Are Your Capacitors Installed Backwards ??

[karlson3]

Hi Dave A - I'm still looking for the VOTT/Danley stuff and posted a couple of questions which hope Tom sees over at AA.  The stock drivers should have enough bandwidth to do whatever he did with 2226 & BMS4550

 

https://www.audioasylum.com/forums/hug/messages/18/182961.html

[awsjr]

just an fyi for Klipsch forum people... 

this guy Jeff Medwin has been banned from forums... 

he is an antagonistic, arrogant "do it my way is the only right way" kind of guy.. 

 

do not get drawn in to his BS

[karlson3]

as my house is packed, I toyed with the notion of a toy 0.7 scale VOT.  If built that way, it would look cool & be nearly as loud according to a sim (probably have a lot less "hit" as the horn is smaller), and the sim for the little one would have the LF "bump" at cutoff like the real thing.  Cutting down the height to get 2 cubic foot rear chamber would flatten the response but of course put the front horn real close to the floor - and lose the cool look ;^(

[glens]

Thank you awsjr.  We're not drawn in in the least.

 

Jeff, you seem to be enamored with sub-harmonics.  You do realize that the VAST majority of audio equipment (electronics, mainly, but also reproducers) are not designed to handle "out-of-band" (20-20,000 Hz) signals, right?

 

When exposed to them, they (both) generally create (harmonic - both above and below - and "intermodulately") distortion that's disproportionate to anything programmatic.  If you're hearing any "resultant"s of out-of-band signals, that's most definitely a result of faults in the system.

[glens]

12 minutes ago, karlson3 said:

as my house is packed, I toyed with the notion of a toy 0.7 scale VOT.  If built that way, it would look cool & be nearly as loud according to a sim (probably have a lot less "hit" as the horn is smaller), and the sim for the little one would have the LF "bump" at cutoff like the real thing.  Cutting down the height to get 2 cubic foot rear chamber would flatten the response but of course put the front horn real close to the floor - and lose the cool look ;^(

 

Where's the typical "haystack"?

[karlson3]

fwiw - I've never perceived Jeff Medwin as "arrogant"  - rather the opposite and very helpful.  He's gone a decades long journey of triode amplifier builds and all of those which I've seen schematic have had attention to keeping power supply choke dcr down and solid attention to tube operating points and power supply ripple & turn-on behavior (Duncan's PSUD) Whether all the eighty-skate bypass caps, heavy composite gauge wiring, etc. = "audible" = ? (one would have to try it to hear).  He does suggest the Loftin-White approach these days.   When I messed with tube preamplifiers, whatever could be thrown out (excess gain stages, switch contacts,etc) would generally result in a cleaner - more detailed sound (assuming enough drive for the power amp and preamp's final stage not loaded down from cable capacitance.  Much of our sound today comes from chip op-amps from the mic preamps up - lets hope those are more transparent than the simple tube stuff (done right).

Can one make a cheap solid state power amplifier kinda emulate some tube amplifiers?  Certainly a high output Z will interact with the speaker's impedance curve's peaks. Decware sold a "Gizmo"  - I think I faked one with a 1K pot on a 115v winding of a 5vct filament transformer with the low Z winding in series from the amp with the speaker.  With the pot turned down to "zero", the overall Z was lowest and one on the fly could adjust the reflected Z and thus series Z (to some extent) with the pot for interesting effects.

[billybob]

...

 

https://video.search.yahoo.com/yhs/search?fr=yhs-pty-pty_converter&hsimp=yhs-pty_converter&hspart=pty&p=haystack+calhoun#id=3&vid=0489ee52d39624edb37fa3f4e4d973c4&action=click

 

[karlson3]

Cool O Rama Billybob !  the glory days of Haystacks and Dick The Bruiser !!

 

Back to Jeff Medwin, that 2 watt amp he built uses a 6005 output tube - those can be found for $2 each (sans shipping) - that sounds a hellva lot more sensible than $695 for a "born again" Western Electric 300B made in the "USA".   

[glens]

I, too, would not characterise him as arrogant.  Mis- or ill-informed, perhaps, but certainly not arrogant.  He has exhibited exemplary composure in the face of (I'd say "attack"s, but it's more along the lines of "wake-the-f***-up") responses to his viewpoints here thus far.

[karlson3]

if ripple and hum can be kept low enough in a SE tube amp then Dennis Fraker's low energy power supply technique (can't find its proper acronym) would be worth investigation.  Maybe single point grounding at the input of the amp keeps things in check - ?

 

Even tho Jeff comes from a non-Klipsch-Centric background - maybe its time to accept him ;^)

 

 

[Marvel]

1 hour ago, glens said:

Thank you awsjr.  We're not drawn in in the least.

 

Jeff, you seem to be enamored with sub-harmonics.  You do realize that the VAST majority of audio equipment (electronics, mainly, but also reproducers) are not designed to handle "out-of-band" (20-20,000 Hz) signals, right?

 

When exposed to them, they (both) generally create (harmonic - both above and below - and "intermodulately") distortion that's disproportionate to anything programmatic.  If you're hearing any "resultant"s of out-of-band signals, that's most definitely a result of faults in the system.

