Orions sound great because dipole?

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I am concerned about replying here because it always seems as though I am selling my side of the issue - well thats true, I am, is that so wrong? I have my opinions on the topics and not an insignificant amount of data and experince. So why not share it here, talking about OB?

To Goskers, I don't think that "coloration" is bad word, its actually used quite a bit in psychoacoustics to mean "linear distortion", but perhaps linear distortion is the better term. At any rate as long as we all have the same understanding then the word is not a problem.

There is no doubt that a box and an OB will behave differently, but which is "correct" or "better". Well of course we have to exclude the subjective aspects as there is no answer there and so whats the point of thrashing it around. So lets look at some objective aspects.

An OB will have a very large diffraction at the baffle edges - much larger than a box of the same size. This is because the back wave creates a pressure release at the edge while the box only has a change is the spatial loading. The diffraction from an OB baffle will be almost double that from the box. Now generally speaking diffraction is not a good thing, although maybe some people like it - who knows. IT IS NOT accurate reproduction.

What about the back wave from the speaker. Well this is potentially a problem. If this back wave excites the enclsoure into a resonance then the enclosure can resonate long after the speaker has decayed - again a bad thing in general, although again, some people may like it (but that too is not accurate reproduction). Suffice it to say that in my experience its not too hard to create a box such that this ring down of the enclosure resonance is very small and actually hard to measure. There are those who claim that this kind of resonance can be heard well down in amplitude - say 30 dB down or so. Unfortunately this has never really been confirmed with scientific tests and so I have to rest on the data that says that if the box ring down is well below the systems ring down - which should itself be low - then this effect will not be audible.

I've tested this idea myself with boxes of several different constructions from carbon-fiber enclosures (ultra rigid), regular fiberglass with CLD and without, baffles made from Corean material that weighed a ton, all CLD enclosures, and simple MDF. There are box parts for which CLD is very effective - the baffle for one, and in my designs the back panel because it is not well supported - so dampen it. But beyond that I have not seen nor heard any effect of enclosure rigidity once the box is sufficiently stiff and/or damped.

And that back wave IS a factor in the driver because it is what creates the box stifness, which is not a bad thing, because air stiffness is much more linear than spider stiffness. But the real advantage of enclosing the back wave is the excellent efficiency of the monopole, which is as good as it gets.

So talking about OB, I can only see potenial negatives from its use, except for its better directivity, which is a positive. Does this positive outweigh the negative of the baffle diffraction? That's a tough call. At low enough frequencies I would say "yes" (ignoring the low efficiency, which is hard to ignore), but at higher frequencies I would prefer "alternative" ways to increase the directivity that don't have the baffle diffraction issues. (I wonder what those are!?)
 
hm
please tell me
why in quite all recording studios
the big monitors are flush mounted in wall?
There was an Augspurger sorry if miss spelled paper on this
decades ago, the AES should have papers too.

Near field is sitting on the mixing desk, there is
some research regarding the reflection of sound by the desk,
and how to overcome.

The infinite baffle approach of in wall mounting is in home use
quite not applicable but in a corner a huge baffle from ground
to ceiling could work.

Coloration is not a very good word,
only to show that there is something we even don't quite understand.

maybe edge diffraction, back waves, echoing and all that,
are different between dipoles and any box design.

The term "so airy, so open" for dipoles sound
is a kind of feeling like
"it's so live" for horn design.

Most could be a matter of taste,
like with a good wine....

I do have Quad's,
I'm building the famous, small corner frugel horn from this forum,
I'm dreaming of Unitys
and I do have Bose 301

I do have tubes, Manley uhhhhh
Aussie Amps
Bryston and gainclone-clone
I do like them all

crazy yes, as i do have a May piano and tons of cd's, disk's and books
moving to London next year, a challenge
but did moving 17 times since handmade in Berlin

my living is about 75 square meters
and living you can take for real
 
Dear Gedlee
well it could be done
a box from recycled plastics and fiberglass very rigid, heavy and
a crazy damping factor
In PA it does exist as they are doing big numbers,
cheap too.
In France in L'Audiophile, times of HIF glory
and horn mania, sorry mister Hiraga,
they had plans of the famous Onken box,
double birch heavy braced and double walled with dried sand filling.
The golden age of HIFI and DIY mania.
Friends of me do have a restored JBL Hartsfield,
there are French DIY plans on the net.

Going crazy I know where to go
to get wild by a restored Paragon.

HIFI don't knew, but it is playing music

go there
http://www.me-geithain.de/index2.html?eng
and look at The Studio Monitor Speaker RL 901K
it is still there and has been famous for classic production
since DDR times, they did classic recording at this time!!!!!
 
serenechaos, I was trying to think of a way to isolate this "box sound" we are often told is so detrimental in boxed speakers. There are many other probably more significant differences between open baffle and sealed, so a test would need to eliminate those differences if it had any hope of actually comparing the "boxiness" of the sealed speaker to the open one. I can't think of any way to isolate this one element from the others though. I know Lynn Olson has mentioned more than once simply putting your ear against the box and listening. This may be as good as we can do but it will mechanically couple vibrations from the cabinet to your ear that would not necessarily have coupled to the air and then your ear. It is a common mechanic's trick to put a long screwdriver against an engine case and press your cheek bone to the other end. Works like a stethoscope to hunt around the engine for bad bearing etc.
 
