ETL vs. T/S Parameters

[no. 5]

I'm not sure thats exactly what he's saying.

Point taken. After rereading BioLinkAudio's post, it seems he isn't saying ETL speakers are not affected by the room, but that the room has a minimum effect on ETL speakers. Nevertheless, measurements will show if what he says about ETL speaker's capabilities is legitimate or not.

However room modes and reflections can affect the performance of a driver.

Correct me if I'm wrong, but under normal circumstances, room reflections and modes don't radically change a driver's T/S spec's, or a driver's frequency response, do they?

By removing the driver from said environment, at least PART of the problem is eliminated.

But no matter how perfect the speaker (or subwoofer's) design is, critically dampened ETL or not, the room is in control at low frequencies. Where the driver is in the box doesn't change that. And based on his statements:

The big difference here is that ETL subs have a completely enclosed driver that is operating in a high pressure, non-resonant environment. So, the room modes do not alter the driver’s acoustic impedance thereby allowing room modes to behave smoothly.

but, there will very few location/orientation positions in the room where they do not sound good.

I can only assume he is saying ETL speakers are not bound by the same acoustic rules any other sound source is.

But anyway, for anyone with the working capital and measurement know-how, ETL speaker's can be bought on Amazon.com.

 

[adwilk]

Point taken. After rereading BioLinkAudio's post, it seems he isn't saying ETL speakers are not affected by the room, but that the room has a minimum effect on ETL speakers. Nevertheless, measurements will show if what he says about ETL speaker's capabilities is legitimate or not.

Agreed. What measurements would you like to see....?

Correct me if I'm wrong, but under normal circumstances, room reflections and modes don't radically change a driver's T/S spec's, or a driver's frequency response, do they?

T/S param's.. probably not. As far as the frequency response, my very limited understanding of how "sound" works, I would say that the actual response of the driver probably wouldn't change a significant amount, but it could change it. Audible or not, I can't answer that. [/quote]

But anyway, for anyone with the working capital and measurement know-how, ETL speaker's can be bought on Amazon.com.

I have a feeling that those products are possibly what he is talking about.

 

[BioLinksAudio]

T/S param's.. probably not. As far as the frequency response, my very limited understanding of how "sound" works, I would say that the actual response of the driver probably wouldn't change a significant amount, but it could change it. Audible or not, I can't answer that.

Yes, the ETL doesn't eliminate the effect of the room but it greatly reduces it. The ETL matches the driver acoustic impedance from behind the diaphragm so that the output of the driver is a function of this impedance thereby resisting the lower pressure reflections from the room.

 

[no. 5]

Agreed. What measurements would you like to see....?

At the very least, high resolution anechoic and in room measurements of an ETL subwoofer. And in room measurements of a 'typical' subwoofer at the same location would be a good comparison. And again, credible third parity data is preferred.

T/S param's.. probably not. As far as the frequency response, my very limited understanding of how "sound" works, I would say that the actual response of the driver probably wouldn't change a significant amount, but it could change it. Audible or not, I can't answer that.

I'm inclined to believe reflections have a negligible, if any, effect on a speaker's frequency response; if a speaker is measured in room, the resultant data is room + loudspeaker, but as the microphone is moved closer to the speaker, the less room is in the data, and the more the data looks like an anechoic measurement. Certainly, though, reflections can change what we hear from the speaker, but I doubt it's because the sound coming out of the speaker is changing.

Yes, the ETL doesn't eliminate the effect of the room but it greatly reduces it. The ETL matches the driver acoustic impedance from behind the diaphragm so that the output of the driver is a function of this impedance thereby resisting the lower pressure reflections from the room.

I'm having difficulty beveling that 'matching the driver acoustic impedance... resists the lower pressure reflections from the room'. Placing a sound source half a wavelength from a wall causes a cancellation at that frequency simply because the direct and reflected sounds are out of phase with each other. Aside from making the source highly directional, there's nothing that can be done to it to change that because it's not the sound source that's at fault, it's the reflective surface behind it.

 

[TLS Guy]

It's patented, and is in some consumer products, so yes, it does exist.


