[Bghead8che]

I'll pose a question.  Is bamboo worth the added cost? 

I thought bamboo was a novelty that while great for the environment added very little in the sonic upgrade department.  I then stumbled across this thread:

http://forum.ascendacoustics.com/showthread.php?t=2597

According to Dave at Ascend a .75 inch bamboo cabinet is as inert as a 2 inch thick MDF cabinet! (WOW! )  The measurements show bamboo provides a better spectral decay measurement and helps with impulse and cabinet resonance.  I'd imagine that in an AB comparison the bamboo speaker would have the upper hand in clarity, especially in the mids and highs. 

My question for Jim and others is it worth $1200 to upgrade the SS8s (and other speakers) to bamboo.  Has Jim heard an audible improvement?  What is the thickness of the SS8 when using bamboo?  Does a more inert bamboo cabinet require any tweaks to the cabinet and/or crossover design and implementation? 

I'm serious mulling over the thought of ordering the SS8s.  I'm just wondering if $1200 investment would provide an audible improvement or would I just be saving the trees? 

Thanks for the feedback!

-Brian

[pstrisik]

Sounds like you might save overall on weight and dimensions.  Dimensions if Jim made interior dimensions the same.  With 3/4" bamboo, it seems you would save an inch plus twice the thickness of other veneer in width and depth.

Also, if you were considering custom veneer, I think it would only be the difference between the cost of veneer and the bamboo you would be adding.

.........Peter

[planet10]

According to Dave at Ascend a .75 inch bamboo cabinet is as inert as a 2 inch thick MDF cabinet! (WOW! )  The measurements show bamboo provides a better spectral decay measurement and helps with impulse and cabinet resonance.

There are 3 broad categories of Bamboo ply. Horizontal surface layers, vertical, and stranded. The stranded is quite a bit better than the vertical that Dave tested (thanx for that BTW). Stranded also has a much harder surface so resists dents & scratches better. It is heavy thou.

Solid/Vertical/Stranded from the Plyboo spec data

ASTM D 3043 Method D Flexural Strength (MOE/MOR)
    i.  ¾ inch thick, 1-ply, Edge Grain: 179 MOE/11,371 MOR average
   ii.  ¾ inch thick, 3-ply, Cross Core: 148 MOE/9,109 MOR average
  iii.  ¾ inch thick, 3-ply, Cross Core Strand: 268 MOE/14,762 MOR average

2" is no surprise, 18mm of good ply is as good as 1 1/4" of MDF, and without the energy storage issues.

The Bamboo is harder to work with, and care must be taken to ensure it does not warp before assembly (more so with the lower grades) but requires no veneer (so more care durinf assembly -- you can't fix them up with bondo). A bit of trickery with the joinery can use the edge grain to advantage, but that also increases labour. Example diy build showing edge grain:



A sheet of 18mm bamboo (vert or stranded) is 3-4 x as much as quality plywood, which is 2-4x as much as typical MDF. I wouldn't have a speaker  made of MDF, whether the extra for bamboo is worth it, only you can decide. If you can afford it, i wouldn't try to dissuade you.

dave

[planet10]

Just reading the Ascend piece... He calls bamboo hardwood, it is actually a grass. In theory the same tech could be used with hemp.

dave

[studiotech]

I have nothing scientific to contribute, but I can add that I built the prototype out of ply-mdf-ply and the final version with bamboo-mdf-bamboo is much more stiff.  Plus, as has been mentioned, no need for veneer or paint.  Just leave the raw bamboo showing.

Greg





 

[ricardojoa]

I dont think there is any doubt that those bamboo is much harder material then mdf. The question is, is it worth it, or is the money better spend in better drivers and other things. I think a properly brace cabinet with proper thickness of mdf should have no problem controling the resonance. Similar bamboo in contruction is going to have better control in that regard but is not going to be a free lunch, and wether that difference is going to be audiable, we certainly need a AB test.

[srb]

The question is, is it worth it, or is the money better spend in better drivers and other things.

If the question was asked about spending money on veneer versus spending money on better drivers and crossovers, the answer would unequivocally favor the drivers and crossovers.  However, with bamboo there is the possibility that it could contribute to slightly improved enclosure acoustics, and the fact that it is a greener, more sustainable material puts a tick in the plus column.

But the choice is a bit easier to make on the $300 bamboo option for the HT2-TL versus the $1200 option on the SoundScape 8.

Steve

[ricardojoa]

If the question was asked about spending money on veneer versus spending money on better drivers and crossovers, the answer would unequivocally favor the drivers and crossovers.  However, with bamboo there is the possibility that it could contribute to slightly improved enclosure acoustics, and the fact that it is a greener, more sustainable material puts a tick in the plus column.

But the choice is a bit easier to make on the $300 bamboo option for the HT2-TL versus the $1200 option on the SoundScape 8.

Stevek

Thats why i use drivers and things as comparison because driver will definetely have an impact on sound. I guess my comment doesnt aplly to the SS8, the already have world class drivers. The question is, how much improvement in controlon resonance have despite being much stiffer. For example if mdf can control 90% of the resonance and bamboo can control 95%, is that 5 % worth it? As far as beeing greener, sure but thats going to be another discussion.

[Nuance]

If it was me the money would be better spent being put towards a SoundScape C or subwoofer, but if you have the extra cash laying around then why not? 

Regarding the audibility of bamboo vs. MDF, this doesn't apply to those two exact materials, but I believe it is pertinent to the discussion: 

Years ago, Stanley Lipshitz and John Vanderkooy at the University of Waterloo did some experiments where they built and tested a number of loudspeaker cabinets of the same dimensions and volume that varied from being completely inert to being very flimsy with almost no bracing and thin cabinet panels. They then measured the effect of the different cabinet constructions on the measured acoustical response of the loudspeaker noting the change in frequency, level and Q of the resulting resonances. They found that the audibility of these resonances were in most cases below the absolute detection threshold of audibility for music signals using the threshold data from the resonance detection study Floyd Toole and Sean Olive conducted at the NRC.

In other words, Lipshitz and Vanderkooy concluded that you could get away with loudspeaker cabinets that were relatively light-weight and flimsy as long as you had adequate bracing judiciously placed etc to make the resonances fall below their detection threshold, which brings us back to bamboo vs. mdf.  If semi-flimsy cabinets, according to this study, don't effect sound quality provided the resonances are below the detection threshold of audibility, how could bamboo make a difference?  It is also worth noting the SS8 cabinets are not flimsy or lacking in bracing.  On the other side of the coin, though, technology has changed since Lipshitz and Vanderkooy's study, so one could argue their methods are now dated.


Regardless of the new or old data you find, this will still remain a highly debatable topic.  Due to that, go with your gut and choose whichever gives you a bigger warm and fuzzy.

[bunky]

http://http://www.stereotimes.com/speak021107.shtml Nomad Audio had the Ronin loudspeaker made from bamboo.

[audiotom]

Just buy the 2 inch thick soundscape 12s and be done with it

Sounds like a question to call Jim on