Monday, July 21, 2014

Outdoor Party Speaker Pair Upgrades

In June, 2014, I found the Party Speakers next door at a yard sale.  Considering that they appear to have been built as long ago as 1958, they were in remarkable condition "as found".

However, I have been able to make several upgrades to improve the overall condition and sound.  First, I was listening to a pure sine wave generator played through the speakers outside from a distance of about 40 feet and noticed that the output between 400Hz and about 1200Hz was somewhat diminished.  Later, I disassembled the Calrad crossovers and discovered that the original crossover capacitors had developed leakage and no longer worked as well as they probably did 56 years ago.  I removed a couple of new film capacitors from a pair of crossovers that I had on hand and replaced the old ones.  This helped to improve the uniformity of sine wave response vs frequency.

The finish laminate had begun to separate around the bottom edges on both speakers so I glued it back down.

To make it easier to connect the speaker wire, I removed the old terminal blocks and replaced them with banana jacks spaced about 2 1/2 inches apart.  I filled the old screw holes with Durham's water putty and applied mahogany stain over the putty and on scratches in the original finish.  Finally, I applied a coat of varnish to the whole exterior.

A couple of days ago, I removed what appeared to be burlap used as grille cloth.


Upgraded Party Speaker Pair
Upgraded Party Speaker Pair

Meanwhile, I have installed the Jensen horn tweeters on top of the corner cabinets.
 


Corner Speaker Pair and Jensen Tweeters

I set up the Jensen tweeters atop the Corner Speaker Pair after winding new air-core inductors and connecting film capacitors in a "series connected" crossover similar to the Calrad CN-2.


Jensen Tweeter with EV Corner Speaker
Jensen Tweeter with EV Corner Speaker

Jensen Tweeter with EV Corner Speaker and Series Crossover
Jensen Tweeter with EV Corner Speaker and Series Crossover
This combination sounded great so I made a more permanent installation.


Jensen Tweeter with EV Corner Speaker Nearly Complete
Jensen Tweeter with EV Corner Speaker Nearly Complete
These work best when placed in a corner.  I would like to try them in a much larger room.