In room measurements for a start. BioLinksAudio said ETL technology doesn't energize room modes, if measurements show that to be true, then what was said was legitimate.


Look at it this way; say someone claims to have made a light bulb that can be plugged into any fixture in your house and will only illuminate book pages. Wouldn't you be a bit skeptical?

BioLinksAudio seems to be making the claim that ETL speakers don't energize room modes because the driver is in a well dampened chamber that isn't directly exposed to the room, now as far as I know, room modes are a function of wavelength and room dimensions. In other words, the problem comes from room acoustics, not the loudspeaker. If BioLinksAudio can provide credible third parity data that shows ETL speakers don't energize room modes I'll be very interested to look at it.

I need to see the T/S parameters of the driver to see if it even capable of producing significant bass.

I want to see in room response and valid measurements of the F3. I want to know Qtc, to see if is indeed critically damped.

I want to know the Spl that can be achieved without distortion or driver bottoming.

I want to see the impedance curve to see if there is a ghost of chance this is in fact a critically damped TL.

I want to know the sensitivity of the device.

I want to see the math. He claims this is a TL. This is a small box, and the length of a TL has a direct effect on the lowest frequency produced. The volume of the pipe is related to the Vas of the driver.

I want a convincing theory and math to back it up. I highly doubt it exists. This is nonsensical smoke and mirrors almost certainly.

Biolinks says this product of his is patented, so there is nothing to stop him giving the details.

Peter Walker invented the feed forward current dumping amplifier, and his patent is still held by Quad. Everyone at the time was incredulous that a feed forward amplifier would be stable. Peter of course knew that, so right away he published all the circuits, theory and measurement, and the mathematics behind the design. The Quad 909, is my top recommendation for a domestic amplifier.

If you are going to tout new technology, you don't promote it with this nonsensical BS we are getting about this product. You show your cards, and produce the goods and allow others to verify. If there are patents the inventor is protected. You can patent just about anything no matter how daft. So if this guy needs to be taken seriously he needs to put up or shut up. If he can't deliver the goods, he needs to remove himself or be removed from these forums. So far all we have from him is gibberish.

 

[lsiberian]

I need to see the T/S parameters of the driver to see if it even capable of producing significant bass.

I want to see in room response and valid measurements of the F3. I want to know Qtc, to see if is indeed critically damped.

I want to know the Spl that can be achieved without distortion or driver bottoming.

I want to see the impedance curve to see if there is a ghost of chance this is in fact a critically damped TL.

I want to know the sensitivity of the device.

I want to see the math. He claims this is a TL. This is a small box, and the length of a TL has a direct effect on the lowest frequency produced. The volume of the pipe is related to the Vas of the driver.

I want a convincing theory and math to back it up. I highly doubt it exists. This is nonsensical smoke and mirrors almost certainly.

Biolinks says this product of his is patented, so there is nothing to stop him giving the details.

Peter Walker invented the feed forward current dumping amplifier, and his patent is still held by Quad. Everyone at the time was incredulous that a feed forward amplifier would be stable. Peter of course knew that, so right away he published all the circuits, theory and measurement, and the mathematics behind the design. The Quad 909, is my top recommendation for a domestic amplifier.

If you are going to tout new technology, you don't promote it with this nonsensical BS we are getting about this product. You show your cards, and produce the goods and allow others to verify. If there are patents the inventor is protected. You can patent just about anything no matter how daft. So if this guy needs to be taken seriously he needs to put up or shut up. If he can't deliver the goods, he needs to remove himself or be removed from these forums. So far all we have from him is gibberish.

I'm fairly certain he still stated some patents as pending. I do find it to be gibberish as well so far, but I don't think we need to toss him out just yet. He's not flooding the forums and has yet to link an actual product. His posts are confusing though.

 

[BioLinksAudio]

ETL products are real

I'm fairly certain he still stated some patents as pending. I do find it to be gibberish as well so far, but I don't think we need to toss him out just yet. He's not flooding the forums and has yet to link an actual product. His posts are confusing though.

Check out the post by No. 5 above for the Amazon link to ETL products.

Nine major companies are currently producing products under license with this technology. There is a U.S. utility patent issued plus a second one that has been awarded and will issue on 10 Nov. 2009. There is a third US patent pending on the application of ETL technology to the driver itself. Other international patents are pending.

