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I did a tour of the YG facility and their process was super impressive, and the speakers did sound great. They CNC all their own parts/drivers/cabinets out of 2" thick aircraft grade aluminum. No parallel surfaces, double walled cabinet construction. Apparently it takes 120 hours of CNC milling for them to make a single pair of Sonjas. |
From the AudioMachina website, “AudioMachina XTAC Master Reference System is designed and manufactured to the very highest and most uncompromising standards in every way, from the smallest parts to the meticulously perfected layout to the manufacturing process to the final finished product. All enclosures are precision CNC machined, in our own manufacturing facility, from 100% aerospace-quality solid Aluminum Block. The XTAC Amplifiers are each made up of solid precision machined blocks, and the XTAC Speaker Modules represent, to our knowledge, the most advanced cabinet design ever achieved in the history of the world: Each XTAC Speaker Module is precision CNC machined, inside and out, from only one solid block of solid Aluminum. Yes, you read that correctly: The XTAC Speaker Module cabinets are one single piece of solid machined metal, with no joints, no separate pieces, no hardware to bolt those pieces together, or anything else that would reduce the insane stiffness, strength, and inertness achieved by making them out of a single solid block of metal. This is but one example, out of dozens upon dozens of examples, all leading to the same conclusion: The AudioMachina XTAC Master Reference System is so far beyond any other loudspeaker ever made, in so many ways, that there is simply no comparison.” |
As Erik_Squires noted, Celestine SL600 and SL700 had cabinets made from Aerolam. Two sheets of aluminum with aluminum honeycomb in between. Adapted from aerospace industry. Inert and light in weight and thin allowing a relatively large internal volume. But very expensive and, therefore, used only in small speakers. |
kenjit, it is easy to build passive cross overs. First class parts are ready available and the math is not that complicated but unless you stay first order phase coherence and efficiency matching drivers with various impedance curves without adequate test equipment is virtually impossible. The easy way around this is to use active cross overs and bi or tri amp. My favorite way of making a very high quality system for friends with a limited budget is to make a D’Appolito array using two 6” drivers up an down from a dome tweeter on a plate sandwich of MDF and solid surface material. I’ll use a simple 6dB/oct cross over and tweak it measuring the frequency response until I get it reasonably flat. Then I’ll cross over to subwoofers at around 125 Hz. You can mount the plates on stand but my favorite stunt is to hang them on chains. |
Mike Lenehan of Lenehan Audio in Australia, uses differential bracing including 6mm and 4mm sprung steel plates inside his ultra high end loudspeakers. Connected electrically to the ground terminal, as a ground plane. (I suspect also acts much like a Faraday Cage as well.) He also uses depending on the outright high end models, cast iron rod as well as silicone filled rigid copper tube bracing (due to it's high Young's modulus). Which is why he uses very pure copper screws to secure the drivers in his all of his two way speakers. To help alleviated ringing of the spiders on the drivers against the baffle. I have even heard a pair of his standmount speakers with an external crossover, and the cabinets were lined with 4mm solid copper plate. Curious recording studios in LA and NYC learning of his achievements have enquired and purchased his nearfield monitors to satisfy their curiosity after being informed; immediately ordering a second pair for another studio room after verifying the reviews. In a sea of well advertised audio equipment, his speakers are a well hid pot of audiophile gold. I worked for Mike and still own two pairs of his speakers, after giving my brother an older model, and selling my first pair to help pay for them. I have built them myself, and I would welcome anyone who may be interested why they out perform speakers costing more than 10 times their cost. Real science, why it's superior and not salesman hyperbpole. The benefits of metals in an enclosure are real, so long as you can also account for the limitations. Even metals have a resonant frequency, attenuating the ringing of metal is also why it benefits being laminated to another material. |
It has been out of production for ages, but don't forget the Celestion SL600 in Aerolam. http://www.hifi-classic.net/review/celestion-sl600-505.html |
Wilson's solution of using composites to make individual small enclosures is a good one. MDF is just as good you just have to increase wall thickness and keep the enclosures small with rounded edges and flush mount drivers. Right. The problem with metals is they may look and seem strong to us while on a microscopic level they are actually vibrating and ringing like crazy. So they work great on one level because they are strong on that level. Being a lot harder than MDF they dampen macro-dynamics a lot less than MDF. Yet when it gets down to the microscopic level, well that is where the real action is because that is where you either get or do not get that spooky real degree of refined inner detail. This is why the future of speaker design is like everything else composites. With composites the vibration control happens at the microscopic level. No longer a continuous medium like all the alloys composites are a, uh, composite of different materials. As such they get both their strength and ability to transfer mechanical energy into heat at the molecular level. Combined with multiple small cabinets custom shaped to optimize each driver, its hard to beat. Except that like jon_5912 pointed out, it has to justify the cost. Designing with composites is extremely expensive, especially in the beginning when almost everything goes in the dumpster because you don't really know what you're doing. The first Porsche Carrera GT was supposed to be impossible to make profitably from carbon fiber. Then it was supposed to be possible but only in a $750k car. Then it came out for less than a third of that. Its still not common construction but the technology is filtering down, and the same is bound to happen in audio. |
jon is right. Look what Magico has to do to quiet things down. These guys must love to do CNC machining. That would be the only reason to make speakers that way, YG also. Great speakers if you can afford them. Wilson's solution of using composites to make individual small enclosures is a good one. MDF is just as good you just have to increase wall thickness and keep the enclosures small with rounded edges and flush mount drivers. Finding great drivers is easy the problems come in designing the crossover. |
I'd guess it doesn't provide enough performance improvement to justify the cost. There are probably other areas where the money spent on metal cabinets can provide more performance. The companies that moved away from it are capable of doing a lot of different things, have tried various materials, manufacturing techniques. I'd guess it's more of a sales feature in cases where companies are making entire big square boxes out of aluminum. Something to talk about that differentiates them from other brands. |
Genelec still does aluminium speakers. ATC did aluminium speakers for many years. Aluminium works well but I believe it is more expensive than mdf and 3 to 4 times heavier. Impractical for anything bigger than a two way monitor due to weight. Advantageous material for cooling of heat sinks, good damping, naturally corrosion resistant and non magnetic. My six channel amp is extruded and billet aluminium and is extremely heavy (about 50 Kg) but would be even heavier if cased in thick steel! |
I think a lot of companies have dabbled in metal cabinets but most don't stick with it. Infinity did it with the intermezzo line and the Prelude MTS. Thiel had a number of models - powerpoint 1.2, viewpoint. ATC had a metal line for a while. B&W had some metal boxes. My Thiel 3.7s have aluminum baffles and an aluminum top. |
