"Too often we enjoy the comfort of an opinion without the discomfort of thought" John F. Kennedy
Are carbon fiber speaker cabinets inherently better than wood or metal ones
There seems to be a pretty big jump in speaker prices when moving to carbon fiber cabinetry when all else is equal (or what seems like equal). Is this because it is able to be molded into more acoustically correct shapes or simple the characteristics of the material?
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Years ago I worked for Jon Dahlquist as a his rep in Chicago. He developed a series of loudspeakers called DQM that used Magnat drivers inside a revolutionary cabinet (to me anyway) using a double wall of variable density MDF with a layer of Nextel sprayed in between these two sheets. About as inert as I had experienced up until that point. Was the late 80s I think??? Well ahead of most, the idea of using the best drivers possible and an inert box. |
@lonemountain: Right you are! To see how NOT to build a speaker enclosure, look inside a Tekton (no offense owners of them. They have their strengths, but a non-resonant enclosure is not one of them). Another cost-effective way to damp enclosure wall resonances is a product designed by and made for Danny Richie of GR Research: NoRez. It has a damping layer (with self-stick adhesive for attaching to the wall) topped with a 1" thick layer of open cell foam.. For an even cheaper method, Danny recommends gluing heavy floor tiles onto the interior walls. That works especially well with open baffle loudspeakers, which don't need the foam layer. |
@bdp24 I'm with you. Adding mass/bracing to loudspeakers dramatically helps sound, especially when you're aware of the resonant frequencies you are trying to avoid. Carbon fiber is for looks, not speaker structure- especially when variable density MDF is available for cheap (and is 95% of the time the actual cabinet with a carbon fiber veneer). Ideas about rounded/elliptical cabinets or rooms- these are all mistakes to be avoided at all costs. |
@tweak1 - to me the only negative of the open baffle design are their looks. If they are for a dedicated listening room (or man cave/basement) where a physics lab type look is not a big deal they're fine, versus in a den (where my system is) where you don't want them to look out of place or as a curiosity . I had open baffle speakers for 25 years and liked them. Alons, but only the tweeter and midrange were open - but they were hidden behind a well designed grill so unless you walked up to them you wouldn't know they were open behind the drivers on top behind the front and side grill. After all that time I had an opportunity to get a closeout bargain on a pair of KEF R500s that are thin piano black rectangles which are a more dynamic and detailed with better bass response. Alons were more relaxed. KEFs are improved tremendously by multi layer platforms I put them on (Symposium acoustics Stealth Segues) that both isolate them from the suspended floor and drain distortion from inside the cabinets. Much better than the spike/disc combos that KEF supplies. I wonder if the new R5 Metas are worth the huge price increase (over 20% over the R5s which were a 10% bump above the R500s). KEF is now closing out the R5s which are a bargain. Big companies inventory miscalculations are a benefit to audiophiles, versus small ones who can manufacture very closely to demand. I am still curious to hear from anyone who thinks the unusual potential shapes of carbon fiber speakers' cabinets adds to their SQ with all else being equal, or is it just a matter of the overall design. |
@sounds_real_audio: Incorrect. The primary and most important reasons for and benefits of bracing is to: 1- Minimize the ability of the enclosure to expand (like a balloon being blown up)---thereby propagating sound---in reaction to the internal pressure created within the enclosure when the drivers move inward. That pressure is extreme, like a pot of boiling water with a tight lid on the stove with a high flame. Wall-to-wall braces prevent the enclosure from doing that. Again, look at how Jim Salk braces his subwoofer enclosures, and how Magico braces their loudspeaker enclosures. 2- Raise the resonant frequency of the enclosure panels to that above those excited greatest by the most problematic of the enclosure frequencies---the low ones (bass). |
What speaker's walls/baffle/floor base is carbon fiber solely. A .030-.050" veneer does not make a speaker carbon fiber nor does a Rosewood veneer make a speaker rosewood. Carbon at a thickness to resemble a wood cabinet would be very brittle in nature if using sheet form to construct. It will need to be thermoformed to make it very stiff and rigid. How many speakers are thermoformed with carbon entirely? Zero!
