The Titanium Dome

garylkoh

WBF Technical Expert (Speakers & Audio Equipment)
Sep 6, 2010
5,599
225
1,190
Seattle, WA
www.genesisloudspeakers.com
When Genesis Technologies was founded in 1991, one of the objectives was to bring the high-end down to a more affordable level. Thus, the company founded by the designer of the IRS V started with smaller speakers, and only the tweeter was a ribbon design. The midrange was a 4-inch dome made of solid titanium - this actually turned out to be much more expensive than expected. It also beamed at midrange frequencies.

It was explained to me by a physicist why a dome (and also a convex panel) would beam. It sounds totally counter-intuitive because you would expect a light-bulb that is a dome to spread out the light more. I don't remember all the math, but he showed me that a dome would beam at any frequency that had a wavelength longer than twice the diameter of the dome whereas as a guideline a cone would beam at a frequency that had a wavelength longer than the diameter of the cone. This means that a dome midrange of any given size could only be used up to a frequency that was about half that of the equivalent cone midrange or inverted dome.

Nevertheless, the dome did sound good. It was used on quite a number of loudspeakers from 1991 to 1993. They were the Imaging Module series: IM8200, IM8200F, IM8300 and IM8300F. These were the "black dustbin" series utilizing round cabinets and a slightly sloping front. It was also used in the "high-end" line. Two of them were used in each Genesis III ($6,000 per pair when they were launched in 1993). I never got a real good answer why two midranges were used in the G-III. Later, in 1995, the dome midrange was also featured in the Genesis V.

The problem with this driver was that sticking out like that, they were prone to damage ('My wife was vacuuming near the speakers and she jabbed it with her elbow."; "The pesky nephew came running and smacked nose first into my speaker.") and a large number got dented over the years. We manufactured a big batch of this driver 10 years ago when we re-started production, so that we could support owners of these early speakers.

The tooling was lost when the supplier closed down 5 years ago. Given that it's now nearly 20 years since the speakers using this midrange was last built, and the slowing number of requests in the first 5 years for this driver, we expect that our supply should continue to last us for the next 5 years at least. Then, unfortunately it will be no more.

4-in Titanium Dome sm.jpg
 

RICARDO TORRE

New Member
Oct 19, 2018
2
0
1
63
The question is wether, if upgrading to the newer 5.5" means any change in the crossover or if you can just change it for the bigger one will definetly sound better?
 

garylkoh

WBF Technical Expert (Speakers & Audio Equipment)
Sep 6, 2010
5,599
225
1,190
Seattle, WA
www.genesisloudspeakers.com
Hi Ricardo, I would not recommend changing from the Ti-dome to the newer 5.5-inch Ti cone midrange. They are different drivers and require different crossovers even if you could modify the cabinet to accept the new drivers.
 

Valentijn

New Member
Feb 6, 2020
3
2
1
72
When Genesis Technologies was founded in 1991, one of the objectives was to bring the high-end down to a more affordable level. Thus, the company founded by the designer of the IRS V started with smaller speakers, and only the tweeter was a ribbon design. The midrange was a 4-inch dome made of solid titanium - this actually turned out to be much more expensive than expected. It also beamed at midrange frequencies.

It was explained to me by a physicist why a dome (and also a convex panel) would beam. It sounds totally counter-intuitive because you would expect a light-bulb that is a dome to spread out the light more. I don't remember all the math, but he showed me that a dome would beam at any frequency that had a wavelength longer than twice the diameter of the dome whereas as a guideline a cone would beam at a frequency that had a wavelength longer than the diameter of the cone. This means that a dome midrange of any given size could only be used up to a frequency that was about half that of the equivalent cone midrange or inverted dome.

Nevertheless, the dome did sound good. It was used on quite a number of loudspeakers from 1991 to 1993. They were the Imaging Module series: IM8200, IM8200F, IM8300 and IM8300F. These were the "black dustbin" series utilizing round cabinets and a slightly sloping front. It was also used in the "high-end" line. Two of them were used in each Genesis III ($6,000 per pair when they were launched in 1993). I never got a real good answer why two midranges were used in the G-III. Later, in 1995, the dome midrange was also featured in the Genesis V.

The problem with this driver was that sticking out like that, they were prone to damage ('My wife was vacuuming near the speakers and she jabbed it with her elbow."; "The pesky nephew came running and smacked nose first into my speaker.") and a large number got dented over the years. We manufactured a big batch of this driver 10 years ago when we re-started production, so that we could support owners of these early speakers.

The tooling was lost when the supplier closed down 5 years ago. Given that it's now nearly 20 years since the speakers using this midrange was last built, and the slowing number of requests in the first 5 years for this driver, we expect that our supply should continue to last us for the next 5 years at least. Then, unfortunately it will be no more.

