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lascala imaging improvements (AKA best $100 you can spend)


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10 minutes ago, garyrc said:

Don't get me wrong, I have heard La Scalas sound harsh on occasion, but I've heard them sound wonderful much more often.  I have quite rarely heard Klipschorns (with the same mid horn and driver) sound bad, maybe 5% of the time.  Program material?

 

+10 to this!!

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7 hours ago, seti said:

I believe a well known member of this forum and Klipsch employee got tossed out of PWK's house for asking about dynamat on horns.... If you bolt down a horn it does not ring....

 

 

 

 

 

There is an echo of 1999 in here.

 

I think both things are untrue.  But the K-400 does indeed still resonate when the mouth is screwed down.  Play a powerful female singer like Thelma Houston at a good volume and wrap your hand around the throat. 

 

Wrapping the exterior of the squawker horn CANNOT reduce the sensitivity of the squawker.  It WILL reduce a tiny bit of spurious noise that might be misinterpreted. 

 

After rapping on the top of the cabinet with my knuckles, I tightly stuffed the upper cabinet with polyester fiberfill.  That cut the ringing of the top panel, that sounded a lot like knocking on a guitar.  Since there is no significant source of sound inside the upper cabinet, it will not become a Helmholtz (typically requires a small opening and a large volume connected by a tube) and there is no worry about escaping sound.  LOL!  Bass frequencies can excite the top panel a little if it is not damped. 

 

We can do these mods because we aren't selling speakers to make a profit.  Klipsch could, but the price would float toward the stupid expensive Wilson.  

 

You also have to remember that at least 90% of audio claims are B.S.  I have 2 yellow buttons to proclaim them thus.  That big Wilson costs $100k because he sells maybe one pair a year and Mr. Wilson likes to drink Pappy! 

 

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8 minutes ago, JohnA said:

Wrapping the exterior of the squawker horn CANNOT reduce the sensitivity of the squawker.  It WILL reduce a tiny bit of spurious noise that might be misinterpreted

 

That matches my conclusion as well.

 

9 minutes ago, JohnA said:

After rapping on the top of the cabinet with my knuckles, I tightly stuffed the upper cabinet with polyester fiberfill.  That cut the ringing of the top panel, that sounded a lot like knocking on a guitar.  Since there is no significant source of sound inside the upper cabinet, it will not become a Helmholtz (typically requires a small opening and a large volume connected by a tube) and there is no worry about escaping sound.  LOL!  Bass frequencies can excite the top panel a little if it is not damped. 

 

I concur but would add that there could well be a dB here or there extra output as the open / undamped top section finds a few notes to "hum along with," but doubt it would ever be detrimental unless listening very nearfield.

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45 minutes ago, JohnA said:

 

 

After rapping on the top of the cabinet with my knuckles, I tightly stuffed the upper cabinet with polyester fiberfill.  That cut the ringing of the top panel, that sounded a lot like knocking on a guitar.  Since there is no significant source of sound inside the upper cabinet, it will not become a Helmholtz (typically requires a small opening and a large volume connected by a tube) and there is no worry about escaping sound.  LOL!  Bass frequencies can excite the top panel a little if it is not damped. 

 

 

 

 

 

Just about any solid structure containing containing a volume of air with an opening that amplifies a frequency can be considered a Helmholtz resonator.

 

For instance a violin or guitar has no source of sound inside the body but is considered a Helmholtz resonator.

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I'm pretty sure a "Helmholtz resonator" is a bit more specific in configuration than what you're describing.  The violin and guitar work quite a bit differently than a Helmholtz resonator, or really any "resonator" for that matter.  Certainly there is some resonance at "play" in their overall outputs but I really wouldn't consider it a terribly primary factor (certainly nothing to get "excited about").  Their bodies themselves are the producers of the sound, at least the development of and transference of same to the air, and are, overall, best not too resonant to any particular frequency the instrument might produce.

 

There is a "wolf note" on a cello...

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37 minutes ago, glens said:

I'm pretty sure a "Helmholtz resonator" is a bit more specific in configuration than what you're describing.  The violin and guitar work quite a bit differently than a Helmholtz resonator, or really any "resonator" for that matter.  Certainly there is some resonance at "play" in their overall outputs but I really wouldn't consider it a terribly primary factor (certainly nothing to get "excited about").  Their bodies themselves are the producers of the sound, at least the development of and transference of same to the air, and are, overall, best not too resonant to any particular frequency the instrument might produce.

 

There is a "wolf note" on a cello...

 

Guitar

 

Violin

 

Any solid structure

 

Lots more if you google.

 

If you have evidence to the contrary post it, happy to look.

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Jason, thanks for the guitar link. I've gone through a lot of luthier websites and guitar designs, but there was some great info there. Not just on the Hemholz, but generally speaking.

 

Bruce

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I have seriously thought about enclosing the top sections of the Belle clones I built a couple years back.  There are times I do hear certain resonance frequencies from certain vocalists, instruments, etc., that I have to go hack and play again at different volume levels to confirm I heard them.  Sometimes I'll play the same song on another pair of speakers to confirm my belief.  I've played guitar for 45 years and there is no doubt instruments have their certain sounds they make at certain frequencies and the designers do the best they can to compromise those anomalies.  

