Why can't HF + mids be in "paraline" feeding horn?
This is hardly new ground, but I am still fascinated by the idea of the Paraline. Based on prior experimenters, was it unsuccessful? I've read (nearly) everything on this here at diy. Much of the best is by Patrick Bateman, on threads such as:
http://www.diyaudio.com/forums/multi-way/209799-sunshine-4.html#post3084751
and
http://www.diyaudio.com/forums/multi-way/217298-square-pegs.html
My current "Why can't I do this?" idea is not even a paraline: it would be a radial horn (in folded fashion), with one HF and four MF (mids) at the appropriate distance, as per the Synergy patent (8284976 Fig. 8), one deflector disk for the middle, and the exit port just a hole in center of bottom disk.
Pros: my design avoids all that silly need to transform from a point source to a line source and drawing "eyes." 🙂 What I propose is to "mix" the HF and MF sources into a (say) 1" hole that then feeds a (I guess) conventional conical horn to chosen dispersion characteristics.
I'm sure this idea has one or more fatal flaws 🙁 I recall the humorous dictum:
2 + 2 = 5 for suffiently large values of 2
OK, there is my idea balloon. Fire when ready 🙂
This is hardly new ground, but I am still fascinated by the idea of the Paraline. Based on prior experimenters, was it unsuccessful? I've read (nearly) everything on this here at diy. Much of the best is by Patrick Bateman, on threads such as:
http://www.diyaudio.com/forums/multi-way/209799-sunshine-4.html#post3084751
and
http://www.diyaudio.com/forums/multi-way/217298-square-pegs.html
My current "Why can't I do this?" idea is not even a paraline: it would be a radial horn (in folded fashion), with one HF and four MF (mids) at the appropriate distance, as per the Synergy patent (8284976 Fig. 8), one deflector disk for the middle, and the exit port just a hole in center of bottom disk.
Pros: my design avoids all that silly need to transform from a point source to a line source and drawing "eyes." 🙂 What I propose is to "mix" the HF and MF sources into a (say) 1" hole that then feeds a (I guess) conventional conical horn to chosen dispersion characteristics.
I'm sure this idea has one or more fatal flaws 🙁 I recall the humorous dictum:
2 + 2 = 5 for suffiently large values of 2
OK, there is my idea balloon. Fire when ready 🙂
I'd think (but wouldn't want to try to prove!) that any arrangement that would give equal path lengths to the center, via the outer edge of a circular disk would have to have equal path lengths already without the disk. Because the distances from anywhere on the outer edge of the disk to the center is always equal, so the closest distance from each driver to that edge must be equal, so their distances from the center would also be equal. Or something like that.
Removing the disc and using plane wave tubes of varying length, the goal could be accomplished.......not sure how it will sound though! Lol
But I need the centre disk to bring me to the mother ship where They study me :-D
Sent from my SPH-L300 using Tapatalk
Sent from my SPH-L300 using Tapatalk
And now, back to the Yorkville Unity U15!
OK, I am leaving aside the Paraline for now. If even epert DIY-ers including those who've built Paralines say "Don't build a paraline..." 🙂
Today I will confine myself (because Society has not yet confined me
) to that domain of DIY in which I'm competent: taking a retail item and not damaging it beyond recognition 🙂
I've managed to disassemble each U15 and clean parts as best I can. I've tested each of the drivers using the easiest method: sine sweeps over the expected frequencies at the not-quite-scientific amplitude of "pretty darned loud." I can't find anything objectionable, other than apparently I don't hear above 11 KHz 🙁
I'm happy that the drivers seem to have No Issues since (1) replacements are expensive and (2) not usually sold to the hobbyist (mids.)
I'm assuming that my earlier FR variations and a few crackles and pops are due to buggy crossover. This is no issue for me since I plan to actively amp them.
