Yes, the weight distribution is key but it may not be easy to calculate the optimium ratio as the maths with the spurious properties can alter the true dynamic beyond recogntion
It can be disappointing when a new driver arrives on the market it is slotted into a bracket to suit, either as an update for an existing driver or with enough new features to be a step change to be a wake up call to any audiophile. The Be diaphragms of course in quite a few new driver brands is just this. But when magnesium was touted again, a few years back there were those who felt this was a must have. Then it was Be until they find out that Be sputtered or plasma formed instead of HIP is not really the same metallurgy as a tough foil like the Truextent. But so much still relies on the surround interaction and the dynamics of a wobbling jelly so the metal stiffness adds rather less precision to the high frequencies. We could ask why doped silk remains so popular.
Is anyone out there, that has seen any of this HS photographic motion analysis of a selection of diaphragms and surrounds whether dome or cone. If so does it relate to drivers we know.
Boldname,
I don't think that many manufacturers will list the equipment that they are using to analyze their speaker designs. While many are still using simple analysis equipment to get their T/S values others are using higher dollar equipment like Audio Precision or laser analysis using Kippel test setups. The actual laser analysis is nothing new, it has just become more available to more companies as you don't have to be a mad scientist and make your own test setup and equipment. If you look back years ago in some of the early versions of Martin Colloms High Performance Loudspeakers, V3. you will see this being used. I don't know what information this would give the average DIY builder that they would truly need? Analysis at that level I would think would be closely held as a trade secret.
On the Be point of view I am in agreement that the Be diaphragms from Brush Wellman/Materion are superior in strength to the diaphragms from say TAD/Pioneer but at the same time you have to realize that the density is also much higher on the Materion material given the differences in physical molecular structures. It is very interesting how the TAD diaphragms molecular structure lines up and gives the lowest density for such a material but that comes at the cost of a weaker bond structure. So for something like the TAD ET-703 I am not sure you could get the same high frequency response with the denser Materion foil material, it will be higher density for sure and the diaphragm will weigh more and changing both the efficiency and first breakup modes. It is a challenging proposition to compare the two different manufacturing methods and the ultimate end results. I would think the Young's modulus of the two materials would be different enough to make a very measurable difference.
I don't think that many manufacturers will list the equipment that they are using to analyze their speaker designs. While many are still using simple analysis equipment to get their T/S values others are using higher dollar equipment like Audio Precision or laser analysis using Kippel test setups. The actual laser analysis is nothing new, it has just become more available to more companies as you don't have to be a mad scientist and make your own test setup and equipment. If you look back years ago in some of the early versions of Martin Colloms High Performance Loudspeakers, V3. you will see this being used. I don't know what information this would give the average DIY builder that they would truly need? Analysis at that level I would think would be closely held as a trade secret.
On the Be point of view I am in agreement that the Be diaphragms from Brush Wellman/Materion are superior in strength to the diaphragms from say TAD/Pioneer but at the same time you have to realize that the density is also much higher on the Materion material given the differences in physical molecular structures. It is very interesting how the TAD diaphragms molecular structure lines up and gives the lowest density for such a material but that comes at the cost of a weaker bond structure. So for something like the TAD ET-703 I am not sure you could get the same high frequency response with the denser Materion foil material, it will be higher density for sure and the diaphragm will weigh more and changing both the efficiency and first breakup modes. It is a challenging proposition to compare the two different manufacturing methods and the ultimate end results. I would think the Young's modulus of the two materials would be different enough to make a very measurable difference.
Yup, there is little more one can really say, that has not already been said
If no EQ is available, yes. But when you have EQ at hand a stronger motor (and rising response on a flat baffle) is always a good thing IMHO.
But having said that, I think Be Materion is a major step forward for the larger diaphragmed drivers and real PA work, a revelation, but at the 1" diaphragm level aluminium alloys are in reality almost indistinguishable in performance. You really cannot get any better audibly. Aluminium with magnesium is perhaps slightly better, and so would be hard anodised finish. And there are many other cheap options, and if you like the sound silk makes then go with that. They are still at the state of the art for reproduction quality, thank goodness.
If I ever do a horn job, it will be because I want 140dB peak and I cannot see any use unless I want to fill a hall or tent.
Just a quick note: About a dozen members of the "Sound DIY" Club crossed the "Big Sea Waters" of Puget Sound to attend a special listening session at Gary Dahl's house. The members were very interested to hear his recently finished system. Besides Gary's music collection of CDs and LPs, some of the members brought some of their music, including pristine LPs that have never been played before.
Gary, his wife and daughter proved to be perfect hosts for an event of this sort. They were so nice that I began to believe that they were actually glad that this "hoard of DIY'ers" had come to visit.
Anyway, it was a wonderful visit for us and I believed everyone enjoyed themselves listening to his system.
