JBL Concert Speakers: power & Connections?

[kyrvas]

Here are some larger images:

 

[TLS Guy]

The speaker connection is a Neutric Speakon connection.

You need a plug like this to connect to the speakers.

That is a very good speaker connection by the way. It should have become standard but did not.

There is a control shown with no knob on it. I suspect that is to level the midrange driver.

I strongly suspect these speakers are DIY.

You can not connect these speakers to a mix desk. I suspect in performance he connected the mixer left and right main outs to the input of the BGW ppwer amps. In their day, I thought the BGW amps where the cream of the crop of high powered amps in the seventies and later. They were much better and more stable than the Crown amps.

He then would have connected the speaker connections of the BGW power amp to the speakers with the speakon connector.

I suspect he powered them from the receiver when at home. If the receiver has preouts, then he might well have connected the preouts to the BGW and then to the speakers.

So we need pictures of the connectors in the mixers and the receiver.

 

[TLS Guy]

Yes, that receiver is early to mid seventies. It does have preouts and main ins. These are connected with "jumpers".

I suspect that your relative did use the preouts to power the speakers via the BGW at home. In which case the jumpers may well be missing. So we need a picture of the back of that Marantz receiver.

You can get a copy of the user manual on Hi-Fi engine. You will need to register.

I have done a lot of this sort of thing in my time, and I will likely know how your relatives mind worked and how he connected this when I get the details of the the mixers. He would not have used all the mixers at once, but selected the most suitable for the job at hand.

 

[lovinthehd]

A larger image of the speakers is available, if it would help.

Today, I found a receiver, amp, and several mixers.
- Marantz Model 2270 Receiver
- BGW Stereo Power Amp Model 210
- Mixers are different sizes: Tangent, Mackie, Yamaha (smallest)

When looking at the backs of the receiver and amp, I see only standard speaker wire connections.
The JBLs have heavy shielded? cables with one blue end (canon-plug type) that goes into the back of the JBL, and the other end is a plug that I've seen plugged into mixing boards. So, how do the JBL cables connect to my amp or receiver?

I suspect that's a speakon or similar type cable going into the JBL speakers, some amps have those connectors, generally pro-style amps will, consumer gear not so much, but you should be able to use speaker wire with bare ends just fine for the connection to an amp's speaker output. Mixers probably use an XLR-type connection or maybe a 1/4" plug of some sort....and that's a pre-amplifier signal for the mixer.

I used to have a similar Marantz receiver many many years ago (late 70s). Not familiar with the amp. Seems like you've got enough to make some tests if the gear still functions.

 

[kyrvas]

Yes, that receiver is early to mid seventies. It does have preouts and main ins. These are connected with "jumpers".

I suspect that your relative did use the preouts to power the speakers via the BGW at home. In which case the jumpers may well be missing. So we need a picture of the back of that Marantz receiver.

You can get a copy of the user manual on Hi-Fi engine. You will need to register.

I have done a lot of this sort of thing in my time, and I will likely know how your relatives mind worked and how he connected this when I get the details of the the mixers. He would not have used all the mixers at once, but selected the most suitable for the job at hand.

TLS guy - thanks for the link to the Marantz 2270 Rcvr manual.
Regarding foam mountings, I don't know but can try a closer image capture.

Here are some images that I think you all are asking for:

This is a 20"; he had two. There are also a couple probably 30' long; one has 1/4" male end with the Neutrik on the other; one has a Neutrik and bare wires on the other end.

Online image; will take a better image tomorrow.

Online image; will take a better image tomorrow.

 

[kyrvas]

I suspect that's a speakon or similar type cable going into the JBL speakers, some amps have those connectors, generally pro-style amps will, consumer gear not so much, but you should be able to use speaker wire with bare ends just fine for the connection to an amp's speaker output. Mixers probably use an XLR-type connection or maybe a 1/4" plug of some sort....and that's a pre-amplifier signal for the mixer.

I used to have a similar Marantz receiver many many years ago (late 70s). Not familiar with the amp. Seems like you've got enough to make some tests if the gear still functions.

lovinthehd - my BIL has probably a hundred feet of speaker wire; gauge? XLR connects he did mention with mics and something else but don't remember what. I hope I can keep up with you guys.

 

[TLS Guy]

TLS guy - thanks for the link to the Marantz 2270 Rcvr manual.
Regarding foam mountings, I don't know but can try a closer image capture.