If you need to evaluate the technology in an inexpensive product, we have already mentioned in a previous post that the licensed Sharp DK-AP7N & DK-AP8N for the iPod® and iPhone® are available from Amazon and many other vendors. This little unit has an embedded woofer operating in an enclosure volume of approximately .007 cu. ft. and produces bass under 100Hz at personal listenable volumes with 2 watts of power. The midrange and highs are produced by speakers less than 2 inches in diameter without breakup or compression. The port diameter for the subwoofer is 7mm in diameter. This type of performance is unattainable with T/S parameters.

For the record, I am not directly affiliated with the company that owns ETL technology and not privy to all of the technical aspects requested by TLSGuy; but if certain forum members want to purchase the product and hear for themselves that what I am saying really does exist, then follow this link: http://www.sharpusa.com/ForHome/HomeEntertainment/Audio/DKAP7N.aspx. Also, click on the review tab on this link: http://www.bhphotovideo.com/bnh/controller/home?O=&sku=609577&Q=&is=REG&A=details#reviews.

 

[BioLinksAudio]

I'm not sure thats exactly what he's saying. There is nothing a driver can do to affect the way an environment 'handles' sounds or waves. However room modes and reflections can affect the performance of a driver. When both of these actions are in place, nasty things happen. Particularly summing and cancellations. By removing the driver from said environment, at least PART of the problem is eliminated.

To be fair, thats how I understand it. I don't know that thats whats going on, but from my limited research, thats what I was able to make up. The technology seems to make more sense in a midrange or tweeter if my understanding is anywhere near what it should be.

I definitely think Alex needs a couple of them....

100 % correct on the first point.

On the second, your understanding is correct. The company is currently applying this technology to individual drivers.

 

[BioLinksAudio]

Happy New Year!

I need to see the T/S parameters of the driver to see if it even capable of producing significant bass.

I want to see in room response and valid measurements of the F3. I want to know Qtc, to see if is indeed critically damped.

I want to know the Spl that can be achieved without distortion or driver bottoming.

I want to see the impedance curve to see if there is a ghost of chance this is in fact a critically damped TL.

I want to know the sensitivity of the device.

I want to see the math. He claims this is a TL. This is a small box, and the length of a TL has a direct effect on the lowest frequency produced. The volume of the pipe is related to the Vas of the driver.

I want a convincing theory and math to back it up. I highly doubt it exists. This is nonsensical smoke and mirrors almost certainly.

Biolinks says this product of his is patented, so there is nothing to stop him giving the details.

Peter Walker invented the feed forward current dumping amplifier, and his patent is still held by Quad. Everyone at the time was incredulous that a feed forward amplifier would be stable. Peter of course knew that, so right away he published all the circuits, theory and measurement, and the mathematics behind the design. The Quad 909, is my top recommendation for a domestic amplifier.

If you are going to tout new technology, you don't promote it with this nonsensical BS we are getting about this product. You show your cards, and produce the goods and allow others to verify. If there are patents the inventor is protected. You can patent just about anything no matter how daft. So if this guy needs to be taken seriously he needs to put up or shut up. If he can't deliver the goods, he needs to remove himself or be removed from these forums. So far all we have from him is gibberish.

Sorry, but it took me awhile to come up with this. Enjoy.

 

[BioLinksAudio]

T/S of driver

I need to see the T/S parameters of the driver to see if it even capable of producing significant bass.

Here are the T/S curves for the 10" driver

 

[BioLinksAudio]

ETL vs. T/S graphs

Sorry, but it took me awhile to come up with this. Enjoy.

The attached file contains the graphs with explanations that you seek. For clarification, the enclosure has a 3" port diameter.

 

[Shock]

I think I understood a total of 5 words in this entire thread.

 

[BioLinksAudio]

It's patented, and is in some consumer products, so yes, it does exist.


In room measurements for a start. BioLinksAudio said ETL technology doesn't energize room modes, if measurements show that to be true, then what was said was legitimate.