Even some of the earlier suggested mods are too much trouble for me, at least for now:
Seal the box and ports and use the woofer as a sealed suspension. Add fiberglass batting (ok that is easy!). I modeled the 18Sound 15" in hornresp and would not get much better low end even in sealed box. Lazyiness prevails. I am going to just work on the Unity "highs" and use the existing Sub (Frankenclosure) ... while it was "designed" (using the term loosely) to only go to 100 Hz or so, I can get it up to 300 Hz to meet the Yorkville horn.
I can't resist at least a little Soldermizing and in spirit with my "keep it reversible" goal, I am going to do a ghetto "Synergy" tweak which is the high tech mod to gorilla glue the stock ports and cave a mini frustrum with an X-acto knife 🙂 I have faith that actrive EQ will heal all and that I will have made a qualsi-Synergy without all that silly theory and hours of experimentation 😀
OK, I am leaving aside the Paraline for now. If even epert DIY-ers including those who've built Paralines say "Don't build a paraline..." 🙂
Today I will confine myself (because Society has not yet confined me
) to that domain of DIY in which I'm competent: taking a retail item and not damaging it beyond recognition 🙂I've managed to disassemble each U15 and clean parts as best I can. I've tested each of the drivers using the easiest method: sine sweeps over the expected frequencies at the not-quite-scientific amplitude of "pretty darned loud." I can't find anything objectionable, other than apparently I don't hear above 11 KHz 🙁
I'm happy that the drivers seem to have No Issues since (1) replacements are expensive and (2) not usually sold to the hobbyist (mids.)
I'm assuming that my earlier FR variations and a few crackles and pops are due to buggy crossover. This is no issue for me since I plan to actively amp them.
Even some of the earlier suggested mods are too much trouble for me, at least for now:
Seal the box and ports and use the woofer as a sealed suspension. Add fiberglass batting (ok that is easy!). I modeled the 18Sound 15" in hornresp and would not get much better low end even in sealed box. Lazyiness prevails. I am going to just work on the Unity "highs" and use the existing Sub (Frankenclosure) ... while it was "designed" (using the term loosely) to only go to 100 Hz or so, I can get it up to 300 Hz to meet the Yorkville horn.
I can't resist at least a little Soldermizing and in spirit with my "keep it reversible" goal, I am going to do a ghetto "Synergy" tweak which is the high tech mod to gorilla glue the stock ports and cave a mini frustrum with an X-acto knife 🙂 I have faith that actrive EQ will heal all and that I will have made a qualsi-Synergy without all that silly theory and hours of experimentation 😀
Last edited:
It can't be this easy...?
Just some relatively simple testing with REW. "Disclaimer::
The measurement mic is not calibrated.
These sweeps are with JRMC active (must, because it's my EQ).
REW reports the "measurement may be corrupted"; there are audible "pops" in some sweeps.
That said, the readings seem to be consistent from one set to the next.
My only "port mod" so fair is this: of three mids, two are plugged shut (no drivers behind them duh) and the active mid is only about 1/3 of the default, closest to throat. With this config, I appear to get a cancellation notch about 980 Hz. This is quite lower than the stock config, since its x-over is about 1200 Hz. Nevertheless, I can run the "tweeter" (BMS4550 "OEM") to 900 Hz or below. Thus with the x-over at 24 db/Oct, L-R (I think), and 900 Hz, with best delay at 0.6 mSec, this is the suspiciously good amplitude/phase plot, 500 Hz - 2KHz.
Yes the amplitude is variance of ten dB across the x-over. But the phase is too good to be true. What am I overlooking
Just some relatively simple testing with REW. "Disclaimer::
The measurement mic is not calibrated.
These sweeps are with JRMC active (must, because it's my EQ).
REW reports the "measurement may be corrupted"; there are audible "pops" in some sweeps.
That said, the readings seem to be consistent from one set to the next.
