ported vs transmission line

[old_el_paseo]

Is the difference between a transmission line speaker and a simple ported one really worth it ? is the difference noticeable or is it just a slight difference. apparently a transmission line can go a half octave lower before the -3db and have a better soundstage. so that means that the location of the sub would be less obvious ? and how much is a half octave anyways on a sub ?

 

[shadyJ]

Is the difference between a transmission line speaker and a simple ported one really worth it ? is the difference noticeable or is it just a slight difference. apparently a transmission line can go a half octave lower before the -3db and have a better soundstage. so that means that the location of the sub would be less obvious ? and how much is a half octave anyways on a sub ?

Subwoofers do not have a soundstage. The low-frequency extension does not affect the ability to localize a subwoofer. That happens when the sub plays higher frequencies, not lower ones. A half octave lower on a subwoofer or any other kind of loudspeaker depends on the frequency. Take the -3dB low end of the sub, divide that number by two, and then multiply the quotient by 1.5. The product will be a half octave lower than the original -3dB point.

 

[TLS Guy]

Is the difference between a transmission line speaker and a simple ported one really worth it ? is the difference noticeable or is it just a slight difference. apparently a transmission line can go a half octave lower before the -3db and have a better soundstage. so that means that the location of the sub would be less obvious ? and how much is a half octave anyways on a sub ?

Yes, they are much better. However they are very large if they reach 20 Hz, somewhat complex and difficult to design

Here are my dual TL speakers.

But they do deliver the goods.

Not the very tight impulse response.

The room has to be designed to take them, to disguise how big they really are.

The center is also a TL.

 

[old_el_paseo]

what are the advantages of a center in a tl design ? i still have a sub and a center to build for my system

 

[TLS Guy]

what are the advantages of a center in a tl design ? i still have a sub and a center to build for my system

Funnily enough, we just had a Question about TL design this week. Please read this thread and what I wrote.

As you will also see from this thread, I'm going to be very busy and preoccupied this next year or so, and certainly will not be able to help you with a major TL speaker design, much as I would like to.

This is the FR of that center speaker. Note the smooth extended bass response which is only 12 db down from the small coaxial drivers.

The big issue is low Q non resonant reproduction as I explain in my writing in that post.

 

[Danzilla31]

Yes, they are much better. However they are very large if they reach 20 Hz, somewhat complex and difficult to design

Here are my dual TL speakers.

But they do deliver the goods.

Not the very tight impulse response.

The room has to be designed to take them, to disguise how big they really are.

The center is also a TL.

Wow sir I am in awe of your system that is amazing what you created. And that room simply looks stunning.

 

[old_el_paseo]

s you will also see from this thread, I'm going to be very busy and preoccupied this next year or so, and certainly will not be able to help you with a major TL speaker design, much as I would like to./QUOTE]

sorry to hear about your health issues . hope all ends well. im almost done building the front tower that you modeled for me, they sound very nice ! just need to sand everything and veneer them and then i will post pictures of the build. for now they are bi-amped on my denon home theatre amp (105wrms x 2 to each tower). so they are nowhere near their full potential. but still sound pretty damn good. but we are buying our first house this month so not much spare money for now.

i was just planning the rest of the system. the center and subwoofer. for the rears i will use my infinity il10 and il30's.

funny that someone posted the same question as me. i heard about those on caraudiofabrication on youtube. some young guy builds all sorts of boxes and explains very well how they work, advantages/disavantages of everything.

he said wlhe would model a tl subwoofer box for 80$ (u.s). i find that very expensive, but i dont have the knowledge to do that myself so maybe ill just pay him and i will be sure that the specs are good.

if you say that even a subwoofer would be much better in a tl design i might do that too. we listen to a lot of movies and a center channel is very important in a home theatre.

anyways, hope it all goes well for you.

 

[KEW]

I don't know how much of a compromise the 1/4 wave TL design represents as compared to the real deal, but I will say I experienced some of the cleanest and tightest bass I have ever experienced listening to the Philharmonic Phil3's w/o subs at TheWarrior's house!
Here is a thread with some good links on the 1/4 wave design. I suspect the full wavelength design is better, but if you have constraints from the size requirements of a full wave TL, they seem like a not-so-terrible compromise.

https://forums.audioholics.com/forums/threads/quarter-wave-loudspeaker-enclosures.94393/

 

[TLS Guy]

I don't know how much of a compromise the 1/4 wave TL design represents as compared to the real deal, but I will say I experienced some of the cleanest and tightest bass I have ever experienced listening to the Philharmonic Phil3's w/o subs at TheWarrior's house!
Here is a thread with some good links on the 1/4 wave design. I suspect the full wavelength design is better, but if you have constraints from the size requirements of a full wave TL, they seem like a not-so-terrible compromise.

https://forums.audioholics.com/forums/threads/quarter-wave-loudspeaker-enclosures.94393/

You are under a miss apprehension. All stopped pipes (closed at one end) are a quarter wave length. There is no pipe with a fundamental the length of the pipe. An open pipe (open at both ends) is one half the wave length of the fundamental.

The difference between the TL,s I build is that they are just that stopped pipes. The TLs you are talking about are quarter wave stopped pipes that exit at their open end into a tuned quarter wave ported resonator just like any ported speaker.

Their behavior is largely that of a ported speaker or Helmholtz resonator. their behavior is that of any ported speaker, but with some bass extension. The characteristics of a true TL (damped pipe and no resonator) is quite different. Although the behavior of an undamped pipe and tuned resonator share a lot of the same characteristics.