LQ & OSD: an acoustic alternative

[Radugazon]

Hello guys,

Nothing is new under the sun, but is it possible to escape from the main audio stream?
One of the possible ways is here.

[CLS]

How dare you!

Congratulation for the brave move. Let's see what others will say.

[el`Ol]

An alternative to the naked compression drivers could be this open back dome:
- Shop

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Albert Einstein once said, "If at first the idea is not absurd, then there is no hope for it."



120 views to this thread but only 30 downloads of the attached file (the real content)...

So, Radugazon,

How about posting the picture of the overall view for the lazy people?

[jrenkin]

Amazing read! Take the trouble to go through it, it is not that hard to open and worthwhile.

I wish I had the time and space to play like that! At least we don't have termites eating our drivers here in Denver...

My take on your final questions of how it can sound as good as it does with all the problems it has. It has to do with processing. Our brains are amazing and what we "realize" in terms of sound is what our brain can do with the information fed it's ears. There are errors in timing, interferences, omissions, additions and so on, but there are nuances that determine if these are important to our processing or not. Just because it looks bad on the computer screen, doesn't mean that you aren't feeding your brain with all the information it needs to determine what to "hear" and what not to.

[pedroskova]

Great read, great "lab", and evidently, great "lab assistant".

[Radugazon]

You are right jrenkin, the most appealing is the conclusion of this experience: how comes a normal subject () can perceive a good imaging through this apparatus?


Of course, statistically it’s not valid but I do my best to be honest. A DSP is a good ally for that, thanks to it’s endless memory: only a few set up produce a nice imaging . The comparison is immediate and fool proof. If I had to work 3 hours, iron solder in hand and then claiming for some improvement, here, I would’nt even trust myself.


These spatial properties don’t come from the room. Recently, I’ve put the system in a classic configuration (takes 2 hours only) that produces almost square waves and that’s average in off axis dispersion. This has some qualities, but it’s not playing music, just HiFi. Before I was biased on it, but now, it’s really kicked out.


I am pretty sure that these properties come mainly from the darn semi circular distribution. The first day I tried it I had a schock so much it was promising. But why ?


The original paper of the OSD publication (10 yrs old !) is a mathematical demonstration, without any reference to the localization processes, strange, as this is supposed to be the target.
To put more trouble in the minds, the pink noise localization that I describe (e.g. a line between the speakers) is classified by Toole as “center image totally destroyed” (confusers and confusion), and you know that we can respect Toole. Anyway, this case must be an exception to the rule.

I wish we could measure spaciousness, imaging and all this stuff, like this we would definitively escape from these psycho-acoustic-feeling-subjective reviews.



For el’Ol, you could say “a safe alternative”, because I’ve been destroying 3 membranes on one year.

About the reduction of size, neodynium could be a better choice (my 1” is already neo but the 2” are 17 cm at the magnet, far too big), the 92 dB efficiency is not an issue, but where do you see the specifications ?

Lab assistant? Maybe more...was the Pacific Connexion.

[el`Ol]

Specs can only bee seen in the german version of the page.
IT Speaker Shop - MD9550 | Gradient Select Tief-Mitteltonlautsprecher :: Gradient Select :: Lautsprecher ::

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[Radugazon]

Hello,


Link works for me, I must be closer from Germany.

Generally speaking, making a HF dipole is more complicated than removing the back chamber of a compression driver. Revisit the dedicated Rudolf's thread to take the dimension of the debate.

For making LQ, if the priority is the omni dispersion, it's not very difficult. (If the priority is dispersion + phase, here I failed). It means that the drivers I use are not the only formula. Maybe small wide range with beautifully openened baskets ?

OTOH, the Gradient can be open back, but isn't it just a resonating vent? (cf dynaudio D54 that was sealed). Without phase plug, it's almost impossible to make a working WG and the back wave must suffer.


If we stay in the dipole tweeter thread, posts 96 and 99 have to be read twice...