??? 411s are 3-6 dB less efficient than 416, 515 [at least the originals], so at minimum you'll probably need two/channel if you want similar efficiency.

GM

[Earl K]

Are you sure you saw 411-8as ( & not 421s ) ?

<> EarlK

[adam_ecofan]

hi all,

hi gm, hi earl:

think 411's - still new to altec
- didn't eyeball them - should
be at least 4 of them.

fellow may have other woofers - has
a big library of drivers from the last
50 years or so...

will still pursue 909/515 for now but
good to know other drivers 'to hand'
for further experiment.

thanks for following,

a

ps - gm - thanks for help with little
coral driver calc at diyaudio the other
year - had to pass on the drivers to
another enthusiast though....

[adam_ecofan]

hi all,

slightly off topic - there is a new p.a. about
to have it's debut in ak - horn loaded wall of
sound for reggae & dub shows.

something i'd been idly dreaming about for
a while - glad some folk have realised it.

only pics i could find are on a radio station
gig guide page (or the builders f*book) but
i'll hit the show next week and grab some
details.

old friend 'dubhead' is playing records on the
night...

cheers,

a

Lion Rockers Hi-Fi Soundsystem

[adam_ecofan]

hi all,

hey geekstar - what do you reckon about
dave's fastlane 'eliptrac' hybrid flare for
klipsch drivers?

New Horns

perhaps a similar strategy for the 909's?

cheers,

a

[Geekstar]

No idea how that elliptical would sound but it sure looks cool!

I like to tell myself there is a link between looks and sound, and on some level there probably is, but in my case it is mostly ex post facto rationalization! If I like it, I find a physical visual explanation and if i don't I find a geometric explanation for that too...but I'm just guessing for the most part.

I can say that the horns I mentioned above really sounded fine and some like the Eurodyn tractrix and Emilar EH-500 are well lknown for their performance. I don't doubt that there are cheap and available horns that are competitive but I can't name any beyond the few specimens I've tried.

Horns that look about the same can have a very different flavor. Gotta try them out.

There are a lot of horns, guess they call em waveguides, around these days. It might be worth buying a few hot contenders and if you like them, then laser scan and CNC them out of more exotic materials....although perhaps molded plastic isn't the worst.

[adam_ecofan]

hi geekstar,

still kicking tires here - my friend who can
run the sims is still busy finishing work for
his masters degree...

eurodyn's very handsome - (not sure if there
are klangfilmists here) - square format interesting.
how do they image compared with round tractrix?
do they also throw a tight image with a small
hotspot?

oval makes sense for me as it seems to present
fewer discontinuities in flare, easier to blend an
oval into a circle than a rectangle.

also, should the calc for the flare start from
the exit of the compression driver or include
the 'root' of the flare back to the phase plug?

cheers,

a

[Geekstar]

Presumably the flare begins at the phase plug, but this is not really something you have much control over.

The Klangfilm horn is considerably less beamy than the round Edgarhorns, which was my personal clash with the ultimate in beamyness.

Beyond the question of frequency response and dispersion there is the fuzzier but critical notion of sonic "presentation," which includes but is not limited to these measurable quantities. I guess I'm trying to get at something like "musicality" which there are no meters for.

The Klangfilm horn is easy and unstressed sounding, colorful, detailed...just a real joy to hear. I have heard these with the AlNiCo Klangfilm drivers and the WE 594A, both superb drivers, which surely flavors my impressions.

The round wood Edgar horn with 288s or TAD 2001s(with Edgar's adapter) struck me as very narrow, super high rez, and a little bit hot and edgy. The Edgarhorn had insane 3-D portrayal in a small sweet spot though and most of my friends really liked them...guess it is a question of taste, as always.

If you look for horn shootout from European Triode Festival 2010, JM LeCleach gave a paper which provides polar measurements on the Klangfilm and other horns, including his JMLC flare. I think the Klangfilm "won" the listening test, which like all such events was a bit thrown together but surely instructive. Google "Klangfilm ETF horn shootout"

One thing the Klangfilm horn has going for it is small size. Many of the contenders are far longer and far larger, more challenging to mill out.

I never heard the LeCleach horns but a few of my friends own or build them and they love em, e.g. Jeffrey Jackson of Experience Music (blog hifiheroin) made some short fast flare JMLCs and he is a believer. Certainly worth researching.

[Geekstar]

ETF horn link is here:

European Triode Festival - ETF 2010 Shootout


I should add that the Klangfilm horns are often used with diffusers which look like air duct vents. They call them "acoustic lenses":

See here under "documentations" Klangfilm Home!

Although this might be a beneficial addition for the intended theater application, I didn't find these horns to be objectionably beamy without the acoustic lens.