Advanced Cabinet Materials Versus Wood

[treitz3]

Hmmm. There are a plethora of different materials that make up sound and the end result as to hits one's ears.

This thread may only touch on the material but lays no foundation to the internal bracing, design aspects, resonance factors, filling, etc...

Only the material used. Everything affects everything and it is everything that makes an effect on the end result as to what hits one's ears.

Tom

 

[andromedaaudio]

The lack of smearing over the freq range and decay of tones due to an inert cabinet use makes it instantly capable of better performance .
Most of these thin cabinets which resonate with the music don t even qualify as high end audio( in my view .)
There is also no way to achieve proper extension and bass definition on either a thin cabinet or open baffle


But in the end its good there is choice available on the market , if one doesnt like ( expensive ) phenolic resin based cabinets , ...easy dont buy them


Ps

If no travel issues ill be hearing the latest Vivid s on Halcro amplifiers coming saturday .
Vivid has a completely different built philosophy then mine , it ll be interesting to hear

 

[Robh3606]

I use a combination of MDF, pine bracing and a coat of vibration dampening compound to build my cabinets. I see no need to go for aluminum or phenolic resins. You can easily build good quality cabinets out of these basic materials. You just have to glue screw and brace. I add the dampening compound to both seal and help damp the panels between the braces.

I don't understand why you would think larger high efficiency speakers are less immune to box issues. Because of the larger box size it makes it harder to keep the box rigid. They may be more efficient and have less cone movement but that doesn't help box issues. What matters is the acoustic power that is radiated into the cabinet not the cone motion. The more radiated acoustic power the more likely you are to excite any resonances in the box.

Rob

 

[PeterA]

I use a combination of MDF, pine bracing and a coat of vibration dampening compound to build my cabinets. I see no need to go for aluminum or phenolic resins. You can easily build good quality cabinets out of these basic materials. You just have to glue screw and brace. I add the dampening compound to both seal and help damp the panels between the braces.

I don't understand why you would think larger high efficiency speakers are less immune to box issues. Because of the larger box size it makes it harder to keep the box rigid. They may be more efficient and have less cone movement but that doesn't help box issues. What matters is the acoustic power that is radiated into the cabinet not the cone motion. The more radiated acoustic power the more likely you are to excite any resonances in the box.

Rob

Rob, I think most of this has to do with taste and the sound one is trying to achieve. I’ve heard reports of people reinforcing old vintage speaker cabinets so that they are stiffer or building new cabinets out of birch plywood and lots of glue and screws and internal bracing and then putting the old drivers and crossover into the new cabinets. The sound definitely changes, and some would say the magic gets lost.

I know in my old Magico speakers, the cabinets were built to be incredibly stiff and damped. Part of the reason was the enormous pressure inside the sealed cabinet created by the small driver’s large excursion. These pressures would lead conventional mounting hardware for drivers to loosen overtime. Even the through bolts they use to overcome this need to be tightened periodically.

My open backed corner horns do not have much internal cabinet pressure. There are a lot of factors that designers take into consideration. I don’t think we should assume that simply making heroically stiff and damped cabinets will automatically lead to better sound. It will lead to a different sound which may or may not be preferred by the listener.

edit: I experienced something similar when I directly compared my vintage and modern 12 inch SME tonearms. The newer design has a magnesium arm tube tapered and very stiff and damped. I came to realize that the sound was also a bit damped and lost some of the nuance that the vintage arm has. Technology can march forward, and things need to change because the industry needs to sell new things or designs have to adapt because older parts are no longer available or become too expensive, but that does not always mean that the newer technologies lead to better sound. Sometimes they do and sometimes they don’t, and in the end the listener makes the decision.

 

[andromedaaudio]

I had a good 1 hour listen to the Vivid speakers last saturday( and 1 hour Grimm speakers )
And i must say i was impressed , he uses a very light cabinet of glass fiber composite and light balsa wood internally braced , with the 2 woofers working in opposite directions " cancelling out " cabinet resonances .
I also watched the vid that was posted here on site of laurence dickies talk last friday.

From all the light cabinet solutions i have heard over the years i think his is the most succesfull design .
Besides that the curved shape certainly helped to get a spacious sound .
I myself probably still prefer the Phenolic resin / HPL composite way of taking cabinet resonances for 100 % out of the equasion , especially on high volume , Bass freq .
But his sounded also very good in the bass to my ears

 

[Tim Link]

Good thread! I have been surprised in the past to find myself preferring the sound of speakers with more lively cabinets, or at least liking it a whole lot more than I expected I would. Audio Note comes to mind. Also I'm starting to suspect that early reflections off adjacent drivers, diffractions off cabinet edges, and other such very early reflections can sometimes have endearing effects. Technically I like the idea of a perfectly clean wave launch off the speaker with the purest possible impulse response reaching the listener's ears before the room echoes arrive. The reality of what I actually end up enjoying the most can definitely deviate from that. When we're working with 2 channels of audio playing in a room with all it's reflective surfaces it's hard to know for sure what the theoretical ideal should be. As has already been said, it comes down to taste to a large degree. "Performance" is a word I see used here in a way that refers to how well the speaker satisfies one's tastes. In that sense a speaker may perform well for one person and not for another. My co-worker recently demonstrated some DIY speakers that surprised me with some kind of magical effect, creating a sense of 3 dimensional sound generating areas that seemed to blossom up around the speakers. I didn't expect to hear anything like that since they had horn loaded tweeters with good directional control and generous round overs on the baffles, with everything mounted flush for minimal diffraction. After experimenting with them for a while he discovered that the side panels became quite resonant and sound emitting at certain frequencies, which perhaps explained this strange and strangely enjoyable sonic effect. Another recent surprise I had was experimenting with angling my horn tweeters more outboard. The idea was to illuminate same side wall reflections more and opposite side less to see what effect it had on imaging. I didn't notice anything amazing changing with the imaging, but there was a bit more air to the sound, which I suspected had to do with more illumination of the side walls. But I also noticed that the angled tweeter was probably spilling more sound into the bass horn mouth behind it, which I figured had to be a bad thing. So I put some pillows well behind the tweeter mouths in the bass cabinets, which totally killed the airiness I had added and made it sound relatively dry and boring. So it turned out the "airiness" was coming from allowing some high frequency sound to bounce into the bass horn opening, creating a bunch of very early reflections. I would have never guessed that would have any kind of positive perceptual effect. I think 2 channels coming in dry and clean in an anechoic space would not make many people happy. More channels might do it, but I don't think 2 is enough. With 2 channels, certain "special effects" are helpful to dither the otherwise serious lack of directional resolution. Cabinet liveliness can be one of those effects.

