Hello Metralla -
Thanks for taking the time to write back and clarify your stadium wave post. I'm a bit slow sometimes, and didn't understand that the point you were making was about the particles returning to equilibrium position, which of course the familiar stadium wave illustrates perfectly.
On the matter of truth versus good ad copy, that's a tougher issue. I agree that if Gilmore Audio's claim of a diaphragm lighter than the air it displaces is true, then it can only be true at certain frequencies and volume levels. I'm not engineer enough to know the measurement and calculation protocols behind such a claim - maybe they're straightforward, and maybe not. The ideal would be a complete set of data qualifying all such claims, though in the end we'd still have to rely on our ears to tell us which set of compromises sounds the most natural under our anticipated listening conditions.
Obviously, you think things through pretty thoroughly. If I should ever come out with my own speaker, I'll run my claims by you first!
Hello Lugnut,
Again thanks for taking the time to write back. No problem at all with the name thing; I just didn't want people to think I was posting under two names, nor to take undue credit for doing hard time in the hotseat.
Best wishes to both of you.
Duke |
Duke & Sellerwithintegrity,
Sorry for addressing my last post to you Duke. It was, in fact meant for Sellerwithintegrity. |
Duke, The example given above of the "wave" in the football stadium is actually a transverse (or shear) wave, with particle motion perpendicular to the direction of wave propagation. Of course it is. I noted that waves could be classified into three types. My point was to indicate that the particles do not move from their equilibrium position, but vibrate about it. Sound waves are pressure waves, and most importantly are set in motion by physical displacement of the air particles. That's close enough. The mass of the air displaced by the diaphragm movement can be calculated and compared to the mass of the diaphragm itself. On the face of it, this seems like a reasonable statement, but please describe how we should do this. We surely count all the molecules of air in contact with the diaphragm, since they are certainly disturbed. They in turn disturb their neighbours - do we count those? They have neighbours too. Where do we stop? If we only count the molecules in contact with the diaphragm, is that the mass we seek? It surely would be lighter than the membrane. Do we reason like this - we consider the maximum excursion of the diaphragm (this would be for the loudest possible volume at the lowest frequency the membrane can produce) and multiply this by the area of the membrane and come up with a volume. Now we consider the density of the air (depends on temperature and humidity) and thus we have a mass. Is this it? But the speaker hardly ever plays at this volume or at that low frequency, so does the statement "the mass of the membrane is lighter than the air it moves" have to be qualified with volume and frequency specifications? This was not done. The problem I see is that the phrase is colourful and exotic, but not reasonable. It's a turn of phrase, an advertising slogan. That I don't mind, as the world of hifi is filled with such slogans. But it's not truth. Regards, |
Planar,
I'll take a shot at some of your questions, though I don't have answers for all of them.
1. horizontal dispersion. you say -3dB at 60 degrees dispersion (plus or minus 30 degrees, for those reading). At what frequency?
a: The horizontal radiation pattern will be the classic dipole figure-8 pattern at low frequencies, and will still be quite wide when we cross over to the ribbon (okay, technically planar magnetic) high frequency driver because its diaphragm is fairly narrow. It looks to me like the ribbon's diaphragm is maybe an inch and a half wide. The radiation pattern will become progressively more narrow with rising frequency, and will be about 60 degrees wide (-3 dB) at roughly 9 kHz. This estimate is based on an assumed diaphragm width of 1.5 inches.
2. vertical dispersion...
a: The vertical coverage at high frequencies will be effectively limited to the height of the diaphragm (with maybe a few degrees of vertical beam widening), and will be oriented perpendicular to the diaphragm plane. So by tilting the speaker back a bit, you improve the high frequency coverage within the listening area. Note that because the bass drivers are in a vertical line array, you won't have the height-dependent tonal balance phenomenon typical of point source woofer/line source planar hybrids, as long as your ear is within the ribbon's vertical "window".
3. comb filtering. you said, "Whatever comb filtering effect is created by our topology, it is less than anyone elses -- not more because of it." the accuracy of that statement is dubious, but that's beside the point. a full range line source has its element(s) aligned without timing anomalies. remember the old beveridge electrostat? before my time and it's been quite a while since hearing a pair, but that's a full range line source. some people might consider the gilmore to be planar.
a: I presume you are referring to horizontal comb-filtering caused by the vertical side-by-side driver configuration, in the crossover region. At the crossover frequency of 200 Hz, the woofers and ribbon are less than 1/4 wavelength apart. Any comb filter effects due to their lateral spacing will be of negligible significance. The Gilmores' approximation of a full range line source is pretty close, and in theory compares favorably with other commercial multi-driver line source approximations that I'm familiar with (Magnepan, Pipedreams, Wisdom Audio, Newform Research, Martin Logan hybrids). The Beveridge and Sound Lab single-driver line-source speakers of course have an inherent advantage in coherence over a multidriver speaker, but in practice a less than 1/4 wavelength offset is unlikely to be audible.
4. will post a followup on doppler distortion.
a: I do not know what the audibility thresholds for doppler distortion are at different frequencies. Paul Klipsch maintained that doppler distortion was quite audibly significant, and I have heard full-range single-driver loudspeakers lose articulation on complex passages at high volume levels. Note that for a given sound pressure level air volume displacement must be quadrupled each time we go down one octave, so doppler distortion can be minimized by using very very large full range diaphragms (Sound Lab and Beveridge) or by using a multi-way system and choosing crossover frequencies that free the midrange and/or treble driver from long excursions at the anticipated loudness levels (accomplished by many, many manufacturers to a greater or lesser extent).
