I settled on the FT90H, unfortunately no longer available.
All Fostex supertweeters are quite different in performance and construction (the replacement membranes that are all quite different). The one that currently best resembles the FT90H in construction and measurements is the T96AEX2.
Lynn,
I have nothing against vacuum tube amplification, no axe to grind. There really do seem to be two different directions that vacuum tube designs have taken though. We have what you are talking about and have worked your magic on and then we have the other half of this equation which are the SE amplifiers that have such high distortion harmonic production of euphonic 2nd's that I just don't think are anything like what you have been talking about. I think many get lost in the hype when it comes to what is said about some of these obviously flawed ideas. As you have said before the Williamson type of tube designs at least tried to follow a low distortion path even if they weren't perfect. You have approached your designs based on trying to improve every area of design, low distortion is your end point.
The Bosendorfer designs are what I would consider also in the vain of the SE amplifier, an attempt to create a euphonic sound, not an accurate reproduction through accurate acoustic design. Yes there are always things that we don't understand, but in the case of the Bosendorfer designs I do understand the premise and it is just plain wrong. A misplaced concept of musical instrument sound production being applied on the reproduction side of things.
I have nothing against vacuum tube amplification, no axe to grind. There really do seem to be two different directions that vacuum tube designs have taken though. We have what you are talking about and have worked your magic on and then we have the other half of this equation which are the SE amplifiers that have such high distortion harmonic production of euphonic 2nd's that I just don't think are anything like what you have been talking about. I think many get lost in the hype when it comes to what is said about some of these obviously flawed ideas. As you have said before the Williamson type of tube designs at least tried to follow a low distortion path even if they weren't perfect. You have approached your designs based on trying to improve every area of design, low distortion is your end point.
The Bosendorfer designs are what I would consider also in the vain of the SE amplifier, an attempt to create a euphonic sound, not an accurate reproduction through accurate acoustic design. Yes there are always things that we don't understand, but in the case of the Bosendorfer designs I do understand the premise and it is just plain wrong. A misplaced concept of musical instrument sound production being applied on the reproduction side of things.
I understand some of it. Unfortunately I cannot find the reason why the tweeter is not flush mounted (see picture). Do you know? I think speaker design has close relationship with Physics, so I expect a little measurement or Math or meaningful chart will help to attract engineer-type customers. Instead, "(our cable is) developped in nuclear Physics labs, used by NASA" is what they are using to convince their target customers.
I have said it many times, that it is okay to alter the recorded sound to make it more like music (I have been doing the same thing many times), but if you want something beyond that, there is no other way... Because you cannot make a dynamic alteration such that the type of alteration will depend on what instrument is playing in the recording.
When I left my tube amps behind, and entered the world of solid state and multi-way speaker, I had a very long years full of frustration. But I didn't give up 🙂
Attachments
Don't know about Bosendorfer, but I've done it to use it as a phase/loading plug in a vent kind of like Altec did with its 'horn in vent' designs.
GM
GM
Jay,
That way of mounting a dome tweeter is going to cause a real diffraction effect, perhaps they wanted to do that or maybe they didn't want to cut into the veneer and mess up the look? The response curve is surely nothing to get excited about, it is one of the worst I have seen for some time.
That way of mounting a dome tweeter is going to cause a real diffraction effect, perhaps they wanted to do that or maybe they didn't want to cut into the veneer and mess up the look? The response curve is surely nothing to get excited about, it is one of the worst I have seen for some time.
I prefer listening evaluation over design 'analysis'.
I'd encourage people to hear the speakers prior to stating that they 'alter the recorded music', or have 'euphonic sound', or any other similar statement. To me it looks pointless, like criticizing a cooking by analyzing its' recipe, without tasting it.
Though it looks like some others have different preferences than me. That's perfectly okay, of course – to make whatever statements one may feel like, without actually hearing the speakers.
I'd encourage people to hear the speakers prior to stating that they 'alter the recorded music', or have 'euphonic sound', or any other similar statement. To me it looks pointless, like criticizing a cooking by analyzing its' recipe, without tasting it.
Though it looks like some others have different preferences than me. That's perfectly okay, of course – to make whatever statements one may feel like, without actually hearing the speakers.
What I know you claim they don't sound real with good recordings so absolutely not worth the time to investigate further for either of us..