My impression was that it was absolutely excellent playing Orchestral Works with an absoluely correct sense of dynamics, scale and drive necessary to offer a realistic and convincing sonic presentation. For these "large" works, I believe these may be as good as any speakers I have heard.
The speakers seem to capture and recreate a sonic event readily, although smaller events "may" not have risen to the stratospheric levels that they achieve with large scale works. This was an impression that I formed based on part of one recording and a snippet of another one and would really need to spend more time to actually be sure of this notion that I arrived at perhaps altogether too rapidly.
I just now got off the phone with Gary and he mentioned that the speakers are actually voiced for a central "Sweet Spot" and not off to the sides, where I sat a fair amount of time when the smaller works were playing, so I may have actually introduced variables into the equation unintentionally!
Gary will continue to adjust and experiment further with his system in the days, weeks and months to come. I understand that some of our members left some gear for Gary to try in his system. This included a couple of much modified DIY DACs that one of our members had not only built, but also devised and performed the modifications!
These are some scanty and hastey thoughts of yesterday's meeting.
Best Regards,
TerryO
Gary, his wife and daughter proved to be perfect hosts for an event of this sort. They were so nice that I began to believe that they were actually glad that this "hoard of DIY'ers" had come to visit.
Anyway, it was a wonderful visit for us and I believed everyone enjoyed themselves listening to his system.
My impression was that it was absolutely excellent playing Orchestral Works with an absoluely correct sense of dynamics, scale and drive necessary to offer a realistic and convincing sonic presentation. For these "large" works, I believe these may be as good as any speakers I have heard.
The speakers seem to capture and recreate a sonic event readily, although smaller events "may" not have risen to the stratospheric levels that they achieve with large scale works. This was an impression that I formed based on part of one recording and a snippet of another one and would really need to spend more time to actually be sure of this notion that I arrived at perhaps altogether too rapidly.
I just now got off the phone with Gary and he mentioned that the speakers are actually voiced for a central "Sweet Spot" and not off to the sides, where I sat a fair amount of time when the smaller works were playing, so I may have actually introduced variables into the equation unintentionally!
Gary will continue to adjust and experiment further with his system in the days, weeks and months to come. I understand that some of our members left some gear for Gary to try in his system. This included a couple of much modified DIY DACs that one of our members had not only built, but also devised and performed the modifications!
These are some scanty and hastey thoughts of yesterday's meeting.
Best Regards,
TerryO
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Hello, looking at the design and crossover points of Mr Dahl's system I'd have to say if you weren't in the sweet spot you haven't heard it's true capabilities. I know it's tough to get in that seat at multi - geek gatherings - when i had a sytem with this typr of power response we used to fight over the spot - the type of midrange horn being used will be pretty dead sounding outside a pretty narrow window when used wide range (upper mid low treble energy) like that compared to the way the horn radiates it's energy to the sweet spot - go back and listen again
- when i had a sytem with this typr of power response we used to fight over the spot - the type of midrange horn being used will be pretty dead sounding outside a pretty narrow window when used wide range (upper mid low treble energy) like that compared to the way the horn radiates it's energy to the sweet spot - go back and listen again
~~~~~~~~~~~~~~~~~snip~~~~~~~~~~~~~~
- go back and listen again
Excellent suggestion! I'm so used to being thrown out of places, that I never thought of actually going back again!
Thanks for sharing your listening experience, TerryO! Gary Dahl and I have been collaborating on amplifiers and speakers since the early 2000's, and I'm really pleased that Gary has gone ahead and built the second version of the speaker (the first was built a couple of years ago in Dallas, Texas by an audio-friend).
Gary tells me his latest version has an improved crossover suggested by a French-Canadian builder who is part of the project, so you'll have something new to hear when you return to the sparkling blue waters of Puget Sound.
Gary tells me his latest version has an improved crossover suggested by a French-Canadian builder who is part of the project, so you'll have something new to hear when you return to the sparkling blue waters of Puget Sound.
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Lynn,
Wow! That's pretty quick I think. Just so I'm clear on this, Gary already has a new version of the crossover? We were over there just this last Saturday! I know he just finished (evidently last night, or this morning) his new stand-alone computer-based Music Server! Gary certainly doesn't stand still for very long once he has a plan.
Best Regards,
Terry
The French-Canadian builder has experimented with various supertweeters (RAAL Lazy Ribbon, EV T350, etc.), comparing them to a HF lift circuit that bypasses the autoformer at very high frequencies (and omitting the supertweeter). The HF lift circuit, as you might expect, delivers a rising response on axis, but this is corrected by listening to the AH425's 10~15 degrees off-axis (either by pointing them inwards or upwards).
