[kfr01]

Some of you lot really need to get out more. In my eyes Danny and John are innocent in all this and its the shit stirring, paranoid, inferiority complex, internet nonses that are to blame. If you read that and took offense, your the ones that I'm talking about.

Facts:

Zaph Audio is a valuable resource to the DIY'er.

GR Research is a successful driver, kitset and loudspeaker manufacturer.

Who gives a shit about the rest?

Bravo!  I was wondering if someone else was thinking this. 

[dlr]

Rather than banter back and forth about the data specifics I will reply simply with this observation. While measurements in themselves are a valuable and objective tool it is obvious that reading that data is just as subjective in observation and analyst as listening impressions.

On that we'll have to disagree. There are certain aspects of the physics that are not subject to interpretation. Resonance with its manifestation in driver measurements is but one of them. I'm puzzled that you think of measurements as valuable and objective, yet do not want to accept the objective evidence within them, as in the 5.5K resonance. It's not an interpretation. It simply is what it is and appears without question in your own measurements.

The perception of them and some of the other immutable aspects are certainly subjective, with that I take no issue.

[Vapor Audio]

On that we'll have to disagree. There are certain aspects of the physics that are not subject to interpretation. Resonance with its manifestation in driver measurements is but one of them. I'm puzzled that you think of measurements as valuable and objective, yet do not want to accept the objective evidence within them, as in the 5.5K resonance. It's not an interpretation. It simply is what it is and appears without question in your own measurements.

That's not true either, there's plenty of room for interpretation.  If John is going to point out that relatively benign peak in the CSD plot as "energy storage problems at 5.5khz", then he should also point out other peaks of similar or higher amplitude in any driver that exhibits them ... but many times he doesn't.  If he did, he'd have notations of energy storage problems in practically every driver ever tests, many drivers with multiple notations. 

I don't buy that John is totally unbiased in his opinions, his personality simply won't allow it.  Maybe with age he'll mellow, as Danny has ... and as I myself have.  If he did, it would do nothing but help his analysis.  I use his site all the time, as pretty much any DIY'er does.  But John can stand to be set straight from time to time, and that's the only point of this posting by Danny.  Danny was right to speak his mind, and knowingly opened himself up to all this, which probably made him think twice about doing so. 

Speaking from my own experience, I'm glad I didn't lets John's tests dissuade me.  These MTMWW towers I just finished using nothing but GR drivers are simply amazing.  I've had a lot of speakers in my system, and many DIY projects using lots of manufacturers, but these are the best speakers I've ever heard in my house.  And the only reason I ever made it to this point was trusting Danny.  As I know from my own past experience in other fields (motorsports, photography, journalism) there's a HUGE difference in being a hobbyist in a field, and living that field as your career.  Danny lives this stuff every day, and while that doesn't make him the final word, it certainly does count for a lot. 

[dlr]

That's not true either, there's plenty of room for interpretation.

No, there's not. A resonance is a resonance. That was my point. Everyone seems to want to dance around that issue.

If John is going to point out that relatively benign peak in the CSD plot as "energy storage problems at 5.5khz", then he should also point out other peaks of similar or higher amplitude in any driver that exhibits them ... but many times he doesn't.  If he did, he'd have notations of energy storage problems in practically every driver ever tests, many drivers with multiple notations.

I cannot understand why you argue against John when posting to me. Address my points, not John's attitudes. I am not debating John's attitude or positions.

I don't buy that John is totally unbiased in his opinions, his personality simply won't allow it

Neither do I, but that's irrelevant to my posts. I don't give a d@mn about John's likes or dislikes. I'm not addressing that. You need to get John off of the mind when he's not the issue. My points relate to the physics of the drivers and the tests.

There's no need trying to respond to the rest  of it. It all has to do with your dislike for John. Don't foist that on me. Address what I say, not what you think about John.

[Vapor Audio]

Ha, funny ... you say I made no point simply as a means for ignoring the point I made.  Johns summary of the M-130 brings attnention to a resonance that's relatively insignificant compared to other drivers where he makes no mention of energy storage problems. 

I have no 'problem' with John.  I've sent him drivers for testing in the past actually, and my dealings with him have always been amicable.  I appreciate his efforts as much as anyone.  He can be wrong though without it being some sort of attack on him personally.

[Danny Richie]

Here you go dlr. This ones for you and you can call it whatever you like.

Here is a M-130 mounted in a box with damping material. The measurement was taken at 7" (near field just like John's) with a 4ms gated time window. This is an un-smoothed response.

Yep there's a handful of tiny resonances in the top end. The biggest one is at 5.5kHz too. They die pretty quickly though. Personally I wouldn't call it a stored energy problem, but you can call it whatever you like. It looks pretty clean to me, especially in the usable ranges, and especially if compared to any other woofers.

[dlr]

Ha, funny ... you say I made no point simply as a means for ignoring the point I made.  Johns summary of the M-130 brings attnention to a resonance that's relatively insignificant compared to other drivers where he makes no mention of energy storage problems.

I need no "means", I am ignoring it. What part of "Neither do I, but that's irrelevant to my posts." didn't you notice? I couldn't care less about whether or not John gives identical coverage to all drivers in a comparison. That's others' issue here, not mine. You're spending a lot of time debating John in posts to me when I really don't care about that.

I have no 'problem' with John.  I've sent him drivers for testing in the past actually, and my dealings with him have always been amicable.  I appreciate his efforts as much as anyone.  He can be wrong though without it being some sort of attack on him personally.

Agreed, I made no attacks myself. That he can be abrasive, yes, I've seen that in some posts to others. It can be easy to get him a bit riled up. But that doesn't bother me, as with you he's always been amicable with me. I do, however, take his measurements as another perspective, not an absolute. They are useful in any case. I tend to get more from the data than from his analysis, anyway.

[Vapor Audio]

I need no "means", I am ignoring it. What part of "Neither do I, but that's irrelevant to my posts." didn't you notice? I couldn't care less about whether or not John gives identical coverage to all drivers in a comparison. That's others' issue here, not mine. You're spending a lot of time debating John in posts to me when I really don't care about that.

I think you're giving yourself way to much credit.  My point isn't about you, my point is the entire point of this thread ... if you haven't noticed.  If you agree that Johns worded analysis of drivers isn't fair to all, then we're in agreement, and you agree that Danny was right to point those things out.  The rest is just people with a few spare moments, a keyboard, and a procilivity towards arguing.

[JoshK]

The rest is just people with a few spare moments, a keyboard, and a procilivity towards arguing.

A wise man once told me, when you point your finger there are three pointing back at yourself.

[dBe]

Danny, Dave, et al,

I have been watching this attack on Danny from several sides and it really bums me.  I see people talking about Zaph having "no agenda" and it makes me think back to the email I got from John, unsolicited, on a topic that is not relevant to this discussion.  What IS relevant was the tone of his email.  It was filled with profanity and sanctimonious ramblings that made me shake my head in amazement.  I know of a few others that have gotten similar emails from him and it makes me wonder what his real motive for testing is about.  I can appreciate the EE in him wanting to quantify, but he makes statements drawn on his measurements that just don't wash with me.  I guess the "bashing" mentality is a little foreign to me.  I see no reason for the abuse that is dished here in cyberspace.

It is humorous watching some of the alledged "objectivists" wind up on people (us) that claim to be able to discern differences in CD players, caps, wire and on and on...  A true objectivist is easy to talk to.  Rationality rules the discussion.  There are those that hide behind the objectivist label that are just too lazy to do the work to see what changes are wrought by trying different things.  The MadBored and PE is littered with a few posters that delight in trashing others that try to make a case for anything outside of their limited experience.  People that shout down and ridicule with no experiential basis are, unfortunately, some of the most frequent posters when anyone tries to get a meaningful discussion going.  That is too bad... if I see "lol" one more time from one particular moron, I may puke...

Anyway, I think that Danny should stand his ground and not let the dweebs do to him what they did to George Short.  Danny, I've heard your system(s).  I know what they are capable of resolving.  Remember the sources of grief out there are people that have no clue to what quality playback is all about: emotional involvement.  It is my guess that more than a few are involved with alcohol a great deal more than they are with excellent sound.

Try not to feed the monkeys, but please, please keep on doing what you do.  Maybe Zaph should put his butt on the line and develop a line of drivers............

Be well, guys.