Account Closed
Joined 2001
Doc,

I understand the diffraction differences and possible resonances with the baffle or enclosure. Neither of those effects contribute to box "coloration" do they? I also understand your point that the back wave creates "box stiffness" and thereby greater efficiency.

Those are certainly differences between the two baffling approachs which result in different performance (good or bad), but they are not aspects related to box "coloration"....IMV.

I think what most folks are referring to when discussing box "colorations" are (predominantly) the very high SPL's existing in the box modifying the output produced by the "front" of the transducer. This has to be considered a distortion of some kind because it's not a valid representation of the driving voltage....such as it is....(I'm thinking in relative terms in comparison to an open-baffle design.)

I don't see how you can conclude there are "only potential negatives" (except for directivity) from an OB approach. The potential problems you noted....and others....can surely be addressed with proper design and construction techniques, no?

Cheers,

Dave.
 
Is there some study infinity baffle VS Box attached to back side of same IB? I think this will be only correct way to measure if box has effect and how effect it is. Of course provided that test signal will be hipassed enough so box will not limit LE extension.

Sorry for weak english
 
gedlee said:


But isn't the point that I did show that HOM existed and that they were audible. You seem to be discounting the fact that I HAVE looked for "box coloration" and I can't find it. Why would I acknowledge one and not the other? I have described my tests and my conclusions and I think that you should show some valid data to make the claims that you do. Where has it been shown in a controlled test that box coloration is audible for a reasonably well built box? I know of no such work.

Well, with all due respect, noone knows all the answers. I'm sure lots of people have looked into horn distortions before you, even if they are not measurable, and it took a long time before someone actually did something practical about it.
You openly state your HT preferences, and maybe with type of music you are familiar with 'box colorations' (feel free to use a different term, I haven't got a better one) aren't as obvious. After all, 'familiarity' with, say, rock music stems from hearing amplified events using - guess it - boxes ! I am a classic music goer, I do attend a live event regularly, on average perhaps twice a month. To me, 'boxines' is evident, but as Poptart has eloquently pointed out, maybe is a combination of many other things OB's are doing differently that is really my preference. I simply cannot be sure, as to have a truly controlled experiment - compare in isolation box vs no box, without affecting directivity, polar response etc. etc. - is impossible. For now.
But seeing that even major players are venturing into OB (eg Jamo), and labeling such designs as a flagship model, tells me that where is smoke there is a fire, too.
 
Try to get rid of the back waves of an OB aka ESL.
Acoustic sump, go there
http://www.top-audio.de/taweb/speaker/activ/ch-2/ch2.htm
it is German but look at the pictures.
I did hear them at the time in Switzerland.,they still exist.
There is an AES paper on them

And it has be done later too.
The sound was still what you call ESL.
Maybe the transient response time
and quite no ringing, overshot etc
like a Manger explains the sound somehow.
Manger does say that an ESL is close to his approach


let us take a different look
Genelec is using waveguides quite a time.
Digital in, digital x-over, box dead as it has to be
digital room eq.
But in hifi terms called
analytical, fast, clinical, not colored, neutral, cold, not warm, dead clean,
no marvel, not zen etc.

They are mixing work tools for hours, I'm used to.

OB are called no fatigue, warm, pleasant, airy, no boxiness.

It is like red wine and a good meal.
Ambiance and psychoacoustics ob's does give
a somewhat panoramic window to the sound.
Not so a tool.

It is like horns, perfect no!!
but somehow live with
only some watts,
where a sealed box does need
a 100x more watts.

ok
all the diffraction, back waves and all this
in a typical living with an OB like Linkwitz,
and you have a 16x9 pleasant sound.

Mingus told the people
make it simple, you are a genius,
but mankind tents to make it way to complicated
it is human.

Enjoy the sound

A May is not a Steinway, but the sound
is nice, it is a piano, it is live
 
Markus,

I don't think it is that simple. I'm fairly aware of extra cues as to 'spaciousness' with OB/planars and I'm also rather sure I can 'exclude' them. There is something else that is bothersome and it is a form of distortion, I can't really describe it in words easily.

I've given up on multi channel, first only a small percentage of my collection is recorded as such (not even all SACDs are multichannel, and I have less than 100 of SACDs in total) and second, even hearing some of those in 'full surround' left me rather underwhelmed. I think there is a long steep learning curve for producers/mastering engineers on how to actually record a complex classical event in 5/7 dot whatever. I'll stick with two channels for now :xeye:
 
markus76 said:
There's only one way to reliably transform a concert hall experience to a living room: multichannel.

