Siegfried Linkwitz on OB

0 Members and 1 Guest are viewing this topic. Read 19540 times.

Russell Dawkins

Re: Siegfried Linkwitz on OB
« Reply #80 on: 7 Apr 2017, 05:13 pm »
Hmm, so is this why planar drivers sound so much cleaner and more detailed than cone drivers?  Not because the material is "lighter and thinner", but because there's magnets at the front and back of the driver so it's physically started and stopped more quickly/precisely?
Actually, the settling behavior of planars tends to be really messy and random, but at least it also tends to be very quick and low in level. What helps planars is the excellent coupling of the diaphragm to the air, such that the air itself puts a brake on large scale overhang. It's a function of the diaphragm mass to the mass of the air to which it is coupled; vastly better in planars (especially electrostatics compared to planar magnetics which have more mass per square inch of radiating surface) than cones of any type.

Certain materials in cones and domes are also superior due to their inherent self-damping characteristics, coupled with lightness and tensile strength, such as magnesium and alloys of magnesium which can make wonderful midrange cones and beryllium.

http://www.6moons.com/audioreviews2/fostex3/2.html

Here, the advantage of magnesium over aluminum is demonstrated by dropping two cones, one of each metal, onto a hard surface. Fostex makes the same speaker with cones and domes in both materials, with the magnesium version being roughly $1000 more expensive.
https://youtu.be/wrdYofPYD4M?t=77
Incidentally, Joachim Gerhard of Audio Physic has been observed using the same technique to choose likely cone materials!

There are three graphs comparing the settling time, or post ringing as it is called here, of aluminum, titanium and magnesium halfway down this page: http://www.6moons.com/audioreviews2/fostex/1.html

FullRangeMan

  • Volunteer
  • Posts: 19908
  • To whom more was given more will be required.
    • Never go to a psychiatrist, adopt a straycat or dog. On the street they live only two years average.
Re: Siegfried Linkwitz on OB
« Reply #81 on: 7 Apr 2017, 05:42 pm »
people need to stop believing in this stuff, i also did years ago. the absolute worst speaker is one consisting of a fullrange driver, polarresponse will be terrible and distortion goes thru the roof. + phase issues and...well virtually all problems you can get in a speaker = obvious coloration.
its not really an oppinion, its a scientific fact. would you use tweeters as woofers? no, you shouldnt use woofers as tweeters either. long wavelenghts = large cones and some excurtion, small wavelenghts = tweeters.
a crossover does not color the sound when its done correctly :)
I cant imagine what FR driver you listened, maybe a hi power raw pro FR and dislike the sound.
With 1 FR driver per channel you get 1 point source for all the freq, you will have zero probs in polar response and phase, even in pro audio coaxial drivers you dont have probs in polar response and phase.

If the FR is a low power hifi model it have power handling about 30W, when it is over powered you will listen it and should turn down the volume or it will blow, even in this case you wont get coloration. I unknow how afew grams paper cone may add coloration.

Among the various probs xovers introduce in the music what bother me is the lack of the rich musical harmonics after the signal pass an xover, the result is poor image of the musical instruments and an sound stage flat.

To know what the soundstage Iam talking about please listen a Carver Amazing(with no toe-in) and plenty space around, it have tone controls but no xover, or a quality FR direct from the amp as Fostex, Alpair, Omega or even Dayton.

Even 50 years old FRs are better than tweeters and woofers>
http://glowinthedarkaudio.com/zenith-49cz852.html

AJinFLA

  • Industry Participant
  • Posts: 1114
  • Soundfield Audio Loudspeakers
    • Soundfield Audio
Re: Siegfried Linkwitz on OB
« Reply #82 on: 7 Apr 2017, 05:47 pm »
I have never attempted a definition of settling time, but here goes: "the time taken by the driver or the system (driver and box or panel) to stop generating acoustic output once the input signal stops".

In an ideal transducer, whether microphone or loudspeaker, settling time and its inverse—rise time—would be instantaneous. In an imperfect world we have to be satisfied with 'quick'.

