Hi Amco
You got me going on this issue- so I passed your Harman article to Zel and got his comments. Please note that Zel is a very difficult person to deal with and is an "acquired taste". I remember chatting to Zel one day on the phone and afterwards my wife said "who is that bastard?" On another day I visited his place one morning to have breakfast and a chat and he greeted me at the front door with a gun pointed to my head, then escorted me to the breakfast table and told me to sit down an eat my f#$%ing breakfast- quite normal for Zel, was not bothered at all. Having said that he really is the best guy I know of on bass.
Here is the slightly cleaned up conversation! ....Flyscreens are my electrostatics
Z)
Dutch Bitch,
I am not a marketing expert so I don’t understand any of this.
I just do science and I can’t see any here.
But, if you’ve read all this, can you tell me what exactly interested you and perhaps I can comment. And save me time.
I’m not sure how much Harman pays these guys to write this. I expect that it’s beneficial to their bottom line. It looks techy, and most readers would not be able to check it.
Humbly
King of Bass
CHUCKY)
Says 1 woofer sucks
Justify yourself!
Z)
To be frank, Harman are an embarrassment on this occasion. And you can’t see it. So I have to assume that you really do not understand the basics.
However, the difference between having one loudspeaker or 4 quarters instead is worthy of some consideration,
Comparisons must be made on the same Box Volume (Vb) basis.
Similarly, you can ponder what’s better a single 10W resistor or 4 X 2.5W resistors. That is, on the same Power handling basis.
There are 2 critical aspects to “Subwoofers”, the total Vb and the total Piston Area (Sd).
If these 2 quantities add up to the same value whether as a single big one or multiples of little ones, then sensible comparisons can be examined.
For example, If you only have one then you can only put it in one location. Think about the logic.
But if instead you had 2 X ½ size ones, well, the sky’s the limit. You can put them both in the same spot giving you the same answer or now you can put them in 2 separate location giving you something different.
Of course, you would prefer 2 halves because you now have more options to goof around with. But, the question is can you come up with a better sound with any of those options.
Stupidly, these experts compare 1 vs 2. And the winner is 2, unless you put them outta phase, Ha!
And then, are all the Subwoofers used the same?
Shall I continue or you had enough ?
CHUCKY_)
I know less than shit, continue.
But what about room modes/ standing waves?
Luv
Flyscreen boy
Z)
If you place a subwoofer in the front/left/lower corner and you listen to it in the rear/right/upper corner you get the right answer.
Anything else is worse.
Sitting in the middle of the room is not the worst, just pretty bad, regardless where the Subwoofer is.
Place a Subwoofer somewhere in the room, then walk around until you get the least amount of LF, that’s the worst.
To predict in 3D where all the SPL is at all frequencies is near impossible even in a perfectly rigid room. In a non-rigid room (all rooms) it is impossible to predict.
All this only matters if you like good Bass and LF.
“Room modes” is a marketing term. Non science.
Rigid environments of regular shapes can be studied for nodes and anti-nodes. SPL dips and peaks.
“standing waves” have a real definition. See “travelling waves” also.
In any case, what you get at a point is a Vector some, of course.
And what lies between a send/receive pair is a “Transfer Function”.
To determine the TF you divide the output by the input. In 3D and for every frequency. Have fun !
I have not tried every combination of Subwoofers possible, only about 3,000. Most of them are shit.
Also, don’t confuse Bass with LF. Bass is a full-range thing.
If you have any further specific questions, please ask.
I also have some good questions of my own.
CHUCKY)
I think those guys just picked one example of a "room"
Z)
If they don’t like rooms they should go and sit in a paddock.
Actually the most disgraceful part of this report is their “Primary consideration” – Minimize variation of frequency response within the seating area.
Don’t matter if it sounds like shit so long it’s shit everywhere.
F#$%ing funny
CHUCKY)
Also I woofer is a better cost effective solution than infinity
In one of the surround sound forums I was asked for the best position for a woofer and how many. I passed on your recommendation and was replied with that stuff I sent you.
Love in a soggy bucket
Chazzles
Z)
My recommendation ????
What recommendation ?
CHUCKY)
One woofer front center
Z)
Prove it !!!!!!
CHUCKY)
It's what you told me f#$%knuckle!
Z)
OK, good. Together with the corresponding listening position being at the back of the room. You can’t miss. Better still for LF is corner to opposite corner.
But, if you want to sit anywhere else you’re in trouble with LF. Like in the middle of the room.
It’s simple stuff. You don’t need anyone to tell you anything just try it yourself.
Pick a spot, sit in it and get someone to move the Subwoofer around the room.
Alternatively, pick a spot for the Subwoofer then move yourself around while the music is playing.
Then do both until you’re happy.
If you think that somehow you can get a better sound using multiple Subwoofers, good luck. Including multi-way Subwoofers in various locations.
So, put a Subwoofer in the front centre and sit in the rear centre and get a dose. If you can then demonstrate a better sound by placement, I’m all ears.
But, remember, all the Subwoofers used must add up to the same Box Volume.
How’s that ?
CHUCKY)
Bless you bass boy
Z)
Yes, Bass. Bass is a full-range sound, LF + MF + HF.
If your HF is bad then your Bass is bad.
If your LF and/or MF is bad then your Bass is bad.
CHUCKY)
Indeed we agree, it is a major challenge to get bass to not sound shit with my flyscreens
Z)
Let’s look at this.