Here are some images that I think you all are asking for:

View attachment 21170
This is a 20"; he had two. There are also a couple probably 30' long; one has 1/4" male end with the Neutrik on the other; one has a Neutrik and bare wires on the other end.

View attachment 21171
Online image; will take a better image tomorrow.

View attachment 21172
Online image; will take a better image tomorrow.

View attachment 21173

I need a good picture of the back of the Marantz, to see if the jumpers are present.

If they are you can connect the speakers to the Marantz. Use the bare wire connector to Speakon to the speaker outputs of the Marantz. Make sure both +ve go to the positive speaker outputs and the -ve to -ve. The you can hear what the speakers sound like.

We will get into mixers, if you are going to use them. However I doubt you have a use for them.

 

[kyrvas]

I need a good picture of the back of the Marantz, to see if the jumpers are present.

If they are you can connect the speakers to the Marantz. Use the bare wire connector to Speakon to the speaker outputs of the Marantz. Make sure both +ve go to the positive speaker outputs and the -ve to -ve. The you can hear what the speakers sound like.

We will get into mixers, if you are going to use them. However I doubt you have a use for them.

TLS guy - thank you, this is sounding doable. Tomorrow, I will get a shot of the back of the Marantz rcvr..

 

[lovinthehd]

lovinthehd - my BIL has probably a hundred feet of speaker wire; gauge? XLR connects he did mention with mics and something else but don't remember what. I hope I can keep up with you guys.

Here's a gauge table in terms of speaker impedance and distance of speaker wire runs...http://roger-russell.com/wire/wire.htm#wiretable

 

[-Jim-]

Kyrvas,

The Marantz is an old classic, and quite collectible to the right person. Ages ago I had a couple of Marantz receivers of this vintage ( a 2245 and a 2325). For your tests, let's use the 2270 without a mixer. Here's the rear connections:

The speaker connection are quite simple on the 2270. As you don't know the model of the JBLs I'm guessing they have a 1/4 inch phone plug as that was common at this time with semi-pro gear, but I could be wrong. Please post a photo of the connection point on the rear of the JBLs.

You need to turn the volume knob all the way counter clockwise before plugging in the 2270. It's okay to see if it lights up without anything else connected to it. If it does (you will hear some protection relays click in after a few seconds), and you have some headphones with the correct adapter, you can see if you pick up anything on AM radio with it's built in antenna. If this all works, then the amplifier section will probably work as well.

 

[kyrvas]

Here's a gauge table in terms of speaker impedance and distance of speaker wire runs...http://roger-russell.com/wire/wire.htm#wiretable

lovinthehd - thanks for the link to the Maximum Wire Length Table. There are commercial grade cables for two speakers; see image below (16 AWG, 46' each). Then there is many feet of brown speaker wire; don't know what gauge.

 

[Verdinut]

Kyrvas,

The Marantz is an old classic, and quite collectible to the right person. Ages ago I had a couple of Marantz receivers of this vintage ( a 2245 and a 2325). For your tests, let's use the 2270 without a mixer. Here's the rear connections:

The speaker connection are quite simple on the 2270. As you don't know the model of the JBLs I'm guessing they have a 1/4 inch phone plug as that was common at this time with semi-pro gear, but I could be wrong. Please post a photo of the connection point on the rear of the JBLs.

You need to turn the volume knob all the way counter clockwise before plugging in the 2270. It's okay to see if it lights up without anything else connected to it. If it does (you will hear some protection relays click in after a few seconds), and you have some headphones with the correct adapter, you can see if you pick up anything on AM radio with it's built in antenna. If this all works, then the amplifier section will probably work as well.

Jim,

His JBL speakers don't have ¼ inch phone jacks. They use Neutrik SpeakOn male connectors for connecting female cable plugs.
Refer to the pics which the OP provided in a previous post. You will also see that he already has the proper SpeakOn female connectors on the cables that he took the pictures of.

 

[kyrvas]

Kyrvas,

The Marantz is an old classic, and quite collectible to the right person. Ages ago I had a couple of Marantz receivers of this vintage ( a 2245 and a 2325). For your tests, let's use the 2270 without a mixer. Here's the rear connections:

The speaker connection are quite simple on the 2270. As you don't know the model of the JBLs I'm guessing they have a 1/4 inch phone plug as that was common at this time with semi-pro gear, but I could be wrong. Please post a photo of the connection point on the rear of the JBLs.