My only "port mod" so fair is this: of three mids, two are plugged shut (no drivers behind them duh) and the active mid is only about 1/3 of the default, closest to throat. With this config, I appear to get a cancellation notch about 980 Hz. This is quite lower than the stock config, since its x-over is about 1200 Hz. Nevertheless, I can run the "tweeter" (BMS4550 "OEM") to 900 Hz or below. Thus with the x-over at 24 db/Oct, L-R (I think), and 900 Hz, with best delay at 0.6 mSec, this is the suspiciously good amplitude/phase plot, 500 Hz - 2KHz.
Yes the amplitude is variance of ten dB across the x-over. But the phase is too good to be true. What am I overlooking
Attachments
Now the 1/2 wave notch has vanished!
Ok I standarized on a port size of about 3 mm "long", roughly 1/2 the stock size. Now testing a horn with all 3 mids and the tweeter and ...
Why can't I find the cancelation notch when I run a sweep of the mids? I see the roll-off about where it was when just one mid;
I know my test rig is unreliable. These are the kind of results that lead a man to
but now am not supposed to. Therefore I'm going to bed! Jury duty tomorrow (Joy!) 
Ok I standarized on a port size of about 3 mm "long", roughly 1/2 the stock size. Now testing a horn with all 3 mids and the tweeter and ...
Why can't I find the cancelation notch when I run a sweep of the mids? I see the roll-off about where it was when just one mid;
I know my test rig is unreliable. These are the kind of results that lead a man to
but now am not supposed to. Therefore I'm going to bed! Jury duty tomorrow (Joy!)
Further along the Ijit Itinerary 🙂
The Yorkville U15 have been worked on. They are now more or less "sealed box" with my Gorilla Glue "foam" plugs in the ports, caulked whisting nail or screw holes, etc. They are now gutted for the stock EQ and have easy connect terminals for the drivers.
Acoustically they sound very good. I'll apparently never figure out how to do "loopback reference" with REW so my delays are somewhat guesses but EQ sounds fine. I've made a poor man's version* of the Geddes foam plug, doesn't even violate the patent because instead of open cell foam (far too expensive) I used furnace filters (made of ???) and made a ***/2 "cone" of glued-toogether (Gorilla of course) discs that fit the cone -- sort of. In a rare case of non-Gorilla, I then adhere the mute into the waveguide with regular caulk, trying to reduce the chance of caulking or glueing the compression driver or mids.
I know the U15 stock is not rated for much below 50 Hz but I was hoping to do a big boost on the EQ for the low end. Some improvement, but I am still a bit surprised that you can't really get low bass out of their 15" woofer.
*Although I'm not poor, my DIY skills certainly are 🙄
The Yorkville U15 have been worked on. They are now more or less "sealed box" with my Gorilla Glue "foam" plugs in the ports, caulked whisting nail or screw holes, etc. They are now gutted for the stock EQ and have easy connect terminals for the drivers.
Acoustically they sound very good. I'll apparently never figure out how to do "loopback reference" with REW so my delays are somewhat guesses but EQ sounds fine. I've made a poor man's version* of the Geddes foam plug, doesn't even violate the patent because instead of open cell foam (far too expensive) I used furnace filters (made of ???) and made a ***/2 "cone" of glued-toogether (Gorilla of course) discs that fit the cone -- sort of. In a rare case of non-Gorilla, I then adhere the mute into the waveguide with regular caulk, trying to reduce the chance of caulking or glueing the compression driver or mids.
I know the U15 stock is not rated for much below 50 Hz but I was hoping to do a big boost on the EQ for the low end. Some improvement, but I am still a bit surprised that you can't really get low bass out of their 15" woofer.
*Although I'm not poor, my DIY skills certainly are 🙄
Flower pot/planter for horn (enclosures)?
