JBL Speaker Questions

Raycomics

Active Member
I just recently acquired a vintage pair of JBL Speakers.

These do not have a model number, but writng on the back of the large, heavy Cabs that says: "JBL Solid State Energizer/Transducer"

There are 1/4" inputs for connecting the two speakers together, with standard speaker terminals (4) on 1 Speaker.

On the same speaker cabinet there is a female end plug, with a switch above it. (The previous owner cut the male end plug.)

I opened up on of the Cabs, and saw a 15" Speaker marked "D-130".

I looked this particular speaker up on the JBL Website and was fairly excited, as it was designed by/for James B. himself!

My questions are: Just what do I have, where can I find the missing male plug, and what sonic properties does this add to the speakers? (I am sure that the switch (crossover?) does something)

Thanks for any and all info. (esp Don if he chooses to answer)
 
Vintage JBLs Update

I went to Radio Shack and purchased a 25 ft 1/4" plug speaker cable.

Hooked the speakers together, plugged in the speaker wires, (attached to the Onkyo) turned everything on, and...... No Sound!

Next Thing: Tried connecting an extension cord to the Male End on the Cabinet, (Female End Plug was cut by the original owner)
and Still No Sound!

I read that this is a 16 ohm speaker, and I am running juice from a receiver (Onkyo) that provides for an 8 ohm load, could this be the problem?

Could it be that the speakers are blown, or does the Engergizer/Transducer thingy plays an essential part in getting the speakers to operate properly?

Are these speakers part of a pro system setup?

Questions, Questions, Questions.

BTW, 1 Speaker Cab (the 1 with all of the electronics) weighs a ton more than the other. Could this 1 have a built-in Amp?

Stay tuned.
 
Hi Raycomics.

I would be surprised if your system was a D208, but anything is possible. The reason I say this is because it is the wrong vintage to be used with the Energizer/Transducer. As I stated in my previous post, the Energizer is a power amplifier that JBL offerred as an option in the 1960's. My guess is that your system is one of those shown on the following page from the 1967 catalog:

http://www.lansingheritage.org/images/jbl/catalogs/1967/small-boxes.jpg

Look closely at the C36 Viscount and C35 Fairchild. These are pretty close in appearance to the D208 and I would suggest it may be one of these. If it is one of these enclosures, we are still only part way to identifying the entire system. You have to understand that JBL sold enclosures separately from drivers at that time, so once the enclosure is indentified, the actual speakers used would still be unknown. JBL sold a number of kits that would fit into the two enclosures mentioned above. To positively identify them, you would have to remove the back of the speaker and note the model numbers of the drivers and cross-over inside the box.

The problems you are having in getting the speakers to work are probably due to the presence of the Energizer/Transducer and not the 16 ohm impedence of the drivers. Your Onkyo reciever is not limited to 8 ohm loads. The 8 ohm rating is just used as reference impedence for standardized power rating. Any solid state receiver should work well with a 16 ohm load.

Back to the Energizer. Again, this is a powered, stand alone amplifier rated at around 40 watts/channel. You can read about it here:

http://www.lansingheritage.org/images/jbl/catalogs/1967/amps.jpg

To use this amp, you need to have a preamplifier, or at least pre-amp outputs on your receiver. DO NOT CONNECT THE SPEAKER OUTPUTS OF YOUR RECEIVER TO THE ENERGIZER INPUTS. This can cause severe damage.

To simplify matters, and check that the speakers work, disconnect the Energizer. This means that the wires from the Energizer to the corss-overs should be disconnected at the cross-overs. Just as a precaution, make sure the Energizer is both turned off and unplugged (i.e. not connected to a wall outlet). Connect the speaker outputs of your receiver to the speaker inputs of the cross-over networks for each channel. This should work. If not, there are other wiring options that can be explored.

BTW, the Energizer/Transducer is a relatively rare device. They were not in production long since few were sold. They contain custom equalizer cards that are designed for specific speakers. Once you get the system working without the Energizer, it would definitely be worthwhile to try and get that device up and running.
 
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JBLs

Thanks Don!

The Cab is a C-36 Viscount.

I will and will post pics to give everyone a visualization of the current state of affairs.


Ray
 
JBL Mystery partially solved

The reason for no sound?

The Energizer/Transducer was not hooked up!

