Hello,
I have several sets of Boston VR-M 2-way speakers. A couple M60 and a couple M50. These are identical except five of cabinet and driver. Each has dual sets of posts for bi-amp/bi-wire with the connection pieces for using single wire.
On a couple of them (one of each size) there is no longer any low end sound. Whether the connection piece is in place as usual or not (and connecting wire to the lower end posts only) there is no low end.
Where do I start to diagnose this problem? What is the likely culprit?
Thanks
I have several sets of Boston VR-M 2-way speakers. A couple M60 and a couple M50. These are identical except five of cabinet and driver. Each has dual sets of posts for bi-amp/bi-wire with the connection pieces for using single wire.
On a couple of them (one of each size) there is no longer any low end sound. Whether the connection piece is in place as usual or not (and connecting wire to the lower end posts only) there is no low end.
Where do I start to diagnose this problem? What is the likely culprit?
Thanks
One thought comes to mind as you have multiple failures... is there any possibility these have been used with an amplifier with a 'DC offset fault'. That means an amplifier that puts out a high DC voltage from the speaker terminals which can cause damage to speakers, possibly burning out the voice coils of bass drivers.
If you measure the resistance of the speakers at the terminals on the cabinet you will see what a good vs bad one reads. Going further I suspect you are going to have to remove the drive units and measure them to prove if they are open circuit.
If you measure the resistance of the speakers at the terminals on the cabinet you will see what a good vs bad one reads. Going further I suspect you are going to have to remove the drive units and measure them to prove if they are open circuit.
You only need a 1.5V penlight battery and some wiring arrangement to test a bass unit,
Even paper clips. Unscrew the basses for access.
You get crackles and cone movement if all is well. Then look for broken wires and solder joints.
Even paper clips. Unscrew the basses for access.
You get crackles and cone movement if all is well. Then look for broken wires and solder joints.
thanks all - I will begin further investigation - a bit more info - everything looks perfectly "new" from the outside (cone, foam, etc) and they have never been used with anything but standard modern receivers like mid/low -level generic denon/onkyo stuff.