Months ago, I was earnestly experimenting with very easy ways to make DIY waveguides using the fabric and stiffener method (fiberglass, or Gorilla Glue in my case 🙂 ) ... having OK results but not for a true Synergy. Then Fate derailed my experimentation in half-a$$ clones of an SM-100 by deviously selling me a pair of Yorkville U15 upon which I am still happily tweaking 🙄
I have, in fact, made a few more "horns" as getting measurements close from one unit to the next is a challenge due to the "artistic" (e.g. sloppy) methods used... it occurrs to me that a round horn is easily made using a (say) 30" (approx) diameter regular metal home trash can 🙂 This seems to be the upper size of "reasonably sized" home waveguides. OK, but what for the enclosure? I suppose a wooden or other material box can be fabircated but, hmmmm... what about those larger planters sold at Home Depot, Lowes, etc. ? They seem the right diameter and depth. Most of these are some type of plastic and cost $30 or less. I suppose you could fine ceramic, fracture it, and then have a truly crackpot project 😀 I'm not building such a speaker ("yet") but just tossing it out for any other fellow (lazy) DIYers here 🙂
Months ago, I was earnestly experimenting with very easy ways to make DIY waveguides using the fabric and stiffener method (fiberglass, or Gorilla Glue in my case 🙂 ) ... having OK results but not for a true Synergy. Then Fate derailed my experimentation in half-a$$ clones of an SM-100 by deviously selling me a pair of Yorkville U15 upon which I am still happily tweaking 🙄
I have, in fact, made a few more "horns" as getting measurements close from one unit to the next is a challenge due to the "artistic" (e.g. sloppy) methods used... it occurrs to me that a round horn is easily made using a (say) 30" (approx) diameter regular metal home trash can 🙂 This seems to be the upper size of "reasonably sized" home waveguides. OK, but what for the enclosure? I suppose a wooden or other material box can be fabircated but, hmmmm... what about those larger planters sold at Home Depot, Lowes, etc. ? They seem the right diameter and depth. Most of these are some type of plastic and cost $30 or less. I suppose you could fine ceramic, fracture it, and then have a truly crackpot project 😀 I'm not building such a speaker ("yet") but just tossing it out for any other fellow (lazy) DIYers here 🙂
Attachments
Last edited:
Silly time
For your abusement, here is a list of fanciful Soldermizer Technology Products.
Turd Polish.
They said it’s impossible, but ST comes through with this innovative product. While it can, indeed, be used to put a shine on the feces of your choice, it is more commonly used by the hobbyist and disreputable salesman to make a “crappy” product appear better than it really is. Used with nearly all ST goods. From the same company that invented DIY Jelly.
Lit Wire.
Do not confuse this with “Litz” Wire. ST’s Lit Wire is speaker wire that is soaked in alcohol for six months. This has the obvious effect of getting the wire “lit”, catching a buzz, (but not interference), and will add a smoothness to your audio that is similar to how you feel after downing half a bottle of Dom Perignon or a six pack of Natural Ice. Makes your music sound good until you wake up with a jagged hangover.
Frequency Grease.
Originally invented by the U.S. Army Signal Corps to mess with innocent newly arrived soliders, this elusive lubricant may be used to grease the inner surface of horns or waveguidees (if you can stop arguing about which is which long enough). It will ease higher order modes (HOM) by smoothing the echoes of these high frequency bandido tones. In all, results in smoother frequency response at the listening position.
HOC (Higher Order Commodes).
For use with Geddes Waveguides, the HOC will make your speakers from the listening room sound better when you are in the bathroom taking a dump or just in the shower. Requires porcelain tiling or other reflective surfaces for best effect.
30 PPI reticulated foam (factory seconds):
another product insipred by the patented Geddes treatment, this foam is intended for use with audio horns/waveguides. Specify the shape of your horn, and your foam will be cut-to-size for easy fitting. Rather than damp HOMs, which would get us in trouble with Geddes due to patent issues, our foam is actually an air filter that removes dirt, dust, cat hair, and floating cigarette butts from the air that is being sucked into and out of your speaker horn hundeds or thousands of times per second. This has the benefit of protecting the delicate cone or compression drivers until your lungs can filter that gunk out of the air. Filter is easily washable with regular dish detergent.