You need to turn the volume knob all the way counter clockwise before plugging in the 2270. It's okay to see if it lights up without anything else connected to it. If it does (you will hear some protection relays click in after a few seconds), and you have some headphones with the correct adapter, you can see if you pick up anything on AM radio with it's built in antenna. If this all works, then the amplifier section will probably work as well.

-Jim- thanks for the input; see Posts #21 & 31 for the Neutrik connection and cable end.

Regarding 1/4" phone plugs, there are a pair of brown cables with male & female 1/4" ends; but since the JBLs have the Speakon? connections, I assume these brown wire cables with the 1/4" connectors will have to be modified.

I appreciate the heads up on the volume to be turned down, listening for the protection relays, and testing AM via headphones; I'll look for appropriate connector for the headphones.

 

[kyrvas]

I need a good picture of the back of the Marantz, to see if the jumpers are present.

If they are you can connect the speakers to the Marantz. Use the bare wire connector to Speakon to the speaker outputs of the Marantz. Make sure both +ve go to the positive speaker outputs and the -ve to -ve. The you can hear what the speakers sound like.

We will get into mixers, if you are going to use them. However I doubt you have a use for them.

TLS Guy - below are front and back images of the Marantz 2270. I see what you mean about jumpers; although I don't know the usefulness of these. Regarding the +ve / -ve, when looking at the bare wires in Post #31, one is black and one is white; which is positive and which is negative?

 

[kyrvas]

In this thread, someone asked if the drivers had foam; I don't think so; the midrange and woofer appear to have paper or cardboard. See images below.

 

[lovinthehd]

I think I've read about JBL speakers where the cones and surrounds are integrated, with some sort of doping treatment for the surround portion. If the material isn't showing tears or gaps it's probably fine....ready to fire 'em up and see if they work?

 

[TLS Guy]

TLS Guy - below are front and back images of the Marantz 2270. I see what you mean about jumpers; although I don't know the usefulness of these. Regarding the +ve / -ve, when looking at the bare wires in Post #31, one is black and one is white; which is positive and which is negative?

View attachment 21188

View attachment 21189

The jumpers are in place, so you are good to go. Just make the white cables the +ve and the black the -ve. As long as left and right are connected the same way everything is fine.

If you want to try the BGW later, remove the jumpers and connect the preouts to the BGW inputs with screened audio cable. Connect the speaker outputs of the BGW to the speakers instead of the Marantz. Don't make this complicated because it is not.

 

[kyrvas]

I think I've read about JBL speakers where the cones and surrounds are integrated, with some sort of doping treatment for the surround portion. If the material isn't showing tears or gaps it's probably fine....ready to fire 'em up and see if they work?

lovinthehd - fire them up is right; but first I am using the cautions of the Audioholics. Today, I powered on the Marantz rcvr, with the volume down; turned to AM and saw the Signal Strength Multipath? meter needle enter the fourth strength bar; but no audio through my headphones. So, I'm looking through the manual now.

 

[kyrvas]

The jumpers are in place, so you are good to go. Just make the white cables the +ve and the black the -ve. As long as left and right are connected the same way everything is fine.

If you want to try the BGW later, remove the jumpers and connect the preouts to the BGW inputs with screened audio cable. Connect the speaker outputs of the BGW to the speakers instead of the Marantz. Don't make this complicated because it is not.

TLS Guy - all these pieces of info are useful to me;and, yes, I would like to use the BGW also.
One thing I just realized, my BIL probably had not used the Marantz rcvr. for some time because when I found it in its original box, the power cord had the styrofoam melted to it. But the rcvr. came on nice and quiet with all the lights coming on; and the knobs turned solidly.

 

[lovinthehd]

lovinthehd - fire them up is right; but first I am using the cautions of the Audioholics. Today, I powered on the Marantz rcvr, with the volume down; turned to AM and saw the Signal Strength Multipath? meter needle enter the fourth strength bar; but no audio through my headphones. So, I'm looking through the manual now.

At least part of the electronics are functional. I'd think the headphones would be functional on insertion but you might also make sure there isn't an accumulation of crud in the headphone jack; even lint in a jack can cause issues....when will you try speakers?

PS You were sure to use the headphone rather than dubbing jacks?