Saturday, June 9, 2012

Consumer vs pro amps - big difference?

There's a lot of misinformation floating around the audiophile community, and most of it stems from rumors and fuzzy facts about how useful pro audio items (amps simply as a common example of the level of confusion present) are in home theater/2-channel settings. This couldn't be farther from the truth of how these excellent amps can be utilized in integrated setups.

Not only can an audiophile use pro amps in a home stereo rig, he/she can use a mixture of consumer and pro audio items in one big happy system. A common misconception is that pro amps are big, rattly and their fans, used to perform cooling duties, are too noisy to be of any resonable audiophile usage. Wrong! I've seen people hide them under floor joists to get them out of the visual plane, but I rather like the "industrial" look of a big, gnarly set-up. It comes from my years as a musician, gear salesman, and sound person. To me, Crown power amps, for instance, always have a place in my rigs because they are reliable, sound great, and as time goes on, they're getting lighter than ever. QSC and Peavey are two other alternatives, and you can find them cheaply, being sold by starving musicians (I are one, believe me!).

I have an analog set up that is as natural and organic as possible. When I strip it down (which I can do with no difficulties), it only consists of a SET amp, a phono stage, and a pair or two of speakers. SET topology, by virtue of its design, desires low impedance (down to a dead short, according to the manufacturer) and is mostly in want of sensitive, easy-to-drive loads. I use two 4-ohm-per-side loads (impossible to run with larger, high-power home stereo amps, you'll kill them trying this) to optimize the 4-watts-total output. Commonly, pro amps will do down to 2 ohms per stereo side, like I mention in my SET rig, but, conversely, a common 2-channel home stereo integrated of receiver wants to see 4 or 8 ohms per side. I know people who see three speaker connections on the back of a Pioneer or a Sansui receiver and feel like they can use all three at the same time ("hey, if there are three connections, you ought to be able to use all three at once!") This is what makes the distance betweeen their listening room their repairman a well-worn path. Or, on the other hand, the distance betweeen their listening room and the trash can...

Home stereo users, uneless they are big DIY'ers, eschew the use of pro crossovers, too. They're paranoid of turning on the amps and sending lows to the high drivers by mistake. To this, I say that if you're overtly concerned, make sure some gremlin or 3-year-old hasn't assumed the role of personal audio assistant! Check the settings, you did set them originally, and there's no reason you can't commit the settings to memory.

I've seen conventional audiophiles rig up lightbulbs to act as fuses, or resistors inline to prevent surges. I say (YOUR MILEAGE MAY VARY) that anyone who's smart enough to integrate pro and consumer components, should be able to run a pro crossover in a modern/vintage pro/consumer rig without incident. I have done such for years, and I definitely took the time to learn how to do it, and how to set it up in the first place. Your ears alone will tell you if you're leaving a big midrange frequency gap if you're doing a two-way setup, and unless you're well-experienced, I'll advise againgt doing three-ways unless an expert sets it up and you take due diligence to learn the concept (first of all), then take notes or memorize the particular crossover settings so you can revert back to them in case things get mixed up somehow. A good rule of thumb is to let the bottom speakers do the brunt of the heavy lifting and let the tweeters do the highest, airy stuff, set as high as you can allow.

This is one of my pro amps. I use it in a number of configurations, one of which is in a basic 2-way configuration. I use another Crown amp (a vintage D-75) to run Electro Voice full range speakers on top, and big JBL/Bag End cabs for low end. This way, the bass is crossed over at 80 hz.  For this configuration, I use the big Crown/JBL set-up for low bass management strictly. Alternately, I'll use both amps with Seleniuim horn drivers and JBL lenses to do a more conventional 2-way set-up where the JBL/Bag End combo is doing most of the work. In this iteration it operates at 2400 hz and below, and at 800 watts per channel at 4 ohms a side I rarely turn it up (both amps on one half) over half! It's nice to have headroom at this level, and it sure sounds nice with JBL E-140's and Selenium horns. I use one half as a nominal reference point, you can choose your own optimal point without problems. Just be careful to watch your power meters, or you'll hear a crappy, clipping system. It will sound bad, and before long, you'll smell burning copper. If I'm traveling light and only want to do mono, I use this amp alone, lows on on side and highs on the other. It operates as two separate mono amps (another benefit of pro amps in this configuration).

So, kiddies, don't be afraid to mix and match your pro and consumer components, because, by and large, they will play nice together and sound excellent. If you have any reservations whatsoever, consult someone who will assume the responsibility of replacing everything if they set things up wrong!

Tomorrow we'll delve back into the world of michaelhigh, and by then my 18-year-old son will have graduated high school without incident (hopefully...I'd hate to see him do a faceplant with all those teenage and parental cameras running! That's a sad memory to carry into perpetuity, especially when you hometown is roughly 2500 and YouTube is so accessible!!). So, until then, remember! Keep your tubes hot and your antenna up! See you tomorrow!

No comments:

Post a Comment