Help - Subwoofer Crossover when both REL T/5i & Marantz AV7702mkII have Crossover settings

System is:
* Marantz AV7702mkII
* Marantz MM7055 - driving Triad Silver Center, L&R Surround and L&R Back Surround in-ceiling speakers
* Marantz MM7025 - driving Sonus Faber Cremona L&R floor standing speakers
* REL T/5.1 Subwoofer

I used the Audyssey microphone on a tripod and Marantz's AV 7702mkII's on-screen software to set up the baseline. Audyssey detected that the Sub was too loud and I dialed it down to around 73dB until Audyssey was happy and said it was OK. I then ran through the Audyssey protocol twice. 

Here's my confusion.

The Marantz has a setting for the Sub crossover, with stepped settings ranging from 60 Hz to 250 Hz. Mine is currently set to 250 HZ, but I don't know if that was set automatically by Audyssey or if that's just where it was set by default or a previous setting when I first took it out of the box and set it up without knowing anything about what I was doing.

The REL has an infinitely variable dial for the Crossover that ranges from 30 Mz to 120 Mz. I have it set to about 55-60% of the dial's range because my ears thought that sounded best.

Here's the question: do these 2 Crossover settings compete with each other? If I lower the Marantz to 60 MZ (I'm thinking that only sends 60 MZ or lower to the LFE line?) does that mean if I raise the Crossover on the REL to 120 MZ (which does have an audible effect, although a bit boomy) it then takes all the Marantz 60 MZ-or-lower signal and reprocesses it to produce sound up to 120 MZ?

Likewise, if the Marantz is kept at 250 MZ and the REL at 30Mz, does that mean the REL cuts off everything above 30 MZ regardless, even though the Marantz is sending 250 MZ-and-below through the LFE?

Should I instead try to MATCH the Crossovers and some selective level? Such as Marantz 120 MZ and REL 120 MZ?

Unrelated question: The REL has a Phase toggle switch, 0 or 180. The REL instructions describe why I want the sub to be in-phase and which ever produces LOUDER bass is correct. But when I try it, I can't tell the difference (and I think I have pretty discerning ears).

Any other suggestions on how to tell? I am sure that my L/R Cremonas are phased +/- correctly and the wires to the five theater Triads are correct at the back of the Marantz. But my ceilings are 14 ft. high and getting up there to pull the speakers out to confirm that the tech wired all five correctly is a 4-5 hour job. So I'm hoping that he did it right. But if I'm thinking that whichever phase setting I use does not produce identifiable louder bass, might that mean that one or more of the Triads is out of phase with the others?

THANK YOU SO MUCH in advance for any opinions and assistance you can provide. This is a great resource!!!

Showing 1 response by jacobatrel

The crossover control on the back of the T/5i only affects the High Level and Low Level inputs, and does not alter the signal coming in through the .1/LFE input since the crossover for this channel is set by your AV processor. For home theater applications we recommend using both the High Level input (connected to your Marantz MM7025) and the .1/LFE input (connected to the AV7702 AV processor), which means the subwoofer will provide low-frequency extension for your SF Cremonas and at the same time play the LFE channel for surround sound material.


We recommend setting the front left and right channels to large, then setting the T/5i’s crossover control below where the Cremonas are naturally rolling off in their low-frequency extension. This is most easily tuned when listening to music with rhythmic and deep bass, rather than using a movie. After tuning the High Level input disconnect the Speakon cable from the back of the sub, leaving only the .1/LFE input connected, and run the room correction. After the room correction is finished you can reconnect the High Level cable and use the system with both connected. We have a good blog post on our website which details this and hopefully makes things clearer:


Regarding the phase setting, you are absolutely correct regarding what to listen for, but we have noticed that in some rooms and systems switching the phase control back and forth does not make an audible difference. In this case you can leave the switch in the zero degree position.