I’ve been hearing about the “Magic Box” for a good six months now, maybe more. Friends of mine who tried it raved about how it mysteriously increased gain before feedback without altering the tone of the original source significantly. It took a little doing, but I finally got my hands on one one to try out. In fact, we’ve had it for a few weeks and tried it in several “worst case” scenarios, and it’s done very well. But before we get to that, let’s look at what this is.
To be sure, I’m not entirely sure how it works. The manual is a little bit vague as well. It’s sort of like an expander, but it uses some other mojo to make it work the way it does. Similar also to a noise gate, the 5045 drops the level when it detects that the primary source is not coming through. By dropping the level, it breaks the feedback loop and prevents feedback from gaining a foothold. Jake Cody, the Yamaha House of Worship rep started explaining the inner workings of the device to me when he dropped it off, but admitted that he was lost during the description he received. So I’m not embarrassed to say I don’t know how it works, what I can tell you is that it does work.
The 5045 is a simple device. It’s two channel, and each channel operates completely independently. There is no stereo combine mode. The controls are simple; three encoders and two switches per channel. And actually, one encoder is a six-position dial. From left to right on the front panel, you have a process engage switch (which you could also consider a bypass), the Time Constant six-position dial, an RMS/Peak selector button, the Threshold control and a Depth control. Also furnished is a process active LED.
The device runs on line level only, so you can either put it inline with your mic preamp, or insert it into the channel. I didn’t try the inline mode, as it would very inconvenient; I simply inserted it into a channel strip. As this is a Rupert Neve design, both the inputs and outputs are fully transformer coupled and fully balanced.
Operation is very simple. They recommend setting the RMS/Peak selector to RMS mode, and having someone talk into a the mic. Starting with the Time Constant at C or D, adjust the threshold until the Process Active LED is on steadily when they are speaking and off when they stop. Then take the Depth control to -10 or so. And see what happens.
We tried this on several sources. The main reason I wanted to try it was purely selfish. For Mother’s Day, we had a small children’s group singing on the front edge of our lower stage. This is out in front of the PA, and we would have a full, live band backing them up. Though I have my DPA 4098 mic’s to rely on, I knew a group this small (8 kids) would need some extra help.
After setting up the mic’s and getting things patched in, we started cranking up the threshold. I had previously rung the mic’s out with a few parametric EQ bands to remove the worst offending feedback frequencies. After that, we let the 5045 do it’s thing. To everyone’s amazement, we had way more gain before feedback than we needed. Moreover, the sound coming from the mic’s was much cleaner than I expected. We got the kid’s voices above the band, and everyone was pleased. Portico 5045:1, Feedback: 0.
The next week we had baptisms planned. Our baptismal is in almost the worst possible position acoustically speaking, and try as we might, we never get good sound there. Basically, one of my down fill speakers is pointed right at the mic when the mic is positioned toward the people in the tank. Awesome.
Again, we followed the instructions. And again, we were amazed. Not only could we hear the people sharing their testimony, it actually sounded good. I did again insert a few parametric EQ filters to tame the bad frequencies but I didn’t have to cut more than 4-6 dB (normally it’s much more).
Just for fun, since I had another channel sitting around, I patched it into my pastor’s mic. Now, I don't have a feedback problem with him. The DPA d:fine sounds really good and never gives us any trouble. But I figured, what the heck, let’s try it out. This time, the device did what it’s subtitle claims, it enhanced the primary source. It’s hard to describe what we heard, but the signal was cleaned up quite a bit. Rather than picking up all the crazy reflections we normally get in there (our room is pretty gnarly, acoustics-wise), it just sounded like Ken. Very clean, very intelligible. It just sounded really good.
The Portico 5045 is not inexpensive; in fact it retails for somewhere around $1500. However, if you have ongoing gain before feedback issues and your only other options are replacing the PA or extensive room treatment, this might be a cost-effective option. Of course, you should still fix the problem, and the 5045 will not magically cure all your audio ills. But it will, when properly implemented, give you an additional 10-20 dB of gain before feedback.
As my friend Dave pointed out in his review of the device, the only real downside is the external power supply. I never really like those, but what do you do. That and the price. Still I put one in the budget for next year as we are doing more choir stuff and we have baptisms several times throughout the year. In that sense it’s one of those, “worth it” devices for me. And honestly, I’ll use it every week on our pastor’s mic just to clean that up a little bit.
The 5045 is distributed in the US by Yamaha Commercial Audio Systems.