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Old 25th March 2007, 01:42 AM   #101
freddi is offline freddi  United States
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depending upon coupler angle, Karlson will be warmer than direct radiator due to some gain, etc. RCA-Fan's V-vent box has double or more the excursion of K15 and half its output from ~55-200. At high spl couplers will win I think over reflex on drums. Use low mass cones. a new 15" coupler with less back-tilt might be cool. Could a cut-down K like X15 size be good with tapped-horn type sub?

at ~1/10-1/8" p-p excursion I get pretty good drums. A B&C 15 in reflex is weak, flabby, "colored" and dynamically challenged.
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Old 25th March 2007, 02:35 AM   #102
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Greets!

Look at some of Freddy's measurements. If you don't think that resonant behavior higher up will bother you, then go for it. It may not bother me if I tried it today with my old man's hearing, but as a young teen it sounded horrible to me.

Dunno about the HPL, but the original 2035 was only good to 500 - 600 Hz to my ears, but I guess you could XO it at 1200 Hz with some EQ just like Altec did with the 416, which I don't like either, but I seem to be in the minority on this one.

Anyway, I understood the Q, but good luck getting it in 2.5 ft^3 with this driver since a transient perfect sealed cab will be at least 4.618 ft^3 net or a highly damped TL ~8.616 ft^3 net and this assumes zero output impedance, so driven with a SET these numbers will increase considerably. You'll probably have to OB them to get the transients 'tight'.

Getting them 'tight' and with 'impact' is two different things though and neither of these alignments will give you both without digital EQ, but the two I originally suggested I consider an acceptable compromise without resorting to a compression horn, but forget 2.5 ft^3 with or without factoring in a SET.

GM
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Old 25th March 2007, 02:50 AM   #103
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Greets!

Well, in this case we are only interested above ~80 Hz, so don't think the 1/2 horn's extra excursion is an issue and it should have a better impulse response than the K. Any decent BP is going to 'blow the doors off' a BR over a narrow gain BW since both sides of the driver is acoustically damped.

?? What do you mean by 'cut down'? Until someone proves otherwise to me, I'm of the opinion that a TP needs to be XO'd fairly low, so the 'K' will need to get to 40-50 Hz for XOing purposes. I noticed TD has lowered the TOP's HF3, which implies that he agrees.

GM
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Old 25th March 2007, 03:55 AM   #104
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I certainly defend RCA-Fan's V-vent but also defend Karlson, I would sometimes like "leaner" balance K and have achieved it several times with other couplers or using K-tube on top.

The horrible sounding things in my book include high-mass woofer like B&C (whether shorting ring or not) in 2-way reflex and some folded horn :^)

I'm surprised that folks don't as fun or challenge try to build new couplers yet meander with pipehorn, OB, etc.

its not like I've not heard nor own other types----- even John Tucker likes K15 for something.

Freddy

ps

Posted by Steve Schell ( A ) on September 27, 2004 at 17:21:15

In Reply to: Karlson -- why? posted by serenechaos on September 27, 2004 at 15:42:59:

I sense a bit of serene skepticism in your question. No problem, Karlsons do look pretty goofy at first glance. There is something exceptional in their performance, however, that audio writers and hobbyists have been struggling to explain for 50 years now.

It took me many years to appreciate accuracy in bass reproduction, which is quite different from sheer level or extension. Karlsons are exceptionally clean sounding as well as very extended for their size. It takes a bass horn of considerably greater bulk to outperform them. They impose no limitations on bandwidth- Karlson Associates used to recommend their use with the coaxial and triaxial drivers of the day. I much prefer them loaded with field coil theatre woofers, and big ol' midrange horns and compression drivers sitting on top.
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Old 25th March 2007, 11:06 AM   #105
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Hi GM

Iíd rather avoid resonant behavior, even if itís higher up . .

> driven with a SET these numbers will increase considerably
Youíre right, for tightness I should use the SET elsewhere

> the original 2035 was only good to 500 - 600 Hz to my ears
. . then I think I should count on using a mid, especially if Iím dropping the use of an SET here.

Earlier Iíd thought of sealed (not room for OB on *this project), but no Iím thinking of vented - 2.5 ft^3 tuned to eg 40 Hz has an F3 of 69 Hz; then cross to a sub/ TH/ TL at about 70-80 Hz.

'Tightí is probably a better word for my aim than 'impact'.

