[jrebman]

Sorry, didn't mean to throw the baby out with the bathwater, and I meant to post a request for people to repost those things.

Glad the train is back on track for everybody,

Jim

[mor2bz]

you all forgot a really nice one , and cheap too      pioneer b20       great on an open baffle
with a 1st order tweeter added on top.        could be the worlds best $100 system

[JLM]

A friend used the B20 in TWQT with a cheap piezo tweeter on the back to add "air".  It put commercial stuff to shame that cost hundreds.

[Folsom]

It's the cone excursion that really hurts a single driver speaker's ability to sound clean and clear, especially at high level. Extreme excursion doesn't mean much in a single driver speaker....the trick is to lower it (the driver excursion) as much as possible while raising system efficiency.   An inch of excursion in a single driver speaker, if possible, would be of little practical advantage. High excursion works great for sub woofers and multi way speakers though. Of course this is only my opinion and I'm sure Seas knows what they are doing.

I think I get what you are trying to say... I just think the order is a bit strange if not counterintuitive. A driver with very long excursion has a chance of being literally sloppy as it needs to have control for the higher frequencies. High efficiency if pulled off with great control is nice. You can use low well controlled power, and the speaker does I would guess a logarithmically less value of movement for SPL. However it seems you could short change yourself real fast with a logarithmic scale that is not in your favor. It is inevitable you will need excursion for certain levels of SPL, at certain frequencies. At say volume level of the tested efficiency, 1v, you can get as low as 25hz from a speaker, but as soon as you crank that up it all falls apart and all of a sudden due to limits of excursion it drops off at 100hz.

That is my understanding and experience with single drivers so far... I am sure horn loading and other various things greatly change the drivers relatively low amount of excursion into something much more, literally moving the logarithmic scale around, or shrinking it, depending on tuning. However I will mention tuning of horns etc is not far from using an equalizer and I refuse to believe it is inherently the same exact sound! I think OB speakers are the most just with proper amounts of excursion. I however also believe in stereo subwoofers (OB or not) because even expensive speakers often leave something to be desired at loud volumes.

I may be quiet wrong, and have never had the pleasure of hearing Ed's speakers though.

[Scottmoose]

I think what Ed's primarily refering to is the relatively limited Xmax of most FR units. As there's only one driver doing everything, keeping excursion within linear displacement as much as possible to prevent distortion occuring tends to take on greater importance than it often has for multiways. That's one reason that horns like Ed's are favoured, especially for small FR units, as they provide a better load for the driver across the range where it needs most help.

[Ed Schilling]

Thanks Scott.

DoS,
If one thinks about drivers in general and how each type is used and what they, within the group of the same type have in common, trends appear. Sometimes by design and sometimes because it is the only way that works!

The HF are the hardest for the single driver to do. What makes a good tweeter? How many world class tweeters are known for their excursion? How would one suppose a "high excursion tweeter" might sound? Is "transient response" somehow influenced by excursion? Ever thought about the excursion of an electrostat or planar driver (any size or brand) or for that matter ANY type of speaker that is producing FR sound from a single driver? These are not "trick questions" but rather things to ponder for starters.

Minimum excursion and maximum output are crucial for a single driver speaker to be able to play both loud and clean. Size of the driver is WAY less important than many believe.

This is just the tip of the ice berg.........a good single driver speaker is MUCH harder to build than a good 2 way. And there are things to consider that are not apparent.

I hope this helps and as always....just my opinion.

Ed
added****
DoS...."However I will mention tuning of horns etc is not far from using an equalizer...." This is completely wrong......horns are "acoustic transformers".......if you believe Paul K. then you know that horn loading "increases efficiency while at the same time lowering excursion and therefore distortion"....and they do this over  several octaves (usually). For starters!