First was the connection stage: cables and adapters. Getting from Male XLR ports in an 896mk3 to the inputs of headphone amps (or the headphones themselves if the resistance works out, as in earbuds) was a surprisingly difficult task using commercial products. It would be much easier to build your own cables, but I was determined to do it with commercial products, so you can click my link to find out where I ended up. (there are pictures later in the thread)
Next was the headphone stage: I needed a good headphone amp. After learning about the Behringer HA8000 (aka: the PowerPlay Pro-8) I decided to give it a try. This post is about that device and how it fits into this overall picture. First, some pictures:
Here's the HA8000 at Sweetwater:
Here's a sample of the front panel:
And the back:
One can see that each section (8 separate amps) has both a discreet TRS input, and the ability to use the global Main Inputs, either 1 or 2, selected with a 2 position button. In addition, there is a mono button and a gain control, along with an output level meter for each of the 8 amps. So, each headphone can choose one of three sources, two global or one direct. The two global inputs each have gain controls on the left side of the front panel. Direct input for each amp is a TRS jack in the rear, for 8 total direct inputs. The global inputs are also in the back; more on that in a moment.
First the good stuff: The headphone amps are not bad. They're not great, either. They have a lot of noise at any volume beyond about the middle of their range, but that's awfully loud. One generally does not need for them to be that loud. Which brings up the fact that they are more than adequately powered. These will blow your ears off if you turn them up. Sound quality, on a scale of 1 to 10 (where 10 is the best possible sound) is about a 6. Better than average. When compared with the source itself, I can tell the difference, but it's not a big difference. But you must connect it properly or it can sound terrible.
The connections feel solid, as does the construction of the box. The rack ears are just L-brackets, but seem adequately secured to the box. It would take a lot of road wear to jar them loose. The gain knobs are digitally stepped, not analog, and all the buttons and knobs feel kind of cheap, but again, adequate. When the 2 buttons in each of the 8 amp sections are in depressed position, yellow or red lights come on to indicate that you've chosen input source #2 or mono, relatively, for each headphone. I've no real complaint about its quality, construction, or design. It feels like quality hardware. I don't have a metric with which to measure that empirically, so I'll go with feel and leave it there.
Now for the less-than-good, at least as far as my purposes go. The motive that triggered this whole investigation was to give each person a mix of their own to emphasize possibly their own sound, or maybe the sound of the rhythm section, or wherever the beat is. So that brings us to...
Stage 3 of this project, CueMix:The idea was to to use CueMix to provide that mix, delivered directly to each of the 8 discreet headphone amps in this single rack-space box. If you're recording live musicians playing together, and not overdubbing, this is a fine idea. But the problem emerges when you want to punch in or to record with pre-existing material, whether a click track or a rhythm section or even a piano or drum. Here's why: CueMix is set up to provide up to 8 discreet mixes of the live inputs. Each is assignable to its own mono output, or you can make 4 discreet stereo mixes assignable to their own stereo output pairs. CueMix is NOT designed to include sound from your host DAW in those mixes. So, the idea of mixing the current output from DP along with the live microphones won't work in CueMix. You'll have to do that in Digital Performer, monitoring through effects, not direct hardware playthrough.
So, let us say we take a feed from DP, and put it through the global inputs of the headphone amp. The global inputs distribute their source to all 8 headphones. Why not do that and blend in the Direct Input? Because the Behringer HA8000 is not designed to mix those inputs, but select between them. You have your choice of global 1, global2, or direct input; not some mix of any two of the above. Further, the selection of direct input happens when you plug a TRS cable into the TRS jack in the back. As with normalized patch bays, inserting the plug disengages the other input sources. The two global inputs cannot be mixed with each other, because there is a panel switch on the front which selects between them. (I think the design would be improved with at least a switch for the direct option, too, rather than the patch-bay approach, which requires you to get behind the box to plug in the direct input, or to unplug it if you want to return that channel to the global inputs.
The ideal would be to have a global input and a direct input, with a knob that mixed them to any degree from fully one or the other, or any wet combination of the two. With such an arrangement, you could output your current mix in Digital Performer directly from the Main Outs to the global input, and then add as much of the CueMix live mix as you wish. THAT would be the perfect setup, but it's not to be found in the HA8000.
It so happens that Behringer makes a box that fills that exact need. It's called the PRO-XL HA4700. I wish I'd figured this out before buying, but this would be more the ideal box for the particular setup I'm trying to create. It only can handle four headphones, but one could probably use splitters and satisfy pretty much everyone with just four mixes. Or you could get two HA4700s and connect the 2nd one to the XLR outputs of the first. Yes, it uses XLR inputs for the global input source, which greatly simplifies the whole cable/adapter issue. The individual direct inputs on the four headphone amps are still TRS stereo jacks, so you still need to have adapters and cables for the directs.
Lastly, let's talk about the global inputs on the HA8000. It has left/right inputs for each of the two global sources. Each of the two global inputs has a pair of TRS jacks, one marked for MONO input, and the other channel labeled "balanced." The idea, of course, is to run a balanced cable from each of the output channels from your Main Outs of your source, with XLR Female on one end and a TRS on the other. It must be properly wired in order to work, and in this case, "properly" means:
- Sleeve to Pin 1 (ground)
Tip to Pin 2
Ring to Pin 3
- Sleeve = Pin 1 (Common or Ground)
Tip = Left
Ring = Right
So, after all this, I still don’t have exactly what I need. I need to be able to combine live inputs with one or more outputs from DP, emphasizing whatever live inputs I want over the background of the pre-recorded tracks. The HA8000 is an either-or proposition. It cannot mix inputs, only choose between them. It appears that the one I need is the Behringer HA4700. But for what it is, the HA8000 is a very nice device. Its only failing is that it cannot compensate for CueMix’s failings! Why MOTU did not design CueMix with a fader for an output from DP, I’ll never know, but I cannot find anything that suggests it is there, so it appears that MOTU did not think of that when they made CueMix.
Maybe I’ll snag the HA4700 before all this is done. Or maybe I’ll just monitor through effects, with low buffer, and create different emphasis for each of the outputs channelized from DP to the 896mk3.
I hope this isn't too rambling and dense to make sense of. The problem is that we're really talking about several stages of a process, each of which has its own challenges. When doing this, its easy to look at any of those stages and think "if only they'd done this or that, it would make this whole thing very easy." I thought that if I found the exact process and steps, I could simplify it for everyone else. Instead, I think I've complicated it. The other Behringer headphone amp might be the solution for anyone wanting to do this. I think that would greatly simplify it.
Shooshie