It could be measured in terms like room reverb time—R60—where the time for the reverberation in the room to drop to 60dB below the triggering impulse is measured in fractions of a second.

Years ago I cleverly (not!) named my speakers "Quiet Speakers" in deference to this target characteristic. The idea that a good speaker would be quiet—ideally silent—in terms of producing no sound of its own in the process of converting the input electrical signal to acoustic output.

In Europe they sometimes include a revealing  multitone-graph which displays the amount of noise generated by the speaker (intermodulation distortion) quite clearly, when fed by multiple discrete tones. Here's an example from this page (click on 'Intermodulation Distortion'):
http://www.neumann-kh-line.com/neumann-kh/home_en.nsf/root/prof-monitoring_knowledge_glossary_measurement



I think this is a revealing measurement and should be as important as a waterfall plot in aiding visualization of a speaker's distortion characteristic. I'd like to see this included in Stereophile's measurements, for example.
Sorry Russell, but you're all over the place there, no clear definition at all. For any of it to relate to audibility, a clear definition of what is being tested is needed...and controlled listening tests with "other" factors accounted for and things like perceptual masking etc. in play. Especially when listening to music, vs tone and even multitone test signals.

cheers,

AJ

Russell Dawkins

Re: Siegfried Linkwitz on OB
« Reply #83 on: 7 Apr 2017, 07:34 pm »
Sorry Russell, but you're all over the place there, no clear definition at all. For any of it to relate to audibility, a clear definition of what is being tested is needed...and controlled listening tests with "other" factors accounted for and things like perceptual masking etc. in play. Especially when listening to music, vs tone and even multitone test signals.

cheers,

AJ

I don't understand what your point of confusion or contention is. To me it's pretty straightforward: transducers don't 'shut up' after having produced a sound and that adds mud to the signal. The slow the settling time, or post-ringing, if you prefer, the more mud.

AJinFLA

  • Industry Participant
  • Posts: 1114
  • Soundfield Audio Loudspeakers
    • Soundfield Audio
Re: Siegfried Linkwitz on OB
« Reply #84 on: 7 Apr 2017, 09:42 pm »
I think the issue of bass quality and variability is a huge one—perhaps the biggest untamed region in the whole issue of the processing and reproduction of recorded sound. I also think a large part of that is due to the way bass response is measured, particularly not taking into account the settling time of the system in response to signals at various frequencies through the range.

In other words, two speakers that measured identically flat right through the range of, say, 200 Hz on down when fed by a slow sweep might sound very different through that same range when fed a music signal

I don't understand what your point of confusion or contention is. To me it's pretty straightforward: transducers don't 'shut up' after having produced a sound and that adds mud to the signal. The slow the settling time, or post-ringing, if you prefer, the more mud.

The IMD test you showed has nothing to do with "settling time" as you seem to define it, so I guess my confusion is your conflation of issues. You also first mentioned a music signal and seem to be ascribing cause>effect. Multitones are used as probes for non-linearities, which can range from motor distortions, cone/suspension/mechanical distortions and in the case of a Neuman system test, perhaps even enclosure. They don't provide any references for their audibility claims, so I'll have to investigate that one.
You seem to be claiming cause>effect audibility of an effect that you have self defined. I don't see any evidence to support such conclusion, hence me inquiring.

cheers,

AJ

DaveC113

  • Industry Contributor
  • Posts: 4344
  • ZenWaveAudio.com
Re: Siegfried Linkwitz on OB
« Reply #85 on: 9 Apr 2017, 02:09 pm »
Actually, the settling behavior of planars tends to be really messy and random, but at least it also tends to be very quick and low in level. What helps planars is the excellent coupling of the diaphragm to the air, such that the air itself puts a brake on large scale overhang. It's a function of the diaphragm mass to the mass of the air to which it is coupled; vastly better in planars (especially electrostatics compared to planar magnetics which have more mass per square inch of radiating surface) than cones of any type.

