Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Planars & Exotics ESL's, planars, and alternative technologies

Sound Quality Tests on "Exciter" type speakers.
Sound Quality Tests on "Exciter" type speakers.
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 18th August 2016, 04:02 PM   #1
ElevetyCo is offline ElevetyCo  Canada
diyAudio Member
 
Join Date: Aug 2016
Default Sound Quality Tests on "Exciter" type speakers.

I am looking to test the sound quality of a number of "exciter" type speakers which transmits vibration energy through a substrate. We want to test the audio quality and frequency range of different setups and iterations of the speakers (different substrates, using intermediary materials between the exciter and substrate, etc) to identify "optimal" sound. What is the best/ simplest way to go about doing that?

We have already purchased a Behringer ECM8000 calibrated microphone, and the Project Series USB dual preamp with phantom power. We also have a copy of ARTA measuring software. In addition, we have built a makeshift anechoic chamber out of foam and a box (don’t laugh).

With all that said, and with all of the equipment we have, what would be the best steps and/or software to use in order to get usable sound quality measurements as well as measure output effect of various setup changes?
  Reply With Quote
Old 18th August 2016, 08:52 PM   #2
bentoronto is offline bentoronto  Canada
diyAudio Member
 
Join Date: Jan 2008
Location: Toronto and Delray Beach, FL
Sound Quality Tests on "Exciter" type speakers.
It would be helpful if you could escape from using totally abstract terms and simply describe what these "substrates" just happen to be, "set-ups", and whatever you could possibly mean by "optimal sound".

In other words, what are you talking about?

B.
__________________
HiFi aspirations since 1957. Currently working on motional feedback again... the final frontier in audio (and just posted data for a folded 17-foot pipe sub)
  Reply With Quote
Old 18th August 2016, 10:18 PM   #3
ElevetyCo is offline ElevetyCo  Canada
diyAudio Member
 
Join Date: Aug 2016
Sorry, Thought it might be more descriptive.

Anyways, basically, if you check out our website domio.co, our device mounts to a helmet. The unit uses and "exciter" which is basically a bone conduction style transducer to vibrate on the hardshell of the helmet and that in turn generates sound within the helmet.

We want to test different mounting designs and materials to find what gives us optimal sound (quality sounding, good range of frequency, etc.) quality. Our question is; using the measuring equipment we have already purchased, what would be the best way to go about testing our different iterations of the device and getting a good indication of which versions deliver the best sound experience?

Hope this clears things up a bit.

Cheers!
  Reply With Quote
Old 18th August 2016, 11:47 PM   #4
sreten is offline sreten  United Kingdom
R.I.P.
 
Join Date: Nov 2003
Location: Brighton UK
Hi,

Whoa. Your way off kilter. You need an expensive dummy head
and expensive in ear microphones to get remotely anywhere.

And of course you cannot predict what your device will do
with different models of helmets. I note your video is just
utterly wishful thinking rather than anything pragmatic.

Its also full of nonsense. Over ear phones allow you
hear stereo whilst still being environmentally aware.
They can easily be battery powered bluetooth.

You don't have a product that will perform consistently.
Or in stereo by the looks of it. You have no idea how
to make it even comparable to bluetooth over ear.

You also have no idea how to test it, which means
you have no idea how to design it by definition.

As an idea, its fine. Practically its a non-starter
without far more advanced technology and
investment than you could possibly provide.

It would need to be stereo and adaptive to the helmet,
advanced DSP, in the realm of noise cancelling, with two
units and a way of monitoring the sound at each ear.

Given all that, you seem to have no proof of concept,
that an exciter driven helmet can provide full range
sound to each ear, or how much head bone conduction
will affect the sound, which to me is the technical killer.
That you cannot compensate for, you can't measure it.

Sorry to be such a downer, but engineers build bridges
that don't fall down / collapse under load, its the job.
They have to poo-poo stuff that does not work well.

rgds, sreten.
  Reply With Quote
Old 19th August 2016, 06:37 AM   #5
JMFahey is offline JMFahey  Argentina
diyAudio Member
 
JMFahey's Avatar
 
Join Date: Mar 2009
Location: Buenos Aires - Argentina
Wow,you got answered by a no clue who shouldn`t have bothered to answer just to state that and Mr Negative.