I have no comments on the binding post/crossover topic.
Of course I'm neither an engineer nor a Gilmore owner (at this point), so don't take my answers here as gospel or even attempted gospel. They're just my $.02 worth.
Best wishes,
Duke |
I've been out of town and/or very busy the past couple of weeks, so just now got back to this thread.
Sellerwithintegrity, I apologize for mistakenly typing "3 mil" as the thickness of the kapton diaphragms; of course it should have been ".3 mil".
Lugnut, just for the record, "Duke" and "Sellerwithintegrity" are different people - "Duke" posts under the Audiogon moniker "AudioKinesis", and over at the Asylum under "Duke". So please don't give me credit for "taking the heat" here - I wasn't even in the kitchen!
The reason for using a weak magnet/low Qts woofer in a dipole was well laid-out by Bob Carver years ago, and goes something like this: Dipole cancellation results in a 6 dB per octave rolloff in the bass region. This is in addition to the inherent shape of the woofer's response around resonance, as predicted by its Qts. If we use a woofer with a carefully chosen very high Qts (weak magnet) and appropriate resonant frequency, taking the baffle size and shape into account, then the natural response "hump" of the high-Qts woofer can compensate for that 6 dB per octave rolloff. The baffle shape and woofer parameters can be optimized together to approximate an ideal target response.
I would expect that at very low frequencies the output of the Gilmores is displacement-limited long before the approximately 2000 to 4000 watt peak thermal limit is reached, as predicted by the spreadsheet on Siegfried Linkwitz's site (mutual coupling between drivers and large vertical path length will give greater bass output than predicted by the driver area and baffle width alone, but by how much I cannot say). Most loudspeakers will displacement-limit at low frequencies well before their thermal limit is reached. For example, I've played around with JBL woofers that have a thermal power handling limit of 600 watts RMS, but are displacement-limited to less than 1/10th of that figure below 25 Hz in a vented enclosure. Nevertheless, JBL is in compliance with AES power rating conventions to claim a power handling capacity of 600 watts RMS (which would imply far greater power handling on peaks, though they don't specify the peak power figure).
The example given above of the "wave" in the football stadium is actually a transverse (or shear) wave, with particle motion perpendicular to the direction of wave propagation. Sound waves are pressure waves, and most importantly are set in motion by physical displacement of the air particles. The mass of the air displaced by the diaphragm movement can be calculated and compared to the mass of the diaphragm itself.
While I wasn't the one sitting in the hot seat this time around, I hope to be there one day. I've dreamed of bringing out my own loudspeaker for some time now, and will probably be disgustingly enthusiastic about it when that day finally comes. In the meantime, I'm looking forward to getting to know the Gilmores first-hand.
Best wishes,
Duke |
if you want to feel sorry for sellerwith that's your choice but i don't, considering his self-assertiveness, his demeaning characterization of those who express doubts as "silly", and his lack of factual response to all technical questions and challenges. in my experience a customer is treated with kid gloves as a guest and is respected, and the seller is the one who has to earn respect. nobody "owes" the seller anything. quite to the contrary. |
I really don't blame Sellerwith... for taking a break. I am beginning to feel sorry for him, like the poor bank loan officer in the Ditech TV ads. |
it's four days later and no response to questions and comments. it makes you wonder why, and how they're going to react when people ask the same things. |
i mentioned 18" jumpers between woofers but that would be based upon a series configuration which may well not be the case. perhaps sellerwith or gilmore himself will say how they are wired. |
merganser: the only thing that is certain is that sellerwith has not responded to questions and challenges with technically complete answers and has offended many with his grandiose claims and condescending attitude. sellerwith: apparently you aren't a technical person. that's fine, but that's no excuse for not getting the correct and complete information from Gilmore and presenting it here. just because people ask questions and a few might make erroneous comments doesn't give you permission to grandstand, spindoctor, and insult. this isn't the place for self promotion either, since nobody asked about the other stuff you sell. you can consult the moderation guidelines or ask the moderators. you haven't given factual answers to my questions, so i'll try again: 1. horizontal dispersion. you say -3dB at 60 degrees dispersion (plus or minus 30 degrees, for those reading). At what frequency? 2. vertical dispersion. since when is bass below 500 hz "pretty much omnidirectional"? that's one of the most preposterous statements i've ever heard! first of all, 500 hz is midrange, not bass. if somebody can't tell where a 440 hz tone is coming from, they're probably deaf. care to quantify "pretty much"? engineers don't use that phrase in specifications. 3. comb filtering. you said, "Whatever comb filtering effect is created by our topology, it is less than anyone elses -- not more because of it." the accuracy of that statement is dubious, but that's beside the point. a full range line source has its element(s) aligned without timing anomalies. remember the old beveridge electrostat? before my time and it's been quite a while since hearing a pair, but that's a full range line source. some people might consider the gilmore to be planar. 4. will post a followup on doppler distortion. 5. binding posts and crossovers. i still don't see the binding posts on the ribbons. with each woofer having binding posts, you need to run jumpers about 18" long between them, and since the posts aren't lined up you'll need to bend the wires. not to mention the possible need to buy more cabling for between the woofers, from the woofers to the crossover, and from the ribbon to the crossover. sounds unattractive and a hidden expense. the crossover should be in the pictures. i agree with merganser's remarks. $20k, not $19k, plus shipping, and then more for other colors, plus the cost of all the jumpers, is a lot for kitchen countertops. |
One thing is certain, these "new" Carver's have a lot of people talking. Good questions have been raised and the answers seem to me to have fallen a little short, but I will reserve judgement until I can actually listen to a pair. I would like to offer one observation, no matter how good they sound it's going to be tough getting folks to plunk down 19K for the "standard" Corian colors and then upcharge for the others. I, for one, do not want a pair of kitchen counters in my listening room.