View attachment 4155
Dear Gary,

Would you please tell me if there are any Ti-domes left, because unfortunately the "pesky nephew" from your post came by and in an unattended moment damaged both my domes! I would very much like to replace them, so I hope you can help me. Thank you in advance!
 

carolkoh

[Industry Expert] Member Sponsor
Sep 17, 2010
907
226
955
Seattle, WA
www.genesisloudspeakers.com
Dear Gary,

Would you please tell me if there are any Ti-domes left, because unfortunately the "pesky nephew" from your post came by and in an unattended moment damaged both my domes! I would very much like to replace them, so I hope you can help me. Thank you in advance!

Hi Valentijn,

Sorry to hear about the "pesky nephew" but yes, we do have some Ti-domes left. Drop me an email info @ genesisloudspeakers.com and we will get you replacement & shipping cost.
 

Valentijn

New Member
Feb 6, 2020
3
2
1
72
:D:D Yes, that may be right but still: the nephew's nose has healed (even growing!), and that can't be said of my domes ....:(
I sent an e-mail to "the sister", but got no reply. It arrived I assume?
 

Valentijn

New Member
Feb 6, 2020
3
2
1
72
I can end my part of this thread with very good news: the Titanium-domes appeared still available and after replacing the damaged ones ("pesky nephew" as we know) my V's are playing again! Happy as ever after this unexpected service for my old beloved Genesis V loudspeakers! Thank you very much dear Carolyn and dear Gary!
 

rwvision

New Member
Feb 17, 2021
4
1
3
46
Hello,

A happy user of Genesis III here. Are the Ti-domes still available if needed? Would shipping to Poland be available?
(dropping you also an email).

Seeking for a backup for future years. If not, are there ANY replacements of these domes?

I also would like to ask another question - do you think that the Titanium Domes could deteriorate after so many years?

Cheers
Rafal
 
Last edited:
  • Like
Reactions: garylkoh

garylkoh

WBF Technical Expert (Speakers & Audio Equipment)
Sep 6, 2010
5,599
225
1,190
Seattle, WA
www.genesisloudspeakers.com
Hello,

A happy user of Genesis III here. Are the Ti-domes still available if needed? Would shipping to Poland be available?
(dropping you also an email).

Seeking for a backup for future years. If not, are there ANY replacements of these domes?

I also would like to ask another question - do you think that the Titanium Domes could deteriorate after so many years?

Cheers
Rafal

Yes - we remanufactured a batch of these when I realized that elbows and domes have an affinity. "Help!! The wife was vacuuming and her elbow crushed my dome midrange!!" However, we did that many years ago, and these speakers are approaching 30 years old and we have less and less requests, so getting a pair for backup would be a good idea. When we run out, we run out. I cannot keep an inventory of another 1,000 midranges for the next 10 years when we run out of this batch.

All drivers will deteriorate. However, with tweeters especially and midranges too, there is a long, slow break-in and then a very long plateau. How long this plateau is depends on how hard this particular driver is driven. It could be 20 to 30 years before a long, slow decline.
 

rwvision

New Member
Feb 17, 2021
4
1
3
46
Thanks Gary for such a quick reply!

If my emails reached you, please let me know of the costs. Will surely plan to order some soon.

How does exactly look the dome touched by elbow ? :) Did not really seen any broken ones on picture.
Does any slight dome touch or dent destroy them completely?

Wondering if fine looking Ti-Domes could be really broken in some way.
 

rwvision

New Member
Feb 17, 2021
4
1
3
46
Thanks again Gary - really appreciate the info.

Does this state mean they are no good? What causes those wrinkles? - it's hard to see them in perfect state these days.
 

LL21

Well-Known Member
Dec 26, 2010
14,411
2,509
1,448
I can end my part of this thread with very good news: the Titanium-domes appeared still available and after replacing the damaged ones ("pesky nephew" as we know) my V's are playing again! Happy as ever after this unexpected service for my old beloved Genesis V loudspeakers! Thank you very much dear Carolyn and dear Gary!
Now that's great service! Enjoy for many many years to come! Then upgrade to the Genesis Dragons! ;)
 

Sky

New Member
Feb 17, 2021
5
0
1
57
Dear GaryIkoh,

Can I still buy the Titanium Dome?

Thank you very much
Yong Han

 

Sky

New Member
Feb 17, 2021
5
0
1
57
Dear Gary,

Should I change the genesis V tweeter to dome tweeter or not?

Thank you very much

Yong Han
 

About us

  • What’s Best Forum is THE forum for high end audio, product reviews, advice and sharing experiences on the best of everything else. This is THE place where audiophiles and audio companies discuss vintage, contemporary and new audio products, music servers, music streamers, computer audio, digital-to-analog converters, turntables, phono stages, cartridges, reel-to-reel tape machines, speakers, headphones and tube and solid-state amplification. Founded in 2010 What’s Best Forum invites intelligent and courteous people of all interests and backgrounds to describe and discuss the best of everything. From beginners to life-long hobbyists to industry professionals, we enjoy learning about new things and meeting new people, and participating in spirited debates.

Quick Navigation

User Menu

Steve Williams
Site Founder | Site Owner | Administrator
Ron Resnick
Site Co-Owner | Administrator
Julian (The Fixer)
Website Build | Marketing Managersing