For a change, I understand what you want to do

There´s some problems though:

1) your exciters are not driving a paper cone, not even a plastic but properly mounted one, think a small polypropylene one, but the helmet shell itself, which has its own peaks and resonances, I´m quite certain anything but what´s needed for Music reproduction.

2) to boot, they cover anything but the ears.

3) that said: if driven from an amplifier output, will they produce sound?
I bet they will.

Will it be wide range, flat and smooth?

Are you kidding?
You are directly driving a head shaped shell f*ck´n piece of injected hard plastic or molded resin and fiberglass .

Will you recognize Music played through it?
I bet you will.

A relatively minor point: will you have Stereo?

You answer that, I guess you will have some, sort of.

Just make a little experiment: put a helmet on, tap it on the right side , say 40 or 50mm over the right ear, then same over left , about where I see you are mounting your exciters.

Have somebody tap there from behind you, who sits with eyes closed.
Can you tell right from left ?

if so (I bet you will), you can have some Stereo.
Poor quality, lots of crosstalk, poor separation (two ways to say the same thing), but our wonderful brains will decode Right from Left.

IF not, just chalk it off, you have what you have, be happy with it.

4) you do NOT repeat NOT want to publish frequency response curves, believe me, any tiny plastic PC monitor or intercom or even a pinky nail sized cellphone speaker will be miles ahead of what your helmetspeaker can provide, but hey !!!:
a) it´s a novelty
b) there´s nothing like it
c) did I mention it´s novelty and may sell based on coolness factor?
Try it and see what happens.

5) you *can* measure frequency response, just keep it locked inside a strong safe box and let nobody but yourselves see it.

a) expensive dummy head?
Why not use our own? , the flesh and bone one I mean.
No, I´m not calling you dummy, hehe

b) expensive in ear microphones?
Cool if you have them, but if not , get a couple tiny electret microphone *unmounted* capsules, solder them to the end of thin Audio cables, and tape them to your skin, so the end of each floats roughly above each ear hole.

Not "in" ear but so close that what they pick up will be practically the same sound field as your ears will be picking.

Measure, gasp at the weird uneven response and hide it, anyway flat smooth extended frequency respose will NOT be a selling point.

All you need is already shown in your video

NOTE: If you want to pack a couple exciters inside a nice little cardboard box and send them for personal evaluation, I wouldn´t mind

Just sayin´ and .... good luck with your project !!!!

PS1: even if helmets float on plastic straps or foam or plain rubber there WILL be direct bone conduction, at least that should improve perceived Bass somewhat.

PS2: the main problem I see and that will probably be a deal killer, sorry, is that exciters driving hard helmets are **inefficient** , probably requiring hundreds of milliWatts to get the same (or worse) result than just 1 or 2 mW applied to a real earphone.

Battery life will be severely compromised, compared to the conventional alternative.
__________________
Design/make/service musical stuff in Buenos Aires, Argentina, since 1969.
  Reply With Quote
Old 19th August 2016, 09:23 AM   #6
TNT is offline TNT  Sweden
diyAudio Member
 
Join Date: Apr 2003
Location: Sweden
Quote:
Originally Posted by ElevetyCo View Post
Sorry, Thought it might be more descriptive.

Anyways, basically, if you check out our website domio.co, our device mounts to a helmet. The unit uses and "exciter" which is basically a bone conduction style transducer to vibrate on the hardshell of the helmet and that in turn generates sound within the helmet.

We want to test different mounting designs and materials to find what gives us optimal sound (quality sounding, good range of frequency, etc.) quality. Our question is; using the measuring equipment we have already purchased, what would be the best way to go about testing our different iterations of the device and getting a good indication of which versions deliver the best sound experience?

Hope this clears things up a bit.

Cheers!
So you launch THAT web page and then come here to find out how to develop it?

Scheeese... scam.


//
  Reply With Quote
Old 19th August 2016, 11:43 PM   #7
bentoronto is offline bentoronto  Canada
diyAudio Member
 
Join Date: Jan 2008
Location: Toronto and Delray Beach, FL
Sound Quality Tests on "Exciter" type speakers.
I have a certain personal interest in your product since I have been a devoted motorcyclist for the last 55 seasons*.

