JBL Olympus S8R

[Eddycycles]

:(Please help me find out is JBL Olympus have this look of grills

[Eddycycles]

with out grill it different how to set up the spaker. Is JBL have make this look? I can't see any Olmpus look like my spaker.Please HELP:banghead:

[Eddycycles]

sizeway look

[rgwalker]

If it isn't real it's a damn good copy.

Bob W

[Robh3606]

It close but it's not the originals

http://www.lansingheritage.org/images/jbl/catalogs/1974-home/page04.jpg

Rob:)

[Eddycycles]

Thanks for the answer but I have open and look insize it very good make . That why I don't think my is copy. Plesae give me some advice way to sand the picture to.

[rgwalker]

Thanks for the answer but I have open and look insize it very good make . That why I don't think my is copy. Plesae give me some advice way to sand the picture to.

There were cabinets built to JBL specs and perhaps even with JBLs blessing. My own Olympus S7s are not JBL although they look identical, inside and out. Every detail down to the veneer insert along the top edge has been copied and the only real differences are no logos and the fretwork on the grille is different.

Bob Walker

[rgwalker]

Thanks for the answer but I have open and look insize it very good make . That why I don't think my is copy. Plesae give me some advice way to sand the picture to.

I could be wrong but OEM Olympus cabinets have front mounted woofers using clips.

Bob Walker

[Ducatista47]

He has a working pair of Olympus or Apollo in his house and is in any case a go-to man for information like this. For all I know he may have built some.

Clark

[mech986]

After reviewing the JBL Factory literature and a number of photos in my archives, I think we could make a strong arguement for your speakers being very good copies of the real JBL Factory C50 Olympus speakers.

First thing though, that is not a bad situation in that many, many copies of the JBL Olympus cabinet were built over the decades. In fact, in the US there were a number of furniture and cabinet makers in the late 50's and early 60's who would build custom and copy cabinets for people and many copied JBL. In fact JBL published some detailed drawings of baffle layouts that could be used.

Below you'll find 5 photos showing the cabinet details. These photos were pulled from an auction but are very similar to my Olympus speakers. Here's the details that distinguish the factory JBL cabinet from yours. Again, do not take this as a negative, just pointing out the differences.

1. The JBL factory cabinet will most of the time have the small raised badge on the back indicating the cabinet type and identifying it as a JBL product. If it is missing, there should be evidence of it being attached there with 2 nail or brad holes. Of course if the back has been refinished, this evidence would be lost.

2. Some JBL cabinets have a cutout as pictured below for the JBL "Energizer", a bolt in amplifier that makes the speaker a powered speaker (pretty advanced for those days). However, that is not always on these cabinets and I've seen genuine cabinets with a flat back.

3. The 2 crossovers are usually mounted on the bottom edge of the speaker back. That placement is fairly consistent. They are screwed directly to the back panel cutouts.

4. The grilles on the JBL's are carved and fitted fretwork and are obviously much more detailed than yours. Yours are a decorative stamped wood cutout pattern which is much more open but lacking in detail and depth. Nothing wrong with it but it is not the factory grille. I'll try to get another picture which shows the grille really up close.

5. Here's some of the real detail in the differences in the JBL vs. yours. All JBL cabinets of that era were built in a furniture type shop. The cabinets were made by precision cutting and joints were lock mitered and glued. On the Olympus/Sovereign type cabinets, no exposed screws or removable baffles or backs were ever used, if I recall correctly. You can see that the JBL baffles and backs are smooth all the way to the edges all around.

The reason for that is it makes for the most solid and airtight of cabinets and provides for real longevity. In the JBL enclosure plans for do-it-yourself cabinet builders, it does mention using screws and seals becasue most DIY builders do not have access to making lock mitered joints.

Your cabinets have screws showing at the front and I suspect the back panels. This provides for easy building and access to the components, a different choice than what JBL did or does.

I'll continue the discussion in the next post with additional pictures.

Bart

[mech986]

Cabinet differences continued:


6. C50 cabinets had the drivers mounted on the front of the baffle and the vast majority used 4 screwed on clamps to hold the woofer and passive radiator. Occasionally you might see the drivers held on by screws but I could not say whether those were original or changed by the owner or factory. In any event, the drivers were NEVER mounted from inside. There are a number of reasons for this.

