Driver Replacement

[philviral]

I found a pair of Realistic MC-1500's in my Dad's garage this past weekend, and the cabinet looks to be in great shape but the drivers are not. The tweeters are completely destroyed, woofers have a bit of life left but not alot.

Want to bring these guys back to life with some new drivers, but can't find hardly any info on the original speakers! Google searches have turned up very little aside from a few pictures and a reference to the ad in the 1977 Radio Shack catalog (page 21). Anybody know anything about these, or the best way to get started identifying replacement drivers?

I checked out Parts Express and their calculater gave me a couple suggestions but I'm not familiar with any of the brands on that site.

[PeteMcK]

The first thing to do is measure the internal dimensions of the cabs, and if they're ported, the dimensions of the port.
Then someone may be able to recommend a suitable driver

[Inductor]

You can look for similar speaker in size.

[infinia]

Cheap at less than half.
You can get a closer match on the tweeter if U take it apart and measure the hole and flange. Better still post a bunch of pics of drivers and crossover bits.

Parts-Express.com:JAMO 20316 8" Paper Cone Woofer | JAMO 20316 8" Paper Cone driver Woofer speaker midrange mid
Parts-Express.com:Goldwood GT-25 4" Cone Tweeter | tweeter gt-25 4"cone tweeter cone tweeter goldwood

Woofer response will peak 1.5 dB at 100Hz & F-3 is about 60Hz it's typical for these small closed boxes to get the illusion of low bass. U can do better to add a port and shop for better woofer

[philviral]

Thanks for those replies. I guess I didn't really phrase a proper question, what I am looking for is either:
-more information on the drivers in that speaker, if it exists
-or information about what driver specs to look for to find a good match

FWIW Parts Express recommended these 3 woofers:
Goldwood GW-408D 8" Poly DVC Woofer
Goldwood GW-208/8 8" OEM Woofer 8 Ohm
Dynavox LW8004PMR 8" Woofer

The outside measurements of the cabinet are 23.63/13.758.5 inches. Seems to be made out of half inch boards, giving inside dimensions of 23.13/13.25/8 inches for a volume of approx 1.43 cubic feet. Not sure how to calculate the volume of the bracing and hardware inside the cabinet.

You mentioned adding a port, Infinia. How would I go about determining placement and size of port required? Is the port size dependent on woofer choice or cabinet size?

[Inductor]

Let's say we use one of this woofers. Then we simulate it for a box like yours (volume), and check for final xover with tweeter.

[infinia]

Originally Posted by philviral

You mentioned adding a port, Infinia. How would I go about determining placement and size of port required? Is the port size dependent on woofer choice or cabinet size?

box modeling software gives tuning and box volume based on
the woofers 3 specs ( Qts, Fs, and Vas)
If you want to keep it original, stick to closed box alignment
So for closed box your looking for Drivers designed as acoustic suspension Qts>0.4 to 1 and the lowest Fs you can find.
http://www.diysubwoofers.org/sld/

[philviral]

Great information thanks guys.