Some of what sreten introduces is meaningful even if inevitably critical of your approach.

I'd say you are getting off on the wrong foot: you should consider subjective testing in an environment of noise resembling motorcycle noise (which luckily for you, is mostly white wind noise rather than the muffler roar ill-informed people associate with ill-mannered bikers).

Not hard to perform various kinds of threshold, articulation, discrimination, direction, and other tests on functional human heads.... in any room with a loudspeaker to generate the noise or even at 60 MPH. And your test stimuli could be whatever you think represents the type of signal you want the biker to hear - natural speech, music, SIRI giving GPS directions in synthetic speech, etc. OR using the test equipment you have to generate calibrated test signals. Perhaps sreten would volunteer his head.

Ummm, maybe I should point out to JMFahey, assaultive anonymous poster with anger management issues, that stereo separation is not usually an issue with headphone-sort-of devices, except possibly in the case of his head.

Ben
*BMWs, of course, although only for the past 51 riding seasons.
__________________
HiFi aspirations since 1957. Currently working on motional feedback again... the final frontier in audio (and just posted data for a folded 17-foot pipe sub)

Last edited by bentoronto; 19th August 2016 at 11:51 PM.
  Reply With Quote
Old 20th August 2016, 02:17 AM   #8
SamAnytime is offline SamAnytime  India
diyAudio Member
 
Join Date: Jul 2016
Have you considered starting a line of helmets with headphones built in? Thay way you get the sound you want, and you control the materials.

If you want to stick to the add-on design to any helmet the user wants to use, focus on the auto-calibration aspect that you have mentioned on your website. That is what will save your butt. DSP, DIRAC modified for this purpose, etc.

To the naysayers: if you haven't heard a demo of the room equalisation capabilities of DSP based systems, walk into a high end audio showroom and ask for one. I heard one at a BOSE showroom - the guy turned the speakers this way and that - the sound readjusted to what it was before. He even put a box over one of the speakers - terrible sound at first, but then the system compensated and readjusted the sound to what it was before (almost - I still can't believe it.) I may not like their specs; (I certainly don't like their prices), but the fact remains that such systems take the pain out of setting up your listening room just right.
  Reply With Quote
Old 21st August 2016, 02:43 AM   #9
sreten is offline sreten  United Kingdom
R.I.P.
 
Join Date: Nov 2003
Location: Brighton UK
Hi,

Motorcycle helmets are not open ear and are designed to completely
different standards that typical bicycle and skateboarding helmets.

The shell of the latter is largely cosmetic, not so for motorcycles.

I'm not sure its even legal to stick a rigidly mounted protuberance
on a motorcycle helmet, watch out for the inevitable lawsuits.

The same might /probably applies to cycling / skateboarding.

Strikes me the OP has no idea what he's really dealing with.

rgds, sreten.
  Reply With Quote
Old 26th January 2018, 02:04 PM   #10
jfetter is offline jfetter  United States
diyAudio Member
 
jfetter's Avatar
 
Join Date: Jun 2012
Location: North Houston
I’ve used this set-up for years. Thats the second pair of Grados shown. Wore out the first pair spills etc. They are open back non resonant baffle so sound great plus you can still hear what going on with traffic.
Attached Images
File Type: jpeg 8EE816C3-DFCD-414A-80C3-F3CB53CD9CBD.jpeg (804.6 KB, 164 views)
__________________
“A grounded grid is a happy grid”. jfetter
  Reply With Quote

Reply


Sound Quality Tests on "Exciter" type speakers.Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Sound quality of "PI" speakers? G Multi-Way 21 3rd March 2015 01:43 PM
Loving the AudioSector LM3875 - What next for "better" Sound Quality?? dakku Chip Amps 47 8th May 2014 08:38 PM
question on ESL panel size vs "sound quality" beanbag Planars & Exotics 40 30th January 2014 11:29 AM
"Smithereens" type speakers dmitriy167 Multi-Way 1 18th August 2006 09:41 AM
Can anyone suggest the "best" 300B SE sound quality schematic for a beginner like me? calico88 Tubes / Valves 42 18th July 2006 02:33 PM


New To Site? Need Help?

All times are GMT. The time now is 01:35 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki