[ICOM] SP-20 - long post, sorry

[bonddaleena at aol.com]

Allow me to add one comment: (long)

While you have the SP-20 speaker apart, put some sort of rigid material 
(baffle), 6 inches or so, behind the speaker. On the speaker side of 
this material, attach some fiberglass, foam, whatever, to absorb the 
sound. You really don't need an 'echo chamber'. The size was selected 
to cosmetically match the 761, 765, etc, 'big radios'. I have the SP-20 
for the 761 and an SP-21 for the 756PRO. I have them wired so I can use 
either speaker on either radio, but after the 'baffle' mod to both 
speakers, they both sound good. The SP-20 having the edge, due to 
speaker size and filters.
Both were bought off of ePay, er, eBay, for a fraction of the new cost. 
Easy to repaint, etc.

I have kind of a speaker 'fetish', no that's not really the term. Guys 
will spend $12K on a new radio and try to get away (cheaply) with one 
of the most important aspects of communication: getting the audio 
pressure to the human ear. Yes, I KNOW headphones are even better, but 
I'm a 'speaker' quest here. Sometime, I'll tell you how you can build 
EXCELLENT headphones for < $10.

Near me there is a 'thrift store' that always (!!) has a lot of 
speakers for sale, CHEAP!! I am always looking for the ultimate 
radio-to-ear interface, so I visit about once a week.

Since this 'store' is associated with the local Sheriff's department, 
they almost always have some nice 'recovered' stuff on sale. Yes, it's 
legal.

Here's a perfect example. I have a nice but about 10 year old Sony 
Surround Sound System. I was in the store and found the center Sony 
speaker in MINT condition for $2. How can you go wrong? After a clean 
up (you never know where this stuff has been!!!), I tried it on my 
various Icoms. Sounded EXCELLENT. Gee, even the color matched.

Anyway, it's too confusing to play one speaker, disconnect it, plug in 
another and try to make subjective calls.
I built a small metal box with a 6 position switch and various 
connection options. This way, I can test 6 speakers at a time, 
instantly, A versus B, etc. SAME radio.

Although she sometimes balks at the prospect of listening to 'that 
noise' (ha ha), I usually recruit my girlfriend to give a listen. I 
explain that we are NOT looking for high fidelity, just MAXIMUM 
intelligibility on SSB and CW, both strong and signals in the noise.


What does this have to do with the SP-20? Easy, the SP 20 has become 
the 'standard'. Try as I might, it is VERY difficult to find a better 
speaker than the SP-20. On the Hi Fi speakers, I usually put a switch 
in the Tweeter line to disable the 'highs'.....
Almost always, she points to the SP 20 and says "I like that one 
best".... And I have to agree. How many have we done this purely 
subjective test on? If I told you you would NOT believe me... ha ha.
My 3 rd bedroom and 1/2 my shop is full!

By the way, I have picked up some smaller mobile speakers there (CB 
type, GROAN!!), and believe it or not, some sound EXCELLENT. Narrow 
bandwidth / cavity size, I'm sure.

I always wanted a Clear Speech Speaker. I ordered one and it was just 
as they were moving. Finally (!!) they re-opened but the cost was MUCH 
greater. I'm NOT saying they are NOT worth the $, but with the sample 
size I have so far gone through, ....I'd LOVE to do my A= B test on one.

One more thing.... On good 'ole ePay, er, eBay, I once bought a 
complete 5 piece Surround Sound Speaker System for the grand sum of 
$4.99 plus $10 shipping. New In the Box!

It seems there are more than a few RV builders in the Elkhart, Ind. 
area. Some of these companies buy the complete systems, BUT install 
'flush mounted speakers'. They have NO need for the satellite speakers. 
One of these is usually a heavy, bass reflex type that sounds real good 
in the shack.
The smaller ones, I have tucked under the dash of my 1965 AC Cobra and 
with an MP3 Player and small amp, sound excellent.

Above all (!!!), have FUN, life is SHORT!

ron

N4UE