INTRODUCTION
Thank you for choosing LOUD Technologies’ Mackie active sound reinforcement loudspeakers.
The SRM450v2 is a redesigned version of our popular SRM450 active loudspeaker. With its newly designed Class-D Fast-Recovery amplifiers, high-output compression driver, and 12" woofer, it produces an even smoother sound than the original. SRM means Sound Reinforcement Monitor, and the SRM450v2 truly produces a studio quality sound in a sound reinforcement speaker.
Our design goal was to build a sound reinforcement speaker with:
1.High precision, high output, and accurate playback.
2.Very wide, smooth dispersion of mid and high frequencies.
3.Ergonomically correct physical design for easy transport and set up.
Through the combined resources of our top-notch mechanical and analog engineers, and our experienced transducer engineers at EAW, we were able to achieve our design goals in every aspect. The result is a sound reinforcement system equally at home in a concert setting, in the studio, impromptu concerts on the studio roof, in the cinema, or in a home theater.
The Transducers
The SRM450v2 active speakers feature a 12-inch high- power low-frequency woofer with a 3-inch voice coil and a 1.75-inch titanium diaphragm high-output compression driver. This high-frequency driver is mounted on an acoustically non-resonant exponential waveguide, providing a wide, controlled dispersion and precise reproduction of the critical upper mid-range and high frequencies. The result is an unbelievably smooth off-axis response that allows everyone in the audience to experience the same high-resolution audio no matter where they are seated.
The Power Amplifiers
To power these beauties, each SRM450v2 includes two of our acclaimed FR Series “Fast Recovery” power amplifiers. In addition, the low-frequency amplifier uses a Class D design for improved efficiency and cleaner power. Our exclusive designs use low negative feedback, yet allow the amplifiers to maintain low distortion and stability and to quickly recover when driven into clipping.
The amplifiers include the following features:
•The low-frequency amplifier produces up to 540 watts peak (300 continuous) before clipping.
•The high-frequency amplifier produces up to 150 watts peak (100 continuous) before clipping.
•Each amplifier has its own compressor circuit that acts when the input signal is large enough to cause clipping, distortion and excessive voice coil heat. The compressor will automatically decrease the input signal to a safe level. The compressor in the low-frequency amp works independently from that in the high-frequency amp.
•The low-frequency amp uses a servo feedback loop which senses the current flowing in the woofer coil. This controls the low-frequency response and maintains low distortion at high output levels.
•The low-frequency amplifier also has a sweeping filter.
This will automatically move the low cut-off frequency up or down depending on the amplifier output. For example, if the amplifier is below clipping, the low-frequency cut- off point is 55 Hz. As it approaches clipping, this shifts up smoothly to 120 Hz, providing more power reserves and less distortion before clipping. This happens quickly and continuously, protecting the amplifier and the woofer and reducing any noticeable distortion.
Warning: Although the amplifiers have these protection circuits, you must still make sure the PEAK light is not blinking continuously. If it is, turn down your mixer faders, or preamplifier gain, or turn down the SRM450v2 LEVEL control.
The Crossover
The built-in electronic crossover is a 24 dB/octave Linkwitz-Riley design. Although more expensive than other crossover designs, the benefits provided by the Linkwitz- Riley design have been well documented. These benefits include:
•Absolutely flat frequency response throughout the bandpass, without the characteristic ripple near the crossover point exhibited by other designs.
•The sharp 24 dB per octave roll-off of the filters ensures that the transducers aren’t reproducing frequencies outside of their capabilities.
•The acoustic sum of the two driver responses is unity at the crossover frequency, resulting in perfect power response.
•Our heroic engineers have worked carefully to ensure that the SRM450v2 also provides perfect phase response. This diligence has yielded phenomenal accuracy, even if you are standing 20 feet away.
