2 things come to mind. First the sub is not in phase with the mains. You don't want the sound from the sub either leading or lagging the mains. My Rel B3 has a phase switch of 0 or 180 degrees. I had to physically move the sub forward or back to get it to blend in properly. Second if using the high level input the stock Rel cable is as poor as you can get. On a whim I ordered a Nordost baseline cable made to Rel spec ($35 upcharge from Norsost) and the effect was very noticeable. I heard attack and decay that I didn't know was there. Also when I put in the Nordost cable I found the timimg/phasing still wasn't quite right. Once dialed in it is fantastic.
That being said I use the Rel to pick up where the mains drop off.My Dyn C1 speakers are rated to 45hz but I cross the sub over at 34hz and have the gain about 10 o'clock.
That being said I use the Rel to pick up where the mains drop off.My Dyn C1 speakers are rated to 45hz but I cross the sub over at 34hz and have the gain about 10 o'clock.