Orthodynamic Roundup

[clc77]

Thanks!!

 

[scompton]

That's a lot easier than what I did, looking at everyone's signature for the last 3 or 4 pages, and not finding it

 
clc77, smeggy puck might be a good thing to start your search with.

 

[wualta]

Ludo's search engine had stopped updating itself as of August 10, 2010 due to a big change in the HF site, but now it's working again! Kermit yaaaay!

 

[scompton]

Was that the switch to the new forum software?
 
Edit:  Just tried a google trick and it worked.  I always knew you could restrict a goggle search to a particular site and I was wondering if it would just search this thread if I put the thread's url in as the site and it worked.
 
Just type your search phrase and add site:http://www.head-fi.org/forum/thread/111193/orthodynamic-roundup
 
http://www.google.com/search?q=smeggy+puck+site%3Ahttp%3A%2F%2Fwww.head-fi.org%2Fforum%2Fthread%2F111193%2Forthodynamic-roundup&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-USfficial&client=firefox-a
 
It's not as good as ludoo's search engine since you can't limit it by poster

 

[Antistase]

Quote:

 
Not sure what you mean by "mid-low honk", but if by that you mean that there's a lump in the midbass where it meets the midrange, you might need to use denser felt right behind the driver-- ie, you may need to increase the amount of damping. Always get this part right before you take care of anything else, even the top end.
 
Which brings us to reflex dots, but let's use the euphemism "reflection discs". To answer your question, yes, the effect of a reflection disc is very much dependent on its size.
 
Reflection discs have become anathema in some quarters, so prepare to be shunned if you use them. Their use was originally intended to prop up only the top two octaves (5k to 20k). The theory goes like this: A disc of a certain diameter will let sound wavelengths greater than that diameter diffract, or bend, around the disc. Wavelengths shorter than the diameter of the disc will reflect back, adding to the original sound, since the reflection point is virtually on the diaphragm itself. In real life there's no sharp cutoff-- as frequency rises from the bass, a reflector disc will reflect nothing, then a little, then there will be a more sudden increase around the point where the sound wavelength matches the diameter of the disc, then back to a gradual rise to a shelf or plateau after that. In speakers there's an analogous (but reverse) phenomenon called the "baffle step".
 
Or in ballet, the pas de baffle. But that's not important now.
 
By combining porous tape (MicroPore, TransPore) with felt, you might be able to make a reflector large enough to reach down to the point where the dreaded Ortho Droop begins (according to Yamaha's response graphs, this could be as low as 1kHz !) without sealing the driver and creating a tweeter. And to do this right, you'll want to experiment with several disc sizes. Try a whole bunch of little ones. Or one big one (maybe 19mm or so) smack in the middle. Then add a circle of little ones orbiting around the big one. Since the ear is not omnidirectional at all frequencies, some experimentation (and research) is in order, because it may be possible to cheat. I love it when that happens.
 
Of course, since the traditional treble control hinges at about 1kHz, you might just want to take the easy way out and do the correction electronically. It's only about a 3dB/octave slope, so nothing radical is needed.
 

Thanks Wualta, I will play with it  following your suggestions.  Any way I'm a bit at loss about the wavelength/dot diameter match. At 10Khz the wavelength is supposed to be around 3.5cm which makes for 70% of the surface of the driver with a single disk.
Also, as the hp1 driver has a perforated magnet enclosure, isn't the magnet holes diameter the only reflection area you can really work with? In this case the reflected frequency is far above audible. Am I doing a mistake and should instead apply the disks on top of the felt and not directly on the driver? What's the effect of the distance of the disks form the diaphragm (in terms of phase for example)?
 
I seldom listen to digital streams from my computer. Mostly youtube stuff. Couldn't find any computer/USB dac yet able to even get my vintage modded TDA1541 NOS cdp stop laughing at it.I may be able to resume an old UltraCurve dusting in the loft back in service if I can find the space for it or buy the newer 24/96kh slimmer version of it. Luckily enough those Bheringer are terrific value for money.
 
Cheers,
A
 
 

 

[wualta]

I'd like to think that if reflectors had no effect, they wouldn't be hated so much. Maybe you can convince the haters that it's all in their heads.
 
Let us know how that mid-low honk is coming along.

 

[wualta]

 
Quote:

Was that the switch to the new forum software?
 
