Can one use 2 sets of monoblock amplifiers to one stereo set of speakers?

 My preamp can output to two sets of monoblock amplifiers simultaneously. At present, only one set of monoblock amplifiers is connected to a pair of soundlab speakers. Are there any positive or negative outcomes if I connect both sets of monoblock amplifiers to one set of stereo soundlab speakers?
I see no issues, though I doubt your speakers can handle more than you are currently feeding them (unless you are using tubes).
If I’m not mistaken most Sound Lab speakers employ an electrostatic element covering the entire frequency range.

If that is the case with your speakers, connecting two sets of monoblocks to the speakers would amount to connecting the outputs of the two monoblocks on each channel to each other, i.e., the outputs of the two amps would be paralleled. I would strongly recommend against doing that, unless the specific amps are known to be suitable for paralleling, which would be unusual.

And while there are some tube amps for which paralleling may be a reasonable thing to do, provided that the four amps are identical models, the only case I can think of involving a solid state amp that **might** be suitable for paralleling would be some McIntosh amps which incorporate autoformers at their outputs. And I have my doubts even in that case.

Consider what would happen if one of two paralleled solid state amps developed an internal failure, resulting in its output not being able to produce a signal. The other amp would be loaded by the near zero ohm output impedance of that amp, likely resulting in either blown fuses, protective shutdowns, or smoke and damage.

And if the two amps are not identical models, and do not have identical gains, their outputs would be constantly fighting each other trying to establish differing output voltages. That would apply whether they are tube based or solid state. And if they are solid state, to the extent that their gains differ each amp would be loaded by the near zero output impedance of the other amp. Resulting in degraded sonics at best and damage at worst.

Not a good idea, except under very special and well understood circumstances.

-- Al

He’s talking about bi-amping, which wouldn’t be similar to parallel wiring. Though I may be mistaken.
@mzkmxcv, perhaps that is so. But as I mentioned I believe that most Sound Lab speakers run a single electrostatic element full-range, rather than having low frequency and high frequency sections that are separate and independent. If that is so in the OPs case the speakers could not be biamped, of course, and connecting two amps to each speaker would amount to paralleling them. Hopefully the OP will provide further clarification.

-- Al
I thought Sound Lab speakers to be one of easier to drive electrostatic speakers. If that is the case, I can't think of why you'd want to use two sets of monoblocks, as I don't think it would yield a significant improvement in sound reproduction.
Just my 2 cents...
You may do this IF and only IF the speakers you are driving allow you to separate the two halves.

You may NOT allow the two amplifier's outputs to cross connect.

The reason has to do with feedback. If one amp is off even by 0.1V, they will dump all possible current into arguing over which voltage is correct.