Regards |
I believe he is referring to me as the one he is done with, mainly because in spite of his 'welcoming skepticism' he is unable to answer the questions.
He incorrectly stated the Xmax, then says proper testing is unnecessary when a finger is just as good.
He has stated they didn't even bother testing the vertical dispersion, which was the point in question with the ribbons, not the horizontal dispersion.
He has made the rather unusual statement that his speakers are louder at 3 meters than they are at 1 meter because they are line sources (!).
He has also stated that they produce 'louder and cleaner' bass than any other speaker they know of, in spite of being dipoles.
While professing admiration for Mr. Linkwitz, who probably knows more about dipole bass than any other on this planet, he has failed to provide any information on how his speakers are able to ignore the fundamental truths about dipole bass SL espouses, especially in the area of maximum volume.
And in the midst of all that he has intimated that I am a liar, ignorant etc etc. I'm quite happy to admit I'm wrong, when shown precisely why.
Just for the hell of it, I will reiterate the problem. You have used this forum to tout your speakers while making very grandiose claims. When questioned about these claims you have failed to respond in any meaningful way other than to say 'trust us', and insult those who ask the question.
You may be a 'buyerwithintegrity' at eBay, but as a 'sellerwithintegrity' you still have a ways to go.
Still, best of luck. Having heard other ribbon/dynamic hybrids of a very similar design, and owned many dipoles from Martin Logans to Audio Artistry, plus having build my own Linkwitz inspired dipoles I am sure they will sound great. Within their limitations.
Take a chill pill and have a great day. |
Dear Sellerwithintegrity,
Could you PLEASE refer to the poster you are replying to?
You just made 6 posts and I'm having trouble connecting the dots. On a previous occasion in this thread, you made 5 posts in a row, and one of them was a reply to me - so I had a vested interest in working out which was which.
Regards, |
WE are done with you. You don't know what you don't know and it is clear that you don't want to learn either. You clearly have no conception about what we are doing because you are blinded by a paradigm which is totally irrelevant to our speake. In turn your arguments totally miss the mark. We are very familiar with Mr. Linkwitz and his marvelous work and I dare say, we understand it perhaps a bit better than you .. among other things. FInally, we don't need any machine to test our excursion. You can push the planar woofer with your finger and measure it. Now its just a matter of getting enough power to make it move that far -- which someone couldn't stand to listen to anyway.
BYE for good. |
One more try:
At 60 degree horizontal dispersion, it is 3dB down. Considering that bass is not directional, 500 HZ is when this becomes significant (directional); below that things are pretty much omni-directional.
In terms of the vertical dispersion, what I can tell you is that it is enough. You stand up, you sit down, nothing really changes. That's why we really haven't bothered to measure it. There's another neat thing about well constructed line sources -- they are often louder at 3 meters than one meter, even though we measure sensitivity at 1 meter because every one else does.
Isn't life grand? |
I do not know Mr. Errivera; but it is obvoius that he has first-hand experience and has some important insights for all to read. Mark GIlmore has a set of modified Amazings in his living room. As I said before, Mr. Carver's speakers were a wonderful inspiration to Mark to reach even higher -- to achieve something even more remarkable. The efficiency issue has been solved and the GIlmore speakers offer many other enhancements. I appreciate Mr. Errivera's comments. Thank you sir. |
If you go on ebay, you can see the reports on me as "buyerwithintegrity". A perfect record with over 600 transactions. I took this name on audiogon several years ago before I even met Mark Gilmore. I took this moniker because I believe that integrity is one of the most important qualities that anyone can have in their business dealings. And I believe that I set a standard when it comes to doing business with integrity. I have been that way my whole life. I hope that you will have the opportunity to meet me so that you can look me in the eye and see for yourself. Fortunately, some of you have seen the satirical tone in the ads. A big part of audio for me is having fun. One of the most fun things in life is being involved with beautiful things. I have been involved with music for most of my life -- still play with some of the best guys on their instruments in the world. I have dreamed my whole life of having the finest musical reproduction system in the world. And when you think about what very serious audiophiles spend, what we have to offer brings the "best of class" within many more people's reach. I am sorry that we can not sell these speakers for 1/4 the price. That would make me very happy. My father was one of the founders of the discount store industry in this country -- discounting is in my blood. But I can say without reservation that these speakers are well worth the money relative to those offerings that aspire to be the best.
Some of you know that Duke and Albert Porter are serious folks and well-meaning folks. WE have a lot of such people assoicated with us: Mr. Tri Dung from Tri-Planar; Mr. Roger West from Soundlab whose speakers changed my life; Ralph Karsten from Atma-Sphere, winner of more Golden Ear Awards than any other company as far as we know; Donna and Kirk from SOTA turntables; Bob from Sound Anchor; the Magnans from Magnan Cables; All wonderful people, trying to do the right thing, with a great passion for music and music reproduction.