For your abusement, here is a list of fanciful Soldermizer Technology Products.
Turd Polish.
They said it’s impossible, but ST comes through with this innovative product. While it can, indeed, be used to put a shine on the feces of your choice, it is more commonly used by the hobbyist and disreputable salesman to make a “crappy” product appear better than it really is. Used with nearly all ST goods. From the same company that invented DIY Jelly.
Lit Wire.
Do not confuse this with “Litz” Wire. ST’s Lit Wire is speaker wire that is soaked in alcohol for six months. This has the obvious effect of getting the wire “lit”, catching a buzz, (but not interference), and will add a smoothness to your audio that is similar to how you feel after downing half a bottle of Dom Perignon or a six pack of Natural Ice. Makes your music sound good until you wake up with a jagged hangover.
Frequency Grease.
Originally invented by the U.S. Army Signal Corps to mess with innocent newly arrived soliders, this elusive lubricant may be used to grease the inner surface of horns or waveguidees (if you can stop arguing about which is which long enough). It will ease higher order modes (HOM) by smoothing the echoes of these high frequency bandido tones. In all, results in smoother frequency response at the listening position.
HOC (Higher Order Commodes).
For use with Geddes Waveguides, the HOC will make your speakers from the listening room sound better when you are in the bathroom taking a dump or just in the shower. Requires porcelain tiling or other reflective surfaces for best effect.
30 PPI reticulated foam (factory seconds):
another product insipred by the patented Geddes treatment, this foam is intended for use with audio horns/waveguides. Specify the shape of your horn, and your foam will be cut-to-size for easy fitting. Rather than damp HOMs, which would get us in trouble with Geddes due to patent issues, our foam is actually an air filter that removes dirt, dust, cat hair, and floating cigarette butts from the air that is being sucked into and out of your speaker horn hundeds or thousands of times per second. This has the benefit of protecting the delicate cone or compression drivers until your lungs can filter that gunk out of the air. Filter is easily washable with regular dish detergent.
Last edited:
Kinda sort horn related
Nothing much new to report re diy, but found a URL to a cool horn design. I've previously mentioned
Hifi Pig - hifi reviews and hifi news.
Which is one of the "audio-fool" (with money to be soon parted with) type of sites, but i like the name. (Aside: many of my exes call me a "f-----g pig" but I am actually a celibate pig between ladies 😀 )
hORNS.pl – GPoint Audio
Said site linked to a new (to me) site that has the super-artistic Universum III horns (I don't want to know what they cost). Surprisingly, same Co. offers the well known SEOS for the DIY crowd and St. Geddes is also mentioned. 🙂
Hmmm. what's the exchange rate dollar to zloty ?
Nothing much new to report re diy, but found a URL to a cool horn design. I've previously mentioned
Hifi Pig - hifi reviews and hifi news.
Which is one of the "audio-fool" (with money to be soon parted with) type of sites, but i like the name. (Aside: many of my exes call me a "f-----g pig" but I am actually a celibate pig between ladies 😀 )
hORNS.pl – GPoint Audio
Said site linked to a new (to me) site that has the super-artistic Universum III horns (I don't want to know what they cost). Surprisingly, same Co. offers the well known SEOS for the DIY crowd and St. Geddes is also mentioned. 🙂
Hmmm. what's the exchange rate dollar to zloty ?
I think you need a new project to violate,
This turntable makes your records float with magnets - The Verge
This turntable makes your records float with magnets - The Verge
Those are my thoughts too but the idea of the entertaining Soldermizer doing his own"interpretation" amuses me 🙂
Probably just as well...