 

Backs would be easy to enclose and I wouldn't have to do them out of Baltic Birch.  They could be plywood or MDF....whatever I have around to work with, really, as long as it's straight and solid.  Just 3/4" glue blocks all around the inside inset the thickness of the back panel (3/4" most likely) and then painted the same black that the bass bins are on the back.  They I would add 4 banana jacks to them for wire connections....one pair of inputs to crossovers and a LF output to the bass bins connections down low.  Not sure when I'd get to that but at some point.

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"By one definition a Helmholtz resonator augments the amplitude of the vibratory motion of the enclosed air in a chamber by taking energy from sound waves passing in the surrounding air.  In the other definition the sound waves are generated by a uniform stream of air flowing across the open top of an enclosed volume of air."

 

I forget from where I copied that to the clipboard.  Likely wikipedia.

 

We agree that the second definition doesn't apply to the discussion, right?

 

The first is applicable only in that if it's indeed Helmholtz resonance occurring in the guitar and violin, then it has to be under that first definition because it can't be under the second.  (As a side note, the first definition could only very loosely be applied to a top hat on a LaScala; but as I hinted at earlier I disagree that it's "Helmholtz resonance" proper.  There's extremely little spring to the air flowing in and out of that large opening to the "chamber.")

 

I'll fix the first definition to accurately apply to a violin or guitar:

 

"a Helmholtz resonator augments the amplitude of the vibratory motion of the enclosed air in a chamber by taking energy from sound waves passing in the surrounding air."

 

Since the structures of those instruments are creating the (airborne) sound waves in the first place, the source being amplified, resonantly, certainly cannot be "sound waves passing in the surrounding air."

 

Heck, forget it.  I concede.

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3 hours ago, Marvel said:

Jason, thanks for the guitar link. I've gone through a lot of luthier websites and guitar designs, but there was some great info there. Not just on the Hemholz, but generally speaking.

 

Bruce

 

Happy to help Bruce.

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The paragraph before I conceded should not be construed (just got notified you just replied, I'll look at it in a minute) to be me saying violins and guitars can't or don't Helmholtzly resonate because I've experienced them doing it.  Got to have your ear close enough to detect it.  It's unrelated to the way they produce their own sound.  Now you know how long it takes me to peck this stuff out on my phone.

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2 hours ago, avguytx said:

I have seriously thought about enclosing the top sections of the Belle clones I built a couple years back.  There are times I do hear certain resonance frequencies from certain vocalists, instruments, etc., that I have to go hack and play again at different volume levels to confirm I heard them.  Sometimes I'll play the same song on another pair of speakers to confirm my belief.  I've played guitar for 45 years and there is no doubt instruments have their certain sounds they make at certain frequencies and the designers do the best they can to compromise those anomalies.  

 

Backs would be easy to enclose and I wouldn't have to do them out of Baltic Birch.  They could be plywood or MDF....whatever I have around to work with, really, as long as it's straight and solid.  Just 3/4" glue blocks all around the inside inset the thickness of the back panel (3/4" most likely) and then painted the same black that the bass bins are on the back.  They I would add 4 banana jacks to them for wire connections....one pair of inputs to crossovers and a LF output to the bass bins connections down low.  Not sure when I'd get to that but at some point.

 

I just cut a piece of scrap ply one inch larger than the existing hole in the back of the cabinet.

 

Drilled very small holes around the piece and into the cabinet evenly like i was making a hatch cover, removed the piece and drilled out the holes so the screws slipped in easily.

Be sure to mark each piece and each cabinet to tell witch goes with witch and witch end is up so you don't mismatch lined up holes.

 

Ran speaker gasket tape around to seal.

 

Installed a terminal cup & wire up being sure to use the most expensive wire i could find.    :rolleyes:

 

Washers on the screws, install and snug.

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16 minutes ago, jason str said:

 

I just cut a piece of scrap ply one inch larger than the existing hole in the back of the cabinet.

 

Drilled very small holes around the piece and into the cabinet evenly like i was making a hatch cover, removed the piece and drilled out the holes so the screws slipped in easily.

Be sure to mark each piece and each cabinet to tell witch goes with witch and witch end is up so you don't mismatch lined up holes.

 

Ran speaker gasket tape around to seal.

 

Installed a terminal cup & wire up being sure to use the most expensive wire i could find.    :rolleyes:

 

Washers on the screws, install and snug.

 

I'm at work and trying to visualize - I guess that by going this route you didn't have to cut a hole in the middle for the squawker driver, yeah?

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2 minutes ago, Thaddeus Smith said:

 

I'm at work and trying to visualize - I guess that by going this route you didn't have to cut a hole in the middle for the squawker driver, yeah?

 

Can I borrow your DeWalt when you're done?  Here hold my beer!

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2 minutes ago, jason str said:

The cover will fit without drilling a hole for the K-55

 

THAT's no fun!  Guess I'll shrink tube something w/a hair dryer!  I'm feeling productive today!  Neighbor saw me bringing my garbage can in and asked me what I was up to today.  NOW I'm inspired!   😂

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