Dome tweeter research

[Audiophilenoob]

we're trying to work on making a 1" dome and we want to know what's more important for you guys:

we have two 1" dome options right now... using diamond cones and our new technology for the voice coils that we're patenting (Dylan and I) that offers ultra light weight and extreme power handling:

here's what we have for specs as most ideal... F3 is 1khz so a bit better low end than the seas millenium and a much much better top end:

Fs = 550 Hz
Qms = 6.01
Vas = 0.136 liters
Cms = 1.5 mm/N
Mms = 0.0558 g
Rms = 0.0321 kg/s
Xmax = 3 mm
Xmech = 4.5 mm
P-Dia = 31.92 mm
Sd = 8 sq.cm
P-Vd = 0.0024 liters
Qes = 0.455
Re = 6.8 ohms
Z = 8 ohms
BL = 1.7 Tm
Qts = 0.423
1-W SPL = 99.01 dB

yea that 99db/w is true for real life...

we're going to try for solid silver voice coils but can't promise getting it to that weight this way... however it doesn't matter much in this respect

what should be changed before we go to production on this?

BTW price will be right around $400-600 each or so... if we use silicon carbide and not diamond for the cone... (neither one matters much just that the SiC is lighter and melts a TAD sooner, which doesn't matter... no real difference in hardness... our SiC cones are 13,000 vickers and around 30 microns thick)

oh and that Xmax is for real... and power handling is around 1000w RMS on this speaker... depending on the tech used and such

cheers

[ShinOBIWAN]

I thought you'd had reservations about the diamond tweets? I think you said the B&W and Accuton variations weren't very good. Actually you said dome's sucked full stop

Be interesting to see if this actually does what it says on the tin. Those are awefully ambitious T/S and not just better than the rest in one area but virtually every area. The theoretical goals make me wonder if this will actually be possible and sound better than anything else at the same time.

BTW that tweeter has as much xmax as an ATC mid (if its one way).

[Audiophilenoob]

Originally posted by ShinOBIWAN
I thought you'd had reservations about the diamond tweets? I think you said the B&W and Accuton variations weren't very good. Actually you said dome's sucked full stop

Be interesting to see if this actually does what it says on the tin. Those are awefully ambitious T/S and not just better than the rest in one area but virtually every area. The theoretical goals make me wonder if this will actually be possible and sound better than anything else at the same time.

BTW that tweeter has as much xmax as an ATC mid (if its one way).

that's one way

the reservations on the diamonds is that they are muted sounding due to inefficency... it's quite clear that's why I didn't like even the thiel

however I like hard domed tweets... and efficency only makes it better IMO

Domes do suck as they stand now because the diamond tweeters are the most inefficent tweeters made that I know of for their size... I'll take a ribbon tweeter anyday... however there's something to be said for dome dispersion

everything is possible with the specs actually... that suspension could be employed into the surround it's so loose... the Mms seems ultra low... be based upon the cone,former, and coil weighing in at 0.04 g in this situation... it's not a big deal

most tweeters are about 0.35g for Mms... so yea... 7x lower is ambicious... but possible using this tech...

the cone weighs what house hold alum foil does if you cut it to this area... and beyond that the coil is the largest weight contributer

how about you tell me if you like it and I'll worry about making it happen ??

I wouldn't have asked if we can't do it /hehehehehehehe

[roland bios]

And a very very very lightweight cone & voicecoil!

Mms = 0.0558 g

Interesting would be an understatement.

[ShinOBIWAN]

Also:

Are you sure those specs are viable?

I'm using cross corelation and some values are considered impossible in regards to others.

[Audiophilenoob]

Originally posted by roland bios
And a very very very lightweight cone & voicecoil!

Mms = 0.0558 g

Interesting would be an understatement.

we can do it... for this size

we have a 6.5" speaker with 10kw-20kw Rms getting worked out now with a Mms around 2.5g

CHEERS to the esoteric builder

[ShinOBIWAN]

Originally posted by roland bios
And a very very very lightweight cone & voicecoil!

Mms = 0.0558 g

Interesting would be an understatement.

The 0.75" Thiel D²20-6 has 0.09g so that seems doable in light of a 30 micron thickness.

[Audiophilenoob]

Originally posted by ShinOBIWAN
Also:

Are you sure those specs are viable?

Im using cross corelation and some values are considered impossible in regards to others.

what do you mean exactly they all work out for me... if weight can be kept down

[Audiophilenoob]

Originally posted by ShinOBIWAN


The 0.75" Thiel D²20-6 has 0.09g so that seems doable in light of a 30 micron thickness.

it is very doable... considering our coil only needs to be around 1/2 that size and is around 20x the power handling of that coil

hence why we're patenting it

we realistically can do a bit more than 20x... just depends on price vs. added performance

1kw seems more than enough though

[ShinOBIWAN]

Originally posted by Audiophilenoob


it is very doable... considering our coil only needs to be around 1/2 that size and is around 20x the power handling of that coil

hence why we're patenting it

Obviously underhung but what magnetic material? Neo I assume?

The BL isn't that high at 1.7 Tm, well that's in light of others using 3 Tm and more usually.

I hope you've given a lot of thought to damping the rear wave, whilst diamond and variants have a great weight to stiffness ratio at the thickness your using you'll have to be very vigilant about rear wave interferance. Probably best to use a rear chamber with a lattice type construction.

Also don't go with any ferrofluid in the gap. If you want proof of the benefits this brings check out the Seas T25C003 vs. T25CF001 - one has ferrofluid and the other is identical without ferrofluid, I don't need to say which sounds better although the difference is small and many related to micro detail.