We are for real...and we respect healthy and respectful skepticism. We have no problem proving ourselves to the audiophile community. We feel confident about our ability to gain the respect of those who are sincere and knowledgeable. The product in our opinion speaks for itself. The claims we make aare as we see it, measure it and hear it. I hope after hearing and seeing Mr. Gilmore's creations that you will agree that it is special. |
Yes, that pricing is correct. Sorry, but I was not permitted by the moderator to state the price. I tried to answer the forum earlier. We are able to offer that price because we will be selling them predominantly through home-based showrooms, rather than through the traditional dealer network -- otherwise they would have to be priced even higher. We hope to have a national network of these home showrooms in the near future. Eight should be open before Christmas. |
Yes, there was a typo. Total excursion is 2 inches, which is plus or minus 1 inch, not plus or minus 2 inches. It's as simple as that. A number of people on the forum figured that out by themselves. I wanted to make sure that it was clear. That' what people with integrity do -- they admit when they are wrong and stand firm when they believe that they are right. |
Apologize for what, o sellerwithintegrity? For pointing out that your claims for these speakers might be a tad overblown?
I have speakers using dynamic dipole drivers for the bass so I have an idea what the tradeoffs are, although dipole bass is as good as it gets. If you want a better idea yourself, examine this site carefully:
www.linkwitzlab.com
Regarding the excursion, here is a link to the subwoofer with possibly the highest excursion out there, the Adire Tumult.
http://www.adireaudio.com/diy_audio/drivers/adire/tumult.htm
Notice the very large roll surround that is clearly visible? The Tumult has a 1.5 inch xmax. Your magic woofers are claiming 2 inch. So the surround should be even bigger.
Without the big, flexible surround the cone cannot move in and out by the required amount, since the surround allows the movement to take place. It's quite simple really.
You can tell even from the poor quality photos on the Gilmore site that the surround is nowhere near enough to allow that kind of xmax. Of course, if you care to have the woofers Dumaxed for us and post the results I will eat my words and even say sorry.
http://www.dlcdesignaudio.com/dumax.htm
You may also notice the very large motor on the Tumult, handy to control the cone at those kind of excursions.
The weak motors on the Gilmore drivers are, you stated, to raise the Qts. Presumably to create a low frquency rise in the response to counteract dipole roll off so you don't need active EQ? This is valid design decision but has its own tradeoffs as noted here:
http://www.linkwitzlab.com/faq.htm#Q34
As for the SPL question, I would simply invite anyone who is interested to download the following spreadsheet and plug in the numbers themselves.
http://www.linkwitzlab.com/spl_max1.xls
The path difference is half the baffle width, in this case 450mm.
The answer I got for four 12 inch drivers with a 25mm xmax is 98dB at 25Hz. Just for giggles, keep adding drivers until you get to 127dB. You'll find you need 100 of them.
Of course, the 'so-called expert' who designed this spreadsheet might not know what he is talking about. In which case I suggest you contact Seigfried Linkwitz and tell him yourself. I assume the name is familiar?
You made the claim "The Gilmore speakers, especially the model 2's, can play bass louder and cleaner than any other dipole or planar for sure and any home audio dynamic speakers we know of."
I find the dipople/planar part of this statement at least plausible, but the second part less so. Any other home audio dynamic speaker?
That's a heck of a bold statement. Price no object?
Finally, to suggest that the height of a line source doesn't matter is rather strange. Anyone who has listened to the Newform R645 speaker or other similar ribbon speakers can tell you what happens when you either stand up or sit too low. The treble rolls off.
To avoid this, your ear needs to be within the range of the ribbon, which may be a problem with the Model 3.
As I said earlier, I'm sure these speakers sound great. But to make all these hyperbolic claims taints them with a strong whiff of snake oil.
Have a lovely day. |
I may be in the minority on this one, but excluding the center channel my design training suggests to me that these speakers are aesthetically challenged. For almost $20K they could have spent a little more attention to designing a front plane with more visual interest and a stand with some flair. The existing stand looks like welded erector set parts. As it is now these speakers bear some resemblence to Martha's old kitchen counter top.
Ouch! |
I just thought I would write down my personal experiences since I currently own a pair of Carver Amazing Platinum IV speakers (whew! that's a mouth full).
I have owned my Carvers since the latter 90's (about 1996-7), I can't really remember and haven't bothered to look for the sales slip. Before owning these speakers, I had owned speakers from M&K, Vandersteen, Beveridge, Rectilinear, Allison, B&W, Infinity, Altec, Martin Logan, and probably a few more that I can't immediately remember. I can honestly say that other than the Beveridge and Infinity IRS Betas, I have not heard a more impressive speaker than the Carvers. Not to say that they do everything right, but for the price, I know that there are no better speakers. That is why I still own them, in mint condition, with the Carver Silver 9t amps (not the greatest, but they work really well with the speakers).
The Caver woofers are really skimpy. The magnets are very tiny however, they are one of a few speakers that I have know that do not need a subwoofer to fill the last octaves of sound. They are really dynamic. True, they need a lot of power just to get them going but when they get going, WOW!!!