Best, Markus
True
my dream setup
the big Yamaha amp
get a third Quad Els 63
building Linkwitz subs
mating some ribbon to the Quad
to have them three way
all on power amp modules
active x-over
back channels my beloved ls3/5a
and with the Yamaha doing room EQ

crazy
i do have a huge collection of famous concert DVD's
going wild with the beamer
and my circle bed just in the center
as I told ya, my living is a living
a petite blonde approach

all theory is somewhat dull,
no pleasant color

Enjoy the music
jazz in a tiny bar can be fantastic,
far from perfect but
in you mind dreaming of
for hours......
 
poptart said:
serenechaos, I was trying to think of a way to isolate this "box sound" we are often told is so detrimental in boxed speakers. There are many other probably more significant differences between open baffle and sealed, so a test would need to eliminate those differences if it had any hope of actually comparing the "boxiness" of the sealed speaker to the open one. I can't think of any way to isolate this one element from the others though. I know Lynn Olson has mentioned more than once simply putting your ear against the box and listening. This may be as good as we can do but it will mechanically couple vibrations from the cabinet to your ear that would not necessarily have coupled to the air and then your ear. It is a common mechanic's trick to put a long screwdriver against an engine case and press your cheek bone to the other end. Works like a stethoscope to hunt around the engine for bad bearing etc.

Maybe
"we are often told is so detrimental in boxed speakers."
is the problem.
Those who OBs bad mouth boxes...

I don't know exactally what "this box sound" means.
box vibrations, bounce back to the cone, edge vibrations...
what is it we're talking about, and can we quantify it?

I can't believe an OBs frame isn't going to vibrate, & you can find that with a stethoscope too.
Doesn't prove a thing though does it...

I do know OBs "colorations" are far more unnatural, bothersome, and the deal killer for me. The only advantage I see in OBs is that they are much easier and cheaper to build.

I far prefer GOOD horns (Not horns that "sound like horns" with bad colorations) for any type of music. Rock, symphony, low-level acoustic, anything.

total black sheep
 
Markus,

when I said 'not that simple', I meant that enveloping and increased directivity are relatively easily identifyable aspects of Orions vs say ATCs. Yet I still hear the 'box sound' from ATCs. It is funny because ATCs are one of the least distorting speakers I know; but this is something different from harmonic and nonlinear type distortion.
It is far from a terminal flaw (after all I still haven't retired them), but I now know there are things that could be done better. So that's the itch ;)

Best,
Bratislav
 
Ex-Moderator R.I.P.
Joined 2005
Theres a big difference between live concert experience and domestic reproduced sound
The mucisians are there at live events and you can see them while playing
At home the closest thing is DVD where you also have a picture of the band
The other day, while listening to a hard disc recorded jazz event, I performed a little experiment
It showed clearly without any doubt that the perceived sound was quite a bit different whether I was looking at the picture or only listening to the sound without the picture
Knowing that the sound was completely the same I would say that its all a trick of the mind :clown:

btw, I know what you mean by "boxed" sound and I would say that its present mostly in a flawed design
xo-design has a lot to say in this respect
A good well balanced design doesnt suffer from boxed sound

Maybe part of the the problem is that we want it to sound better than it actually does in real life
A dipole bass may sound very good, but that doesnt mean that its more correct or true to the source
 
I wonder if this might work:

1) put an accelerometer on a box panel, and measure the frequency response to it from driving the speaker driver.
2) Then, remove the driver and put in a contact stimulator (something with some mass on a voice coil, but no cone), or maybe an open-backed driver glued onto the inside of the wall. Something that can stimulate the wall directly from inside.
3) Seal the driver opening (block it with a disk of MDF, for instance).
4) Then equalize a recording played through the inside stimulator (perhaps by measure the response and then processing the audio file in a computer, not too hard to do) so that it has the same signal to the accelerometer that was obtained with the driver.
5) Now, the sound comes from the wall, but not from a driver exposed to the outside. Listen to see if that can be heard from the outside.

Sounds like a good bit of work, maybe someone has the means and time to try it? (I don't at present).
 
bwaslo said:
I wonder if this might work:

1) put an accelerometer on a box panel, and measure the frequency response to it from driving the speaker driver.
2) Then, remove the driver and put in a contact stimulator (something with some mass on a voice coil, but no cone), or maybe an open-backed driver glued onto the inside of the wall. Something that can stimulate the wall directly from inside.
3) Seal the driver opening (block it with a disk of MDF, for instance).
4) Then equalize a recording played through the inside stimulator (perhaps by measure the response and then processing the audio file in a computer, not too hard to do) so that it has the same signal to the accelerometer that was obtained with the driver.
5) Now, the sound comes from the wall, but not from a driver exposed to the outside. Listen to see if that can be heard from the outside.

Sounds like a good bit of work, maybe someone has the means and time to try it? (I don't at present).

Bill Waslo? Nice! I didn't know you were on here. (Bill's company makes some of the best loudspeaker measurement software in the world : http://www.libinst.com )
 
ATC's are very high regerded
for mastering and mixing UK and elsewhere too,
that was the reason they came up to hifi, audiophile
ore whatever too.

With Mangers the same story but,
but a different beast, anyway.

OB's used for mixing, there have been some Quad ESL
for mastering, some huge B&W too
today mostly Genelec
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.