Dave

[Scotty]

I think a key point from the Zaphaudio website was missed in the course of this thread and it is this disclaimer
published at the bottom of the introduction on front page of the surface5test
Quoted here,[All parts of this test are done with Soundeasy 10.0. This is a modeling package with a lot of extra testing applications included. It is not a full acoustic measurement system such as CLIO or Praxis however, so take these results with a grain of salt. What is important however is that all of these drivers were tested in the same way. Once again, I'll remind you that my test results should not be compared with tests done elsewhere by other people, but comparisons within this group of drivers are perfectly valid. That's why tests like this are best done in groups.

There are a few types of tests that are important, but not shown here in the interests of brevity. Keep this in mind and know that these results need careful interpretation.] Link for where this statement comes from.  http://zaphaudio.com/surface5test/
The discussions regarding what constitutes linear vs non-linear distortion are some what irrelevant to me. Simply because a linear distortion can be corrected with added filter elements in a crossover does not make it a benign behavior. A driver that requires a bandaid to function properly a not preferable to a driver that functions correctly in the first place.
At the end of the day distortion is a bad thing regardless of what type it is.
 I will say that if one reads John Krutke's summary of his viewpoint, and his "manifesto" found here,see link http://www.theaudiocritic.com/downloads/article_1.pdf
you can see that a conflict is inevitable due to irreconcilable differences in worldviews between the two men.
As far as drivers are concerned, I think in the final analysis you actually have to listen to the driver to make any meaningful determination about how it actually
reproduces music. Yeh, I know,what a concept.
Scotty

[dlr]

Hi Dave, good to see you back posting.

This is certainly going to drag this out, but it appears to be inevitable.

I pretty much agree with most of your post, the only thing that I have to say is that none of what I posted was meant or should be construed as piling on. My intent has been and remains accuracy. Danny initiated the thread with the intent to correct for mis-information as he saw it. Then he said rather emphatically that "there is NO breakup node at 5.5kHz or energy storage problem in that area" as well as challenging factually correct information, itself a form of mis-information.

You'll note that I didn't take issue with most of what he said personally about John. He can be abrasive (maybe that's mild compared to others' experience), but never to me.

There is no problem at 5.5K that can't be handled if the application used and the crossover are correct , but the emphasis on "no breakup" is flat out wrong. I see this sort of thing too often and called him on it. I guess this comes down to semantics. A resonance at 5.5K may be a "problem" to one designer, but not the next. So be it, there certainly is no consensus on every design issue. But a resonance is a resonance, that's all. What one does about it is what counts. Some can be ameliorated, some not.

Watson's posts were spot on and mstly addressed the technical issues, as did mine. Danny made patently false replies to some points. I posted to support Watson's posts on the technical issues. Danny has a reluctance to accept certain aspects of the physics and specifically rejected some of the factual corrections. It makes no difference how good or bad any driver is, the basic physics applies.

I see his drivers as being very good quality for the cost. I say that only seeing measurements, having never heard them. So maybe I'm making a poor judgement in saying so, since I haven't heard them. Nothing in any my posts was critical of the driver itself. My posts have been and remain strictly on the technical issues. Some evidently see that as an attack on Danny for some reason. This baseless perception is all too often the case on boards as well. If you take issue with misrepresentations of the physics, it's an attack.

Of course we won't even try to discuss the issue of aspects of the linear distortion from peaks/breakup that amplify the motor-generated displacement distortion that cannot be eliminated by the crossover. That would surely start a whole new round. It is a basic physics issue, but it seems easier just to gloss over some issues.

[brj]

I keep reading posts claiming that someone else is wrong in the use of a term, without ever precisely defining it themselves.  Unless there is an officially recognized reference of acoustic engineering that defines the term in question for the industry, then neither side is wrong and arguments to that point do nothing but antagonize.  I've now seen both sides criticize the other for using terms in both broader and narrower scopes than they themselves do... without ever realizing the irony of it.

I'd appreciate seeing all participants define their terms so the rest of us know where you're coming from.  If you have a reference, even better!  If there isn't one, then some more flexibility in accepting other's definitions would be better still.

Isn't language a pain?  Enjoy the rest of your weekend everyone...

[Danny Richie]

There is a lot of truth to what Brian just said. It also quite obvious that an analysts of the data is subject to interpretation.

dlr, since you have an issue with my interpretation of the spectral decay let's look at.

I have no issue with the spectral decay posted by John. It's his comments that I find objectionable especially in light of his attitude and his mission against those with subjective analysts (listeners).