 
Just type your search phrase and add site:http://www.head-fi.org/forum/thread/111193/orthodynamic-roundup
 

Yes, that's what ludoo told me.
 
 
Thanks for the tip. I've been using Google myself, since the HF search engine has become so nearly useless. I'll add this site search term to post #1.
 
 

 

[gurubhai]

Quote:

Thanks Wualta, I will play with it  following your suggestions.  Any way I'm a bit at loss about the wavelength/dot diameter match. At 10Khz the wavelength is supposed to be around 3.5cm which makes for 70% of the surface of the driver with a single disk.
Also, as the hp1 driver has a perforated magnet enclosure, isn't the magnet holes diameter the only reflection area you can really work with? In this case the reflected frequency is far above audible. Am I doing a mistake and should instead apply the disks on top of the felt and not directly on the driver? What's the effect of the distance of the disks form the diaphragm (in terms of phase for example)?

 
 

Actually having a perforated magnetic structure would mean we already have a huge reflex "dot" behind the driver - the magnet.
 
I wonder if that's one of the reason that fostex went for serpentine design on its drivers meant to have an open shell.
 
 

 

[BoilermakerFan]

Quote:

I wasn't completely serious about this, and I do know that at least the old Lambda Pros can sound pretty terrific. But I still find 9 of 10 Staxes simply boring (the same is to be applied to the HD800 BTW).
 
I'm on a constant search for best-as-possible musicality, other stuff like audiophile merits are partly subordinate for me personally.

 
 

K, I must have misunderstood, but I also didn't want to confuse new peeps.  I love both 'stats and orthos.  Different boats for different rivers...  The Normal bias Lambdas are a much better headphone than the Pros though.  My pair is a pretty golden pair too, and really surprised a lot of folks at CJ '10 off AC's 350V eXStatA SS.  Even after I finish a set of custom HE60s, I suspect I'll keep my Lambdas. 
 


Quote:

well of course you guys couldn't find any.  BMF bought 'em all XD

LOL!  I bought my 100 pairs over 2 years ago for a potential commercial JV that died out.  I grew tired of the delays and lack of communication with the potential partner and went in a much different direction with my goals and planned involvement in headphones and audio.  I have decided I do not to do anything MOT or commercial on my own.  I just help a couple of others now and I enjoy it much more.  I get to focus on the aspects of the hobby I enjoy without the other drudgery that wears me down. 
 
So, I'm selling off the drivers at my cost.  Wish I had taken a pic of my inventory of all the different ortho drivers, headphones, and Stax parts at it's peak.  It was quite impressive and would have made a few folks drool.  Well over 30 pairs of complete headphones alone, though a dozen to 18 were dynamics. I've been slowly selling it off for the last 30 months or so. 
 

 

[wualta]

 
Quote:

I wonder if that's one of the reason that fostex went for serpentine design on its drivers meant to have an open shell.

 
I'd lay bets that it was. Still, even with all the built-in "dotting" and the reflections off the inside of the cup (in the case of the HP-1, at least) the treble still tends to droop. I wonder if a study of ribbon microphones will yield a clue...
 
Time to do some beard-stroking!

 

[gurubhai]

The treble droop , I suppose, is an inevitable consequence of non-tensioned diaphragms.
I guess these diaphragms would need more damping compared to a tensioned diaphragm to produce similar treble response.
Just the reflex won't do.

 

[kwkarth]

Quote:

Here's a picture of my crew setting up my new speakers.  Once they get it into my house, which you can see in the distance, they're going to drill holes in it and slap a diaphragm in there.  I'll let you know my impressions. 
 

 

Oh!  You're down-sizing then?  I suppose, the next thing is swapping out the Hummer for a Prius...
 

 

[scompton]

Quote:

The treble droop , I suppose, is an inevitable consequence of non-tensioned diaphragms.
I guess these diaphragms would need more damping compared to a tensioned diaphragm to produce similar treble response.
Just the reflex won't do.

When micropore tape was first talked about, I had just bought a YH-100.  I went out looking for it  and found some other, non 3M, tape with a similar name.  I but it on the back of the YH-100 and it turned it into a tweeter. 
 

 

[clc77]

Thanks scompton!!

 

[gurubhai]

@scompton : similar experience here. This is of course due to the fact that tapes have a very strong damping effect & moderate reflex properties as well.