I say this in hopes that we may understand that even if the Gilmore speakers are offshoots of the original Carvers, they may just live up to the claims made by the manufacturer. I know that the woofers on the Carvers move an incredible amount of air. The excursion (due to their abnormally large diameter surround) is really incredible. You may also want to make reference to some of the Carver subwoofers currently available.
As Lugnut says, I too am willing to wait for the results to be posted. We will just have to wait and see. However, because of my personal experience with the Carvers, I am more open to the claims being made than most.
Time will tell. |
Let's face it, as Plato said- we're looking at redo of the Carver speaker.
Updated parts, yes, but the same basic concept with the lastest audiophile hype. Don't you love the
"Sellerwithintegrity," spin doctor work.
Mr.Gilmore obviously has smoked too much pakalolo, if he thinks anyone would pay $19K for these plug ugly kitchen counter tops.
Can't wait for the 2004 Gilmore Audio calendar. Hope he includes 3D glasses. |
No, the design of the ad is awful. Body board ads should have bikini clad ladies!! The designer of that ad should take cues from Psychicanimal. His avatar on Audiocircle is something else. |
Ed:
By the time you get past the shirt and the hard lookin mama the speakers don't seem half bad. All in all, a well designed ad. LOL! |
It's funny how Mr. Gillmore is wearing a Hawaii shirt in his product's website. It only further reinforces my opinion that these speakers look like big body/boogy boards.
As DK would quip, these speakers appearance have a "low HAF". |
Pricing info from website:
Model 2: $19,950
Special Introductory Price: $17,500 (for limited time)
Model 3: $14,950
Special Introductory Price: $12,500 (for limited time)
Plus shipping and applicable sales tax
No figures given on shipping and premium color charges. |
Thanks Dawgbyte. I guessed I missed noticing the price, instead focusing on the center channel. Funny, but if I bought them, my wallet would be lighter than air. |
Patrick, according to their web site the Model 2's introductory price (ready for sale on Jan. 2, '04) is set at $17,500 (for a limited time) and $19,500 thereafter. The Model 3 will be introduced in Feb. for $12,500 and then go to $14,500. They also give dimensions for both models. |
you wrote "Vertical dispersion starts at 60 and 40 inches respectively and horizontal dispersion is 60 degrees."
60 degrees horizontal for what frequencies? what vertical angle from the line perpendicular from the panel? in other words, how much above and below the top and bottom of the ribbon?
i'm sure mrs. gilmore appreciates the mention. |
Hi Duke,
Since I was the first to fire a shot across your bow in this thread I now propose we simply allow you to show your wares at CES and other venues. I take no offense at your rebuttals while I still view the parsing of words such as "it's lighter than THE air it moves" akin to what the meaning of IS, is. I've repeatedly expressed that these may indeed be top drawer speakers, and we'll find out reasonably soon, which is good enough for me. What leaves me opened minded is Albert Porter being a Texas dealer. I doubt that Albert would be in this position unless someone who he respects a great deal made this recommendation, and Albert comes closer to soaring with eagles than hanging out with turkeys. I apologize if I've offended and wish for this thread to end on a happy note, urging all members to reserve judgement until we receive comments from trusted sources based on listening tests.
Most of the folks here would snicker at my modest two channel analog system until they heard it but few would question what I've built with my own two hands in my "street legal" race car. Having followed engine, chassis, power trasmission and traction progess since the mid 60's I've discovered that equipment manufacturers who use figures to lie also use partially clad, "fun bag" equipped models to avert the interested party's attention away from their outrageous claims. All of this may not apply to Gilmore speakers but simply be a poor marketing judgement call to folks like myself.
I trust that you are so close to and excited about this potentially great product that you don't understand our healthy skepticizm when faced with marketing statements that may push the envelope for credibility. That's how I'm reading your replies.
There isn't anywhere for this thread to go but way downhill from here unless we all back off a little, give everything the benefit of the doubt and reserve judgement. Since you have picked an especially powerful username I trust that you are hearing great things when auditioning this product.
Peace to all and especially you Duke. I know this hasn't been easy on you. I give you a lot of credit for taking the heat here. You've tried to explain each problem area. The only thing you have not addressed is price. How about a ball park figure here, say within $5,000?
Patrick
|
Two points:
1) Doppler distortion:
Re ribbon: Doppler distortion, which results in intermodulation distortion, doesn't really go into effect until around 180Hz. We crossover at 200Hz for that reason among others, so it is not a factor for the ribbon.
Re woofers: Yes, doppler distortion is a consideration, but there is minimal doppler distortion from our planar hybrid woofers because of the actual technology employed. This is linked to how the planar membrane itself is constructed and excited -- I can't say anything else because to do so would reveal proprietary intellectual property. Also, remember, any distortion is shared among 4 woofers -- overall distortion will be perceived as less for that reason vs a single driver topology. Finally, the fact that the woofer's excursion is 2 inches maximum doesn't mean that it is out there flapping around at the limit all the time, if ever. Most of the time, even at very impressive spl's with very demaning source material, the 4 woofers are cruising along at levels way below maximum performance levels, thanks to their synergistic design. At very high spl's, there is of course increased distortion, but the signal to noise ratio saves the day -- when the distortion is relatively high overall, it is still not relatively high compared to the signal. The Gilmore speakers, especially the model 2's, can play bass louder and cleaner than any other dipole or planar for sure and any home audio dynamic speakers we know of.
