ETL vs. T/S Parameters

[BioLinksAudio]

I read this and found nothing about a good sub's ability to "voice" or "integrate" with the other speakers in a system. Nothing sounds worse than a boom box sound that you can readily locate eminating from said boom box. To be effectively realistic and natural, the bottom end frequencies must be part of the reproducted total audio spectrum not separated from it. This has nothing to do with bass "non-directionality" as some claim.

 

[no. 5]

I read this and found nothing about a good sub's ability to "voice" or "integrate" with the other speakers in a system. Nothing sounds worse than a boom box sound that you can readily locate eminating from said boom box. To be effectively realistic and natural, the bottom end frequencies must be part of the reproducted total audio spectrum not separated from it. This has nothing to do with bass "non-directionality" as some claim.

True; but it does have a lot to do with room acoustics, speaker/listener placement, and subwoofer/satellite integration. And those are things that the subwoofer itself has no control over.

 

[BioLinksAudio]

True; but it does have a lot to do with room acoustics, speaker/listener placement, and subwoofer/satellite integration. And those are things that the subwoofer itself has no control over.

Interesting comment, though it needs expansion, I think. When you say "subwoofer/satellite integration" what are you referring to exactly?

 

[MinusTheBear]

Interesting comment, though it needs expansion, I think. When you say "subwoofer/satellite integration" what are you referring to exactly?

My guess would be relative subwoofer and speaker placement, room acoustics as well as crossover settings.

 

[BioLinksAudio]

My guess would be relative subwoofer and speaker placement, room acoustics as well as crossover settings.

If the subwoofer has no control over voicing with the mains, then how can the environment dictate integration? I think you might be confusing integration with blending. The ability of a subwoofer to produce its bass augmentation in each of the 5 speakers in a 5.1 system (other than the sub itself) goes to the proper imaging of the reproduced audio. If a sub cannot do that then it is a only discrete source of bass frequencies and not integrated with the system to reproduce an accurate soundstage.

 

[TLS Guy]

If the subwoofer has no control over voicing with the mains, then how can the environment dictate integration? I think you might be confusing integration with blending. The ability of a subwoofer to produce its bass augmentation in each of the 5 speakers in a 5.1 system (other than the sub itself) goes to the proper imaging of the reproduced audio. If a sub cannot do that then it is a only discrete source of bass frequencies and not integrated with the system to reproduce an accurate soundstage.

Integration/blending, this is pure semantics and silly. A sub should not be involved in sound stage issues.

Your posts so far have been irritating, and despite you denials in another thread, I suspect you are working your way to a sales pitch for this so called,"Center Augmentation Device" you extolled in your first thread.

You have some honest explaining to do before anyone is, or should, pay any attention to you.

 

[FirstReflection]

Interesting comment, though it needs expansion, I think. When you say "subwoofer/satellite integration" what are you referring to exactly?

Usually, "subwoofer to satellite integration" refers to the cross-over region between the sub and the satellite speakers.

The cross-over is not a "brick wall". It's not as though the subwoofer plays all the frequencies up to an including 80Hz and then completely stops making any sounds above that frequency. And the speakers don't just go from 20,000 Hz down to 80Hz and stop completely below that.

Rather, the higher frequencies from the subwoofer get gradually quieter and quieter and the lower frequencies from the speakers get quieter and quieter. Just how steep the slopes are is decided by the design of the cross-over circuitry.

So sometimes, the speakers will naturally start to roll-off their bass output too soon or have a built-in slope that is very steep. Or perhaps the subwoofer starts to roll-off its higher frequencies too soon or also has a built-in slope that is too steep. If that's the case, you could end up with a "hole" in the frequency response where the low end of the speakers doesn't mesh nicely with the higher end of the subwoofer.

On the other end of the spectrum, if the speakers reach down very low before they roll-off at all and the subwoofer reaches up fairly high before rolling-off, you end up with that cross-over range being too loud and you have a "hump" in the frequency response.

So one, very well known cross-over design is the THX standard cross-over. With a THX cross-over, 4th order slopes are used - which are quite steep: 24dB per octave. The subwoofer should play completely flat from 20Hz up to about 70Hz. Starting at about 70Hz, the subwoofer should start to roll-off so that it is 3 dB quieter at 80Hz and at 160Hz, it should be 24 dB quieter still. The speakers should be flat from 20,000 Hz all the way down to about 90 Hz. At 90Hz, they start to roll off so that at 80Hz, they too are 3 dB quieter. And at 40Hz, they would be 24dB quieter still.

The thing is, the speakers themselves will naturally start to roll-off at some point. A THX speaker is specifically designed to have a 2nd order (12dB/octave) natural roll off starting at about 90Hz so that the speaker, on its own, is 3dB quieter at 80Hz. The real magic of the THX cross-over happens inside the THX processor or THX receiver. The THX subwoofer, completely on its own, should be able to play flat all the way up to 160Hz. The THX processor/receiver will apply the complete 4th order slope to the subwoofer. For the speakers, the THX processor/receiver will apply a 2nd order slope. The natural 2nd order slope of the speakers themselves cascades with the 2nd order slope applied by the processor to create a 4th order slope! Pretty smart

End result - the entire frequency range from 20Hz up to 20,000 Hz is flat and linear. There is no "hole" in the frequency response where the subwoofer and the speakers cross over; and there is no "hump" either. The steep 4th order slopes ensure that virtually all of the bass comes from the subwoofer and also that the subwoofer produces very little in the way of higher frequencies. This keeps the bass difficult to localize and it allows the speakers to be physically smaller and to demand less power because they do not have to try and produce much at all in the way of bass frequencies.

