No one interested in tangband's new midrange?

[454Casull]

What's so good about a titanium cone?

[DSP_Geek]

Originally posted by 454Casull
What's so good about a titanium cone?

In my experience, titanium sounds more controlled than aluminum. I recall when JBL first came out with the 2425 and 2445 compression drivers after the 2421 and 2441. The diaphragm shape was essentially identical, as was the phase plug. The only real variable was the material, and it was no contest: the titanium drivers had clearer high frequencies than the aluminum jobs, which by comparison were prone to sounding harsh in the top couple of octaves.

I'm not sure about translating that to cone drivers. I'd like to see higher resolution graphs made by a third party, especially since the impedance curve shows a couple of interesting kinks in the midrange. Nonetheless, I'm not surprised the first major indicated resonance is a bit above 13 kHz or so, since the distance from the voice coil to the cone edge is about 2/3 that of the Seas W15CY001, and that one's first resonance is about 9 kHz (modulo the speed of sound being the same in Mg and Ti).

I wouldn't use it much above 4 kHz because the peak would amplify any harmonics caused by distortion, and that could make the upper mids sound a bit zippy. Most metal cone drivers have that problem, which the Seas curves show it extraordinarly well:
http://seas.no/excel_line/excel/e0015.pdf

I'd bet the thing would probably be nicely detailed below there, though.


Francois.

[simon5]

I've read that aluminium is slightly ahead of titanium in the ultrasonic resonance department...

[blackreplica]

I do remember reading a post some time back which discussed cone material. and according to the characteristics of titanium, some of which were strength, weight, and speed of sound, and some other parameters which i cant remember:see below for post

In case anyone wonders why i am excited about this driver, its because it seems to me it has the makings of a fantastic driver for playing midrange at very low distortion. rigid cone, underhung motor, and the overall quality of a cast frame really appeals to me. Hence i thought i'd spread the word. Of course, nothing beats having the speaker measured for distortion performance(i did request tangband for distortion measurements but was not replied to ) and thats the only thing which prevents me from picking up a pair at this point in time.

Regards

[blackreplica]

Found the thread!

Here it is:

driver engineering, materials technology

Specifically, with due credit to LineSource for this post:

"Magnesium, due to its lightness, slow sound transportation, and natural dampening from low hardness, would seem the best metal for cones with modest physical stress. i.e. tweeters, midranges and low Xmax high efficiency woofers. A Mg bell would not ring very well.

Titanium is significantly heavier, denser, and stronger, than magnesium. This would make Titanium well suited to subwoofers.

Aluminum's physical properties are close to magnesium. Al is 1.6x heavier, but has lower tensile strength unless alloyed, and absorbs less vibrational energy. Aluminum is much cheaper than magnesium. Most Al alloys, like 6000 series, have higher tensile strength than Mg. Al cone break-up modes are slightly worst than MG due mainly to the higher mass/strength ratio.

Carbon fiber appears to be the best long term cone material for midrange and high efficiency woofers. The ideal carbon fiber cone would likely be a curve-linear profile woven from continuous fiber before thermoset in resin. When a Tiawan company invests in this technology, we could see a new plateau in cone technology. Today, most carbon fiber cones use coarse random fibers in resin, or a cut sheet glued into a linear profile.

Today, low cost Kevlar fibers are smoother and easier to weave than carbon fiber, and hence top labs like B&W have been able to bring up manufacturing lines for woven midrange cones. The weaving technology, cone profile, and resin strongly determine the break-up modes.

element ....Density.....Velocity...Young.. Rigity..Bulkmod..mineral... Brinell..Tensile Strength
Titanium ......4057...... 4140...... 116...... 44...... 110...... 6...... 716...... 345
Aluminum ......2700...... 5100...... 70....... 26....... 76.... 2.75..... 245...... 179
Magnesium .....1738 ......4602 ......45 .......17 .......45 .....2.5 .....260 ......275
Beryllium .....1848 .....13000 .....287 ......132 ......130 .....5.5 .....600 ......300

Carbon Fiber ..1780 .....3200 ......250 .......38 .......80..... 2.6 .....235 ......276



DensityKg m-3
Velocity sound m/s
Young’s modulus /GPa
Rigity modulus /GPa
Bulk modulus /GPa
Mineral hardness
Brinell hardness /MNm-2
Tensile Strength MPa"

[edjosh23]

I contacted Parts Express and asked them about the TB W3- 1231SH and told them that DiY audio was interested in these new speakers and wanted a good prices. The guy I talked to said they had ordered the TB W3 - 1335s and they will be there at the begining of June and they might order the W3 0 1231sh if all goes well with the W3 1335s. He understands that the xmax is not as high and the efficiency is not quite as good but they are a good introduction to the titanium speakers. The W3 1335s will be $34 or $32 each (can't remember which). He said he can make a special order, but if more people request the W3 1231SH he will order them.

Just thought I would ask them and inform you all of that.

blackreplica, thanks for the info, I really enjoyed the stats.

Thanks,

Josh

[blackreplica]

my pleasure josh. Since the speaker you mentioned above is retailing for about $35, i expect the 1231SH should retail for a little more. You can order direct from tangband and it will probably come out cheaper, but the shipping would be another story. I am in australia which is a little nearer to where the speakers are located(taiwan) so i might take the plunge and order the speakers direct from TB. I'm waiting on a shipping quote at the moment. if its reasonable i'll pick myself up a set of em.

[AnthonyPT]

Hi

Tang Band posted a even better basket
option (for a while)for arrays
giving you a 4.2k crossover point
or so, namely the w3-1231SB. Also the
W3-532sg has centre to centre of 81mm
or so. The 532sg QTS of 0.61
is much higher than the titaniums.
With 16 x W3-532s/panel
I am getting a good 109db at 2 meters in a
dipole array tapered configuration and
there is probably more available! Wonder
about the 1285SB too. Pity Tang Band does not
have a really suitable tweeter for arrays
if you want to use domes. There is a
TB25-381s but the PE Daytons look better!
The cast baskets for the new TBscould be in some
sort of nylon mentioned in the 1231SB spec
but the word nylon is missing from the 1231sh spec!
Perhaps the SH is a rethink as listed QTS has dropped
down to 0.30 as opposed to 0.38.


Regards

AnthonyPT