Concerning a forum participant's concerns that these speakers should not be called planars -- I think that the silliness of this perspective has already been pointed out by other forum participants. Let me add three other considerations. There is no box,the panel is flat and the radiating elements are all on the same plane -- thus the term planar.
Thanks again. |
in this message you wrote "We are able to attain big excursions, cleanly -- plus or minus 2 inches!" but then in your latest message you say "One clarification: Total excursion is 2 inches or plus or minus 1 inch." clarification? then you launch an all out attack, calling him "silly" and demanding an apology. yeah. i'm looking forward to your response to my post, mr. "integrity". |
Your questions seem to be mostly in the form of statements, most of which are somewhat off the mark. Let me begin.
What makes you think that in order to be a "line source" that something needs to go from "floor to ceiling". What home speaker that claims to be a line source goes from floor to ceiling? If you want to see some examples of how folks create line sources in the pro audio world for live sound, go to www.meyersound.com. A line source in one sense is anything that is greater than a point source. But you are chastising us for something that we do better than any other ribbon based planar that we know of -- so your complaint is hard to answer. This is quite true of your other comments. But I will try to proceed one by one.
Vertical dispersion starts at 60 and 40 inches respectively and horizontal dispersion is 60 degrees.
If I am a reasonable distance back from the spekaer, I get a very full soundstage from the model 3. The sound doesn't truncate somehow above 40 inches --why would it?
We tilt the speakers back to increase disperson slightly but mainly so the speaker doesn't fall over -- and thus for aesthetics -- this way we can have a cute stand in the back instead of clunky feet on the front and back.
Whatever comb filtering effect is created by our topology, it is less than anyone elses -- not more because of it.
I want to clarify something with Mark concerning the doppler distortion and I will get back to you. I know that it is not a factor and I want to confirm that my understanding as to why is correct.
There are binding posts on the woofers (we are using Cardas) and if you are not seeing them, it is because of the perspective of the shot. The crossover is in a separate box that weighs sixty pounds and rests on the floor behind the speker. We are thinking about having a see through top so you can enjoy the view -- its quite impressive.
I agree with your statement that "I guess the proof will be in the listening."
Concerning the "center channel" and Mark's purported relationship to her:
No, its not Mrs. Gilmore. Mrs. Gilmore is 6'4" tall, weighs 300 pounds and has killed both of her former husbands with her bare hands for their indiscretions. Consequently, Mark has had incentive to concentrate on audio research and development and not stray or be distracted. As a result, marital bliss and his personal well-being have been sustained and therefore he has a lot to smile about. The woman in the picture is an alien from the planet Xenon. She is the latest version of their Humanoid Replications Program HRP. Given the advanced technological sophistication of her alien society, she has been an invaluable asset in helping Mark develop the special technology he is using in his speaker. As a token of appreciation, Mark has allowed her to participate in the photo shoot, thus helping her realize one of her lifetime dreams. It's nice to know that some alien societies share many of the same aspirations as us humans, thus providing a framework for cooperation and peace. These photos are as much a tribute to that cooperative spirit as they are a tribute to the fine example of advanced audio technology epitomized by the Gilmore Audio Model 2's and 3's.
Hope you found this helpful. |
One clarification: Total excursion is 2 inches or plus or minus 1 inch.
I don't know what to tell you and your friendly "expert" when you say that the cone doesn't go "in and out by 1 inch each way", except that you are wrong. Very simply, it does. How you can determine from a web-based pitcutre with resolution around 72dpi that "obviously it doesn't" is beyond me. The fact that you are so self-assured yet wrong should be embarrassing to both you and your "expert" friend. So I guess you are calling us a liar publicly. Then I expect a public apology from you personally and from you on behlaf of your "expert" when you see the physical proof that you are wrong.
You have an interesting strategy -- deny what we say is true as possible based on manufactured evidence and then use that newly acclaimed "fact" as refutation.
In terms of your other silly comment concerning the high QTS and weakness of the magnet, what does that have to do with anything? The magnet is exactly as strong as it needs to be given the open baffle design (no back pressure) and the responsiveness and compliance that is sought. This is called good engineering. Who cares that it doesn't match someone elses specs -- what does that have to do with anything? Heavy magnets require lots of power to make them responsive. Ours is as "heavy" as it needs to be given our design objectives.
Finally, our bass drivers on the model 2 operate from 200 Hz to 17Hz
(-3db at 17Hz, full output at 22Hz). And in terms of your claim that there is "no way 4 -12 inch dipole drivers will come close to (moving) the volume of air talked about" -- well congratulations, you are wrong again. At least you are consistent. |
I agree with Albert.
Anyway, I prefer the center channel I got now, thank you very much...
:-)
-Mike. |
Gregm...If I remember correctly from Bob Carver's explanations of his speaker, the small (weak) magnets in the LF drivers are deliberate and necessary to produce dynamic characteristics needed for free air operation. (I have no idea why). So cost is not the deciding factor. |
I'm still perplex.
And we ARE a civilised group here, I've been around long enough to know -- but I think the speaker presentation took a wrong turn s/where, despite Sellerwithintegrity's kind efforts:
Steved and Planar make excellent points about Qts and comb filter effects... and so have others.
I just still fail to see the "revolution"...
