Loudspeaker perception

[mige0]

Bass reproduction generally is part n' parcel with "loudspeaker perception".

Graaf, you would also have to cut out all about "spaciousness" as this is partly about what a speaker is capable of and partly about the rooms sonic signature ( ambience ) the speaker is perceived in.

Not much left then...

At least to me the thread is still spinning around some fundamentals about *perception* of loudspeakers.

But I have to admit I am more curious in subjective observations than in academic soundfield theory.
So my opinion might not be represantative.

frankly speaking I don't know where did the title "loudspeaker perception" came from?
perhaps it is imprecise[/B]

Earls suggestion


Michael

 

[graaf]

Graaf, you would also have to cut out all about "spaciousness" as this is partly about what a speaker is capable of and partly about the rooms sonic signature ( ambience ) the speaker is perceived in.

still the issue of spaciousness has more in common with issue of stereo phantom imaging then bass absorbers, don't You agree?

for both issues concern specifically the problem of spatial reproduction of sound

bass absorbers and bass management perhaps accidentally

isn't it obvious?

best!
graaf

 

[ScottG]

If its not "apparent" then I guess that it hasn't dawned on me

We certainly differ on the "practical" point of view because I find discussions and pursuits of the "impractical" to be academic and somewhat pointless, but certainly a waste of time. Everything that I do is from the point of view of practicality. Its the definition of "practical" that is up for grabs.

It may not have "dawned on you", but I'll accept this as: "I'm not interested".

Your whole response gives me "pause".

Please consider:

The use of "practical" is specifically a LIMITATION.

This limitation then pervades all, ("everything"), of your replies here and elsewhere.

Noting that "practical" is "up for grabs", you are specifically limiting this discussion to what YOU DEEM AS PRACTICAL (and of course to only that has "dawned on you").

What if *your *method of practical is NOT PRACTICAL FOR ANOTHER READER?

WHAT IF YOU HAVE LIMITED YOUR VERY PERCEPTION OF SOUND BECAUSE OF YOUR OWN BIAS OF PRACTICALITY?

"Loudspeaker perception" implicitly encompasses perception by a multitude of listener's, many of whom may not be limited by your perception of practicality.

-Just something to think about (..especially considering your recent caution to the influences of individual psychology).

 

[markus76]

Scott, so why not talk to someone that actually wants to talk about the same thing things you want to talk about? You want Earl to say something that contradicts his agenda. I guess you have to do something more clever than pushing him to do so

 

[graaf]

Scott, so why not talk to someone that actually wants to talk about the same thing things you want to talk about? You want Earl to say something that contradicts his agenda.

Dr Geddes has his agenda ???

I believe that His agenda is education

best!
graaf

 

[markus76]

That's the problem with beliefs - they can be wrong

 

[JPV]

JPV, yes I think so – but haven't done this, so my answer is no more that a good guess.

Keep in mind that you don't get it without adding some "synthetic" reverberation. Just playing back what the mic's are recording (with some delay) did not sound good / right.
So its not exactly *restitution* you get but rather creating an ambience at will.

What I got back then dropped my jaw, considering the very low effort I made.

Basically it was
- relatively cheap AKG boundary mics
- a simple (Mackie) mixer as mic pre
- a TC electronics two channel reverb

Most astonishing of all - it was *only* two channels

Now I would use a more sophisticated PC solution with the mighty possibilities of convolution reverb you get for free today.



Michael

What kind of bandwith ( LF) is required for the lateral omni for good result?
Same as main channel is difficult.

JPV

 

[graaf]

That's the problem with beliefs - they can be wrong

You have clearly misunderstood me
it is not "belief" in that sense
It is sad how You put Dr Geddes' bona fide into question
I cannot accept it

anyway, ad rem

The stereo listening area is very narrow. For a basis width of 3 m, the listening area at a listener's distance of 3 m is only 21 cm wide (for loudspeakers with normal directional characteristics).
At 5 m distance it is only 38 cm wide (reverberation time about 0,5 s). For a larger basis width the listening area is even narrower. Loudspeakers with a larger radiation angle (spherical loudspeakers) increase the width of the stereo listening area by a factor of about 1,5; they have, however, the disadvantage of reduced sharpness of localization.

see: http://www9.dw-world.de/rtc/infotheque/sound_perception/sound_perc.html

what can be explanation for this?
I mean "increase the width of the stereo listening area" with "Loudspeakers with a larger radiation angle"?

best regards!
graaf

 

[mige0]

To me no opinion of a change can be valid without some quantifiable measure of the change that can explain the opinion. Otherwise the circular problem can be insidious.