JBL didn't use a removable back or baffle so all their woofers HAVE to mount from the front. The clamps provided better holding power since the clamp bolt/T-nut are farther from the cutout edge. This changed in later speakers probably from getting better density particle board wood.
The JBL woofer and passive radiator are built with thick cast aluminum frames with a machined finished edge. By mounting from the front, you can see and touch this exquisite expression of JBL materials, engineering, machining, and manufacturing. The clamps provide an easy method of mounting consistent with some of JBL's early studio monitors with 15 inch drivers.
In your speakers, the T-nuts are mounted on the outside of the baffle and are visible despite the black paint. While not bad from a structural viewpoint, JBL just didn't do that because of the visual look and hiding their driver. Also, you'll see that back mounted, the driver has a small cavity to work in which may affect the response from the cone and the surround. Also, by back mounting the drivers, the magnet and voice coil centers are deeper which may affect the time alignment somewhat although I'm not certain that was a big concern in those days. But it is not the factory method for sure.
7. Look closely at the bottom and top of the front baffles. There are small wood blocks with holes mounted in front of the woofers. These are put there to hold the woofers in while being mounted and to provide a guide hole for a guide pin on the grille. Because the JBL grilles are somewhat fragile, the grilles mounted with guide pins and small clips on the tops and sides.

Your speakers do not have this feature as I suspect it uses a more simplified mounting method. Not a negative, just not how JBL did it, and in keeping with a DIY or cabinet maker copy build and decision.

8. All C50 cabinets were set up for possible mirror imaging of the tweeter. To do this, all baffles were cut with two tweeter holes on either side of the baffle. The unused hole will have a cover plate attached either in front or behind. Your speakers do not have this characteristic cutout.

9. Early versions of the slant lenses used on the C50 are made of wood and have a vertical support in the middle and both sides visible from the front as seen on the pictures. Later versions did not have the supports visible, and even later version were made from plastic. Yours look to be the correct type and vintage but there looks like some black strips of something (velcro?) on either side of the two baffle mounting bars on yours. If you unscrew the lenses, can you post a picture of that?

10. Obviously, your woofer has been refoamed and that is normal for that driver. Please post a picture of your drivers so we can see what they are.

Your speakers appear to be very good copies of the JBL cabinets and if the drivers are all JBL and in good condition, especially the 375 and the crossover, then they should sound pretty close to the real thing. The only thing that would be an issue is if someone represents these as the actual Factory JBL product and charges/or pays for that price.

However, I've seen a lot of JBL C50 auctions where the speakers look very close and many cannot tell the difference between real factory and close replica. In many auctions, there are only selected photos and the backs especially aren't pictured.

Tell us a bit more about what the speakers were represented to you as and how you obtained them.

Hope this helps, remember this is a discussion and in no way meant to demean your speakers. They do look pretty good. If you remount the drivers on the front, and maybe add another tweeter cutout and cover plate, they'd look even closer.

Regards,

Bart

[oldsoundz]

I think they are probably copies due to the woofers being mounted inside, as well as not having the cutouts in the front opposite of the 075. The cutouts allowed for mirror imaging of the tweeter.

[Eddycycles]

Thank you for all answer :) It help me a lot.

[hjames]

Thank you for all answer :) It help me a lot.
But - how do they SOUND - do you like the sound?

[isvasu]

Thanks for the answer but I have open and look insize it very good make . That why I don't think my is copy. Plesae give me some advice way to sand the picture to.



Eddycycles
Did you purchase yours from Singapore or a Singaporean purchased from you?
Copy? I do not know. Do you know the Chinese is building its own Pentagon in over 70 acres at the moment?
I am from Thailand too and I have a pair as well. Mine is just like what a senior member ( mech986 ) described. Isvasu

[frank23]

To revive this thread a little, I have also bought a pair of non original JBL's, but the cabinets are very well built from plywood. And I found out they have a sloping baffle, so probably even better thought through than JBL's own Olympus...

http://www.audioheritage.org/vbulletin/showthread.php?33475-acquired-a-pair-of-JBL-Olympus-with-S8R-kit

[Mr. Widget]

To revive this thread a little, I have also bought a pair of non original JBL's, but the cabinets are very well built from plywood. And I found out they have a sloping baffle, so probably even better thought through than JBL's own Olympus...

http://www.audioheritage.org/vbulletin/showthread.php?33475-acquired-a-pair-of-JBL-Olympus-with-S8R-kit
The JBLs I've seen also had sloping baffles, but they were made of particle board.


Widget