I have tested a lot of woofers. I was once a distributor for Focal, Cabasse, and PHL. I have used the best drivers from Scan Speak, some Usher drivers, Eton, Dynaudio, Vifa, Seas, Peerless, and plenty more. I have upgraded or modified over 100 different commercial speakers and designed speakers for several companies including many award winning designs. Suffice to say I have seen some spectral decays.

Looking at the spectral decay of the M-130, I have to say that it looks great. It looks far better than the vast majority of available woofers. Any resonances or breakup in the top end is well controlled and dies very quickly. You can pick it if you like, but it looks good. Even my competitor that has hated my guts for years came on here and said it looks good.

So let's look at what John posted. Here are the three woofers that were compared.







The M-130 is the one in the middle.

Looking at the group I'd have to say that they all look very good. Resonances across the board are fairly minor and above the range in which they would be used. If I were to pick one with the cleanest spectral decay it would have to be the M-130 by a small margin. The other two have slightly more stored energy in the 4 to 6kHz region and have some slightly longer decay rates. I'd still say that they were good overall. Comparing them to other woofers measured by John I'd say that all three of them were just about as good as any. All good !!!

Now let's look at what John had to say.

About the M-130 (the cleanest of the three): "Breakup node at 5.5kHz with energy storage problem."

Of the other two: "Has smooth breakup node at 8kHz, but does not have serious energy storage" and "Tiny breakup node at 5kHz without much ringing"

What?

The cleanest one of the three has a "breakup node at 5.5khz and an energy storage problem" but the other two that had a slightly longer decay time in that range had a "smooth breakup node", "does not have serious energy storage", and "Tiny breakup node at 5kHz without much ringing"?

Are you kidding me? Do you really think that this is unbiased driver testing? Or is this something else? Do you understand now. Do you see the obvious?

[dBe]

Dave (dlr),

It was not the intent of my post to infer that anyone is piling on, per se, but that people are ragging on Danny for being a "snake oil" guy.  You, sir, are one of the most civil people that I have ever debated on semi-contriversial topics.  I have no doubt that your input is technical in nature.  Any criticisms should be done in the manner that you do them. Let me be specific: Pete, AJ, thylantyr and those of that ilk are just name calling and that is of no benefit to anyone other than to self identify themselves as people with image and anger management issues.  My issue is that people seem to think that Zaph is doing all of this out of the goodness of his magnanimous heart, and i just don't think it is true.

My bottom line is and has always been to debate the issue but keep the insults, personal attacks and epithets out of the discussion unless the instigator is absolutely willing to be called on them and to be identified as to their real motives.

[dlr]

even though I have been stating rather clearly that my comments were all unrelated to that, I'll now toss my hat into the ring.

There is a lot of truth to what Brian just said. It also quite obvious that an analysts of the data is subject to interpretation.

When comparing, yep, there is interpretation in comparing. I had really tried to avoid this. Just don't get bent out of shape if I don't agree fully with yours.

I have no issue with the spectral decay posted by John. It's his comments that I find objectionable especially in light of his attitude and his mission against those with subjective analysts (listeners).

I still refuse to get dragged into this part of it. That's between you and John.

Looking at the spectral decay of the M-130, I have to say that it looks great. It looks far better than the vast majority of available woofers. Any resonances or breakup in the top end is well controlled and dies very quickly. You can pick it if you like, but it looks good. Even my competitor that has hated my guts for years came on here and said it looks good.

Yep, it looks pretty good, I've not said it wasn't. In fact, I also tried really hard to do any detailed analysis of the measurements. It's not a full set of them, but we'll have to work with what we have.

So let's look at what John posted. Here are the three woofers that were compared.







The M-130 is the one in the middle.

Looking at the group I'd have to say that they all look very good. Resonances across the board are fairly minor and above the range in which they would be used.

OK, I can agree that far. It does not address the distortion amplification by the breakup for any motor-generated distortion. This, many may not realize, is not controllable whatsoever by the crossover unless it's to reduce the excursion at the low end by using it purely as a midrange so the motor distortion stays low. If it's used in a 2-way, what is there will remain there. It won't matter how low or what order lowpass is used. The motor generated distortion will get through. Any breakup or peaks will amplify the harmonics that coincide with them. This is a fact of the physics.

With that in mind, let's continue.

If I were to pick one with the cleanest spectral decay it would have to be the M-130 by a small margin. The other two have slightly more stored energy in the 4 to 6kHz region and have some slightly longer decay rates. I'd still say that they were good overall. Comparing them to other woofers measured by John I'd say that all three of them were just about as good as any. All good !!!