 

You should have a look at Waves MaxxBass plugin. It basically uses the overtones from lower bass than what a system can actually reproduce. It is a psychoacoustic effect that your brain then hears the lower frequency. Actually great for smaller playback devices with small speakers. I own the plugin, and want to try it playing back pc based files t my LaScalas. We'll see (or hear) if I can get what is perceived as lower bass output from them.

 

https://www.waves.com/plugins/maxxbass#adding-deep-low-frequencies-with-maxxbass

[karlson3]

years back, I had a Maxxbass box and posted screenshots of its harmonic structure at various settings using TrueRTA.  Besides the added harmonics, it did apply ~6dB boost to the low end.  The sound of it on a little Karlson box (I'd guess ~18dB LF rolloff below 70 - some Hz) reminded me of what one might hear with an open baffle speaker turned sideways - it lacked solidity - still could be attractive.  My box had failed at two weeks of use and had no support from the company or seller.  It'll be cool to hear about the plug-in's effects.

 

here's a note on the "missing fundamental" effect

 

http://homepage.ntu.edu.tw/~karchung/Phonetics II page thirteen.htm

 

btw - Reckhorn sold a little EQ box which was extremely flexible in settings (could approximate a Linkwitz transform easily - or peaking for 6th order assisted reflex)- that worked very well with stock Heresy I speakers and solid state amplification.

[Marvel]

From what I have read, one can easily have too much bass if not paying attention to the settings.

[glens]

If it's not "Maxxbass" proper, I've seen a blurb recently regarding inroads being made for this concept with smartphones &c.  Pseudubass.

[Marvel]

A lot of portable players/phone jave this built in. Waves isn't the only company devoping the idea, but I'm sure they've licensed it to a lot of others to use. It would be relatively cheap to have even a small amount of a perceived increase in the bass output, i.e., hardwired set amount that just works.

[karlson3]

here's an old in-room graph of a horn driven with 41Hz sine vs what my Maxxbass box added harmonically - looks like the box added 20dB or so to H2 and H3

 

 

A distributed slit vent Karlson 12 ("K12" - 2nd model which appeared ~1956 and was published in the July 1958 issue of Popular Mechanics) will generate such harmonics if driven by clean sine in its vicinity of tuning (~63Hz small signal).  Also, bass reflex tuned with many semi-resistive holes (such as one I tried with 43X 3/8" hole in its port panel tuning to ~41Hz) will also generate those harmonics.  Dr. Geddes said the effect was not distortion per se but rather "modulated noise".  Could a wheezy vent reflex do similar to the Bassmaxx? - or does music comprised of ever changing transients not excite that acoustic effect ?  Maybe its important mainly to elevate H2 and H3 as with the Maxxbass method (?)

 

The sine drive below was ~31Hz - a full octave below

the little Karlson's tuning.  At 60Hz, I think the slit vent's harmonics' amplitudes would equal or exceed the fundamental.

 

Another thing I noticed with a Peavey 15" in a 3.6 cubic foot bass reflex tuned with 43 0.375" diameter holes - a pretty good "breeze" could be felt 8 feet away with 10 watts input/40 some Hz sine.  Maybe make one tuned for 60 and run from a 12v tranformer for a "fan" - hahaha

 

[Deang]

I hope this thread doesn’t give me a tumor. 

[karlson3]

21 minutes ago, Deang said:

I hope this thread doesn’t give me a tumor. 

just as a precautionary (B17 tablets "Novodalin" are available besides going with bitter apricot kernels)

https://archive.org/details/World_Without_Cancer

 

Jeff - ~1/3 of a watt A1 isn't enough for my Karlsonish toys - but 1.5-2W class A push pull should run La Scala and K-horn to reasonable levels.

My 18" woofer goes to ~4KHz

A really good triode connected KT88 SE amp would be of high interest. 

 

outdoors - FH1 - the mic on the ground plot is interesting. At 30 degrees off axis and mic at about 12" up (half the cabinet's height in this orientation) F6 appears to be come in around 90Hz and 400Hz.

[Deang]

Yeah, but it’s beaming like a laser. 

[karlson3]

LOL - but beaming proudly.  Speaking of - horn directivity can limit usefulness of midbass horns above a certain frequency - even if can go way "up" (dead on axis) . Hornresp should do ok for examination of square mouth horns.   (John Inlow has some interesting horns)

 

Below is a rough sim of Inlow's 12PE32 135Hz horn and being described as a single segment, beamwidth calculated to around 740Hz for 60 degrees. 

 

The very small back chamber of 4 liters for a 12 inch driver is a plus with regards to keeping excursion way down below horn cutoff.  (IF I weren't so old and decrepit then might try one of JL's 12pe32 or 8pe21 horns)

 

btw, a drive of 1/4 watt like Jeff's little triode amp, shows about "100dB" for 2 pi.

 

Building as such leaves one to figure out what to do from bass up to that area.   Does that prohibit passive crossovers?  The midbass horn really would need no crossover but impedance in parallel with the bass horn might dip low.