A couple of cabinet questions for you all

[nortonrider]

So...... I started thinking about bass cabinets and I came up with a couple of questions that I don't know the answers to,
I'm betting that you guys do.

1st.)
With all things equal, would a cab with 10 8's be as loud as one loaded with 8 10's?
They have the same amount of surface area and so they would push the same amount of air - Right?

2nd.)
Has anyone made a cabinet out of carbon fiber?
If not, why?

[Mr. Foxen]

I don't think you understand how area works, 10 8" diameter things, won't have same area as 8 10" diameter things.

People have made resin/fiber shell over foam cabs, there are too labour intensive for most purposes.

[dhomer]

Those who know the engineering end of it better than i do will probably chime in, but there's too many variables to give a definitive answer on your first question. There's impedances to deal with, a host of driver parameter issues.. and so on.. Probably the best advice i could give is look at the Vd specs on the drivers. No replacement for displacement..

Carbon fiber? Prohibitively expensive for one thing, probably why folks haven't experimented much with it..

[skychief]

Ten 8" speakers would have a combined conal area of 500 sq inches

Eight 10" speakers would have a combined conal area of 628 sq inches.

I dont know if anyone has ever made a cab out of carbon fiber, but i would think that carbon fiber would lack mass & density to make for a proper speaker enclosure. But its just a random guess. Have no data to back that up!!!

[Slowgypsy]

Originally Posted by nortonrider

So...... I started thinking about bass cabinets and I came up with a couple of questions that I don't know the answers to,
I'm betting that you guys do.

1st.)
With all things equal, would a cab with 10 8's be as loud as one loaded with 8 10's?
They have the same amount of surface area and so they would push the same amount of air - Right?

2nd.)
Has anyone made a cabinet out of carbon fiber?
If not, why?

1st.) 10x8"=approx 502.65" 8x10"=approx 628.32"

2nd.) Cabinets are made from wood materials because (1) it works really well (2) it's a relatively inexpensive material to use (3) it's an easy material to incorporate in a manufacturing process. What do you think the benefits of using carbon fiber would be?

[GrowlerBox]

These questions always start out with "all else being equal ..." or some such, but unfortunately, it never can be. The combined "flat face" area of the 8 x 10" drivers is about 628 sq. in, and that of the 10 x 8" drivers is about 502 sq. in, but that tells you little of value concerning their overall loudness, for which you need to account for all the variable mentioned by dhomer.

As for carbon fibre -- how much do you really want to spend on a bass cabinet?

Edit: slow gypsy ahead of me on the numbers!

[nortonrider]

OK, I just broke down and did the math,

the speaker surface area of a 8 10 cab is: 785.30 sq. inches
the speaker surface area of a 10 8 cab is: 502.70 sq. inches

a difference of: 282.60 sq. inches
Approx. 28% less

That answers that question!
__________________________________________________ _________________
Carbon fiber Cab?
I don't believe that cost is a factor,
if it worked and was somehow better, people would pay the price.

[GrowlerBox]

Well, not quite.

Even if the math were correct, it still wouldn't answer the question, for the reasons already mentioned.

[nortonrider]

Originally Posted by GrowlerBox

Well, not quite.

Even if the math were correct, it still wouldn't answer the question, for the reasons already mentioned.

Well,
I did the math, did the math again and then checked it with google.

what did I do wrong?

[GrowlerBox]

Originally Posted by nortonrider

Well,
I did the math, did the math again and then checked it with google.

what did I do wrong?

I suspect you multiplied your 10" driver area by 10 rather than 8.

[alexclaber]

Barefaced Bass - Volume displacement - it's (almost) all about moving air

[GrowlerBox]

Originally Posted by alexclaber

Barefaced Bass - Volume displacement - it's (almost) all about moving air

Excellent collection of resources you have there, Alex! Thanks for posting.

[nortonrider]

Originally Posted by GrowlerBox

I suspect you multiplied your 10" driver area by 10 rather than 8.

you're right - I did, my bad!
I don't think I ever got an A in math class, It shows huh?

Well, my question about the 810 - 108 thing has been answered sufficiently.
They are NOT the same and therefore will not produce the same results.

Now...... the carbon fiber cab ?????

[GrowlerBox]

Originally Posted by nortonrider

Now...... the carbon fiber cab ?????

OK -- what do you want it to do that's not already being done?

There's a bit of composite material cab building going on, but that's already significantly more expensive than wood. The gains in lightness are worth it to some, but I'm not sure there's a huge difference with respect to improved acoustic specifications that wouldn't simply reflect poor construction in the wood cab (insufficient or poorly-placed bracing, for example). And, if a reflex-type cabinet's too light, it might just topple over from the weight of the driver in the front!

[alexclaber]

Carbon fibre would work really well but I can't see many bassists being happy with the huge increase in price. Wilson Benesch have used carbon fibre enclosures in many of their hi-fi speakers but they're not cheap and they don't use half as much material as a high output pro audio loudspeaker enclosure would require.

[1n3]

Originally Posted by nortonrider

Now...... the carbon fiber cab ?????

Have you seen this thread?
DIY Lightweight Composite Cab Build II - ZL1263, 3-way