Glad to hear of the good progress!
Regarding...
To explain why, I’ll first mention that in good designs circuit ground (also referred to as signal ground) will often be connected to chassis through a low value resistor, commonly somewhere between 10 and 100 ohms. In some cases circuit ground and chassis may even be connected directly together (i.e., through zero ohms), although that is poor design because it results in susceptibility to ground loop issues. Also, if the component has a three-prong power plug chassis will usually be connected to AC safety ground.
So in cases where BOTH the sub and the amp have three-prong power plugs, connecting the negative output terminal of a fully balanced amp to the negative speaker-level input of a sub (which is presumably connected to the sub’s circuit ground in most cases) would result in the signal that is present on the amp’s negative output terminal being sent through some unknown but probably low impedance in the sub to the sub’s chassis, then to its AC safety ground connection, then through the power wiring to the amp’s AC safety ground connection, then to the amp’s chassis, then through some unknown but probably low impedance in the amp to the amp’s circuit ground. Resulting in the circuit in the amp which drives its negative output terminal probably being loaded by somewhere between 0 ohms (a direct short) and 200 ohms. If that value is low enough, obviously the amp may either be damaged or forced into a protective shutdown mode. But even if the resistors are high enough in value to avoid that kind of issue, and to prevent sonics from being affected, one or both of the resistors might eventually blow as a result of having to handle more power than they are rated to handle.
I’ve seen a number of cases here where people using REL subs have reported connecting in that manner and getting away with it, presumably because the resistors were high enough in value to prevent a problem. But at best it is not good practice, and as I said it risks overheating and damaging the resistors eventually if not sooner.
Continued good luck! Regards,
-- Al
Regarding...
I was hooking the subs before to the black terminal. Do you think if I ever hook them up again I should avoid that? I did it with my Rethm’s and it worked good but your info is great info!Assuming that the sub has a three-prong power plug, yes I would avoid connecting in that manner.
To explain why, I’ll first mention that in good designs circuit ground (also referred to as signal ground) will often be connected to chassis through a low value resistor, commonly somewhere between 10 and 100 ohms. In some cases circuit ground and chassis may even be connected directly together (i.e., through zero ohms), although that is poor design because it results in susceptibility to ground loop issues. Also, if the component has a three-prong power plug chassis will usually be connected to AC safety ground.
So in cases where BOTH the sub and the amp have three-prong power plugs, connecting the negative output terminal of a fully balanced amp to the negative speaker-level input of a sub (which is presumably connected to the sub’s circuit ground in most cases) would result in the signal that is present on the amp’s negative output terminal being sent through some unknown but probably low impedance in the sub to the sub’s chassis, then to its AC safety ground connection, then through the power wiring to the amp’s AC safety ground connection, then to the amp’s chassis, then through some unknown but probably low impedance in the amp to the amp’s circuit ground. Resulting in the circuit in the amp which drives its negative output terminal probably being loaded by somewhere between 0 ohms (a direct short) and 200 ohms. If that value is low enough, obviously the amp may either be damaged or forced into a protective shutdown mode. But even if the resistors are high enough in value to avoid that kind of issue, and to prevent sonics from being affected, one or both of the resistors might eventually blow as a result of having to handle more power than they are rated to handle.
I’ve seen a number of cases here where people using REL subs have reported connecting in that manner and getting away with it, presumably because the resistors were high enough in value to prevent a problem. But at best it is not good practice, and as I said it risks overheating and damaging the resistors eventually if not sooner.
Continued good luck! Regards,
-- Al