insider9

NXT panel speakers

Recommended Posts

Does anyone have any experience with speakers that use NXT panels? Any reason why these never made it into mainstream? Thanks in advance 

Share this post


Link to post
Share on other sites

Short Answer they didn't work very well

Long Answer see below

NXT were basically inventors of the technology, then a take over etcfollowed. I think the plan was not to make any products but to licence the technology. There were problems with the Bass and Large Panels with multiple transducers not being very good for stereo image.

Here is a PA application for ceiling tiles

https://www.canford.co.uk/ARMSTRONG-NXT-CEILING-TILE-LOUDSPEAKERS

There is a derivative of the NXT as a BMR radiator as uses in the top range Rega speaker

http://www.rega.co.uk/rs10.html

The Military also bought the technology for noise cancellation of Vehicle Body Panels which failed in helicopters using noise cancelling technology.

The Toyota car company presented a car with a head liner constructed of the same material, developed with the help of NXTsound technology, and it will probably be used by mobile phone companies to develop telephones with screens that act as speakers.

Apparently its also used on High Quality greeting cards

So unless someone knows different it never really took of in HiFi. I think the only way they got them to work as a full range panel was to use lots of transducers each with its own delay depending on where it is on the panel and the cost and complexity exceeds the cost of a normal cone driver.

Sony have a new TV which uses speakers mounted on the TV screen, but make it very clear its not NXT technology as I guess they dont want to pay a licence fee.

Regards

Alan

Edited by Radioham
  • Like 1
  • Upvote 1

Share this post


Link to post
Share on other sites

Thank you for detailed explanation, Alan. 

Shame particularly about imaging as I was expecting them to do rather well considering their similarity (at least visual) to electrostats.

Share this post


Link to post
Share on other sites
6 minutes ago, insider9 said:

Thank you for detailed explanation, Alan. 

Shame particularly about imaging as I was expecting them to do rather well considering their similarity (at least visual) to electrostats.

As you suspected, the similarity to electrostatics is only visual. An electrostatic 'speaker's diaphragm  moves as a whole back and forth, and so moves a large amount of air for a small displacement. an NXT 'speaker's panel vibrates resonantly, like ripples on a pond, but with many reflections, the opposite to an electostatic's panel. Ultimately low frequencies require the shifting of a lot of air, and stereo requires precise localisation of the sound source, neither of which NXT panels can do.  

I've got a small pair of PC 'speakers that use NXT panels, and for £30 'speakers, they do the job, but HiFi they aren't.

S

  • Like 1

Share this post


Link to post
Share on other sites

Of course electrostatics, and planar do arrange the "track" patterns into different sectors so the panel is not driven across the complete surface and the dispersion is modified, Also its not unusual to have separate bass and treble panels. I read a little more about the military project, apparently the NXT panels vibrated more than the standard sound deadening panels, so it was decided noise cancelling headsets were a more practical solution.

Alan

Edited by Radioham

Share this post


Link to post
Share on other sites

My recollection of the history is slightly different.  If I remember correctly the ideas came out of government defence research on helicopter cabin noise and were licensed to NXT for commercial exploitation.  I understand that a U.S. company (Tectonic) subsequently purchased the patents and now produce very expensive distributed mode loudspeakers that are amongst other applications used in large stadium sound systems.

i don't think the ideas are dead at all!

Have a look at their web site http://www.tectonicaudiolabs.com

Cheers. Bill

Share this post


Link to post
Share on other sites
Super Wammer
On 8/20/2017 at 15:21, insider9 said:

Does anyone have any experience with speakers that use NXT panels? Any reason why these never made it into mainstream? Thanks in advance 

To get volume and bass you need to move air .. a flat panel is woefully inefficient hence Martin Logan with electrostatics have most of their range with a separate conventional bass driver.  Moving a hard panel is inefficient and so speed and distortion becomes an issue .. so in hifi NXT went the way of the dodo.  If you want background music in a lift or outdoors then NXT has its place (and for the talking cards etc etc) but just not in hifi :) 

p.s. didn't Cyrus make speakers using the technology some years back (but do not now so that provides a hint as to its viability) ?  

