Realistic Optimus 650's ... any opinion on these??

AdamITR

Well-Known Member
Realistic Optimus 650's ... any opinion on these??

Great cosmetic shape, need woofer refoams. Can get them for really cheap, any opinion on them? Thanks!
 
Don't take this the wrong way, but you seem eager to buy a set. Same mistake I made and ended up buying crap. Have patience and the right speaker will find you...Good luck.
 
Goodwill find: Optimus 650 speakers

Just picked up a pair of Optimus 650 speakers today and am listening to them as I type. For $12.00 I couldn't pass them up. Need surrounds on both woofers and midranges. Sealed encloser cabs. Damn, they sound as good as the T-120's I have. Looks like the same midrange used in the Optimus 400's and T-120's. But has a lesser cone tweeter. The veneer is dry as a bone with some scuffs and scratches. But, I've seen worse. I don't know what or when I decide to do with them as I'm restoring a pair of Optimus 5's I bought recently. I really like those 5's so far!!!
 
Just picked up a pair of Optimus 650 speakers today and am listening to them as I type. For $12.00 I couldn't pass them up. Need surrounds on both woofers and midranges. Sealed encloser cabs. Damn, they sound as good as the T-120's I have. Looks like the same midrange used in the Optimus 400's and T-120's. But has a lesser cone tweeter. The veneer is dry as a bone with some scuffs and scratches. But, I've seen worse. I don't know what or when I decide to do with them as I'm restoring a pair of Optimus 5's I bought recently. I really like those 5's so far!!!
Hey, post the driver part numbers when you have a chance. I'm trying to compile a list of drivers for cross reference, making it a tad easier to do restores.

Congrats on the find. Do those have real wood veneer? Having trouble remembering those. That was around the time I parted ways with RS. Our daughter was born that year.
 
Here we go...Optimus 650. Tweeter #07122 6ohms made in 1989 Midrange #1290 6ohms made in 1989. Woofer #2552 7 ohms then there is a ink #9324 Don't know what that is... maybe a date code? All were made in Korea. Do you need the Optimus T-120 driver #'s? The 650's Do have realwood veneer. I also worked at Radio shack for about a year and left in the summer of 1991. I just realized that these have two grills. The lower covers a port hole so these are ported, not sealed.
 
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If the price is right you can't go wrong adding them to your collection!!!:thmbsp::thmbsp:
Jon 56:thmbsp::thmbsp:
 
Rather than start a new thread, I figured I would resurrect this one. I received a pair of these monsters from my FIL. Both the mid and low woofers had their foams rotting terribly from too many years in the attic. Did the refoam, put them in the cabs and fired them up. The mids and lows sound good, the tweeter in one was terribly distorted.....the tweeter in the other, produces no sound whatsoever.

I am therefore in search for replacement tweeters.

I get the following:
Tweeter, 07122, 6 Ohms, Korea, 3 5/8 Hole to Hole or about 93mm.

Will any tweeter do that fits those measurements, is there an obvious inexpensive replacement option out there?

Thanks for any help!
 
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source: www.radioshackcatalogs.com (1989)

Those look to be extremely generic tweeters.

In a perfect world, you want to match the impedance, sensitivity (dB of sound pressure level at a fixed measurement distance per a fixed level of power input), and resonant frequency (Fs) of the original.
In this case, a pair of these is probably fine.

https://www.parts-express.com/goldwood-gt-25-3-cone-tweeter--270-018

or these...

https://www.parts-express.com/t-25-2-1-2-paper-cone-tweeter-8-ohm--279-452

Worth checking MCM Electronics, too -- the site is down as I type this, however.

EDIT: It's worth mentioning that the OP should probably ensure that, for each of the malfunctioning loudspeakers, that the problem really does lie in the tweeter and not "upstream" in the loudspeaker (i.e., in the crossovers). The simplest way to do this is probably to swap the two tweeters and see whether the "distorted tweeter" works the same in either cabinet and the "nonfunctional tweeter" also behaves the same in either cabinet. If not, the problem(s) is/are in the wiring or crossover networks, and not the tweeter(s). The most likely culprits in the crossovers would typically be capacitors. If that particular loudspeaker has any "protection elements" (e.g., a "Raychem" self-resetting fuse, or a light bulb in series, or a fuse) in the crossover to protect the MR and/or tweeter, those are also potentially suspect. Resistors and inductors are less likely suspects (but never say never, you know?).

The other good way to check the health of a suspected "nonfunctional" tweeter is with a DMM (digital multimeter), if available. Set the DMM to measure ohms, remove the tweeter from the speaker (disconnect the wires) and check the voice coil's DC resistance (one meter probe connected to each of the two terminals on the tweeter. If the voice coil is OK, the DMM will read a value of a few ohms. If it reads "open" (infinite resistance), the voice coil is open. If the reading is very low (close to zero ohms), the voice coil may be shorted.

Another way to check a driver is with a battery (e.g., a 1.5 volt AA cell). Remove the tweeter from the speaker (again, disconnect the wires). Connect two tweeters to the two terminals. Hold one cliplead's other end to one terminal of the cell. Touch the free end of the other cliplead to the other terminal of the cell. If the tweeter is OK, you'll hear a "click" or a quick rustle of static. If you hear nothing, the tweeter probably has an open voice coil.

Worth mentioning that, especially for a tweeter, don't leave the voice coil 'energized' with DC (even at 1.5 V) for any duration of time. It's not likely to overheat and fry the voice coil -- but it might.

:confused:
 
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Thank you for that info.

I did actually swap the tweeter to the other speaker and that is how I noticed that the one remained very static-y and the other would not produce any sound whatsoever.

I'll have a look at the links you sent. Any worry if they are rated 8 ohms as opposed to the 6 ohm speaker that came out.

Side question, this speaker is ported obviously, would it benefit from filling it with any additional batting? There is currently a half in batt glued to the back of the speaker and a 1 inch fiberglass batt on the bottom, that is it.

These will be hooked up to a Sony STR-DE980 AVR in my garage.
 
If the original driver is 6 ohm, it would be ideal to replace it with a 6 ohm driver.
This being said, "the perfect is the enemy of the good" ;)

You can certainly try some more batting; hard to say to what Qtc R/S would've tuned these loudspeakers. If you add some & don't like the result; just take it out again!
 
Not trying to be a kill joy, but if you are getting into the Optimus/Realistic you should look into the Nova line.. (some gear that rat shack put out was actually re-branded pioneer gear)

OR save your chips, invest in some nice JBL's or Klipsch of the era.

Kind Regards,
John
 
Some results from the DMM.....

Tweeter 1, 11.6 ohms?!?, Continuity
Tweeter 2, 0 ohms, no continuity

Thanks for the suggestion jobrewer, no offense taken. These will be garage speakers used to blare Allman Brothers and Zeppelin while my wife is away, so no overly concerned about investing much in them.
 
Some results from the DMM.....

Tweeter 1, 11.6 ohms?!?, Continuity
Tweeter 2, 0 ohms, no continuity

Thanks for the suggestion jobrewer, no offense taken. These will be garage speakers used to blare Allman Brothers and Zeppelin while my wife is away, so no overly concerned about investing much in them.


Ohhh how did I miss that!!

Ok garage speakers!! Damn I want a garage!

Do it to it, also look for some crappy Vegas to foam, I've picked them up as low as 10 bucks, foamed them for 20, used for blasting my neighbors, than flipped for 50. CVs seem to be all over in my area...

Good luck, hope you get them!!
 
So both of those have "Cut-out diameters" of 3.125". I measured only a 2.6" or 66.15mm opening. So I would have to modify the holes correct to make these fit?
 
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