Power Struggle: Amps and Speakers

"Which amp should I use to power these speakers?"

It seems that this is a very common question. The answer is relatively easy, once you know the 'secret'. Before I reveal the 'secret', let me take a few sentences to explain power ratings provided by speaker and amplifier manufacturers.

Speaker Power Ratings

RMS? Continuous? Program? Peak? Why can't they all rate speakers the same way? The answer: MARKETING! Bigger numbers are more impressive. Here is a quick rundown of the terms and what they mean (in general)

RMS (Root Mean Square) - The average power which a speaker is capable of handling. Typically the most common standard professionals use to look at speaker power ratings.

Program - This is usually the power rating at which a given speaker should be consistently driven at.

Continuous - Some manufacturers use this interchangeably with RMS, others with Program.

Peak - The maximum amount of power a given speaker can handle at any given moment. In other words, a very short power spike.

Here is a very general rule of thumb: RMS is the lowest rating, Program is twice the number of watts as RMS, and Peak is twice the number of watts as Program.

Here is an example of a speakers power ratings:

RMS: 250 Watts

Program: 500 Watts

Peak: 1000 Watts.

*** Please note that this is an example, and different speakers may have different ratios on their ratings.***

Amplifier Power Ratings

Amplifier manufacturers typically provide power ratings at a specific impedance rating. HUH? This simply means for a number of ohms, 8 ohms and 4 ohms being the most common, and occasionally, 2 ohms.

Here is an example of an amplifiers power ratings:
Stereo 8 ohms: 450 Watts
Stereo 4 ohms: 650 Watts
Stereo 2 ohms: 1200 Watts
Bridge Mono 8 ohms: 1300 Watts
Bridge Mono 4 ohms: 2400 Watts
***Please note that, again, this is an example, and different manufacturers will have different ratios of power from impedance to the next.***

OK, So how do I pair up Speakers to Amplifiers?
Here is a little analogy to use with speakers and amplifiers.

A worker can lift 200 pounds. During his 8 hour shift, all he does is carry 200 pounds from place to place. At the end of his 8 hour shift, the worker is very tired, as he did the maximum amount of work he can do.

This same worker is asked to lift 300 pounds. He can do it, but after 4 hours he is so tired, he cannot do any more work.

The same worker is asked to carry 100 pounds. The worker can do this easily. At the end of his 8 hour shift, he is tired, but not nearly as worn out as when he carried 200 pounds all day.

In this analogy, the worker is the amplifier, and the weight he is carrying is the speaker.

When an amplifier that is capable of 500 watts is put onto a speaker that is rated at 500 watts, then that amplifier is doing the maximum amount of work it is designed to do. When the same amplifier is powering a 700 watt speaker, it is working harder than it was designed to work, and is very very inefficient. When that same 500 watt amplifier is driving a speaker rated at 450 watts, it is working just as hard, but is more efficient at doing the work.

THE SECRET


Power your speaker with +/- 20% of the wattage it is rated at, using the 'Program' power rating.

Example:
For a speaker rated at 500 Watts, power it with 400 to 600 Watts of power from the amplifier.
(500 Watts x 20% = 100 Watts, 500 Watts - 100 Watts = 400 Watts, 500 Watts + 100 Watts = 600 Watts)

It's that easy! Following this system, and running your equipment properly, should lead to a long, happy relationship between you and your sound system.

DPA Visits RockNRollRentals in Austin Texas.

Direct Pro Audio believes in sharing any information that is useful to other retailers in our industry. And, we found another company that feels exactly the same way. In this tough economy it is vital for companies to band together to help one another out, so we can weather the storm together. Although located 1000 miles away in Austin, Texas, Rock'nRoll rentals allowed me to visit and learn how they run the most awesome monthly rental program I've ever seen in the pro audio business. When I first walked in the door, my emotions completely ran away from me. I was simply awestruck by the sheer amount of pro audio gear available in their MASSIVE inventory.

