size of the driver

If you are interested in dynamic speaker drivers and technology, read up on Walsh drivers for something completely different, as they used to say.

Back in the late 70s when i sold gear at tech hifi, bass drivers in most
speakers back then tended to range from 8 to 12 inches mostly with the
occasional 18. I levitated towards smaller drivers mostly for better sound
for most with their amps in their applications. Larger drivers were largely
inadequately built and under damped in many cases i heard resulting in a
muddier sound although typically with more lifelike impact. .

I think both amp and speaker technology has come a long way since and
that those issues can be adequately addressed these days in a variety of
ways, with both larger or smaller drivers, if the overall design is good.
Often though size, large or small, still matters though to many sound
quality being just one of the important considerations.

Probably a topic for a different thread, but I would be really interested in better understanding how the better known Walsh style driver/designs differ from the more conventional approach in terms of these common parameters that help determine speaker performance.

How does a downward oriented, open-back Walsh driver manage to deliver seemingly flat and extended frequency response at very high SPLs horizontally in a largely omnidirectional manner compared to a say a single similar sized conventional driver generally firing more directly at the listener?

The answer seems to lie somewhere in the domain of "wave bending" in the Walsh theory, as opposed to pistonic motion which I believe accounts for most of the output associated with traditional dynamic designs?

I kind of understand the theory based on wave propogation through materials of different density "bending" or diffracting the wave, but would have no clue how to relate it in technical terms comparable to what Drew and others here have so eloquently related, nor how to apply it effectively in practice, other than via trail and error perhaps.

Here's what Wikipedia has to say about it FWIW:

"Bending wave loudspeakers
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Bending wave transducers use a diaphragm that is intentionally flexible. The rigidity of the material increases from the center to the outside. Short wavelengths radiate primarily from the inner area, while longer waves reach the edge of the speaker. To prevent reflections from the outside back into the center, long waves are absorbed by a surrounding damper. Such transducers can cover a wide frequency range (80 Hz to 35,000 Hz) and have been promoted as being close to an ideal point sound source.[49] This uncommon approach is being taken by only a very few manufacturers, in very different arrangements.

The Ohm Walsh loudspeakers use a unique driver designed by Lincoln Walsh, who had been a radar development engineer in WWII. He became interested in audio equipment design and his last project was a unique, one-way speaker using a single driver. The cone faced down into a sealed, airtight enclosure. Rather than move back-and-forth as conventional speakers do, the cone rippled and created sound in a manner known in RF electronics as a "transmission line". The new speaker created a cylindrical sound field. Lincoln Walsh died before his speaker was released to the public. The Ohm Acoustics firm has produced several loudspeaker models using the Walsh driver design since then.

The German firm, Manger, has designed and produced a bending wave driver that at first glance appears conventional. In fact, the round panel attached to the voice coil bends in a carefully controlled way to produce full range sound.[50] Josef W. Manger was awarded with the "Diesel Medal" for extraordinary developments and inventions by the German institute of inventions."

I tend to look at it from the perspective of basi physics.

Size matters in order to pressurize air more effectively.

Larger rooms and lower frequencies at higher volumes require more air be pressurized to maintain a smooth frequency response. Larger drivers have the advantage.

The dilemma is that larger drivers will tend to have more mass. More mass means more inertia. Inertia is the enemy of transient response. Transients are an important part of real music. Therefore larger drivers are at a disadvantage when it comes to transient response.

A lot of what works best comes down to a matter of scale ie how much speaker is needed to deliver the desired scale of performance in the target roo m.

I tend to look at it from the perspective of basi physics.

Size matters in order to pressurize air more effectively.

Larger rooms and lower frequencies at higher volumes require more air be pressurized to maintain a smooth frequency response. Larger drivers have the advantage.

The dilemma is that larger drivers will tend to have more mass. More mass means more inertia. Inertia is the enemy of transient response. Transients are an important part of real music. Therefore larger drivers are at a disadvantage when it comes to transient response.

A lot of what works best comes down to a matter of scale ie how much speaker is needed to deliver the desired scale of performance in the target roo m.

"However, for those whose first-priority is realism, seeking to combine the fore-mentioned attributes with truly realistic tone, the choice seems to be limited to relatively scarce systems with large mid-woofers (dynamism is another benefit that, more often than not, comes with most of the existing large-coned examples)."

In larger rooms, larger drivers or multiple drivers would seem to be the options.

"So I guess the choice between the large and the small driver all comes down to; which attributes are more important to the individual. It's a matter of 'picking your poison', in other words, I suppose."

No doubt about the picking your poison (or pleasure, however one might term it ) part. Personally, I like sound best when it has what I often refer to as "meat on the bones" along with all the rest. Larger or multiple drivers usually accompanied by larger and heavier enclosures are two ways to potentially accomplish that .

I run multiple speakers in multiple rooms ranging in size from 12X12 to 20X34. My smaller speakers work well in teh smaller rooms and the larger ones can as well but only the larger ones can cut it in the larger rooms.

ITs no mystery why in virtually every line of speakers, the larger better built ones tend to cost the most. True even of exclusive high end lines like Magico, I believe. But not everyone needs or can even afford those.

Most people would love to have a Lamborghini but practically settle for Toyotas.

"By the way, if you listen to rock concert music, nothing beats big boxes with high efficiency 15 or 18 inch drivers, for the simple reason that these are exactly what you hear at the concert. Horn mids and tweeters also. IMHO, horrible, but accurate."

Often horrible, yes, but I have heard it done well both in smaller clubs and large stadiums in recent years. I had seats right in the "sweet spot" at the last Paul McCartney concert at FedEx Field in DC and the sound was the best I have ever heard at a large stadium event by far, quite good actually even by audiophile standards I would say. I hadn't been to a similar large stadium event in years because I had sworn them off years ago, bad sound quality being just one of the reasons. Those seats were not cheap though!

Speakers used were large and efficient no doubt in that venue. The sound "columns" on either side of the stage were I would guess 40-50' high and each consisted of many units/drivers functioning in an array.

I would guestimate that if the venue from where I sat, about two sections back dead center, were scaled down to fit into a decent sized home listening room, the speakers would stand ~ 6-7' tall and 2-3' wide and likely each be quite heavy still as well.

I also know of at least one local venue where name acts of all genres including Rock can be heard in an intimate club setting for very reasonable cost and sound quality is also top notch (still best in teh "sweet spot") having heard it from that sweet spot on multiple occasions.

BTw, can anyone guess what the good sounding seats in both large stadium and intimate club had in common other than being in the sweet spot?

Answer:

˙uoıʇɐʇs/sʎnƃ punos ǝɥʇ oʇ ǝsolɔ pǝʇɐɔol ǝɹǝʍ ʎǝɥʇ

"I really can't think of anything much worse than a large system poorly designed/executed "

Have heard such and gotta agree. Glad I only heard and did not pay!