Beolab 8000 and Monitor Audio Apex AW12

[KrisKollar]

Hi!

Sorry for the mess I've been testing for days now.

I recently bought a pair of Beolab 8000 (foam replacement already done) and I love them so much!
But of course they need a subwoofer and I went with the Monitor Audio Apex AW12 and in itself ir also sounds great.

The problem comes when I try to connect them.

The chain right now: PC optical cable to SMSL SU1 DAC (powered with power brick) then passive Y RCA splitter L to L Beolab L Monitor Audio R to R Beolab R Monitor Audio.

This is the best setup so far. But one Beolab plays a constant (sometimes oscillating) 17-18khz sound faintly. It is inaudible when listening to music. I had a passive Fostex pc1e but that made stuff worse (scary oscillation).

Ground loop isolator makes stuff worse Monitor Audio RCA out is for other subwoofers only.

If I remove the Monitor Audio from the chain the problem ceases to exist. My RCA cables are Oehlbach Ice Blue.

Monitor Audio power cable is original, Beolab powercables are not. They are generic. They were given to me when they were serviced.

I've been eyeing with an active RCA splitter like the Rolls DA134. But since I live in Europe something like the Tilear XZD-A1 would be easier for me to get or return if it doesnt work . Could this damage my system?

Is it possible maybe something inside the subwoofer is failing?

Am I missing something or would this be THE WAY to do it. Please help I'm going insane haha. Thanks.

 

[Redacted]

One Beo is likely picking up noise, so try swapping the Y cables (L To R) to see if the noise moves with the cable.
Also try swapping Beo L speaker for Beo right.
Basically try all the permutations and see if anything changes.
Also try without Y-splitters, and go direct to sub from DAC, and then use the sub's line-out ports to the speakers.

 

[KrisKollar]

One Beo is likely picking up noise, so try swapping the Y cables (L To R) to see if the noise moves with the cable.
Also try swapping Beo L speaker for Beo right.
Basically try all the permutations and see if anything changes.
Also try without Y-splitters, and go direct to sub from DAC, and then use the sub's line-out ports to the speakers.

Yes it moves to another Beolab when I swap the Y cable.
I tried the sub's line out but it's for other subwoofers not for speakers. They go crazy.

Would a preamp like the Fosi ZP3 fix this? It also has crossover so Beolabs wouldnt play the deeper frequencies.

 

[Redacted]

Sounds like one Y-cable has a poor internal connection.
Any pre-amp with a sub-out port could be used, but you could also use the pre-amp-out ports from it but if the noise is a bad Y-cable, you don't need a new pre-amp.

 

[KrisKollar]

I'm sorry I checked it again with 3 different Y splitters that I have and the problem was the same everytime. And only the Left Beolab. Even when it was connected into the right channel.

 

[KrisKollar]

I changed up the position of the two Beolabs and the faint noise went over to the other Beolab. Chaos. The Beolabs have 2-pin connectors, the sub has a 3-pin connector. Does this change anything? I'm really out of any ideas. I ordered the Fosi ZP3. If it doesnt work, I return it.