Certain materials in cones and domes are also superior due to their inherent self-damping characteristics, coupled with lightness and tensile strength, such as magnesium and alloys of magnesium which can make wonderful midrange cones and beryllium.

http://www.6moons.com/audioreviews2/fostex3/2.html

Here, the advantage of magnesium over aluminum is demonstrated by dropping two cones, one of each metal, onto a hard surface. Fostex makes the same speaker with cones and domes in both materials, with the magnesium version being roughly $1000 more expensive.
https://youtu.be/wrdYofPYD4M?t=77
Incidentally, Joachim Gerhard of Audio Physic has been observed using the same technique to choose likely cone materials!

There are three graphs comparing the settling time, or post ringing as it is called here, of aluminum, titanium and magnesium halfway down this page: http://www.6moons.com/audioreviews2/fostex/1.html

I've compared the Fostex Al vs Mg horn tweeters, Mg is far, far better. The T500 is really excellent. Al sounds great on cymbals but not much else as it does add metallic overtones.

My other speakers have Mg midrange and Be tweeters, they are very precise and clean sounding.




OzarkTom

Re: Siegfried Linkwitz on OB
« Reply #86 on: 9 Apr 2017, 03:20 pm »
I cant imagine what FR driver you listened, maybe a hi power raw pro FR and dislike the sound.
With 1 FR driver per channel you get 1 point source for all the freq, you will have zero probs in polar response and phase, even in pro audio coaxial drivers you dont have probs in polar response and phase.

If the FR is a low power hifi model it have power handling about 30W, when it is over powered you will listen it and should turn down the volume or it will blow, even in this case you wont get coloration. I unknow how afew grams paper cone may add coloration.

Among the various probs xovers introduce in the music what bother me is the lack of the rich musical harmonics after the signal pass an xover, the result is poor image of the musical instruments and an sound stage flat.

To know what the soundstage Iam talking about please listen a Carver Amazing(with no toe-in) and plenty space around, it have tone controls but no xover, or a quality FR direct from the amp as Fostex, Alpair, Omega or even Dayton.

Even 50 years old FRs are better than tweeters and woofers>
http://glowinthedarkaudio.com/zenith-49cz852.html

I agree, FR is what I have preferred for the last 50' years. Crossovers is like a speed bump, they can be enjoyable to listen to, but for quickness and detail, FR's are the best.


FullRangeMan

  • Volunteer
  • Posts: 19908
  • To whom more was given more will be required.
    • Never go to a psychiatrist, adopt a straycat or dog. On the street they live only two years average.
Re: Siegfried Linkwitz on OB
« Reply #87 on: 9 Apr 2017, 04:46 pm »
I agree, FR is what I have preferred for the last 50' years. Crossovers is like a speed bump, they can be enjoyable to listen to, but for quickness and detail, FR's are the best.
Thanks Tom, I would like xovers dont prejudice the musical signal but it dont happens, even the huge 3D soundstage from the Carver Amazing are not detailed as a FR.

BrassEar

  • Jr. Member
  • Posts: 248
Re: Siegfried Linkwitz on OB
« Reply #88 on: 11 Apr 2017, 06:58 pm »
Thanks Tom, I would like xovers dont prejudice the musical signal but it dont happens, even the huge 3D soundstage from the Carver Amazing are not detailed as a FR.

There is a great deal of magic or musical luck? when you pair a decent full range driver on an open baffle. The only crossover that seems to work and not destroy the magic is the use of a supertweeter crossed very high (10 kHz) with a first pass filter.

AJinFLA

  • Industry Participant
  • Posts: 1114
  • Soundfield Audio Loudspeakers
    • Soundfield Audio
Re: Siegfried Linkwitz on OB
« Reply #89 on: 12 Apr 2017, 02:56 pm »
There is a great deal of magic or musical luck? when you pair a decent full range driver on an open baffle.
Just have anyone who claims this to post a full set of measurements, not just anecdotal subjective opinions.
Will quickly see why filters and multi-way are a very good idea. :wink:

cheers,

AJ

mcgsxr

Re: Siegfried Linkwitz on OB
« Reply #90 on: 12 Apr 2017, 04:07 pm »
While I agree that measurement is a useful tool, ultimately what sounds good to a person who builds their own speakers (ie for themselves) may not find it necessary.