Look at it this way; say someone claims to have made a light bulb that can be plugged into any fixture in your house and will only illuminate book pages. Wouldn't you be a bit skeptical?

BioLinksAudio seems to be making the claim that ETL speakers don't energize room modes because the driver is in a well dampened chamber that isn't directly exposed to the room, now as far as I know, room modes are a function of wavelength and room dimensions. In other words, the problem comes from room acoustics, not the loudspeaker. If BioLinksAudio can provide credible third parity data that shows ETL speakers don't energize room modes I'll be very interested to look at it.

I submitted the attached data in response to TLSGuy's last post in this thread. He has not yet responded so I will again post it in response to your requests for ETL validity measurements. The tested subwoofer had an enclosure size of approximately one cubic foot; used a 10" driver and had a port with 3" diameter measuring 11" long.

 

[BioLinksAudio]

If you are going to tout new technology, you don't promote it with this nonsensical BS we are getting about this product. You show your cards, and produce the goods and allow others to verify. If there are patents the inventor is protected. You can patent just about anything no matter how daft. So if this guy needs to be taken seriously he needs to put up or shut up. If he can't deliver the goods, he needs to remove himself or be removed from these forums. So far all we have from him is gibberish.

I have posted the technical data requested by forum members “TLS Guy”, “No. 5” and “Isiberian.” After being up for all forum members to see for a week now, no response from anyone has been heard except for “Shock” who admitted that he understood none of it. Hence, I am going to start a new thread under the subwoofer category entitled “Where are all the experts now?” Please go there for my post for those who think they know it all.

 

[jamie2112]

I don't think I know it all.I do however know audio both live and studio and HT and am always learning,everyday in fact.I also know that by reading a measurement I cannot tell what the speaker is doing in a real world test.You can throw up measurements all day long,but most people on here are not "pro"audio folks and won't get what you are saying.I understand what you are saying and my thought is show me.I mean really, I would love to hear what you are saying.I am not calling you out at all I just would like to understand your point a little better.

 

[TLS Guy]

I have posted the technical data requested by forum members “TLS Guy”, “No. 5” and “Isiberian.” After being up for all forum members to see for a week now, no response from anyone has been heard except for “Shock” who admitted that he understood none of it. Hence, I am going to start a new thread under the subwoofer category entitled “Where are all the experts now?” Please go there for my post for those who think they know it all.

I have looked at your sparse data. I have not had time until this afternoon to do some calculations.

You T/S parameters are incomplete. The power handling and xmax are not stated. You did not give an adequate sensitivity spec nor provide the inductance of the voice coil.

As far as the 1 cu.ft box with an 11" port I did confirm that the driver would have an F3 of 41 Hz if the port was 2.7" in diameter. Since you did not provide the complete specs I could not calculate spl of vent velocity. The impedance peaks are appropriate to the tuning.

As far as your ETL you have provided no details as to why this is a TL. You have provided no theory of operation.

On the graphs there is now basically one peak of impedance pushed to 120 Hz. The roll off is now second order, instead of fourth. However the roll off is still around 40 Hz. I have to regard that frequency response graph with a high degree of scepticism. In fact for now I'm going to regard the frequency response graph as bogus pending further details from you from which I can make calculations that would show what you claim is even plausible.

Certainly your enclosure is far too small to contain any TL that would load a 10" driver.

Another issue is that you did not state the Qt of your "embedded TL" system. This is a significant issue, as you claim your device reduces the effect of room resonances. Therefore this would imply the design is very low Qt, but again you provided no data. I suspect from the impedance curve that this device actually starts to roll off somewhere above 100 Hz and has inadequate spl to excite the resonances at the frequencies where these usually occur.

You can start all the thread you want, but pending further extensive data, I regard your claims as unproven and far more likely than not bogus.

 

[BioLinksAudio]

You obviously know what you are talking about but not what we are talking about. At this point you and others that actively participate in this forum need to be introduced to Embedded Transmission Line (ETL) technology and then things will become clearer for you. This might sound outrageous, but if and when you get the opportunity to audition ETL equipped drivers, loudspeakers and subwoofers then the sound will be clearer as well. Realizing that every speaker manufacturer on the planet is using the same old technology that’s been around for 50-80 years, does create a challenge for us to get a fair hearing (no pun intended) on the new technology.

