Welcome to the next installment of "Tech Talk." This monthly feature will hopefully help you understand about certain sound and musical gadgets that everyone sees but are just not sure how they operate in the real world.

Big, small, or in-between?

Without getting into the math of room volume in cubic feet to speaker size/numbers, you can quickly narrow down your list by recognizing that a small church doesn't need multiple Peavey PR 15P NEOs to carry you or your group. Conversely, a 1000-seat (or larger) room needs the power and air-moving ability that only multiple pairs of 15" woofers and high-powered HF transducers such as the Mackie SA1532z can fill.

How many (sets of) speakers do you need?

Again, this depends on your venues. If you play a lot of small,150-seat rooms that demand significant volume levels, you might be best served by a pair of column-type speakers like the Peavey PV 215 model, one standing on either side of the stage. If you have more real estate to cover you could use a quartet of stand-mounted 2-way powered speakers, such as JBL's EON 15G2. You could add a subwoofer like the JBL MP255S to a set of stand-mounted 2-ways to effectively cover both a larger space and the full frequency range. Do multiple rooms require extra speakers? If so, they probably also require extra power.

Powered or un-powered?

The deal with Powered PA speakers comes down to convenience and sound quality. Before the affordable active speaker, sound engineers and musicians had to haul around heavy, bulky amplifiers and accompanying cables and speakers - all of which have been replaced with the active speaker! If you're not familiar with active PA speakers, the idea is that the power and all connections are simply built into the same cabinet as the speaker. This all-in-one design also takes the heat off of those of us who don't really know how to marry the right power amp with the right speaker, which can lead to degraded sound quality at best and damaged gear at worst.

Remember that powered speakers require access to extra electrical outlets; do you have that access in the rooms you play? Or the extension cables?

How much power do you need?

Fortunately, you can determine this without having to do (much) math. JBL recommends that, in general sound reinforcement situations, you use an amp that delivers equal to or up to double the IEC power rating of the loudspeaker, i.e., a speaker rated at 300 watts capacity needs a 300- to 600-watt amp. Contrary to popular belief, you're more likely to damage your speakers with an underpowered amp than with one that has too much power, so don't scrimp here!

Do you need a Subwoofer?

A subwoofer can significantly increase the low-frequency capability of your system. It can also help "clean up" your sound by taking some of the low-frequency load - and the accompanying distortion - away from your other speakers, which can actually let you run at lower volume levels while still maintaining the "punch" of your performance. However, there are practical reasons (such as space, weight, and budget) for staying out of the subwoofer scene.

Til next time,

Roger

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