FedEx is playing games with me again... They left this one at my mailbox, at the end of my driveway, 2/10 of a mile away. Despite their scheming, I now have in my possession Sencore's model SP395 Audio Integrator, a handy-dandy little battery-powered hand-held dual-FFT meter of many functions.
For those of you as visually minded as I, here's a link to the photos:
http://www.campuspa.com/images/sencore395/sencore395.htmlThe manual is also an informative read, so here's it:
http://www.campuspa.com/images/sencore395/manual_web.pdfThe unit arrives in a nice padded shoulder bag with foam cut-outs inside for it and the supplied (calibrated!) reference mic and the power supply. There's a zipper pouch on the front that contains a goody-bag of cables for connecting the 395 to your computer, its reference mic, or bare contacts for measuring impedence or what have you. It also includes a software CD, warranty information, a few warning cards about how to charge the thing without destroying your battery life, and a glossy sheet of 8.5"x11" lauding their customer service on high.
If you read carefully, you'll notice nowhere did I say they included anything like a manual... no quick-start guide, no handy photo with a few arrows explaining what all the cryptic symbols on the screen are, nada. I figured, no problem, I'll go download it from their website... of course they'll have it, in some easy-to find section marked "downloads" or "tech support". Nuh-uh. No luck. A listing of telephone numbers I can call to get help (nobody's gonna be there, it's well after closing time) is all I see. Now, I happen to know that this is a former Terrasonde product that Sencore has teamed up with them to market, service, and (soon) build. So I go to the Terrasonde website where I am quickly and easily able to find the manual and download it... a quick leafing-through and everything is explained.
Once I'd given the manual a quick read and figured out what the strange symbols at the top and bottom of the screen were, the unit was simple to use. One or two things aren't under the menu I'd necessarily expect, but there are only so many options and once you've found a feature once you know where it is from then on. Just so's you know, the strange symbols are...
Top, from left to right: Back to main menu, battery indicator, current mode, then polarity, phantom, and gain for the left preamp, automatic or manual gain mode, then polarity, phantom, and gain for the right preamp.
Bottom, from left to right: Monitor input on/off, level, internal speaker on/off, input selector, mono-mix-down, memory settings (memory slot, Store, Recall, Clear), tone generator on/off, level, wave type (sine, square, etc), frequency, frequency selection granularity (1hz, 1/3 oct, or 1 octave).
I would like to take a second to explain the "automatic or manual gain mode" selection, since I think it's a really great feature. Simply put, when you've selected automatic gain mode the unit will turn down its input gains whenever it senses clipping. It does this quickly and seamlessly and adjusts for the change internally so you can go on with your measurement and stop worrying about how hot you might have your mic set. Everything is referenced to the unit's internal calibration for the supplied reference mic, so SPL readings are accurate. It also turns its input gain back up, but only to a "safe" level... I'm not quite sure how it determines that, but in my basement if I scream at the RTA mic with the gain set to +58 (the maximum) it knocks the gain down to +10 or so pretty quickly and then takes it back to +40 within a few seconds and leaves it there.
If you've ever seen one of these things without actually trying to pick it up and use it, your first though may be like mine: It's pretty damn big. Here's a photo of me holding it in my hand, which is pretty average-sized:
After a few minutes messing around with the 395, however, I've decided that its initially off-putting size isn't really a problem except in terms of, for instance, packing it in your luggage to fly to a gig with. It's a comfortable width that fits easily in my hand and the weight is not an issue, even with my atrophied pasty-white-geek hand muscles. The screen is nice and large and readable, although extremely low-res and chunky, and the clickable rotary encoder that is the only HUI is appropriately responsive. No complaints there.
My SP395 came loaded with all the extra "add-ons", like TechBench which allows me to do crosstalk and distortion measurements, and Speaker for measuring impedence and polarity and all that jazz. I asked for it that way, I don't know how much those particular tools add to the price.
As I have alluded to a few times already, the screen on this unit isn't exactly high resolution. It's a big, easy to read, back-lit screen, certainly... but it's about 125 pixels wide, and maybe 100 tall (I tried to count, that's within a few pixels, you try counting something that small). It's also got a very slow refresh rate, so trying to see rapidly changing waveforms in oscilloscope mode, for instance, is tedious.
Fortunately, for nearly every function where the size of the screen is an issue there's a sliding scale on one or both axis that allows you to "zoom in" on a measurement, plus some sort of scrollable cursor to help you pick out particular data-points. All this adds up to make the unit extremely usable without requiring the cost of a large high-resolution screen. Plus, of course, there's the computer interface which ought to make things a lot easier to see.
While we're on the subject of taking measurements, it should be noted that the unit has a number of memory slots that you can store measurements in on the fly... 40 of them, to be exact. It's easy to pause a measurement, save it to a memory slot, and then keep going to measure something else. While scrolling between memory slots the unit thoughtfully tells you what kind of measurement is stored in each so you don't try to, say, recall your impedence sweep in RTA mode or accidentally overwrite your hard-to-get measurement from last week. Each memory slot holds the actual measurement data, too, so you can export it to a computer or look at it on the unit's screen and zoom in and out.
As long as I had my USB->Serial dongle handy, I figured I'd hook the unit up to my computer and see how well the software works. What ensued was a lengthy and exhausting fight replete with meaningless error messages and buttons that didn't work (or didn't appear at all, in some modes) for no apparent reason whatsoever. The software is, of course, only available for the PC, so I'm running it in emulation mode. Figuring that might be the problem, I grabbed an actual PC laptop and loaded the software onto it. All the same problems occurred, actually more of them in this case, so it's not just my platform. There is very little mention of how to use the software interface in the manual, and the error messages it gives you are completely useless or, in many cases, lies. I finally figured out that you've got to have the SP395 in the same mode as you want to view on the computer in order to use "real time" mode, where the computer essentially mimics the Audio Integrator's display. Using this newfound wisdom I managed to capture this screenshot:
Still beyond my reach is the ability to grab data from the unit's memory ("No serial data." it said. Then: "Cannot open connection: Port blocked." it said. "Shutdown Windows Now" I said.) or use any mode other than RTA. There are also several functions available on the SP395 itself that aren't represented in the software at all, as far as I can tell. For a box with a mediocre screen one would think that a multi-platform well-tested computer interface would be way up at the top of their list. Apparently now. I will give them the benefit of the doubt, however, because this whole Terrasonde line is a very recent addition and they're probably still getting un-mixed-up and taking care of bigger problems.
Quick note, before I forget: That USB port on the side of the unit is for the I/O. It uses standard drivers and allows you to send or receive signal to the unit from a computer, which is a pretty handy thing.
That's all I've got for the basic operation of the unit, it's past my bedtime and I need to hit the sack. So far, I like it a lot. It's a quick and easy way to take a few basic measurements without having to break out a computer, and it's small enough to take with you anywhere. The memory functions are nice because you can take measurements elsewhere and worry about getting them off the unit later, so it's really kind of a "one box to do it all" kind of dealy. I'll have to see how well it performs in transfer function applications, and I'll give Sencore a call to see WTF is up with their computer interface.