Dutch Bitch,
We can only continue talks on this Chanel.
Please advise if this is acceptable to you.
Kind Rgds
KOB
CHUCKY)
Acceptable
Z)
I now have new data that I can share with you that doesn't impact what
I'm currently doing.
My main finding is that in the case where a full-range speaker system
(20-20,000Hz) is located in front of you in the middle of the front
wall, as proposed, and you are seated in the middle of typically size
lounge 4 X 6m, you get a pretty good sound, in mono. It sounds better at
the back of the room but you cannot then surround yourself with other
speaker systems.
This is all done experimentally. And I still find it difficult, and
impossible in some cases, to think how theoretically it all works. It's
just what happens. Some things are measurable and some are still not,
like how we actually perceive it all as humans with 2 ears. So it sounds
better to me at the back without understanding exactly why as yet.
If you then separate the HF from the LF so that you can place the HF
somewhere else, I find 2 competing factors. 1. the highest x-over
frequency before you can tell where the 2 parts are and 2. the lowest
x-over frequency before the room wrecks your LF again.
Let's look at the case of a 2.1. The Subwoofer is in the middle as usual
and there are 2 HF units L & R.
I find that the the highest x-over frequency is around 150Hz before you
can definitely hear the 3 speakers separately in your head.
If you move the x-over to 200Hz you can hear that there are 3 speakers,
this is not good. That is, if you, like me, want it to sound like a
single stage.
If you move the x-over down to 100Hz you then again experience unwanted
room effects because the LF (100Hz) components from L and R are low
enough in frequency that the room effects them badly because they are in
the wrong location. As much of the low frequencies as possible should
emanating from the center.
It is a balancing act between being able to localize the 3 speakers and
room effects.
Then whether you are listening from the middle of the room or at the
back is irrelevant to this effect.
For you, you want to be in the middle of the room so that you can place
speaker systems at the back of you as well.
And that's OK because it doesn't matter if you only have L and R or LR
and RR as well but you will pay the price for listening from the middle
of the room on LF and your Bass will suffer.
Bass is the price you pay for Surround.
Anybody can try this and find out for themselves.
Then instead of a single Sub in the middle of the front wall you get 2
halves and put one in front and the other at the back. The sound is
different but equally bad on Bass, but will measure the same on SPL vs
Frequency. It's just a matter of practicality for the designer, take
your pick. I don't like surround, all my music is in stereo from the
front so I choose a single sub in front. For Surround in movies I leave
to you.
I therefore, conclude that for Music in Stereo sit at the back and enjoy
the best sound possible.
Surround cannot be taken seriously for accurate monitoring.
But, many people love Surround for their movies. So I recommend 150Hz as
the fundamental, number 1 requirement.
That brings us to your fly screens.
I'll stop at this point to hear any of your objections or disagreements.
CHUCKY)
Dearest boom boy
Very profound thoughts. I separately have come to the same conclusion and in particular the happy zone of 150 hz. A good example of this is the Martin Logan flyscreens, because they are curved the cover frequency is above 500hz and you get a severe up/ down frequency separation.
It's so bad I cannot listen to them. Another factor I suspect you have not considered is time exposure to sound. I find that initially I hear this positional separation of high/ low but after 30 seconds to a minute the brain puts it together. It reduces the problem but you end up with a headache or listener fatigue as the brain is working overtime integrating the image.
You are correct in that there is a lot we cannot measure at the moment. Many of the things we do in the Surround Master is also done at a level the brain cannot perceive. Our ears/ brain are very sensitive yo many things but very poor at other things.
Do continue.... You bastard
Z)
For just moderate SPL levels, even the largest ESLs will find getting
down to 150Hz really tough.
But, OK. 4 X Large Corner placed ESLs as you propose plus a central
Subwoofer as I propose. Not bad.
Crossed at 150Hz is OK, sitting in the middle of the room is crap but
you want Surround, and 4 X my Subwoofers for 24-150Hz. Then you can
further fuck the sound with DSPs and Class Ds. But, if Surround is your
first priority not Sound Quality then fine. Just don't expect great Bass
and anything special in clarity.
But, as a 2.1 Stereo listening from the back of the room without any
DSPs would be nice.
Each of my Subwoofers is 50 Liters external and has a 12" driver. My
Subwoofers have advanced tech that makes them the best sounding in the
World currently.
You would use 4 Subwoofers not for their SPL capability but their Super
Low Harmonic Distortion at low SPL levels matching the ESLs.
A single Subwoofer will suffice for SPL but not for Harmonic Distortion
because you will have to drive it much harder to match the SPL of 4.
Alternatively we find an EML to operate 150-1,000Hz then ESL. For a
"Bookshelf" solution.
This could reach serious SPL levels, and is a topic I have given a lot
of thought.
This would be a genuine competitor to my glorious satellite.
I can understand you hanging up on me at this point
CHUCKY)
How dare you insult my DSP and class D you tin eared Neanderthal.
But do continue............
The discussion gets rather technical and private at this point and is continuing. And now we are in a possible mutual design project. See what trouble you have caused!!
Below is a photo of Zel and me 10 years ago (me with
black hair!!!!). Don't worry the red thing was part of an experiment we were doing. Note the tiny sub behind us! Also note the early first prototype of the Nakamichi Dragon electrostatic speaker to the left of me.
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