Don't get me wrong, Direct Pro Audio has been doing weekend rentals since we opened our business. The main difference is, that Rock 'n Roll rentals offers their products at a very low monthly rental rate. A rate so low, that it is almost as cheap to rent the gear for a month as it is to rent for a weekend. The real beauty is, this cuts down on labor and wear and tear on the gear as it goes out, to someone who winds up taking care of it for however long they rent the gear.

My visit was in the middle of a rainy Wednesday afternoon. Not only was I surrounded by massive piles of rental gear, but happy customers drifted through the aisles checking out all the awesome offerings. So whether you're looking for a recording set-up, or a massive PA, Rock 'N Roll Rentals in Austin, Texas is the only name you need to know!

Visit them yourself online at rocknrollrentals.com, trust me, you'll be BLOWN away!

Norah Jones Rocks with Sennheiser and Neumann

MONTREAL - Singer/songwriter Norah Jones is supporting her fourth studio album, The Fall, with a tour and performances on late night TV. The album, produced by Jacquire King, is a rock ‘n' roll departure from Jones' earlier work. But Jones' voice has not changed, and FOH engineer Brett Dicus continues to rely on Neumann gear for vocals and a backline of Sennheiser wired mics and wireless PMs.

Depending on the acoustical circumstances, Jones sings into a Neumann KMS 104 cardioid or a KMS 105 super-cardioid. Both microphones deliver the Neumann studio sound with the handling required for a live performance. "Above all else, the most critical sound reinforcement tool that we bring with us to every date is Norah's Neumann vocal microphone," said Dicus. "She's been using some variant of a Neumann microphone or a Neumann capsule with a Sennheiser RF transmitter for almost all of her touring career. On those rare occasions where we're asked to use something else, we miss the studio-quality high-end and lifelike sibilance that we get ‘out of the box' with the KMS 104/105."

More at FOH Online

New Web Site: Hand Held Wireless Microphones

"A hand held wireless microphone allows me the freedom to express myself without worrying about being tethered to a cord. It is essential for my performance. ” — DJ Tasty Jay

For years, musicians around the globe have been cutting the cord and entering the world of hand held wireless microphones. Now, it has never been easier to get started!

Direct Pro Audio has built a new web site to organize the major brands of professional hand held wireless microphone systems. We carry only top brands, like Audio-Techncia, Shure, Sennheiser, and AKG.

We invite you to browse this web site and contact us with any questions!

Visit www.HandHeldWirelessMics.com

Crown Introduces new XLS Power Amplifiers

Today at the 2010 NAMM show Direct Pro Audio saw Crown's latest power amplifier. The new XLS series of power amplifiers promise to deliver huge amounts of power in a robust and affordable package. The XLS power amplifiers feature Class D output devices and weigh in at less than 10 pounds, making them perfect for mobile DJ applications. Best of all the new XLS amplifiers have onboard limiting as well as basic crossover functions.

To ensure compatibility with all types of audio devices the Crown XLS amplifiers feature XLR, quarter inch, and RCA inputs. As if that weren't enough, the Crown XLS power amplifiers are stable into a 2 ohm load.

To make sure your gig goes off without a flaw the Crown XLS amplifiers provide extensive protection and diagnostic capabilities including current limiting, DC protection, circuit breaker and thermal protection.

The best part is of course, the warranty. The Crown XLS amplifiers feature the famous three-year no-fault fully transferable warranty.

Direct Pro Audio Heads to NAMM 2010!

Direct Pro Audio is excited to be attending the 2010 NAMM Show in Anaheim, California!

Follow our NAMM 2010 Blog at:

• http://namm2010.blogspot.com/

Direct Pro Audio Family Remembers Trixie

Today Trixie, Direct Pro Audio's great friend and mascot passed away... We will miss her very much, as she has been with us since the very beginning. Godspeed Trixie!