Audiophool or not, ....

mige0 has expressed a similar sentiment on this thread alone. He may not have gone through similar testing, but somehow I doubt he is "phooling" himself either.

Earl, frankly I avoid such test as I'm not heading to proof for *others* just to get clarification for me alone on issues I am interested in.

Beside I agree with you that you easily can get trapped in circles - I already outlined that I found a way to "learn".
This has very much to do0 with *perception* and to which *perception* we are open for.
IMO the time you spend learning a "difference" cant be shortened to some A / B switching test.
Even more pronounced I would state that all that is found this way is misleading – when it comes to a holistic experience / sensation of sound / music.
Sound / music reproduction has to open the door for you .
*And* sound memory may get coloured over time but still is our most reliable guidance.

It's really time consuming to find out what doors did open and it is even more difficult / time consuming to be aware of what doors got closed (as you outlined quite correct).


Let me illustrate with an example on how I proceed in development.

Right now I am trying to find out how to get the most homogenous transition to my AMT.
Well, the general suspicious to treat would be the XO – not for me – not in this case.
I left the (admittedly inferior) XO in place , just trying to change the AMT's appearance by adding different shallow horns from expanded polystyrene (the rigid one).

It turned out that the use of expanded polystyrene (cheap / easy to cut in different shallow horn shapes / easy to apply) wasn't a good idea at all.
*Not* because the shallow horn idea was bad but because expanded polystyrene adds so much of its own sonic signature that I couldn't tell *anything* about the shallow horn.

It took me many hours to fully learn this coloration. It took me another time in many different moods to re-learn what *exactly* I had lost when going back (trashing the expanded polystyrene horns) to where I was before.

Yes, this example is a very superficial one – to where I am heading to and which path's *I* go or avoid.
For the example above I doubt you could measure something meaningful – could you?

Graaf, would you say my example has *something* to do with "loudspeaker perception"?

If its not "apparent" then I guess that it hasn't dawned on me

May be you not yet have been in the right mood to allow for dawning ?




Michael

 

[graaf]

Graaf, would you say my example has *something* to do with "loudspeaker perception"?

o yes, of course - in a sense - of perception of sound change (coloration) due to loudspeaker's modification

but I doubt whether it has anything to do with "perception of the loudspeaker as such"

I thought the topic here was "stereo imaging", broadly speaking

I wonder what is the topic of this thread now and why it has been changed?

Can You tell me please?

best!
graaf

 

[mige0]

What kind of bandwith ( LF) is required for the lateral omni for good result?
Same as main channel is difficult.

JPV

Guess, I cant answer that scientifically.

But as a rough guidance for you, the speakers I used were JBL 8330 and JBL Control 5 .
Both pretty standard 2-way resp. 3-way vented designs.

I could come as close as about 1m without getting too much aware of the speaker as sound source.
Remember, the SPL needed is *very* low - so you might come away almost with any speaker you try.

Even a relatively small 4"-5" woofer should have enough resources to go down to – lets say 40Hz-50Hz – at the levels needed (equalised to taste)


Michael

 

[poptart]

Earl, it's tough to accept your argument that dipoles are "impractical" in light of your multi-sub bass system and the complex setup routine given in the nathan thread. Adding some eq so your bass stays flat with the back off the box really isn't all that complex or impractical and this leads to another argument you make that I can't accept - You can't see any technical advantage of active systems? Come on, that doesn't ring true. I just gave you one advantage, in an active system it would be trivially easy to adjust the eq of the woofer for dipole operation. Or for being closer to a wall, or any other setup change that ideally should have a crossover change. That's "impractical" in a passive speaker because the frequency shaping components are large and expensive. There are many other technical advantages: You don't waste power padding down one driver to match another and you're free to choose the best drivers regardless of efficiency matching. You can tailor the characteristics of an amplifier to best match it's driver. The amplifier handles a reduced bandwidth etc. Active has taken over a large part of the professional market and I doubt it's because there's "no technical advantage".

Now are dipoles more expensive for the same amount of output? Sure. Nobody is arguing that. But expensive does not equal impractical. Your speakers and four subs are not exactly cheap but personally they don't seem impractical to me.

 

[mige0]

o yes, of course - in a sense - of perception of sound change (coloration) due to loudspeaker's modification

but I doubt whether it has anything to do with "perception of the loudspeaker as such"

I thought the topic here was "stereo imaging", broadly speaking

I wonder what is the topic of this thread now and why it has been changed?