Edited by uzzy

Share this post


Link to post
Share on other sites
1 minute ago, uzzy said:

didn't Cyrus make speakers using the technology some years back (but do not now so that provides a hint as to its viability) ?  

Yes, they did as well as Richard Alan. Not see any other. They were also hybrids and pop up once in a while on second hand market. 

  • Like 1

Share this post


Link to post
Share on other sites

Quite a few companies took NXT licences - I've recently got hold of a few speakers on ebay to evaluate as 5.1 surround speakers - a 100w pair from Carlsbro (NLightN) - originally sold along with a sub as an easily portable PA setup, and a single Fane Acoustics Minipro speaker with an attached 80w amp.

If you look them up you'll see some fairly positive reviews.  They are quite large and I'm not sure how acceptable they'll be up on the wall!

I haven't got around to testing them yet - probably won't be for a few months.

If you read Philip Newell's recording studio design book, you'll see that he recommended and used the Fane Minipro speaker mounted in a shallow box for the surround speakers in a 5.1 monitoring setup in a small cinema in, I think, Spain.  The big benefit in this arrangement is the very wide dispersion and the gradual drop off in SPL with distance due to the distributed nature of the source.

Cheers. Bill 

Share this post


Link to post
Share on other sites

Podium Sound Model One

This is quite similar to NXT-  yet has quite high sensitivity compared to electrostatics.

I love the sound of these- I think perhaps adding a supertweeter would make things "perfect" for me as I think they sound a little rolled off above 10Khz. The sound is just huge and enveloping, fantastic for classical music, and there's more bass (real bass, not low mids) than you might think (though quite dry and not at all bloomy).

Rushing out just now but read the Six Moons review, it's very interesting indeed.

Share this post


Link to post
Share on other sites
30 minutes ago, VanDerGraaf said:

Podium Sound Model One

This is quite similar to NXT-  yet has quite high sensitivity compared to electrostatics.

I love the sound of these- I think perhaps adding a supertweeter would make things "perfect" for me as I think they sound a little rolled off above 10Khz. The sound is just huge and enveloping, fantastic for classical music, and there's more bass (real bass, not low mids) than you might think (though quite dry and not at all bloomy).

Rushing out just now but read the Six Moons review, it's very interesting indeed.

Thanks will do! 

Share this post


Link to post
Share on other sites

I was working in defence industry in Uk in 90's.

Manufacturing kevlar spall liners for tanks .

I believe patent originally came via Racal group and I'm sure they would be trialled simultaneously in helicopter's etc ...anyway these kevlar lined tanks were fitted with NXT type transducers/exciters , cabin noise inverted and played through the spall liner  ...Kevlar speakers well before B&W came up with the gimmick of using kevlar for drivers .....but thats another story ....

Share this post


Link to post
Share on other sites

All I know is I met the designers at a show with a mock-up, - and looking back, I wish I'd bought those shares when they became available.  8p was it?  Reached something like £65 briefly.  Utter madness in the City, but just imagine...    I could then go out and buy an Audio Note £200k DAC!  

Share this post


Link to post
Share on other sites

I disagree with Alan. They do work well, just notes as Hi-fi speakers.

The Fane designs I believe were taken on by SLR who used to supply me, but they do not make those models any more.

The most refined I've seen are made by Amina, but they now predominantly concentrate on in wall solutions.

Price is the biggest factor that rules out most manufacturers and users. (Unless you settle for the really cheap and awful computer type speakers)

We use them in large complex spaces where directionality and reflection are our enemy.

I do have a number of portable NXT rigs which go out for conference hire and they hugely out-perform conventional speakers for clarity and are quick to set up almost anywhere.

Most setups will separate sub bass from the rest to achieve a good sound, NXT are no different.

My bigger panels will achieve 60-80 Hz but are best rolled off at 120-180 Hz @24dB/Oct. This gives a better sound and protects the exciters.

Great technology, good speakers, just not so good as directional stereo drivers.

NXT patents are starting to expire so hopefully prices might come down a bit.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.