Although a HF lift circuit for compression drivers is nothing new ... it was used in the Altec Model 19, and undoubtedly other speakers before that ... it takes advantage of the ~18 kHz first resonance of the beryllium diaphragm, and the much-improved breakup region above that. (The Materion beryllium foil has measurably better self-damping compared to aluminum or titanium foils.) Applying the same HF lift circuit to an aluminum diaphragm would probably introduce a measure of harshness (due to breakup) that's not there with the beryllium diaphragm. It's a clever way to take advantage of the properties of the diaphragm.
Gary Dahl modified the HF lift circuit for the different characteristics of the Slagle autoformer he's using, and the results are promising ... sweeter treble in the 3~5 kHz region, better imaging, more spacious ambience impression, etc. I haven't heard it for myself, but I trust Gary's taste and listening impressions. He is particularly critical of solo and ensemble violin tone, since his wife plays violin and Gary is an orchestra conductor.
As for my version, Thom Mackris (of Galibier Design and a neighbor) and I are contemplating a dual-woofer version with twin GPA 416 Alnico drivers in a configuration similar to the Altec Laguna of the early Sixties. 3 dB more efficiency, 6 dB more headroom, and a reduction in IM distortion compared to the single 416 version. That should give an overall system efficiency around 100 dB/meter/watt, and a closed-box F3 in the 60~70 Hz range (depending choice of system Q).
One of the great things about modern self-powered subwoofers is the main speaker no longer has to struggle for every last Hz of LF response. That was the problem back in the pre-T/S days of the Fifties and Sixties ... stretching LF response down, down, down, with no recourse to T/S theory. When the first papers appeared in the AES Journal in the early Seventies, the bandwidth/efficiency/size tradeoffs became obvious to everyone in the industry.
Although a HF lift circuit for compression drivers is nothing new ... it was used in the Altec Model 19, and undoubtedly other speakers before that ... it takes advantage of the ~18 kHz first resonance of the beryllium diaphragm, and the much-improved breakup region above that. (The Materion beryllium foil has measurably better self-damping compared to aluminum or titanium foils.) Applying the same HF lift circuit to an aluminum diaphragm would probably introduce a measure of harshness (due to breakup) that's not there with the beryllium diaphragm. It's a clever way to take advantage of the properties of the diaphragm.
Gary Dahl modified the HF lift circuit for the different characteristics of the Slagle autoformer he's using, and the results are promising ... sweeter treble in the 3~5 kHz region, better imaging, more spacious ambience impression, etc. I haven't heard it for myself, but I trust Gary's taste and listening impressions. He is particularly critical of solo and ensemble violin tone, since his wife plays violin and Gary is an orchestra conductor.
As for my version, Thom Mackris (of Galibier Design and a neighbor) and I are contemplating a dual-woofer version with twin GPA 416 Alnico drivers in a configuration similar to the Altec Laguna of the early Sixties. 3 dB more efficiency, 6 dB more headroom, and a reduction in IM distortion compared to the single 416 version. That should give an overall system efficiency around 100 dB/meter/watt, and a closed-box F3 in the 60~70 Hz range (depending choice of system Q).
One of the great things about modern self-powered subwoofers is the main speaker no longer has to struggle for every last Hz of LF response. That was the problem back in the pre-T/S days of the Fifties and Sixties ... stretching LF response down, down, down, with no recourse to T/S theory. When the first papers appeared in the AES Journal in the early Seventies, the bandwidth/efficiency/size tradeoffs became obvious to everyone in the industry.
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Hi Terry,
Yes, now you are going to have to come back for another listen!
The new version was in place by Tuesday, thanks to the assistance of our friends in Canada. In my case, the HF lift is set for flat response on axis, which reaches about 14 kHz. The tweeters are not in use at this time.
The change brought substantial improvements in some areas, but it has also resulted in the need for further work on the transition between the woofer and compression driver. Next step will be to take the whole thing outside so I can get some clean measurements. Some nice weather coming up...
Gary Dahl
Yes, now you are going to have to come back for another listen!
The new version was in place by Tuesday, thanks to the assistance of our friends in Canada. In my case, the HF lift is set for flat response on axis, which reaches about 14 kHz. The tweeters are not in use at this time.
The change brought substantial improvements in some areas, but it has also resulted in the need for further work on the transition between the woofer and compression driver. Next step will be to take the whole thing outside so I can get some clean measurements. Some nice weather coming up...
Gary Dahl
BEFORE copying the Pacific Northwest Crossover, Google your local weather.
The speed of sound changes with temperature, humidity, and altitude. Frequency dependent attenuation varies with humidity. At 15Khz over 15ft distance, cold and wet Seattle can have 3db greater SPL than hot and dry Tucson. There are published graphs and on-line calculators for SPL vs. weather.
