Transmission line speakers!

• https://www.usaudiomart.com/details/649184875-tdl-monitor-m-transmission-line-speakersl/images/929958/
  These are the ones that I had with the B110 elliptical bass driver and super tweeter. It was a large speaker, but very good for the time, and the bass was not, but it was able to reach below 20hz.
• The pair in the picture were not mine. Mine had a naked Elac metal dome tweeter and what the brochure called a "mineral" supertweeter.

None of them were. 

Infinity made the claim, not me. Oh, I guess I did...but I was referring to the Infinity's claim. I know they aren't a true labyrinth design but they stuffed the cabinet with absorbent material and lowered the port resonance. Maybe it was just fancy sales writers but they made the claim.  

My Infinity Monitor IIa’s are transmission line.

One of my favorites, only to be replaced by my Reference Standard 2.5s which I kept for many years.

INFINITY WTLC WAVE TRANSMISSION LINE

This is the only one that I could find. A wave transmission line. I would have to take the driver out and look. Simple as that. 

I don't see a fixed throat for the exit port. I guess the hole in the back is the port?

They may use TL tech but in the stricter sense of a TL speaker design, not so much. It's like calling a QLS1 a Line source when the only one they ever produced was the IRS Beta V. Everything was not quite the same or a hybrid of some kind.

As far as deep bass, TL make good bass, the problem is like any speaker that has bass in the same box as the monitor section, timing is the issue. With TL designs it's even worse.. One driver doing double duty.. the back wave is slower.

As far as ports, I haven't used fixed ports in 40 years.. Passive Radiator, OB, or IB but fixed ports are Worthless..

Regards

@russ69  and All,

As I've said, I've owned a couple of different TL speakers. I enjoyed the Clements Audio RT-7 for many years, the Fried for less. However, for the last few years I've been using a pair of sealed enclosures - Infinity RS1.5s. They are a great fit in my room and sound fantastic. Better still, I only paid $264 on eBay and picked them up from the seller as I was driving through his area on a ski trip a few years ago. I love the sound of vintage Infinity speakers! I've even bought a pair of professionally re-foamed Watkins Woofers for them. Paid almost as much for the pair of woofers as I did for the pair of speakers.

Would love to have a pair of RS2.5, 4.5 or IRS, but I don't think I have enough space for them.

Many of the Salk loudspeakers are transmission line...as are the new Philharmonic Audio towers.

https://www.salksound.com/type.php?format=Floorstanding

https://www.philharmonicaudio.com/Measurements-BMR-Tower.html

When executed properly, the bass will usually go pretty deep and with good tone.

Another advantage is the roll off is such that they are easy to blend with sealed subwoofers.