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It can be difficult to grasp the true benefits of carbon fiber as used to make speaker cabinets. Perhaps the stand out feature is that the low bass back waves off the larger drivers moves through the carbon fibers at a very high rate of speed and with the fibers correctly aligned will be directed away from the thinest part of the cabinet, the cone. The fibers vibrate ( resonate ) at an extremely high frequency. Not sure what good this does? Well if you have a nice wine glass give it a ping. Now simply touching the glass with your finger quickly dampens the sound. This demonstrates how composite cabinets work best. The composite material does not have to be any high tech product, rather simply a material with a difference resonance point. |
Carbon fiber in a wet layup application would be absolutely awful in this type of an application. Now if one had a cabinet design and a mold so that this process could be accomplished using an autoclave, or vacuum forming utilizing a prepreg carbon Kevlar weave in multiple layers, final finishing layer in straight carbon fiber with a 2 stage urethane finish, it would look awesome. Not sure about the sound though. To @sounds_real_audio point fiberglass would be 1/3 the manufacturing cost. Can be blow-molded or autoclaved. |
The Blades were initially intended to be made of carbon fiber but they switched to fiberglass, probably due to costs and degree of difficulty Carbon fiber resonates at an extremely high frequency which are very easy to control and isolate and direct away from the large and very thin drivers. You have to know what you are doing however. |
It’s a custom designed material used as an alternative to wood so probably inherently better suited for the task. Wood is wood. But either way can work well if done right. Done right usually cost somewhat more. Is that what KEF uses in their LS 50s, Blades, etc? I don’t think so but a big thumbs up whatever it is they use. I do not miss the wood there. |
Nobody has addressed the more important question I raised. Does the malleability of carbon fiber which enables it to be molded into round or rounded cabinets improve the sound of speakers? Of course room acoustics make a huge difference in achievable SQ, much of that due to the shape/dimensions of the room. I would bet a oval shaped room would sound best, or perhaps horseshoe shaped. Is the same true of speaker cabinets? Can it give more of an open baffle sound without the negatives of open baffles? |
Cabinets as a major contributor to sound can be a rabbit hole depending on the manufacrurers approach. ATC mids and tweeters do not even use the cabinet interior- cabinets are just a "baffle holder". Use of variable density MDF can make such cabients nearly inert- especially at low frequency where the woofer is working. (in ATC"s case, the LF crossover is at 380Hz) . |
Carbon fiber is a great material for many applications because it is both light and strong. That said, no material has been more overhyped in recent times, and used to make all kinds of junk, from cup holders to toilet seats. But do they use it to make acoustic guitars or violins or a bass viola? That would make me skeptical that it's a superior material for speaker enclosures. I'm sure it's a great sales gimmick that adds lots to the cost of a product that is likely to be priced extra high as a result. But better for speakers? Naw, it's just another material, and like others have said, you have to account for its strengths and weaknesses just as with any other material. I think it is way over-hyped but I'll tell you one thing that I just bought that really benefits from carbon fiber- a photography tripod-- where its strength and light weight really makes a difference. I don't find it all that attractive usually, so it would not be my first choice for a speaker enclosure unless it was painted or coated with something. |
Well I would say yes. Carbon fiber cabinets have a huge advantage over other materials...Sound/energy coming off the back of the drivers should be directed away from the thinnest part of the speaker which is the cone. Carbon fibers when done properly are alined to direct the energy away from the drivers. Energy travels thru them at an astonishingly high rate of speed, from memory it is about 18 thousand feet per second. Wood is about 500 feet per second. Carbon fiber resonants at a very high frequency, as we know high frequencies are easy to dampen...ping a fine wine glass and then simply put your finger on the rim to stop the vibration. Heavy cabinets vibrate a lower frequencies and thus are much more difficult to dampen as well as taking more time to dampen, thus the hangover or lag, Wilson Benesch has done so much research and development. Check out their site for more info. |
"Are carbon fiber speaker cabinets inherently better than wood or metal ones" The answer is no. All materials have specific characteristics and need to be used correctly and in the right application. No material is inherently superior across the board, including aluminum or wood. Actually Rockport used cast aluminum enclosure sections which is very different than machined cabinets. Magico used extruded and machined section. Their designs have more to do with the implementation than the materials. We just concluded a year long evaluation of different materials, including cast aluminum and carbon fiber, for our Gen 2 Apollo speakers. For our speakers design we found that a fiber reinforced molded custom engineered polymer had the best characteristics. Cost is between aluminum and composite, aluminum being the cheapest. |
The machined aluminum cabinets by Magico and Rockport (for example) are both complex and very vexpensive to make. No one applies more engineering to their speakers than those two companies, imo (there are others on par I assume). |
All things resonate carbon fiber does so and it sounds plastic-like. Wood resonates and if done right can be low in level and even in frequency this sound good and doesn't detract. Alunimun is a cheap material marketed as a luxury item in audio because audiophiles don't remember that it's used in beer cans. |
Carbon Fiber is an expensive material and very time-consuming to do properly. And very difficult to do at scale. If you want to see what's involved in making CF parts, I recommend spending some time on the Easy Composites YouTube channel |
I’m guess here. The speaker designer is making compromises throughout the design process and view the various designs as a system. I imagine Sonus faber believes using natural materials for the cabinet is a critical aspect of their design. An I think Focal, Wilson and others would make the same comment. Not sure what Magnapan’s perspective would be though! Ultimately it there’s excellent options and beauty is in the ear of the beholder
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