Can You tell me please?

best!
graaf

Right, from this point of view I'm way OT.

I'll keep my mouth closed for a while....


Michael

 

[ScottG]

To me OB does 2 things that give it a sense of superior subjective purity in the power region 200-800Hz over a box. 1. Does not smear the 1st msec as much. 2. Gives a means of radiation control there. I.e. figure of 8 is a type of control.
It asks for more space and money, but that is a discussion of another order.

Thank you for a response!

So (to you)..

#1: it provides a better sense of detail presumably because of linear decay below 1 msec.(millisecond)?

Note that you can radically improve linear decay with substantial "stuffing" near the driver - providing an even better *apparent* decay "pattern" than any open baffle can provide (..even within 1 millisecond).

I do however think you are correct (in result) - and I would also deem this to be the most significant feature in providing better image placement in the depth plane (vs. a traditional monopole).

Some questions then are:

What's different that is audibly better (to some) with an open baffle's decay signature over that of a heavily stuffed "box"? It almost certainly is measurable, but how can it be identified?

Moreover because its a measurable *result*, what MECHANICALLY is going on to the underlying process that makes an open baffle preferable to some (at least in this respect)?

#2: *How* is pattern control contributing to an audible improvement for you?

......................

You are of course absolutely correct that more space and money (for an open baffle approach) are separate issues to be reconciled with latter/on a different thread. (..something I also was trying to emphasize.)

Again, thanks!

 

[gedlee]

IMO "subwoofer" is more properly described as an additional device that extends freq. response below virtually all fundamentals - specifically into the infrasonic region.

This is the historic deffinition, thats true. What would you suggest as a new term for the "woofers" that are LP filtered, but operate up into the range of the mains. "Sub" is a misnomer, but it does seem to confuse anyone.

 

[gedlee]

Once again on dipoles! I sat down once with the intent to investigate the use of an unbaffled mid-woofer. I ran into problems that I did not like and so I did not continue. I've heard the OB two way systems and did find them agreeable, but not up to what I was used to. This could be due to many factors, the rooms being of parmount concern. OB may be a good choice given enough time to work through the problems, but I've found a formula that works for me and everyone who has heard it and I am far more interested in pursuing this line of design. But by all means go ahead and discuss the OB designs, I just don't have anything to add - other than they haven't worked out for me - yet!

 

[gedlee]

#1: it provides a better sense of detail presumably because of linear decay below 1 msec.(millisecond)?

Could you ellaborate on this? 1) better deffinition of what you mean and 2) why does an OB do this?

 

[JPV]

Guess, I cant answer that scientifically.

But as a rough guidance for you, the speakers I used were JBL 8330 and JBL Control 5 .
Both pretty standard 2-way resp. 3-way vented designs.

I could come as close as about 1m without getting too much aware of the speaker as sound source.
Remember, the SPL needed is *very* low - so you might come away almost with any speaker you try.

Even a relatively small 4"-5" woofer should have enough resources to go down to – lets say 40Hz-50Hz – at the levels needed (equalised to taste)


Michael

Tanks for these comments. It makes a lot of sense and it is what I thought without having the experience.

I find this very interesting and very important, even most important.
Do you expect it to be very difficult to achieve enough LF damping in a small room for this solution to perform adequately?

JPV

 

[ScottG]

Scott, so why not talk to someone that actually wants to talk about the same thing things you want to talk about? You want Earl to say something that contradicts his agenda. I guess you have to do something more clever than pushing him to do so

I've just done so.

Actually, part of the point is that I'm not altogether convinced that it in fact DOES contradict his agenda - at least not in "total". (..and "agenda" seems an apt word based on the latest posting.)

Nor was I trying to "push" him into doing something. I was however responding to him (as I've done for others and you now - note the correlation between responses and direct communication to me). I'll admit though that a fair bit of those response were restating previous communication (in variety), but principally because it appeared that Earl didn't really understand what I was asking for, or perhaps why I was asking.

 

[ScottG]

Could you ellaborate on this? 1) better deffinition of what you mean and 2) why does an OB do this?

"#1: it provides a better sense of detail presumably because of linear decay below 1 msec.(millisecond)?"

This was a question that I posed to Salas, but it was also an attempt to provide a slightly more detailed restatement (..and of course with the question of - if it was a correct restatement).

"#2: *How* is pattern control contributing to an audible improvement for you?"

This was another question to Salas, though this time it was not an attempt at a restatement, but rather a question for greater specificity from his previous statement (#2).