 

[jfrech]

Might as well discuss Rockport's DAMSTIF technology. Aside from the obvious jokes on the name regarding certain medications. It's a unique approach on cabinets. Video link below...

 

[Atmasphere]

If maximum vibration damping is an unambiguous goal why hasn't Magnepan developed a frame structure made of phenolic resin or Corian or something which is much more rigid than the wood frame structure? Does the wood frame structure contribute benefically to the sound of those panel speakers?* My guess is that the sound from a vibration-free Magnepan structure would appeal to some audiophiles ("greater resolution and transparency" and "blacker background") but not to others ("less natural resonance and energy" and "clinical-sounding").

As is so often the case, personal, subjective sonic preference drives component preference -- and, therefore, technology preference.

* It is much more expensive to fabricate cabinets with phenolic resin than with wood. The answer may be simply that Wendell does not believe there is a viable market for a more expensive version of current Magnepan speakers.

About 30 years ago I attended CES and George Cardas had a modified MG-3 in his room. The mod was the stands or frames; made of fitted laminated wood, heavy, rigid, dead and looked quite nice. They allowed the MG-3s to play bass really well, noticably deeper and better than stock... Part of the bass improvement could well have been that the frames acted as wings which reduced cancellation from front to rear. But they were quite dead; you can use wood for such things if you want.

My Classic Audio Loudspeakers T-3 cabinets are quite dead- they do not vibrate when playing bass. IIRC the cabinets are not only braced from side to side but are nearly 3" thick. They are about 350 pounds/cabinet if memory serves.

 

[stehno]

In another thread about the high-end audio industry Lee wrote:

Look at loudspeakers…Wilson cabinets just don’t vibrate due to phenolic materials that must be cut with a diamond bit on a CNC machine. We did not have any of that 50 years ago.

I find loudspeakers to be the most interesting component, and so I find this topic to be interesting. (I started a new thread because I did not want to pursue on the other thread a topic not directly related to the subject of that thread.)

For audiophiles who like the sound of vintage loudspeakers with wood cabinets the technological advancement of cabinets which do not vibrate will have little impact. Does the wood in a wood cabinet contribute beneficially to the "liveliness" of the sound of these speakers which some people like?

Perhaps, but I doubt it matters much.

Audiophiles who like speaker cabinets of phenolic resin materials like the "quietness" of such cabinets. Conversely, aficionados of vintage speakers made of wood might find cabinets made with advanced materials to sound "overdamped" or "lifeless."

Well, a set of speaker drivers mounted to a concrete box would certainly have a more "stable" sound than if mounted to a cardboard box. And of couse there's always the psychological comfort knowing that a speaker is made with a superior material.

If maximum vibration damping is an unambiguous goal...

Sometimes preconceived narratives will have us focus on the wrong areas or the lesser of two sonic evils.

... why hasn't Magnepan developed a frame structure made of phenolic resin or Corian or something which is much more rigid than the wood frame structure? Does the wood frame structure contribute benefically to the sound of those panel speakers?* My guess is that the sound from a vibration-free Magnepan structure would appeal to some audiophiles ("greater resolution and transparency" and "blacker background") but not to others ("less natural resonance and energy" and "clinical-sounding").

Case-in-point. Perhaps Magnepan understands that to one degree or another everything and especially a speaker cabinet vibrates, including a concrete box? Perhap Magnepan understands that a speaker's design that includes sufficient rigidity and structural integrity can be similarily beneficial sonically to denser but more costly and/or more exotic (appealing) materials?

As is so often the case, personal, subjective sonic preference drives component preference -- and, therefore, technology preference.

Perhaps many are more focused on vibrations' effects on speaker cabinet materials rather than vibrations' effects on internal wiring and cross-overs? IOW, to some degree many already realize that vibrations negatively impact our electronic components' internals but it seems few if any focus on vibrations' effects on electronic components within a speaker cabinet. Might that explain why some speaker designers wouldn't hesitate to insert more electronics into their speakers by designing an active speaker? And might that explain why many a consumer wouldn't hesitate to purchase an active speaker? Might such a focus also explain why we are forever measuring vibrations at a speaker's cabinet rather than say at a speaker's cross-over?

* It is much more expensive to fabricate cabinets with phenolic resin than with wood. The answer may be simply that Wendell does not believe there is a viable market for a more expensive version of current Magnepan speakers.

Or perhaps Wendell already realizes that vibrations at a speaker's cabinet don't really matter all that much? Just like vibrations at an electronic component's cabinet really don't matter so much. At least in comparison to the potential sonic havoc vibrations can wreak on the internal electronic components.?