Ring radiator tweeters - the future?

.
Gmood1...I assume the the Fostex F200 is what you use. Good choice. No whizzer.

But look at the almost 10dB hump between 4 and 5 KHz. And how about off axis? And you can't really tell about the HF (15 to 20KHz) from a SPL measurement. Sure it puts out loud noises at those frequencies but is it part of the music, or just a rattle? The ear (at least when you are young) senses that there is HF sound present, and "hears" what harmonics ought to be there. The ear is fooled in a way similar to the eyes that sometimes see what you expect (a dog perhaps) instead of what is really there (a tree stump).

Of course if it sounds good to you it is good. Maybe your ears have a notch at 5000 Hz.

The FR driver in a folded horn enclosure was commonplace when I began this hobby in the mid fiftys. I had a really nice wharfedale 8" driver in one at the time. But I never liked horn resonance as a way to boost weak bass. Or vented boxes either. Or boxes of any kind.

So after telling you all the things I find wrong with FR drivers it may surprise you that I am seriously considering some experimental work with one. My idea is to exploit the extended range capability by using a FR to cover the range from 100 Hz to 8KHz or so, with a SW below and a tweeter above. This keeps the crossovers out of the critical range. Of course it will be open baffle, and I may employ multiple drivers in a line array. Most normal woofers start to deteriorate around 2KHz, with a crossover required around 2500Hz.
.

Eldartford,
This is why there's a BSC and zobel used in this speaker.
It does away with the 10dB hump. It has a very smooth response through the 4 to 5khz area. You can tweak it just by changing a resistor depending on your room. A good internet friend uses tractrix line design. He claims it's the closes to not having a box as he has heard. I've never heard a tractix speaker but it sounds interesting.

I can assure you that the MLTL has a very non-boxey sound. I do like the magnepans for this... the MLTL is no different. It just has a tremendous amount of oomhp. Trust me..weak bass is the last thing you'll be worried about.

After having several types of speakers. My ears aren't being fooled by this speaker...I assure you. They have the smoothest response I've heard in my home. Too bad you don't live closer..I could change your mind very easily about this type of speaker. It makes all the horn loaded speakers I've heard sound like toys.

Here's a qoute from a owner of the same speaker that lives in NYC. He's right on the money with his description.

Bemopti123
Hi Ray, thanks for the compliment of the preamp. I will attempt to describe how it sounds.

The system has a "robust" signature. I mean, hearty sound, taut, slamming bass that it has got to be heard to be believed, especially from an 8" driver. I believe that the robust signature comes from the alnico factor of the driver. If you have heard Tannoy coaxials...the Turnberry, it sounds close like it, but the FTAs are more seamless, more transparent when the source calls.

FM via the system, especially due to the Mcintosh, it sounds very organic, once again, with gobs of presence.

The FTAs do not sound midrangey, as some single fullrange drivers, if not the vast majority of them sound like.

When I put some vinyl, you can hear more of the slam and also harshness, if the vinyl recording was badly made.

Depending of the CD track, it can sound bloody awesome, or simple pedestrian. It depends of the recording.

What is most amazing about the system is the idiocyncratic mix of really expensive components with things are are plainly DIY oriented, such as the Scott Nixon sound better than it should ever be.

I have tried something interesting, an idea I got from people who have a single source system, that is I ran the Shigaraki transport, DAC into EVS Ultimate Attenuators and then, into the monoblocks. From there, it all went to 47 Labs OTA and into the FTAs.

There was a difference in signature, but it was about 90% of what I have heard with the preamp.

Why no tweeter?

Read the paragraph "The Quest for that Old-time Religion".

There was a time, two generations ago, when the full-range cone driver reigned supreme. In an age when the radio console together with the shellac 78-rpm record defined audio quality, a frequency range of 60 Hz to 9 kHz was about as wide a window as was needed or desired for the enjoyable reproduction of available source material. If anyone dared to open the window any wider – especially in the treble - they ran the risk of exposing gremlins such as needle scratch and other high-frequency hash and noise. With the advent of the high-fidelity phenomenon in the 50s, the audio industry moved inexorably toward multi-way loudspeakers, such as two and three-way designs, as a means of expanding the bandwidth at the frequency extremes. The advertising campaigns/hype at the time were so effective, that for many people Hi Fi became synonymous with bandwidth. Many consumers expected to pay a premium for a high-fidelity loudspeaker basically because of its increased bandwidth. Even today, many audiophiles and audio engineers seem convinced that the road to hi-fi heaven lies at the frequency extremes. Of course, music lovers know that this is patently false, and that the emotional content and drama of live music have little to do with the frequency extremes.

Multi-ways effectively cut the music in half. Do you really think the speaker designer can put it back together again? Even 1st order is only in the small sweet spot.
People commonly ask, why is a speaker $10,000 for $200 worth of drivers. IMHO the price is for the expertise of the designer making the drivers work together. A very tricky task as the x-over can't just be designed on paper, from what I have read from the guys at madisound.com. You have to tweak it by ear over and over again to make it sound right.

As stereophile wrote on Krell Resolution 1 speaker:

I must assume that Mikey's thinking the Resolution 1 sounded a bit "rich" in the upper bass is due more to the woofers' restricted passband. (The more you limit a drive-unit in the frequency domain, the less well defined its output will be in the time domain.)

Running a driver full range with no high or low-pass x-over is the way to go or timing will be off.

The so called "tweeter" of the Magneplanar QR series, like my MG1.6QR, is not a physically separate driver, like the ribbon used in the MG3.6. It is just a section of the diaphram that has lighter conductors and can vibrate at higher frequency. In some ways it is like a full range cone driver, where breakup of the cone allows the area near the voice coil to vibrate at higher frequencies than the outer cone area. I actually prefer the Maggie QR over the ribbon, and the money left in my pocket is nice too.