HiFi Speaker Dimensional Criterion

[Bookman]

Would anyone know if there is any empirical/rule of thumb analysis criterion associated with speaker sizes.
In this I am referring to how I have been confronted with assessing the repair of a Pioneer 12" 8 Ohm 20W driver cone circumference support diaphragm. In other words why would it be 12" diameter and not 6" or otherwise?
Yes there will be air volume flow characteristics I would presume but this would have some relationship on sound pressure levels with a room of a specific volume would it not?
Similarly, from a domestic viewpoint, room sizes and the potential for a mass of variables would suggest more data in terms of optimum efficiency that refers also to room sizes and not just impedance, frequency and power boundary definition criterion.
My initial reason for the query was how I had always associated large speaker cabinets with medium to high amplifier RMS output values yet these speakers are 20W? Yet, here I am thinking about all of the other questions one could ask?
Incidentally, I have been quoted £40.00 repair cost for the pair?

[peter_sol]

I expect they were large to impress and sell
I would throw them and and get some others or replace the drivers which are quite cheap
Note the impedance if 8 Ohms keep to that.

[Nickthedentist]

Some early Pioneer stuff was not rated for high powers, yet was very well designed and constructed, e.g. http://glowinthedarkaudio.com/pioneer-pe12.html

[Bookman]

Originally Posted by peter_sol

I expect they were large to impress and sell
I would throw them and and get some others or replace the drivers which are quite cheap
Note the impedance if 8 Ohms keep to that.

I had also thought of that but let us not forget some of the Hifi that was coming out of Japan in the 70s & 80s. All the marketing in terms of impression and indeed price was more in a technological format not for the user but as competitive bragging rights.
I also reckon there would have been considerable expenditure in the tooling; especially the steel frames that have been stamped out and formed. Unless of course they were purchased from others.
Yes, the items could have evolved from ill advised development money but why was the concept considered in the first place?

[russell_w_b]

Originally Posted by Bookman

In other words why would it be 12" diameter and not 6" or otherwise?

Possibly to give directional output at low frequencies?

[russell_w_b]

Am I correct in thinking that originally speakers manufactured in Japan were not designed for the 'western' ear and so manufacture was subcontracted to Bowers and Wilkins in the UK, and the relevant badges stuck on?

I can't remember which Japanese company did this.

[peter_sol]

Years ago when things cost the earth a 10w amplifier and 12inch speaker sounded loud and had a very pleasing sound no need for false bass boost, sub woofers etc.Then came transistors and chips and !00's of watts and the sound is not much better in terms of fidelity. so you take your choice. you only have to sit in traffic to hear the racket younger people confuse Hi Fi with.

[Radio Wrangler]

It was Sony that used B&W for speakers in Europe. The speakers were more to European tastes and they avoided shipping large products this way.

Some of B&W's top end speakers got Sony badges this way. Sony was open about it at the time. Sony SS7000 = B&W DM70

David

[Bookman]

I had intended on responding that to associate Pioneer with a low quality speaker would be probably like associating Volvo with the manufacture of wheelbarrow's.
However, further research would suggest significant credence associated with Pioneer speakers as given per a 2014 web based review on the Pioneer HPM 100; it states:-

"When Bart Locanthi was VP of engineering at JBL, the last thing he worked on was the L-100 Century speaker, one of the most successful speakers of all time. The powers that be then decided to take JBL in a different direction, so in 1975 he left to work for Pioneer. He wanted to build a speaker that would challenge the L-100, and that ended up being the HPM-100B. That's the 200-watt version, and you can distinguish it by the ring around the woofer port. The 100-watt version is the HPM-100A, and it doesn't have the ring."
Source: Brent Butterworth; Nov 10, 2014 review


I remember a similar question I posed many years ago concerning how much paint one ought to purchase in terms of its relevance to area coverage; also on an empirical basis. The answer provided (eventually) was that one had to determine the volume of solids in the paint.
We are slowly getting there?

[russell_w_b]

Thanks, David - it was a long time ago and I couldn't remember. Wonder if this influenced the speaker / cabinet design of other Jap manufacturers?