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“Actually, I believe that nobody outside of "Cascadia" could possibly win a Seattle speaker contest, unless they're from Eastern Washington, Idaho, Oregon, Montana or one of the Western Canadian Provinces.
The secret to winning a Seattle Speaker Contest that's held "during a normal cold, wet evening" is to use extremely "fast" drivers to compensate for the effects of humidity. It also helps to voice them for a rather dry, etched sound, as this further helps to offset the effects of our miserable, damp climate.
Best Regards,
TerryO “
The speed of sound changes with temperature, humidity, and altitude. Frequency dependent attenuation varies with humidity. At 15Khz over 15ft distance, cold and wet Seattle can have 3db greater SPL than hot and dry Tucson. There are published graphs and on-line calculators for SPL vs. weather.
=====
“Actually, I believe that nobody outside of "Cascadia" could possibly win a Seattle speaker contest, unless they're from Eastern Washington, Idaho, Oregon, Montana or one of the Western Canadian Provinces.
The secret to winning a Seattle Speaker Contest that's held "during a normal cold, wet evening" is to use extremely "fast" drivers to compensate for the effects of humidity. It also helps to voice them for a rather dry, etched sound, as this further helps to offset the effects of our miserable, damp climate.
Best Regards,
TerryO “
The sound in the Seattle Symphony Hall isn't lacking in HF sparkle ... the hall is on the "brilliant" side ... and the listening distance the last time I was there was at least 50 feet from the orchestra. No PA system (thankfully), no electronics, and no EQ. All acoustic. If a hifi system could sound a quarter as good as that I'd be thrilled.
When I moved to mile-high Colorado, I wondered how sound would be affected by the 14% decrease in air pressure. As it turns out, the speed of sound is changed less than 1%, which kind of surprised me. But the humidity is certainly less, all year round. Do things sound different here? I'm not too sure about that ... and I lived in the soggy Pacific Northwest for forty years. The biggest difference is the surprisingly noisy high prairie wildlife (birds, prairie dogs, coyotes, owls, etc.) and the shockingly loud thunderstorms.
The biggest effect on tourists is a physiological and psychological reaction to the altitude. You don't notice much the first day, then you start to feel weird for several days afterward. I didn't really fully adapt until about three to four weeks later. This varies a lot with the person, and there's no way to tell in advance how you will react to the altitude ... and 5280, 8000, and 10,000 feet all feel quite different from one another. Also, get polarized sunglasses; the UV levels are very high compared to most other cities.
Fair warning to tourists who want to try out our newly legalized crop, the lowered partial pressure of oxygen will make the psychological effect much stronger than you might expect. There's an Oxygen Bar in Boulder if you want to feel "normal" when you visit here. I highly recommend it, you'll love the enhanced color perception and extra zip you'll get.
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The only effect of weather on sound is HF air absorption, which, since there is very little sound > 10KHz, is virtually a non-effect. Claims to the contrary are pure fiction.
Having just returned from Seattle, they have a "crop" as well. So does Vancouver. Maybe this new trend will bring back "stereo"!! I know it was an important aspect when I was growing up.
I once went sleepless for several days in Denver. Altitude will do that. Felt fine otherwise.
Having just returned from Seattle, they have a "crop" as well. So does Vancouver. Maybe this new trend will bring back "stereo"!! I know it was an important aspect when I was growing up.
I once went sleepless for several days in Denver. Altitude will do that. Felt fine otherwise.
Winter is the worst time to go to a concert. On the other hand who wants to go to concert in summer time..
That's air attenuation for 30m distance. For a concert hall, attenuation is noticeable. And the reverberance field is affected heavily.
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An externally hosted image should be here but it was not working when we last tested it.
That's air attenuation for 30m distance. For a concert hall, attenuation is noticeable. And the reverberance field is affected heavily.
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I suspect there will be some effect akin to an air cooled motorbike. Ventures out in hot weather 86 degrees F as the engine warmed it wouild eventually show some slight tailing off in power.
Will not go into the tech details here. But the same presents with the drivers units. Albeit the speaker diaphrams will move further in hot weather with lower air density epecially with lower air pressure from low pressure storm conditions, and surrounds flex more with the slight loss of stiffness and viscostatic properties. Frequencies will rise with loss of air density.
Can we hear it. You betcha. Sure if you are sensitive to it. At least string instruments can retune.
No come on lets be having you with all your ideas out there.
Will not go into the tech details here. But the same presents with the drivers units. Albeit the speaker diaphrams will move further in hot weather with lower air density epecially with lower air pressure from low pressure storm conditions, and surrounds flex more with the slight loss of stiffness and viscostatic properties. Frequencies will rise with loss of air density.
Can we hear it. You betcha. Sure if you are sensitive to it. At least string instruments can retune.
No come on lets be having you with all your ideas out there.