How important a mod is the Fastrac Belle horn?

mike_p

Downhome Upstate
I just brought home some ancient Belles with mismatched grille cloth for a good price, and promptly swapped-out the Klipsch AA Balancing Networks for an NOS pair of original ALK Engineering Universal xovers (also for a very good price). They sound pretty darn good to me, being fed by some EL34s.

I've seen the ALK site promotion for Dave Harris' Fastrac Belle midrange (squawker) tractix horn, and I'm getting ready to pull the trigger. Before I do, has anyone here done a before and after comparison? It's almost a grand with the new covered grilles, and I'm experiencing pre-purchase buyer's remorse symptoms.
 
I've never heard them (so you know my perspective)

That said, if they are the 2" throat, I'd imagine they will sound noticeably better than stock...

I HAVE heard the LaScala using a 2" throated horn and to be blunt... it's not a fair fight. The scale of sound is much larger (not necessarily louder although it does play louder AND cleaner at same time)

I would presume this process to carry over to the Bell again, presuming it's a 2" horn.

If it's a 1" horn, I'd venture to guess you could do better with the Klipsch K510 (which is a fabulous sounding horn) and take your Belle's to a 2-way.

Losing a crossover point will also enhance their coherency.

Downside... I don't know that Klipsch designed a passive for the K510 on the Belle. Actually, I'm 99% sure they didn't. They designed an ACTIVE solution to be used with the LaScala and that would transfer over in large part with maybe some minor tweaking.

I know that creates issues with your ALK's...

The most significant jump in sound quality I've experienced was going from 3-way to 2-way and going from a 1" throat to 2" throat horn.
 
I don't know who designed the passive for this but I'm betting that Bob Crites built it. This is the K510 so this is still a 100% Klipsch engineered speaker.
 

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Very interesting! (Think: Werner Klemperer) That puts things in an entirely new perspective. Best then to look into this some more before plunking down the cash.
 
Doubling the throat to a 2" decreases the induced distortion to 25% of its original level. This, coupled with your ALK crossovers, provide an exceptional level of clarity, even at extremely high dB levels.
 
Doubling the throat to a 2" decreases the induced distortion to 25% of its original level. This, coupled with your ALK crossovers, provide an exceptional level of clarity, even at extremely high dB levels.

Thanks for that. Much more to learn.
 
Doubling the throat to a 2" decreases the induced distortion to 25% of its original level.

(pat on the back) thank you for wording it like that!

So many people would have instead, said "the 2 throat has 4 times less distortion than the 1"....

I then have to get on my OCD platform and try to explain that mathematically, it cannot be 4 times less... I'm sure you know the math as to why.

Kills me when people use that frame of reference... 4 times less.... 4 times as slow... 4 times as small....

arghhhhhhhhhhh!!!
 
Coytee, sorry I didn't want to step on your toes. Maybe I should have said that induced throat distortion for a compression driver follows an inverse squared relationship with throat diameter, from which anyone would glean that a 2" throat would result in 1/4 the distortion. However, colloquial talk is just as easy to understand as physics talk. 1/4 is indeed four times less, in this case, mathematically, by calculation, and by can't get there from here common sense. Whether you divide, or multiply, you get the same number.

For non-math folks, a change from a 1" to a 3" horn would be close to a 1/((3)squared) reduction, or 1/9, or 9 times less, or a nine fold reduction, in distortion. The implied math relationship is there, whether you like it or not. Your career as a financial planner is holding you back from helping people to understand something quickly without reverting to margin, net, and ROI type increments. This is the world of physics, not investment.

The real killer is not just jumping to a 2" throat, but then bringing in a better mid compression driver that also has better linearity, performance, and less distortion as well.

The killer conversation is talking about markup for flippers. We won't go there! :)
 
Dave,

So, did you have any particular 2" midrange horns and compression drivers to match in mind?
 
Coytee, sorry I didn't want to step on your toes. Maybe I should have said that induced throat distortion for a compression driver follows an inverse squared relationship with throat diameter, from which anyone would glean that a 2" throat would result in 1/4 the distortion. However, colloquial talk is just as easy to understand as physics talk. 1/4 is indeed four times less, in this case, mathematically, by calculation, and by can't get there from here common sense. Whether you divide, or multiply, you get the same number.

was wondering about this. "an inverse squared relationship with throat diameter" spells it out quite nicely for my brain, going from 1 to 2 only made me question.
 
Coytee, sorry I didn't want to step on your toes.

My apologies if my comment came across wrong... I was complimenting you (or making an attempt to). In no way was I inferring any stepping on the toes.

I still maintain my position though....

If someone says "I make four times less than you do"

I would ask how for example, $25,000 = 4 x $100,000

It doesn't and can't. To make it less you have to use the inverse which is what you did.

$25,000 = 1/4 x $100,000

So it's correct to say I make a quarter or 25% of what you do.... not 4 times less.

Now, I understand what is being said (inferred) and any rational, normal person knows what is being said.....however, what is being said (when stated like that) is mathematically incorrect.

I also realize "who cares", especially if everyone knows what is meant.

I never claimed to be rational nor normal


:crazy:

:beerchug:
 
The grammar police would parse it this way. If you make $100,000, and I make four times as much as you, I make $500,000. If I make four times what you make, I make $400,000. If I make four times less than you, I make -$300,000.

the difference between cardinal and ordinal values, vs inverse values as a percentage, change according to what profession you work and how that profession has trained you to process computational symbology. and you comment didn't come across wrong, my profession just prizes concise communication highly.
 
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