Not to say that this speaker will not sound spectacular; I LOVE dipoles, anyway. So does Steved, by the way:)
From the info gleamed from Sellerwithintegrity's posts and the pictures, and with all due respect, this *looks* like (no more than) a good passive dipole construction with a wide-band line source , & a point source array for the lower freq. -- passed @ the limit of 2pi radiation of the baffle??
However and IMO there is a lot of merit in designing a dipole with passive equalisation...
Also, designing a top-notch dipole to a cost level, has merit too.
10mm of Xmax is very good; the choice of four (parallel?) woofs explains the compromise of small magnets (woofers with big magnets like, say, the Supravox 400: Xmax: 8mm/qts ~0,4 /magnet +1,5T, cost over $600 EACH -- not the stuff for commercial offerings).
As to how they manage to have 4 high Q woofs outputting "clear" and fast sound to integrate with the low mass magnet ribbon, is a secret probably hidden in the xover Sellerwithintegrity refers to.
There's merit in that too.
The baffle shape is a quarter "heart" (hearts are reputedly excellent for dipole operation -- but think of universal waf with a heart-shaped speaker!)
So, that has been carefully thought out too.
What about the high frequencies -- over 18kHz (they're useful too)? I think that the addition of a tweet on that baffle would create, at least, phase and/or gp delay complications and filtering/equalisation difficulties. Also it wouldn't look as good (and deafen the beautifully engineered centre channel).
As Sean once wrote, I have trouble making my posts brief...
But here it is. What's the bottom line (i.e. the caboodle) for the B&G-like ribbon, the four woofs, the filter and, most of all, the hours and toil that went into finalising the design??? |
These speaker may sound great, but they should not be called "planar". |
the speakers sound interesting but some questions aren't answered.
the speakers are described as acting like a very tall line source. a 40 inch (model 3) or 60 inch (model 2) ribbon doesn't go anywhere near from floor to ceiling. you don't say anything about horizontal and vertical dispersion. tilting the speakers back looks like compensating for limited ribbon length and very little vertical dispersion. could be the model 3 can only be listened to sitting down because of vertical beaming. and how can four woofers in one row about a foot away from the ribbon be called a line source? the distance between them creates an acoustic timing anomaly that produces comb filter frequency response. someone asked about that, no reply. how about doppler distortion associated with such long excursions? funny that the photos show no binding posts or crossovers.
i guess the proof will be in the listening. is the center channel an available option? |
"Second, and somewhat related is the skepticism concerning the ability of our woofers to move sufficient air to accomplish authoritative bass. Cone excursion of drivers on some of the sites referred to are as little as 6mm. We are able to attain big excursions, cleanly -- plus or minus 2 inches! So our four woofers move a lot of air. To do this, "you can't use no ordinary woofer", as my grandmother would say. Not surprisingly, we haven't. It is a very unique, proprietary planar driver with a surround that allows it to function much like a dynamic speaker -- on steroids. The magnets and supporting structure are very robust. As a result, we have a woofer that is very responsive (it moves fast) while remaining very compliant (it tracks the wave form very nicely). It has a very high QTS. The four drivers share the load so they "run cool". Even reasonably high spl levels can be maintained without loss of performance. We think you'll like what we have done, unless your the jealous type."
OK, so it is now 'reasonably high' SPL levels. And you are claiming +/- 2 inches of Xmax. Excellent and unusual.
However, someone way smarter than me suggested I look at the surround of the drivers and consider whether such a surround would physically allow the cone to go in and out by 1 inch each way. Obviously it doesn't.
The high qts is also a sign of a weak magnet, which can be seen from the shots of the rear and compared to a high Xmax driver like the Adire Tumult. But that doesn't matter since bass = displacement in most universes.
Even then there is still no way 4 12 inch dipole drivers will come close to the volume you are talking about.
Unless you would like to share what frequencies we are talking about. |
Hello Again,
If you don't mind, I will use this opportunity to repeat what I have said on another forum, which I hope will be helpful to all the participants.
Thought I would take a moment to shed some light on three subjects.
First, our 127dB compression claim.
1) If you put the power necessary into a traditional woofer and try to push it to 127db, it would probably blow-up long before it got there. But we don't have one driver -- we have four to share the power.
2) We actually used a set-up that could generate at least 4000 watts to test the speaker's compression point. We wore ear-plugs too. We used pulses because we didn't want to kill our neighbors, cause a brown out and also because we were trying to emulate musical peaks. Yes, running our drivers under several kwatts of power continuously would not be tolerated politely by the drivers. They couldn't survive that. But music is "dynamic" after all, hence the term "dynamic range".
3) At around 127dB and around 4000 Watts, compression was noted -- 1 watt = 91 dB; 10 watts = 101 dB; 100 watts = 111dB; 1000 watts = 121 db... you get the idea.
So our whole point again about making this claim is two-fold:
a) The speakers get to the threashold of pain long before they compress. So they will play loudly.
b) More importantly, they will handle dynamic peaks of MUSIC very nicely indeed (as sound reinforcement speakers do) and very cleanly (as top planar dipole speakers do), thus effectively emulating the live concert experience.
