Do Your Speakers have LEVEL CONTROLS or EQUALIZERS? (Vintage or Modern) ???

Of course, the big item I haven’t touched on, besides reliability is power.

All resistive elements waste power, and as those contacts get dirtier the switches and knobs will waste even more power and heat them up.

Modern, passive, multi-way speakers simply can’t avoid using resistors, that’s a matter of fact, but the more of this we can move to the active realm (i.e. low voltage/low current) the better we are.

IMHO, the least audible, most reliable methods of doing this is how Wilson and other high end makers have done it, by using either replaceable resistors or plug in networks that allow you to select the right resistive value through a jumper wire.

Any pics?

So, the answer would be "yes" to many (especially vintage) speakers.

We do custom performance upgrades to modern and vintage speakers. My standard practice (if the customer is interested in performance) is to bypass the level adjustments and replace with high quality resistors. Measure resistance, verify with RTA, than listen. It may a little trial and error, taking the values up, or down a notch, but Invariably the speaker will sound better in my experience. But, admittedly, the ability to "tweak" the speaker a bit is forfeited in the process. I also find it worth noting that the factory attenuators and knobs remain in place, the speaker still looks "OEM" and it can be reverted to "stock" at any point in the future.

I also make it a general practice to bypass protective fuses. These are serious sound de-generators. My rule of thumb is to bypass the fuse(s) IF: a) the driver, diaphragm etc IS replaceable by an OEM (or, better) device, b) the cost is not prohibitive, and c) the customer has had no instances of blowing fuses (maybe some exceptions, but too involved to detail here). If the owner has played the speaker with a high degree of enthusiasm for decades and not blown a fuse, the chances are low (to zero) that damage to a driver will occur in the coming decades. Please keep in mind that it’s not just a fuse. It’s a fuse holder with connections on both ends and a friction contact fit with the fuse. Not the most "audiophilish" approach to best sound quality. But, as mentioned, if the driver/diaphram is irreplaceable or extraordinarily expense, by all means keep those protective devices in place!!

When I designed my DIY triamplified horn speakers a DEQX DSP  was an integral part of the design.  I wanted bass folded corner horns back in the corners and midrange and super tweeter horns well out in the room where they could image better.  The DEQX corrected the large time difference between the woofers and the mids.  The room correction facility, a ten band parametric equalizer,  of the DEQX proved to be very useful and beneficial.

Their literature is clear: to adjust for 'live/hard' rooms, or 'soft/dead' rooms (of various degrees of soft or hard of course); for various locations in a space; for an individual's preference.

@elliottbnewcombjr Yes, I'm sure the document said that; it would have been a bit of a task to get the user to understand that the correct setting is an interaction with the output impedance of the amplifier.

You'll notice that by the mid 1970s these controls had all but vanished. Electro Voice and MacIntosh led the way pushing for the speaker to be 'voltage driven'. That eliminated the need for the controls. 

The Patrician was an amazing speaker. Thanks for the photos.