The fact is that all speakers or any sounds in a room can energize room modes. Room modes are points of pressure and points where the level is lower than if the wave were not reflected back. These modes are related to the room dimension. The big difference here is that ETL subs have a completely enclosed driver that is operating in a high pressure, non-resonant environment. So, the room modes do not alter the driver’s acoustic impedance thereby allowing room modes to behave smoothly.

The typical driver or subwoofer operating in the same room will have the pressure zones and regions of lower pressure amplified by the driver itself. The pressure modes create greater output when they hit the driver cone while the lower pressure modes cause a drop in the effect of the output. Furthermore, room modes are enhanced when the active driver’s diaphragm is exposed to these modes.

The Q of the existing speaker does change on a dynamic basis and this causes the sound to change to something different. But as all other subwoofers operate on a resonant design, the speaker or subwoofer does not have the correct sound character in the first place.

“but they do change what is heard in room compared to what the speaker's designer intended the listener to hear.”

In making this statement you are admitting that the typical speaker or subwoofer will never sound as the designer intended.

ETL speakers and subwoofers always perform exactly as the designer intended even though the end user will experience his own individual acceptable result. This is because the Q of the speakers is constant regardless of the room or the speakers’ placement although placement will have an affect on the final sound presentation. There are ideal placements in the room where ETL speakers and/or a subwoofer perform best; but, there will very few location/orientation positions in the room where they do not sound good.

One must understand the method of providing critical damping of a speaker or subwoofer for its entire frequency range; then it will be revealed why the room cannot affect it like it does all other speaker designs. Only after further reading about the technology and what professional reviewers have said about how ETL speakers and subs perform will one become initiated. This forum has successfully functioned to provide open and honest discussions about anything that might be revealed as new or useful in our industry. Here are some helpful links:

o Subwoofer review: http://www.audioasylum.com/audio/speakers/messages/28/282462.html
o Sub/small monitors review: http://www.videohifi.com/16_TBI_ENG.htm
o US Patent: http://www.patentstorm.us/patents/7207413/claims.html

This would be a good post to absorb. Then follow the links and read the reviews and comment on them please. The patent will take a bit more time. I still haven't heard TLS Guy interpret the graphs... for everyone.

 

[highfigh]

You posted that the Q of the speaker is constant but one thing that's critical is how the speaker's energy transfers to the space it's in. The speaker/enclosure needs to excite the air in the room and not all rooms are equal, acoustically. I see no way one speaker can, or will, sound the same in all rooms without some electronic method of making that happen. You posted that there's no position where it will sound bad but I can think of a few examples where it easily could.

Care to enlighten me, or us on this?

 

[TLS Guy]

This would be a good post to absorb. Then follow the links and read the reviews and comment on them please. The patent will take a bit more time. I still haven't heard TLS Guy interpret the graphs... for everyone.

The reviews are poor quality and anecdotal.

I have gone through the patent for this so called “embedded transmission” line sub.

This is a most disorganized rambling document. When you cut through the drivel, this is actually a second order coupled cavity sub. The so called “transmission line” is closed at both ends, so therefore is redundant and useless. I have modeled this within the sparse TL specs provided. The F3 is around 40 Hz, and roll off starts second order just above 60 Hz. Roll off becomes fourth order below F3. This is dressed up to look like something new, but it is not. I do not think this worthy of a patent.

By the way, with that driver the lowest you can get system Qt is 1.0, so there is nothing special in that, it is far from critically damped. So the only reason for it not exciting room resonance would be low spl!

 

[JerryLove]

The attached file contains the graphs with explanations that you seek. For clarification, the enclosure has a 3" port diameter.

As the non-expert: the ETL alignment seems worse than the T/S.

Looking from about 25Hz, the T/S makes it to almost 200Hz with no more than a +/- 3db (odd scale you've used), while your ETL spike about 18db from 25Hz to 38Hz, and proceeds with a +/- 9db (what is with that dip at 160?).

But whatever. You should be piling up the reviews by now of everyone from here to stereophile putting up the amazingly flat graphs from their tests of your speakers. Right?