I used Visaton b200 on OB for a long time.  I ran them full range on their own for about 2 years.  I later added a set of biamped 12 inch OB subs and liked that more.

I am currently considering a full range plus woofer setup again.  I may go sealed full ranger and ported woofer, but an OB implementation is also possible.  I do intend to use an active Xover (pro) in this case.

I'd be open to measuring the eventual results, but would have to invest in it (REW and a mic) in order to do so.  I don't consider it a requirement for me to build my own pleasing speakers though.

I absolutely get that for others it is.

AJinFLA

  • Industry Participant
  • Posts: 1114
  • Soundfield Audio Loudspeakers
    • Soundfield Audio
Re: Siegfried Linkwitz on OB
« Reply #91 on: 12 Apr 2017, 04:28 pm »
While I agree that measurement is a useful tool, ultimately what sounds good to a person who builds their own speakers (ie for themselves) may not find it necessary. I used Visaton b200 on OB for a long time.  I ran them full range on their own for about 2 years.

I later added a set of biamped 12 inch OB subs and liked that more.
Well, measurements would have confirmed exactly what your ears told you. You had no bass for 2 years. :wink:

I am currently considering a full range plus woofer setup again.
Yep, a subwoofer here, a supertweeter there. Next thing you know you have a 3 way.  :green:

cheers,

AJ

BrassEar

  • Jr. Member
  • Posts: 248
Re: Siegfried Linkwitz on OB
« Reply #92 on: 12 Apr 2017, 07:02 pm »
Just have anyone who claims this to post a full set of measurements, not just anecdotal subjective opinions.
Will quickly see why filters and multi-way are a very good idea. :wink:

I have been following that logic for over 35 years. I finally found that to please my ears, I had to break all of the specification/measurement rules. As a music lover (not a specification lover) I frankly don't care how it measures. Do you put yourself on an EKG and blood pressure monitor when you are watching a movie or eating at a good restaurant to verify that the content/stimuli is a positive experience for you?

S Clark

  • Full Member
  • Posts: 7359
  • a riot is the language of the unheard- Dr. King
Re: Siegfried Linkwitz on OB
« Reply #93 on: 12 Apr 2017, 07:10 pm »
I have been following that logic for over 35 years. I finally found that to please my ears, I had to break all of the specification/measurement rules. As a music lover (not a specification lover) I frankly don't care how it measures. Do you put yourself on an EKG and blood pressure monitor when you are watching a movie or eating at a good restaurant to verify that the content/stimuli is a positive experience for you?
Exactly! And my ears tell me that full range drivers deliver a very musical, but very limited range of music.  If all I listened to was acoustic guitar, all I'd have would be full range--- but I don't. My choice are line arrays.  I have been a big fan of AJ's speakers ever since I heard them years back at the Lone Star Audio Fest.  Good speakers sound good for reasons, and many of those show up in measurements- so i DO care how it measures, because it is related to how it sounds. 

AJinFLA

  • Industry Participant
  • Posts: 1114
  • Soundfield Audio Loudspeakers
    • Soundfield Audio
Re: Siegfried Linkwitz on OB
« Reply #94 on: 13 Apr 2017, 11:43 am »
I have been following that logic for over 35 years. I finally found that to please my ears, I had to break all of the specification/measurement rules. As a music lover (not a specification lover) I frankly don't care how it measures. Do you put yourself on an EKG and blood pressure monitor when you are watching a movie or eating at a good restaurant to verify that the content/stimuli is a positive experience for you?
No, I don't have Red herring for dinner nightly. The fact of the matter is that so called "fullrange" drivers are glorified midranges, more accurately called "wide range", which is fine if you listen only to midrange. Barely a semblance of bass even in huge BLHs and other reflex enclosures and often poor treble and highly colored without any filtering..as measurements concur exactly with ears regardless of understanding or not. Hence the proliferation of so called "helper" woofers/subs and "helper" supertweeters, aka a 3 way. :wink:
But this thread is about OB, which means said fullranges will have near zero bass...exactly as measurements show...and rising response due to the dipolar radiation/baffle combined acoustic response. So no "evil" filter (electrical only, since unbeknownst to many, the driver forms a mechanical/acoustic bandpass filter itself) results in highly colored bassless sound. Fine for some I suppose, but once again, why woofer/subwoofers are used by everyone else wanting some fidelity, like Linkwitz et al.
High passing these midrange/fullranges keeps bass frequencies away from them, significantly improving their midrange performance tonally and dynamically by reducing measurable/audible IMD. That's physical reality, not anecdote.

