josq wrote:
You are right to mention the vertical dimension of the reverb: sound reflecting from the high walls/roof. Good to hear that you are able to achieve satisfying results using multiple speakers and convolution reverb. I guess the reverb/delay needs to be optimized per organ?
Ideally, yes, reverb/delay does need to be optimized for each organ, which can get complicated. Here HW5 would certainly offer an advantage insofar as all the reverb and delay settings for each mixer bus can be customized and saved for each organ--which Martin kindly clarified earlier in this thread. However, I have achieved spectacular results with HW4 and outboard reverb modules (my favorites made by TC Electronics).
I really don't think that any sample set needs more than 6 channels. In fact, even very minimalist organs in absolutely dead spaces like the MDA Buzard chamber organ (2 channels, 16 bit samples, NO natural reverb) can be brought beautifully to life. Extra "channels" can be gleaned from any sample set by routing the signals through a preamp or mixer that has multiple outputs. Some of these outputs can carry the direct dry pipe sound to an amp and speakers, and some of them can go to an outboard reverb and then to another amp and speakers.
I have found it absolutely key to separate the dry sound from the reverberations through separate speaker banks. The principle behind this is no different from that behind surround channels. You don't want the reflected sounds from the rear of the church coming through the front speakers along with the sounds recorded close to the pipes. In essence, reverberation can be introduced to create a synthesized surround with great depth. Again, its use has to be tailored to the acoustics already present in the sample set. With a set like Salisbury, the introduction of additional reverb would be overkill, to say the least. But with a rather dry set like the Portland Rosales, additional reverb can create a wholly different organ.
It helps to have speakers both on the floor and mounted up on the walls, and also to have them in different rooms if possible. The use of multiple speaker selector switches then allows sound channels to be routed here or there at will, and L-pads set the levels. Having all of this external to the organ console and not tying up the screen or computer allows me to custom tailor the organ while the player of the day goes about his business of rehearsing pieces and choosing registrations. Of course, the switch and L-pad settings do have to be carefully written down, but usually just once for each individual instrument.
If it's a vertical dimension you're after, mount speakers in the top of your stairwell and direct them away from listeners. With reverb sent to a different location, you can even create quite the realistic impression of a carillon or tower bells ringing over top the house!