Phase is something we have not really dug deep into on this thread. Lyngdorf doesn't discuss much either [anymore at least]. Maybe because it reveals that RoomPerfect is not always as simple as they make it out to be? RoomPerfect does not automatically set delays like most other Room EQs. Which is why you must manually measure mic to speaker distances precisely. I'm not sure why it doesn't or cannot do this. It is something I wish they would add. I can't imagine why it wouldn't be possible, but perhaps it is not.
Most subwoofer systems have DSPs and add additional delay depending on the features activated (i.e. low-pass filter). On the TDAI-2170 it actually has a seperate field for entering amplifier delay.
The available settings are:
If you are using a setup with speakers and/or subwoofers located at an identical distance to the listening position, you don’t need to set a distance. If the distances are not identical, you need to enter it in order to ensure that the sound from each loudspeaker reaches the listening position simultaneously. To correctly measure the distance, please see Guided Speaker Setup.
On analog and digital out, you can set an amplifi er delay. If you have an active subwoofer or an additional amplifier, there will be a natural electronic delay in these products. Refer to the original manufacturer’s instructions to obtain the correct amplifier delay.
There is no field or mention of the amplifier delay in the MP-50 or TDAI-3400 menus & documentation. The TDAI-3400 manual reads as follows:
To have sub and speakers interact correctly, they must be in phase, so that the part of the music coming
from the sub arrives to the listening position at the same time as the sound from the front speakers. Measure
the distances from the preferred listening position (the focus position) to the front of the speakers.
When measuring the distance to a sub, measure from the preferred listening position to the wall or corner
behind the sub. As the sub is omnidirectional at frequencies below 80 Hz, the acoustic centre of the speaker
must consider the reflection from the wall or corner.
I discussed this with
, a Lyngdorf dealer & installer in the U.K. with extensive experience with RoomPerfect. He told me that for optimal calibration you still need to consider the delays added by subwoofer and even active speaker DSPs/amps. They most commonly deploy M&K subs and have the delay values for each model. On the MP-50 and TDAI-3400 the delay must be converted to distance and added to the measured values. RoomPerfect should be restarted if the distances are changed.
My suggestion for those with REW is to use the acoustic timing reference to fine tune the distances entered to ensure phase alignment. This is no different than the Sub Distance Tweak often discussed.
With multiple subs sharing the LFE output one will have to manually adjust delay or phase on the plate amps or utilize an external DSP like miniDSP (I am using Symetrix Jupiter at the moment).
If you strive for subwoofer perfection, but this is all beyond your skill & desire, contact your dealer or you can contact me.