Reading between the lines of vague description, the resonator panels seem to act as some sort of multiple length port, or maybe even part port, part passive radiator. I'd be surprised if there weren't resonance peaks in the mid/low output.
I've no opinion on the sound, but their instructions make it seem is if it's quite sensitive to panel tuning combined with room placement. Though room placement affects all speakers, the side firing mid/low drivers would make this design especially placement/room dependent. Probably a small sweet spot too.
I am skeptical when I read about the effects of special/secret wires.
Sheldon
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Well, I learned one thing from the PDF: Alaska has a hemp industry!!! That's news to me. The growing season must be short in the far North, so I assume the hemp is grown indoors under grow-lights.
The previous industry scuttlebutt I heard was the hemp for the Tone Tubby cones came from Canadian hemp. Canada or Alaska, which is it? C'mon Colorado, you're missing out on a business opportunity! Yes, folks, marijuana is so mainstream here that the Denver Post has a marijuana section.
Notwithstanding the notoriety, things are pretty much the same as before. The Rocky Mountains attract the tourists, Denver is a regional business hub, we're drowning in locally-sourced microbrews and bluegrass bands, and newcomers get dizzy from the mile-high altitude. Once you get used to the altitude, it doesn't seem to affect the sound of music, as far as I can tell.
Returning to the Bosendorfer PDF, a complex multi-lobe directivity pattern appears to be a design goal, in the vertical plane with the paired dome tweeters, and in the horizontal plane with midbass drivers on each side of the cabinet. Also, no damping or fill inside the cabinet/resonator/horn assembly, so we can expect a "lively" sound, if the woods are chosen carefully.
The exact philosophical opposite of the Gedlee Summa or the Unity horn. A backhorn-loaded Lowther, AER, or Feastrex would seem to be about midway between the two approaches.
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Midnight Sun
You can grow monster green veggies there in summer cuz of long daylight. They grow lotsa spuds which means growing hemp is no prob, man. Cool!
Those with a more pure scientific approach, and of course, there are quite a few different paths, fundamentally underpinned by scientific fidelity. And there are then those that deviate for designers personal multifarious purposes, that establishes a sound that individuals perceive as what they like. When it come to acheiving what it sounds like in the original acoustic, the bias is heavily scientific fidelity. The great thing about the scientific/engineering route is it makes it possible for any body to be able to do a DIY job to achieve a technical goal, and it sounding to pretty good. While the bit of quasi artistic scientific aproach, can find something that meets the soul. And these different speaker designs do that and so do we DIYers at a fraction of the price.
Make and bake your own cakes.
This is just the opposite of what I said. They are the best speakers I heard so far.
There is a reason why the designer chose piano manufacturers to produce those speakers.
I'm yet to hear DIY speakers that sound as good as mine.
This is my last response in this thread to any comment about how those speakers presumably 'sound', derived by 'analyzing' their design, or by anyone who haven't heard them.
I don't want to participate in the game of judging a cooking by its' recipe, without tasting it.
But the recipe and its cooking is done earlier in the recording process. Your speakers just add the same spices to every meal.
With reference to Gary Dahl's speakers-probably still the newest and most successful horn system on this thread-Gary mentioned here that he listens at 11 feet away. I can do this too in my 17 x 9 room,though his room is certainly a good deal bigger.
Also, like me, Gary's average listening SPLs are 70 to 80db, at least as per his iPhone app, he said. So perhaps a relatively big room-or at least one bigger than mine-may not be needed, at least if one can be satisfied with low end response to 35Hz or so.
As for active crossovers, besides my active subs, that was my original plan-or at least partially so, if I went with a three way system. Certainly a two way design with active circuit like this one should give tremendous low distortion performance, along with great flexibility, as least with L-K and S-K filters. http://www.firstwatt.com/pdf/prod_b4_man.pdfHowever, as i sadly learned (though I wish someone here would explain exactly why) , it's seems to be the actual circuit configuration of the crossover filter (e.g. Bessel, Butterworth, L-K, S-K, et al)-not just the resultant Fc, slope and summed frequency and phase response-that determines overall speaker performance.