 

[no. 5]

Interesting comment, though it needs expansion, I think. When you say "subwoofer/satellite integration" what are you referring to exactly?

Basically what FirstReflection wrote. But to add to what he said, it absolutely cannot (repeat, cannot) be assumed that an AVR's crossover will produce an optimum transition between the subwoofer and other speakers.

If the subwoofer has no control over voicing with the mains, then how can the environment dictate integration?

How could a 'better subwoofer' possibly fix a problem that is caused by room acoustics? Or a problem caused by a crossover's filters?

I don't care how 'good' or well reviewed a subwoofer is, if it's energizing a nasty room mode, it will sound bad. And there is nothing the subwoofer itself can do about it, because the problem isn't the subwoofer.

 

[lsiberian]

I read this and found nothing about a good sub's ability to "voice" or "integrate" with the other speakers in a system. Nothing sounds worse than a boom box sound that you can readily locate eminating from said boom box. To be effectively realistic and natural, the bottom end frequencies must be part of the reproducted total audio spectrum not separated from it. This has nothing to do with bass "non-directionality" as some claim.

What you talking about Willis?

Your post doesn't make any sense. I realize you are working from a language barrier so perhaps you can make sense of what you are saying with more explanation.

Any sub worth it's salt will be able to integrate fine into a sound system as long as you use the proper crossover frequency and placement.

 

[BioLinksAudio]

Usually, "subwoofer to satellite integration" refers to the cross-over region between the sub and the satellite speakers.

The cross-over is not a "brick wall". It's not as though the subwoofer plays all the frequencies up to an including 80Hz and then completely stops making any sounds above that frequency. And the speakers don't just go from 20,000 Hz down to 80Hz and stop completely below that.

Rather, the higher frequencies from the subwoofer get gradually quieter and quieter and the lower frequencies from the speakers get quieter and quieter. Just how steep the slopes are is decided by the design of the cross-over circuitry.

So sometimes, the speakers will naturally start to roll-off their bass output too soon or have a built-in slope that is very steep. Or perhaps the subwoofer starts to roll-off its higher frequencies too soon or also has a built-in slope that is too steep. If that's the case, you could end up with a "hole" in the frequency response where the low end of the speakers doesn't mesh nicely with the higher end of the subwoofer.

On the other end of the spectrum, if the speakers reach down very low before they roll-off at all and the subwoofer reaches up fairly high before rolling-off, you end up with that cross-over range being too loud and you have a "hump" in the frequency response.

So one, very well known cross-over design is the THX standard cross-over. With a THX cross-over, 4th order slopes are used - which are quite steep: 24dB per octave. The subwoofer should play completely flat from 20Hz up to about 70Hz. Starting at about 70Hz, the subwoofer should start to roll-off so that it is 3 dB quieter at 80Hz and at 160Hz, it should be 24 dB quieter still. The speakers should be flat from 20,000 Hz all the way down to about 90 Hz. At 90Hz, they start to roll off so that at 80Hz, they too are 3 dB quieter. And at 40Hz, they would be 24dB quieter still.

The thing is, the speakers themselves will naturally start to roll-off at some point. A THX speaker is specifically designed to have a 2nd order (12dB/octave) natural roll off starting at about 90Hz so that the speaker, on its own, is 3dB quieter at 80Hz. The real magic of the THX cross-over happens inside the THX processor or THX receiver. The THX subwoofer, completely on its own, should be able to play flat all the way up to 160Hz. The THX processor/receiver will apply the complete 4th order slope to the subwoofer. For the speakers, the THX processor/receiver will apply a 2nd order slope. The natural 2nd order slope of the speakers themselves cascades with the 2nd order slope applied by the processor to create a 4th order slope! Pretty smart

End result - the entire frequency range from 20Hz up to 20,000 Hz is flat and linear. There is no "hole" in the frequency response where the subwoofer and the speakers cross over; and there is no "hump" either. The steep 4th order slopes ensure that virtually all of the bass comes from the subwoofer and also that the subwoofer produces very little in the way of higher frequencies. This keeps the bass difficult to localize and it allows the speakers to be physically smaller and to demand less power because they do not have to try and produce much at all in the way of bass frequencies.

Your comments are well taken so far as conventional subwoofer design is concerned; however, what I am attempting to explain is that a conventional sub operates due to it resonance frequency. If that resonance frequency is, let's say 40 Hz, then when the input signal tells it to respond at 30 Hz then the subwoofer's resonance signature will make it sympathetic at 40Hz so that it will boom at that frequency. On the other hand, if a subwoofer is critically dampened so as to not have any fundamental resonance responding to the signal other than the signal itself, then both the fundamental and harmonics will be heard in the satellite speaker where the sound stage says it should be – and not emanating from the subwoofer itself. This is what I mean by a sub voicing with the satellites - not describing anything relating to crossover.