I understand that the transient response benefit of sealed, only applies around the tuning Hz, eg if a vented box is tuned to eg 40 Hz but crossed one octave higher at 80 Hz, the transient response diffrence will be minimal.


So maybe there isnít a ďvariantĒ of vented that might do this better in this situation. Unless: I havenít heard of 1/2 horn before, are they suitable for 80 Ė 350 Hz??


> You'll probably have to OB them to get the transients 'tight'.

Donít want to do OB for *this, but for another driver/ situation - Iím very curious Ė I thought OB was something like a Q of 0.7?? are you suggesting that OB might do transients tighter then sealed?

Thanks
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Old 25th March 2007, 12:05 PM   #106
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Found the rudiments of Half Horns
http://db.audioasylum.com/cgi/m.mpl?...rn&r=&session=

They donít seem at all smooth . .
http://db.audioasylum.com/cgi/m.mpl?...rn&r=&session=

Cheers
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Old 25th March 2007, 01:54 PM   #107
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that 70l chamber long-vent hithorn might be OK - doubt if would control cone excursion as well as Karlson - Bill said it should play good cello & bowed bass. Bill's V-vent is pretty good. (for kick-K I'd want ~20 degree baffle and EV15L-type)

here's what AJ-Horn predicts for a few drivers with 70 liter - if one went by bad graphs then a lot of FR BLH would be considered junk

http://img340.imageshack.us/img340/7739/hh5drivegh8.jpg

one more thing - how does one do half and BLH sims in Hornresp? I've only used it on front-load. I'd like to run comparisons. McBean's work seems more stable.

can a Karlson be extended pracically to 42Hz outdoors half-quareter power response? - or will it want to be closer to 50?

with B&C I may try aperiodic but don't expect it to sound good then going high - - high mass only helps to rolloff the mids and highs - hahaha

have fun !
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Old 25th March 2007, 05:25 PM   #108
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Greets!

I'm not familiar with B&C other than what I read or what you consider 'high mass', but the Altec 515B is 'high mass' for a HE driver and everyone who has auditioned them AFAIK consider them the one of the finest 15", if not the finest sounding woofers ever built, so IMO 'high mass' in and of itself means nothing SQ wise beyond potentially lowering efficiency.

WRT to reflex alignments, their SQ is dependent on many variables and to be sure, few vintage and current ones are even remotely high SQ IMO, so again, using a 'broad stroke' to imply they all are too fundamentally flawed to perform well doesn't work for me.

I believe folks as a rule don't experiment with Ks for numerous, very good, reasons IMO:

They're too hard for the casual woodworker to make in their current form.

They can't be ~accurately simmed, ergo don't have a clue which drivers will perform well in them.

The few recommended drivers are relatively expensive, whether vintage or new, so even those with the disposable income are reluctant to gamble on an oddball with a virtually zero credibility among the audio 'cognoscenti'.

Even the few who don't discount them out-of-hand have strongly diverging opinions as to their performance limitations.

While rarely mentioned, another problem is its ultra wide dispersion when used in stereo apps, ergo the need for wide dispersion radial horns or K-couplers, which also suffers from most of the above reasons why they are experimented with.

I'm speculating now since my experience with the K is limited to mono, but in a typical room, I imagine they will interact so much that imaging/sound-staging, things that didn't use to be much of a consideration for sound reproduction enjoyment, will in theory be ~non-existent, like what you get with a B@#$ 901 set-up if used wide BW and one of the reasons why I recommend a low XO point.

WRT Tucker's use, as I previously noted, when used in its optimum BW, a K is going to be hard to beat, so using it to fill in below the A7's mid-horn roll off makes perfect sense to me.

As always though, YMMV.

GM

p.s. - if it's any consolation Freddy, one of my audio goals before we're both too old to care is to extensively experiment with them enough to hopefully get folks to play with them, like TC, Scott did with pipe horns (BIB).
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Old 25th March 2007, 10:30 PM   #109
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Some talk about tapped horns using the lab12 driver over at AA

Rob.
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Old 25th March 2007, 10:41 PM   #110
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Hi!

I've been lurking here for a while,guess it's time to join in.

Last weekend I built a tapped horn to see how it would work. I used the LAB12 genII driver in a horn similar to William Cowan's 30 hz horn,but lenghtened to 90". Results are quite favorable for a first attempt.

Rather than repeat everything,here's the link to the plans and discussion at the Hi Eff forum of Audio Asylum.

http://www.audioasylum.com/forums/hu...es/121254.html
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