Moderator: Redaktörer
MagnusÖstberg skrev:Elementen som ingick i orginalet togs ur produktion.
Såldes som kitt med färdiga lådor under ett kort tag. Ritningar såldes nog aldrig.
Komorok skrev:Hur bygger man egna unityhorn? Nu blev jag sjukt nyfiken.
Aerob skrev:Kör hårt! Här har du en ganska trevlig samling: http://www.diysoundgroup.com/forum/index.php?topic=23.0
Referring to a second aspect of horn design according to principles of the present invention, attention is directed to the local cross-sectional area of the horn where a lower driver is located. At the upper frequency end of each of the lower drivers, the cross-sectional area of the horn, where the driver's output enters the horn, must be no greater than the area approximated by a round cross section that is one wavelength in circumference at that upper frequency end.
]Cancellation notches appear when the frequency is increased sufficiently so that sound from the driver, which travels to the closed end of the horn, is reflected back so as to arrive with 180° of phase shift to cancel that portion of the source information, thereby causing the cancellation notch.
Greets!
To get 'in the ballpark', find one that either is a closed back unit that resonates at ~SQRT(200*1400) = ~529 Hz, or if open back, then ~529 = 2*Fs/Qes. How you get there doesn't matter if you're not trying to get max efficiency out of it with 'X' diameter x 'Y' long vents. IIRC, TD's prototype driver's published specs were ~2*250 Hz/0.99 = 505 Hz, so I wouldn't get too hung up on the apparent need for a low Qt just because it's a horn app.
GM
How in the hell did you get your hands on that Celestion 4" driver? I tried every way possible to get Celestion to sell those to me and they wouldn't do it. Those are the exact 4" that Danley uses in several of his Synergy horns.
Hi guys
For what its worth, the every first one of these below was made using burlap to make the “waveguide”.
Perhaps you can use spandex to do the same thing.
Stretch the fabric across a framework, uniformly stretched a bit.
With something round, the size you need, press in the fabric to the depth you need and clamp in position.
Get some thin epoxy resin from the hobby shop and brush on a few coats until the fabric is ridged enough to deal with. Fill in the rear area with “great stuff” or equivalent polyurethane expanding foam.
Be sure to drill a number of big holes on the back side to let the excess out as it expands.
Figure it will take a couple trys until you get the hang of it but then it will be easy once you figure out what you need for your application.
Good luck
Tom Danley
http://www.danleysoundlabs.com/SH100.html
Hi Nemophyle, Noah
I knew what shape I needed on the outside (square), I knew I needed ports in the corners.
I cut out the center of a board, with a broad radius in the corners, roughly the shape of the flat part of the horn in the photo. I stretched the burlap across the opening and stapled it down on the back sides.
I pressed in the center of the cloth with an aluminum tube. Initially, it was too taught to stretch as far as I needed so I got it wet. After it was in position and dry, I painted on a couple coats of epoxy to make it stiff. After it was hard, I took the cylinder out and cut the opening.
I would try Spandex, it stretches a great deal, easier than burlap (in one direction a little more than the other) and has a nice smooth surface. I would try the same thing, use the built in tension in the fabric to form the curves you need. Then, stiffen it with epoxy into a solid part you can sand and paint.
Good luck, don’t be afraid to do a trial one (I made two) first to get the feel of the fabric, its cheap!
Noah, it would be wrong to tell you what driver it is although there is an Italian company with a short name that makes one VERY similar.
With any coax driver, there is a discontinuity between the compression driver and cone body, which acts as a horn. This driver had the “smallest issues” of all that I looked at for this job.
The SH100 was arranged to continue that horn to a dimension which allows it to have forward directivity down to a lower than average frequency, allowing it to be placed back against a wall without significant reflection
The discontinuity is still present at the transition point however and foam would hot fix it.
I suppose the traditional fix would be to measure at 1 meter instead of 2 and apply more smoothing to the measurement before publishing.
To make the acoustic phase response it has, the seam between the ranges had to be right, radiated power constant (more or less) but the that discontinuity shows up as small changes in on axis level / radiation pattern.
I can send you files we have just received that let you see the speaker radiation in 3-d, in several ways when you download the CLF free viewer. (files are not linked at the web site yet).
If you e-mail me at danleynospamlabs@comcast.net and (remove the no meat by product reference) I will send you the CLF files for the SH100 and SH50.
As you can see, both the SH50 and 100 are free from lobes and nulls normally associated with multiway loudspeakers at crossover.
The arrangement on the seven drivers in the SH50 show no interaction between frequency ranges and is the one, which can reproduce a square wave from about 220 Hz to 2600Hz. (posted some screen shots here a few weeks ago)
The SH100 can reproduce a square wave too over a narrower range.
FWIW, The response curve for the SH50 currently on the web site needs to be changed (has a reflection, time setting is off) but it hasn’t been done yet and theirs still snow on the ground here.
The power rating for the SH50 isn’t determined yet.
Rather than a 2 or 24 hr “death test” rating, the speaker is driven with an iec pink noise spectrum, until the speakers output simply departs 6 dB from linear, given the power.
This is a lower but more realistic rating for music etc.
Got to run,
Tom
Harryup skrev:Borde det inte vara en hyfsat stor skillnad på att sätta hornet i en låda och dämpa mellanregisterelementen bakåt eller spela dom i fri luft?
Har också själv kikat på sådana horn en del över tiden.
MÖ påstår ju att det är det bästa han har hört om jag förstått honom rätt.
mvh/Harryup