Single vs Multiple driver loudspeakers...

Twl: I've heard Lowther's, but not to any great extent. I've also read the entire article that Nelson published. I've seen the response curves and have at least a decent idea of what it took to get that driver to do what it is doing. I can pretty much guarantee that there's nobody other than Nelson Pass in the entire world that is getting that type of response out of those drivers. That is, unless there's someone else out there using similar equalization circuitry and an amp that has an output impedance that is appr EIGHTY ohms.

Even with all of that and a horn mouth that is 5 feet wide and 6 feet tall connected to a cabinet body that is 9.75' tall and 4.5' deep, the speaker is still -3 dB down at appr 48 or 49 Hz. In Nelson's own words "I have been extremely pleased with the results, but i must smile when i see that all of this effort barely gets us below 50 Hz".

Other than that, i have 104 dB horns and have driven them with as much as 400 wpc SS and 35+ wpc tube. Two watts isn't enough power for a speaker, even at that efficiency level. That's because 104 dB's @ 1 meter becomes appr 95 dB's at a 10' listening distance. While this is pretty loud for most people, it is nowhere near the levels that one hears at a live orchestral performance if sitting reasonably close to the performers. This is not to mention a live jazz, blues or rock show either.

Besides the spl levels, with only 2 watts, one is pretty much guaranteed to run the amp into compression and clipping on a regular basis. On top of that, feeding that much steady state power into an excursion limited Lowther is going to create dynamic compression and introduce other forms of distortion into the equation. This is why, even though he had a GIANT horn doing all the work and keeping the driver properly damped and loaded at low frequencies, Nelson Pass stated "Still, they play loud cleanly in a manner that Lowther owners don't usually encounter, and the cones are barely moving". Without the aid of a horn this size, there is just no way that the Lowther can produce ANY type of bass and / or high spl at the same time.

As a side note, Nelson provided the readings as taken from a Lowther in a standard sealed box. Using the output at 1 KHz as a reference point ( industry standard ), this driver is down appr -15 dB's at 100 Hz. By the time we get to 40 Hz, we are down almost -30 dB's. That's why he couldn't squeeze ANY deep bass out of the driver, even in that phenomenally LONG and HUGE horn.

Needless to say, i DO like some of the advantages of a single driver, but i also realize that, at least at this point in time, none of them do everything well. If you want extension, you give up efficiency. If you want efficiency, you give up extension. They are all a trade-off, some to a greater extent than another. Sean
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It just isn't fair to force an excellent midrange driver to perform woofer and tweeter duty. IMHO.:-)

Okay, I suppose we just have drastically divergent listening needs.

Regarding some of your other points, the Lowther isn't really designed for front horn loading, and nearly all of the cabinet designs for Lowthers have rear loading of one kind or another, which is supposed to augment the gradual rolloff below 500hz of the front radiator. The rolloff is well known, and is accounted for by the rear-wave horn or TQWP loading.

I think that some of the nuances of this kind of system is not understood by many people who seek "perfect" response curves and the like. The purpose of this kind of system is the utter simplicity, and the acceptance of less than perfect response curves. It is this seeking of "perfect" response that has caused most of the mediocrity of "mainstream" systems. To get to this perfect flatness, or perfect this or that, ends up sucking the life out of the music, because of all the increased complexity and band aids included to try to attain that at the expense of all else.

I suppose that I must admit that what many would call a "ragged" response curve is okay with me, as long as at least a small portion of the life of the music is still left in it. Call me crazy, but flat response that is virtually lifeless is not my bag. I can see that flat response is very important to some others, so I have no problem with that. But that is not what I want, if it means that I lose what means more to me about the music.

I guess it comes down to what is important to each person. The 90-95db peaks at my listening chair is just fine with me. Suits me fine.

Maybe Nelson should have tried a Voigt Pipe. I have no problems at all getting under 50Hz quite easily, with authority. Lowther EX3 drivers begin audible compression at 108db, which is above my amp's ability to produce, so no worries there.

Somehow I've deluded myself into thinking that a very musical 95db at my chair with a somewhat imperfect response curve can be a quite exciting form of audio enjoyment.
Fancy that.
I wonder how that could be, after all these years of listening to more "normal" and "perfect" and expensive high end systems?
Maybe there's just some unknown aspect to it that intrigues me.

I always thought this poster nailed it, at least as far as SET amps (which are often paired with speakers like single driver units or speakers without crossovers). link= "Reasons why I like SET topology so much"

That's a very nice post you dug up Aroc! Amen Twl!