But as Gary exclaims here http://www.diyaudio.com/forums/multi-way/100392-beyond-ariel-1295.html his speakers-using specific passive filters-enabled the system to sound far better than he had ever expected. Imaging and seamlessness between drivers were spot on. Why mess with this kind of performance, albeit a restricted top end?
Perhaps Gary or the very next one to build his speakers (me?!) will add something like this https://www.madisoundspeakerstore.com/bullet-tweeters/fostex-t900a-top-mount-horn-super-tweeter/ Azurahorn's Martin Seddon and a few of his clients have done so with good results (with Duelund caps, Martin says). Check the gallery at his website.
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Just regarding the tweeter. I have no problem with DIYers using expensive parts where they see a purpose. Only add it if you really need it.
11 ft is really quite close, so unless there is a real droop in HF, a supertweeter may not be required. I have looked at the Fostex spec. and would possibly help with my longer listening distance like Lynn's.
Maybe I only need a smidgeon of super tweeter. A pink noise test just walking backwards, from a meter away from the speakers, will show the attenuation rate from 10KHz up in my set up. There is so little power delivered in wide band audio material a small 30 watt Fostex may suffice if needed at all.
To understand why best practice is to diffuse in the horizontal plane, we should look at what needs to be achieved in a 'best case' scenario:
After the direct signal there should be no high-gain early arrivals up to 10-20ms. After that, reflections should arrive laterally, without any one reflection standing out - it should mimic diffuse field as much as possible.
Now about practical diffusors - even the ideal type has >30% absorption, so the secret of 'diffuseness' is to not use any absorbers (use angled surfaces to redirect sound) and use vertically oriented, temporal! diffusors only where necessary. That is to spread out a single, sparse reflection so that to mimic the ideal diffuse-field scenario.
One way to achieve that is an angled backwall |_/\_| to redirect energy to the sidewalls, then utilize QRD-type diffusors at the back-sidewalls.
Daniel,
I understand what you are saying. At the same time I would think wall construction would also come into this equation. Most houses in the US are still stick and plaster construction so to say but there are the outliers that could be brick or concrete that may not have the same lossy self absorption compared to the typical 2x4 and drywall construction. Room furnishings and carpet vs hardwood floors are again going to skew the reflective properties so we have to look at this on a room by room basis. If you are in a high rise type of building both the floor and ceiling can be basically concrete construction, again different than a suspended wooden floor and lath and plaster construction. So it really is hard to make hard and fast rules that everyone can follow. The basic premise though of scattering the back wall reflections would still hold, and some side wall absorption can come in handy to reduce small dimensional rooms with a very fast side wall first reflection. Some such as E. Geddes want a very dead front wall and scattered rear wall while others will do the exact opposite with a live end dead end room.
I understand what you are saying. At the same time I would think wall construction would also come into this equation. Most houses in the US are still stick and plaster construction so to say but there are the outliers that could be brick or concrete that may not have the same lossy self absorption compared to the typical 2x4 and drywall construction. Room furnishings and carpet vs hardwood floors are again going to skew the reflective properties so we have to look at this on a room by room basis. If you are in a high rise type of building both the floor and ceiling can be basically concrete construction, again different than a suspended wooden floor and lath and plaster construction. So it really is hard to make hard and fast rules that everyone can follow. The basic premise though of scattering the back wall reflections would still hold, and some side wall absorption can come in handy to reduce small dimensional rooms with a very fast side wall first reflection. Some such as E. Geddes want a very dead front wall and scattered rear wall while others will do the exact opposite with a live end dead end room.
You said they don't sound real and you are sniffing for something better. If they don't sound real with a good recording than get something better or hire somebody to build you a speaker that sounds real with a good recording. If you don't think that's possible then .. 🙄 Good luck.
It's not possible.
But that shouldn't be the reason to stop listening to music at home and chasing the sound that reminds us of live event.
It is good you bring out the debate even though you seem to buy all your equipment, rather than DIY.You are now suffering with out of date gear
You find that live concert 2x a month leaves you unable to enjoy your home system. Not really a true comparison. Try a live satellite broadcast of a concert at a concert hall you exemplify on the Bosendorfers. You can do this with Iplayer from the BBC. If you can still see the speakers, then you do need a new system and save the concert money for an upgrade in your flat.
I cannot afford your 2 x live concerts a month. £100 tickets each plus dinner and wine, and about £250 on gas to get to London and home again
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