I have to differ completely, for two reasons. The peak in the M-130 is the highest magnitude as well as the highest Q. Passive crossover limitations make its control more problematic, unless a fairly low Fc or higher order is used with any slightly higher Fc. This makes it the most difficult to control vs. the other two. So for purposes of a crossover, the M-130 comes in third. I might call it a close third, but third it is as I see it.

Now let's look at what John had to say.

About the M-130 (the cleanest of the three): "Breakup node at 5.5kHz with energy storage problem."

Of the other two: "Has smooth breakup node at 8kHz, but does not have serious energy storage" and "Tiny breakup node at 5kHz without much ringing"

I really wanted to avoid all of this, but I can't seem to. OK, considering my first point about the XO and the higher Q, I guess I actually have to agree with him. I've seen far worse, but we're only considering the other two presented in this comparison. Again, it comes down the Q and magnitude. John is spot-on now that I've looked more carefully at the other two.

The cleanest one of the three has a "breakup node at 5.5khz and an energy storage problem" but the other two that had a slightly longer decay time in that range had a "smooth breakup node", "does not have serious energy storage", and "Tiny breakup node at 5kHz without much ringing"?

Once the XO is added, the decay rate is no longer an issue. As John K pointed out some time ago, if you design a XO that traps the peak such a match to a target is achieved, the system decay is simply that of the target. That is, if you can trap a peak and get a good LR2 or LR4, then the system response will be that of an LR2 or LR4. The end result is that if a peak of whatever source, be it breakup or other resonance, is difficult to control to allow a match to a target, it's more of a problem than one that is easier to handle. High Q, high magnitude traps are more problematic when done passively. So this in essence makes the driver a little more limited in application. Not that it's bad, just more limited. Just look at metal cones. They exhibit this, only worse. It doesn't stop Linkwitz from using them. But it takes more care, meaning it's more difficult to do well.

Are you kidding me? Do you really think that this is unbiased driver testing? Or is this something else? Do you understand now. Do you see the obvious?

Obvious? Now that I look closer, no, I don't see what you're implying. Point-by-point I'm starting to agree with John.

Now you have to add the fact that the impact of the motor-generated distortion is out of the hands of the XO designer in a 2-way unless a small closed box is used to limit excursion. All three should have some form of added higher order distortion in their respective peaks areas. The only way to compare that is to make distortion measurements. That is more subject to interpretation since we seldom get to see a large set of test data. Even Linkwitz will point out that his distortion measurements are selective due to the difficulty and time-consuming nature of this testing.

I'm not factoring cost in at all. Yours may still be the best bang-for-the-buck of the three, I don't know. That's a big subjective discussion I will not get dragged into.

Actually, now that I look carefully, John looks to be more objective than I had been lead to believe, at least in reading the quotes supplied here. His abrasive comments and email don't enter into what I see in the drivers.

You pressed me into it. I have to call it as I see it.

[Vapor Audio]

I really don't care how good your product is any longer.  I won't buy from you based on how you treat your potential customers.  If a customer doesn't like your product, does that mean that they don't know what they are doing either?  Is that the point you really want to make?

... blah blah blah

Thanks for joining just to say that 

[pmel]

TubroFC3S, not sure if you are being sarcastic on not

Was the rest of my post deleted?  After you replyed, I can not seem to find it.

[Danny Richie]

dlr,

I appreciate your contribution, but respectfully disagree.

With any of these tree woofers tested the breakup area (what little there is of one) can easily be made 20db down or more with a low order crossover. In fact I can use a first order crossover with a RC to follow and make a very smooth roll off with the 5.5kHz area well down in output.

When these areas can easily be pushed well down in output with a simple second order network or so, then any remaining amplitude peak goes away. It is too far down in amplitude to be heard.

However if that peak in amplitude, even though it is 20db or more down, has a longer resonance decay time then it will still be heard as a smearing effect or low level ring.

I would suggest that you re-think which is the greater of the two evils.  

I also still think that John's subjective evaluation was influenced by a personal bias clearly shown by his attitude.  

[Vapor Audio]

TubroFC3S, not sure if you are being sarcastic on not

Was the rest of my post deleted?  After you replyed, I can not seem to find it.

Me, sarcastic ... pshhh.  I think it's a sign, go back to your home on Troll Island.