I sniff around periodically for a used pair of the legendary SH50's. Sure enough, over on the Asylum there's a pair for $5k which is probably a good deal (new they are what $8K). I could easily scrape $5,000 together: cash advance a few credit cards and maybe sell a few pints of plasma 🙂
Just as well they are in WS (I am in FL). Never mind that I bought a pair of Yorkville U15 from CO and paid "only" about $200 freight. On the one hand, the U15's were about 1/15 the cost of the SH50's. Not saying the seller is a crook, but you'd have to be crazy to buy something inside an Asylum Hmmmm..... nah, better just enjoy my U15's until the shine wears off (and the contact cemnt fumes wheeeeeeeeeeeeeeeeeeee).
In unrelated news, GF and I were perusing local yard sales. I didn't buy nothin' but now have adopted a 4th cat 🙄
I sniff around periodically for a used pair of the legendary SH50's. Sure enough, over on the Asylum there's a pair for $5k which is probably a good deal (new they are what $8K). I could easily scrape $5,000 together: cash advance a few credit cards and maybe sell a few pints of plasma 🙂
Just as well they are in WS (I am in FL). Never mind that I bought a pair of Yorkville U15 from CO and paid "only" about $200 freight. On the one hand, the U15's were about 1/15 the cost of the SH50's. Not saying the seller is a crook, but you'd have to be crazy to buy something inside an Asylum
Hmmmm..... nah, better just enjoy my U15's until the shine wears off (and the contact cemnt fumes wheeeeeeeeeeeeeeeeeeee).In unrelated news, GF and I were perusing local yard sales. I didn't buy nothin' but now have adopted a 4th cat 🙄
Last edited:
Winter report
The Ijit has been vegetating some what. Latest activity is really just re-arranging the living room (turned -90 degrees). The most important aspect of this is that now the sloping (upward) ceiling will be equal for both channels. due to the open plan of the house, there is still some rear wall issues but I am not worrying about them yet. A more trivial matter today!
I'm still enthralled with the U15's. While I've done this before, my current set-up is three way. For each channel, the bass/sub is a 2x2x2' cube with one 15" Alpine car sub in it; A U15 cabinet is set ontop of this, upside down, so that the Unity horn is more or less within the sacred 1/4 wavelength 🙂
I've yet to run updated REW sweeps and re-EQ the set-up, but have an idle question: should I bother with hooking up the U15's 15" woofer too? If so, is it ok to keep the U15's upside down (does this make my system a W-T-W or M-T-M set-up?) Haven't I effectively made a ghetto "Econowave" or FAST type set-up (allowing a Unity horn to be a "full range" assuming full range only goes down to 300 Hz.?)
On my to-do list is to find out how much clean low end I can get from two 15" Woofers ( + 2 of the Yorkville 15" perhaps) and use that as the baseline to pad down the far more than needed Unity mids/highs.
As others have noted, it is of course possible to tame a PA speaker for home duty. Aesthetics is a challenge!
The Ijit has been vegetating some what. Latest activity is really just re-arranging the living room (turned -90 degrees). The most important aspect of this is that now the sloping (upward) ceiling will be equal for both channels. due to the open plan of the house, there is still some rear wall issues but I am not worrying about them yet. A more trivial matter today!
I'm still enthralled with the U15's. While I've done this before, my current set-up is three way. For each channel, the bass/sub is a 2x2x2' cube with one 15" Alpine car sub in it; A U15 cabinet is set ontop of this, upside down, so that the Unity horn is more or less within the sacred 1/4 wavelength 🙂
I've yet to run updated REW sweeps and re-EQ the set-up, but have an idle question: should I bother with hooking up the U15's 15" woofer too? If so, is it ok to keep the U15's upside down (does this make my system a W-T-W or M-T-M set-up?) Haven't I effectively made a ghetto "Econowave" or FAST type set-up (allowing a Unity horn to be a "full range" assuming full range only goes down to 300 Hz.?)
On my to-do list is to find out how much clean low end I can get from two 15" Woofers ( + 2 of the Yorkville 15" perhaps) and use that as the baseline to pad down the far more than needed Unity mids/highs.
As others have noted, it is of course possible to tame a PA speaker for home duty. Aesthetics is a challenge!
- Status
- Not open for further replies.