The Speakers are connected to the 1/4" Inputs with no juice running to them.

Methinks that the previous owner disconnected the "Bunny" to use strictly for Instrument Speakers.

Current State of Affairs Pics to follow.........
 
Success!

OK, so I unhooked the wires going into the 1/4" inputs, then connected speaker wires from the Onkyo, and..... Sound! Sound!

The Speakers are not blown.

Nice smooth, natural sound! Full, Tight Bass (very unusual for a Bass-Reflex)

And Hey, the backs of the Cabs are off.

I like it, I like it!

What are the next steps? (Don?)

I am thinking off to the local Speaker Repair Guy to work on the Enegizer/Transducer.

I would like to keep these as original as possible. Any suggestions?


Ray
 
From your pictures, I assume each speaker has one 15" D130 speaker that is being run full range. This is a bit unusual. The D130 really only goes up to 7khz and is rather uneven in the higher frequencies. However, as you have discovered, this is one of the best midbass drivers around, with visceral bass impact.

The D130 was most often sold with the 075 tweeter and N2400 cross-over to make a very basic two-way system called the "030". I would recommend looking into this since I don't think you will find the 7khz response of the D130 satisfying for any length of time. Adding this tweeter would not change the "original" character since the "030" kit was one of the most popular component systems used in the C36. It should also not affect the system performance with the Energizer since I believe that the EQ was only applied to bass frequencies. If you want even greater performance, you can look for a 175 or 085 as a mid/high driver. Again, this would be compatible with the "original" configuration of the C36.

Before sending the Energizer in for repair, check to see that it works. As I said previously, you will need a pre-amp or an intergrated amp or receiver with pre-amp outputs. It looks like there is a unique connector for the power cord. It's not clear to me if you have such a cord to power up the Energizer.
 
JBLs

Don -

Thanks again for the great info and timely response!

I have an electrician friend that can make a custom cord for the amp. (I had the same problem with a Revox RTR)

It is good to know that this is not originally a Bass-Reflex design.

As far as connections go, in a Amp/Preamp configuration, the speakers are usually connected to the amp.

How do I hook speaker inputs to the SE402? (I noticed that they are 4 screws (2 each - wired) at the base of the transformers.)

Then there is also the matter of the 1/4" inputs that the internal speaker wires were connected to when I acquired them, (some sort of parellel output?) and the switch (crossover?) with cut wires.


Will be seaching for the 175/085 drivers.

Thanks Again!


Ray
 
Hi Ray

Your system was originally, and is currently, a bass reflex design. You can see the port at the top left of the D130 from your interior photo. A D130 will not work well at all in a sealed cabinet the size of a C36.

As far as connecting the Energizer/Transducer, the RCA jacks labeled "Channel A Input" and Channel B Input" connect to the left and right "main out" of a pre-amp. The spring loaded posts connect to the speakers. Again, you need to have a "main out" or "pre-amp out" jack on your receiver. Most vintage receivers do not have this. It was generally only provided on high end models, although there are exceptions. If there, the pre-amp out connector will be an RCA jack like the input. You will need a fairly long interconnect unless you are willing to have the pre-amp/receiver sit on top of the speaker.

There is no cross-over on your speaker since there is only one driver (D130) per cabinet. The cut wires on the back of the enclosure are simply a termination of the internal speaker wires. This is what you would connect to the spring posts of the Engergizer (labeled Transducer Terminals). The Energizer is a stereo power amp installed in one speaker cabinet only. The cabinet it is installed in will only require a short run of wire from the Energizer speaker posts to the temination on the back of the enclosure. The second speaker will require a longer run of wire to connect to the Energizer in the first speaker.
 
JBL Energizer

Thanks Don!

I have a Dynaco PAS 3 Pre-Amp that I am thinking bout using if the Energizer is OK.

I think that this hybrid system might work well with the Alinico drivers.

Will keep you posted.
 
JBL Update

Took the Speakers to my Speaker Repair friend.

The Energizer/Transducer is Working! All that was needed is a heavy custom fitted AC plug.

I also won Ebay auctions for the 075 Bullet Tweets and N2600 Crossovers. Should be here by Friday.

Then its off to my friend for install.

I think that this will be a very fine 2-Way System when it is complete.

Will keep you posted. Thanks for all the help!
 
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