Second, and somewhat related is the skepticism concerning the ability of our woofers to move sufficient air to accomplish authoritative bass. Cone excursion of drivers on some of the sites referred to are as little as 6mm. We are able to attain big excursions, cleanly -- plus or minus 2 inches! So our four woofers move a lot of air. To do this, "you can't use no ordinary woofer", as my grandmother would say. Not surprisingly, we haven't. It is a very unique, proprietary planar driver with a surround that allows it to function much like a dynamic speaker -- on steroids. The magnets and supporting structure are very robust. As a result, we have a woofer that is very responsive (it moves fast) while remaining very compliant (it tracks the wave form very nicely). It has a very high QTS. The four drivers share the load so they "run cool". Even reasonably high spl levels can be maintained without loss of performance. We think you'll like what we have done, unless your the jealous type.
Third, this is not a Carver facsimile. Again, Carver's Amazing speaker (second version in particular) served as a marvelous inspiration and we have tremendous respect and gratitude for what he has accomplished. We could replicate the Carver speaker for much less money. But then it wouldn't do what the Gilmore speaker can do or sound the same either. Essentially, when compared with the Carver Amazing, every component is different.
1) The panel is Corian and essentially non-resonant. Each wieghs about 80 pounds alone.
2) The ribbon membrane is 10 times thinner and has much different topology.
3) Woofers are very different as you can see.
4) Crossover is in another class altogether as we have described earlier.
5) Even the stand, that is made especially for us by Sound Anchor, is very special.
We don't agree that we are engaged in hype and hyperbole and that our goal is the elicitation of cheap thrills. We know that these speakers are expensive compared to most, but few speaker manufacturers aspire to the same aesthetic, even though they claim that they do . For those that do sincerely aspire to achieve greatness, we believe that our speakers represent an exceptional value relative to other top quality offerings. These speakers in our opinion represent a paradigm change -- that is perhaps why some of you find the claims hard to believe. Most of you are open-minded enough though to accept the possibility that what we have created may in fact be exceptional and we thank you for your graciousness. Those who know Mark Gilmore personally know that he is respected universally for his integrity, generosity, self-effacement and knowledge. We invite you all to visit us as CES and THE-expo. Along with that we ask one favor -- for those who have so far chosen to condemn publicly a product they have not heard and don't understand, I hope that you will be able at least to listen to the speakers with an open mind and in turn be as forthcoming with your praise if you feel that it is justified.
I hope that you have found this helpful.
HB |
The statement was not that the ribbons are lighter than air, rather that they are lighter than the air that they push. Big difference. |
how much ? what! yea right. |
I agree with Seadogs1. This is a classy and respectful site where we all share common ground with respect for our love of music and high-end audio reproduction. It's fine to inquire about new technology and ask probing questions about manufacturer's claims, but let's do it in a way that encourages people to share their ideas not inhibit them. The last thing we want or need is to roast people like they do on Audio Asylum.
Cheers,
DB |
I don't purport to be a scientist - or even technical for that matter - but I have a question about the claimed 127db output claim.
According to what I've heard people say on this site, for every 3db increase in output, it takes approximately double the amplification (wattage).
If this is correct, even with the claimed 92db efficiency, it would require approximately 2000 watts per channel at 8ohms to achieve 127db.
If this is peak, maybe I could see it...maybe. But 127db continuous output across the rated frequency response seems a bit unlikely.
Besides, wouldn't 127db result in hearing damage?
As for Sellerwithintegrity's request that you bring your SPL meter to CES - If you attempt to achieve 127db with innocent bystanders anywhere remotely close to your booth, be prepared for the impending lawsuits and negative public sentiment that will surely lead to the company's early demise.
Achieving 127db just for the sake of doing it reminds me of the old joke about why a dog licks his b@##s.
What's the point? |
|
Metralla- Each of the football fans in your analogy moved but they didn't get transported. This type of movement (call it a "wave" or "vibration") is the type I assume anyone in this hobby is refering to when they use the term "moves air". I think most understand that a speaker is not literally like a desk fan that blows air around.
What I thought was more interesting was the claim that the ribbon is lighter than the air it , is totally meaningless. To explain: If one can hear sound eminating from a speaker, the speaker is air. At 127 db, one could hear the speaker from a good couple of miles away. Even with minimal dispersion, the volume of the air within the couple of miles that is is fairly huge and would weigh, literally, tons. So, when Sellerwithintegrity says that the speaker "moves (vibrates, waves)tons of air", he is correct. That the ribbon weighs less than several tons is meaningless. Even the air in my listening room weighs a couple of ounces. I'd be curious for Sellerwithintegrity to define his terms.
The other interesting claim was that the ribbon is .3 mil thick. If memory serves, both Martin Logan and Magnepan (and probably all the other planar makers except Sound Lab) have been using that thickness for years. Nothing new or impressive there.
It seems that these speakers have merit, just got to get past the initial marketing smoke and mirrors!
BTW- Three others have asked before without response- what do these speakers cost????
Jim
|
I believe people have a healthy skepticism of a very expensive new speaker that makes rather outlandish claims yet appears to be no more than rehash of the Carver and a number of other ribbon/dynamic hybrids.
The manufacturer's dealers have posted on a number of sites touting these speakers, which makes them fair game for comment.
I suspect they sound very good, but wish they would go easy on the pseudo-science, cheap thrills advertising and exagerration. |
I don't understand why a lot you are gaining up on this new speaker. This is suppose to be a fun hobby with friendly people, what happened? Sure the speaker may turn out to be a dud but on the flip side it may be very special. Let's wait until we can hear them first hand and then give our opinion. Meanwhile I say hat't off for someone trying to improve our hobby. |