cheers,

AJ

mcgsxr

Re: Siegfried Linkwitz on OB
« Reply #95 on: 13 Apr 2017, 12:06 pm »
Have to agree that most single drivers are most appropriately referred to as wide range drivers. 

And multi way can be satisfying. 

rabbit

  • Jr. Member
  • Posts: 27
Re: Siegfried Linkwitz on OB
« Reply #96 on: 13 Apr 2017, 12:25 pm »
since someone linked to a 12" fullrange driver, here is a visual to what happens to the polars of a woofer of that size:
http://i68.tinypic.com/2d0goye.jpg
already at 1.5k you can see the narrowing, and at 2.5 its complete collapse. without the waveguide loaded tweeter you can imagin how much it would beam in the high end.

by using this calculator you can pretty accuratly tell where you need the xo:
http://www.mcsquared.com/wavelength.htm
1100hz = 12", but since the cone itself is not 12" it can work ok offaxis a little above that. the same happens for all 1" tweeters at 13.5khz, regardless of horn etc.

http://www.linkwitzlab.com/diffraction.htm
"Note that above about 14 kHz the baffle has no effect, because the dome has become too directional to illuminate the edge. The dome diameter becomes acoustically too large at higher frequencies to be considered a point source.."
so even a small tweeter has problems already at 14k.. you might say "well i only listen in the sweetspot so its a non-issue" its a big issue for your room acoustics, which will give you a scewed freq response in form of reflections, the speaker will sound different from room to room.

imo distortion from a fullrange driver in the high-end also give the illusion of its "revealing" character or "details", which is breakup. often people turn to expensive dacs, high impedance SET tubeamps and so forth to smear away the problems of the driver. but every time i get a tweeter and a proper xo the issue is gone with the wind and my cheap amps sounds good again. :)

AJinFLA

  • Industry Participant
  • Posts: 1114
  • Soundfield Audio Loudspeakers
    • Soundfield Audio
Re: Siegfried Linkwitz on OB
« Reply #97 on: 13 Apr 2017, 12:29 pm »
Have to agree that most single drivers are most appropriately referred to as wide range drivers. 

And multi way can be satisfying.
The audible/measurable performance of wideband drivers are significantly improved by band limiting, i.e. keeping bass away from them...and leaving bass to dedicated bass drivers...as you found. Cleans up the midrange and improves dynamics. A <6" wideband + subs OB system can sound quite good and handle the "full" range of music frequencies. I've heard a few of those myself.

cheers,

AJ

Shakeydeal

Re: Siegfried Linkwitz on OB
« Reply #98 on: 13 Apr 2017, 12:58 pm »
If you limit frequency response, be it upper or lower frequencies, of a wideband driver with a crossover(s), what are you gaining? At that point, why not just use a conventional driver? I guess I really don't see the benefit of such a driver if not used full range.

Shakey



AJinFLA

  • Industry Participant
  • Posts: 1114
  • Soundfield Audio Loudspeakers
    • Soundfield Audio
Re: Siegfried Linkwitz on OB
« Reply #99 on: 13 Apr 2017, 01:21 pm »
If you limit frequency response, be it upper or lower frequencies, of a wideband driver with a crossover(s), what are you gaining?
Less midrange distortion, more dynamics, real bass with added woofers.
Aka, real "full range" sound. Especially with open baffles.