 

[no. 5]

It sounds to me like you are talking about the difference between a subwoofer with high Qtc and one with low Qtc. If so, it's not really a myth that low Qtc sounds better than high Qtc.

 

[annunaki]

It sounds to me like you are talking about the difference between a subwoofer with high Qtc and one with low Qtc. If so, it's not really a myth that low Qtc sounds better than high Qtc.

Agreed, that was my thought as well.

 

[BioLinksAudio]

Critical damping

It sounds to me like you are talking about the difference between a subwoofer with high Qtc and one with low Qtc. If so, it's not really a myth that low Qtc sounds better than high Qtc.

No, not really. Critical damping is the goal for all speakers and that is what is achieved with ETL (Embedded Transmission Line) technology. The sub's drivers don't respond to the room reflections therefore are not contributing to room modes which typically alter the Q of speakers.

 

[no. 5]

No, not really. Critical damping is the goal for all speakers and that is what is achieved with ETL (Embedded Transmission Line) technology. The sub's drivers don't respond to the room reflections therefore are not contributing to room modes which typically alter the Q of speakers.

If any sub is in a listening room it is energizing room modes, if any speaker is in a listening room it is energizing room modes... unless the room is an anechoic chamber. Nevertheless, room modes don't change the Q of a speaker per se, but they do change what is heard in room compared to what the speaker's designer intended the listener to hear.

At any rate, our conversation in this thread started after you pointed out Annunaki's link said nothing about "a good sub's ability to "voice" or "integrate" with the other speakers in a system". An ability you attributed to subwoofers that are critically damped (i.e. Qtc of 0.5). Now we could debate the merits of critical dampening and room effects, but as this thread is about subwoofer myths, I must point out that it's neither a myth nor an obscure fact that a critically dampened subwoofer usually sounds better than an under dampened one.

 

[BioLinksAudio]

ETL technology is no myth

If any sub is in a listening room it is energizing room modes, if any speaker is in a listening room it is energizing room modes... unless the room is an anechoic chamber. Nevertheless, room modes don't change the Q of a speaker per se, but they do change what is heard in room compared to what the speaker's designer intended the listener to hear.

At any rate, our conversation in this thread started after you pointed out Annunaki's link said nothing about "a good sub's ability to "voice" or "integrate" with the other speakers in a system". An ability you attributed to subwoofers that are critically damped (i.e. Qtc of 0.5). Now we could debate the merits of critical dampening and room effects, but as this thread is about subwoofer myths, I must point out that it's neither a myth nor an obscure fact that a critically dampened subwoofer usually sounds better than an under dampened one.

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

 

[TLS Guy]

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

At the moment this is myth. Your above post makes no sense in any acoustic physical principles I'm aware of.

The reviews are all anecdotal.

If you want to be taken seriously you need to: -

1). Publish in these forums the exact anatomy of the speakers.

2). The design and T/S parameters of the driver.

3). A sensible theory of operation, not the meaningless meanderings you have so far produced.

4). The mathematics proving the theory of operation.

5). Detailed measurements, preferably by a third party, of a functioning unit, using the supposed "embedded transmission line theory.

Failing the production of this information within 72 Hours, I would respectfully request the moderators ban you from these forums, for the following reasons.

1). You are promoting a highly questionable spurious product in which you have an admitted financial interest.

2). Your posts are highly confusing and misleading to members.

3). Your posts reflect poorly on these forums.

I should caution you that I'm well versed in transmission line theory, and have built and designed many over more than fifty years now. If you click on my signature, you will see my TLs. I consider myself qualified to peer review anything sensible you have to say. There has been nothing of any substance in your post so far. They have been nonsensical musings and vague theories, and a lot of concepts you hold are plain wrong.

 

[no. 5]

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

Yep. Although I said any speaker, not just a 'typical' speaker. Because room modes are a phenomenon of room acoustics, not of a speaker's alignment.

Now, if you have credible third parity in room measurements of your speakers I would happily look at them. After all, it's very easy to say there's a revolutionary technology...

 

[adwilk]

Just for the sake of discussion...

Surely it IS possible that this new technology (ETL) exists, right? Advancements are made all the time in all industries. Whats to say this ETL stuff isn't legit. I agree that some more details might be necessary for validation, but that doesn't mean that there is no relevant discussion. Certainly, we don't want these forums being flooded with people peddling new devices, but when new information about a technology is trying to be conveyed, surely we be a little more open minded.

 

[no. 5]

Surely it IS possible that this new technology (ETL) exists, right?

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

Advancements are made all the time in all industries. Whats to say this ETL stuff isn't legit.

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.

I agree that some more details might be necessary for validation, but that doesn't mean that there is no relevant discussion. Certainly, we don't want these forums being flooded with people peddling new devices, but when new information about a technology is trying to be conveyed, surely we be a little more open minded.

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.

 

[adwilk]

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.

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....