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Mackie SRM450 Powered Speaker

500 Watts RMS, 2-Channel Mixer With DSP

Mackie has been making a wide range of live sound products for decades, ranging from small portable solutions to larger event and main stage setups. The new SRM450 powered speakers, touted as portable yet built for abuse, offer high wattage in a professional sounding and self-contained unit for the everyday light and heavy P.A. system duties. 

The SRM450s weigh 37 pounds each, measure 26x16x15 inches (HxWxD) and are constructed of polypropylene. The outside is black and textured with a metal speaker grille that has a weather-resistant coating. Each box offers three M10x1.5x20mm fly points, and the rear right side of the box is angled at 45 degrees for use on its side as a floor monitor. Pole stand ports on the bottom are provided for speaker stand mounting, along with a tightening screw to help lock the speaker tightly to the pole. There are also feet on the bottom of the cabinet that align with receptacles on the top of the cabinets for stacking and keeping them from sliding around when moving them with a dolly.

For easy transport, the SRM450s use two rounded and recessed side handles with ample hand room. They are mounted vertically, so when lifting them up your hands are at the correct angle. There is also a recessed metal flat handle on top, allowing you to quickly and easily pick up the SRM450 then switch to the two outside recessed handles and lift them up and place them on pole-style speaker stand or into a truck.

Power, DSP, Connections

The SRM450 uses a 400-watt RMS (800 peak) Class-D amplifier feeding a 12-inch custom low-frequency driver and 100W RMS (200 peak) Class-A/B amplifier feeding a 1.4-inch titanium dome compression driver. The amplifier and power sections have thermal protection, and the audio inputs include peak and RMS limiting using Mackie’s Smart Protect DSP. While on the subject of protection, the SRM450 includes a 4-band automatic Feedback Destroyer that worked well on higher feedback squeals, but during my testing it never grabbed any of the lower feedback issues such as a microphone hum around the 200Hz range. Most users will find the feedback destroyer usable and a nice bonus.

The SRM450 comes with a selector to access the four preset EQ curves that help voice the speaker for various locations and styles of music. Mode 1, called PA, is the setting I ended up using all the time. The PA setting is a flat response versus the other three settings, which add a DSP-based EQ curve to the signal path. Mode 2, called DJ, adds a boost to the lows and highs, while Mode 3, called Mon, is the setting when using the SRM450 as a floor monitor. Mode 4 is called Solo and is suggested for acoustic/vocal applications. The different settings do change the sound, but I never felt they sounded as good as the Mode 1 standard setting. Even when trying each setting in its suggested application, I found the EQ curves added a phasey, sometimes a boxy, tonality with a loss of clarity.

The mixer on the back panel allows the SRM450 to be a truly self-contained P.A. system. Mackie has really put some brainpower into the design and functionality. The inputs are on combo XLR/TRS ¼-inch jacks, which can accept anything from an instrument, dynamic mic or +4dBu line level. There is no phantom power available on the unit, so dynamic moving coil microphones will be your only choice. There is a Thru output on each speaker for feeding another SRM or other destination, and each channel offers 50dB of gain. Channel 2 on the mixer also provides stereo RCA input jacks for connecting an unbalanced playback device. 

The Sound

I used a pair of SRM450s both in a live band setting and for pre-recorded music. I found that whether I was feeding the speakers from an outboard mixer or using the built in mixer, the sound was smooth, full-range, clear and produced a good stereo image; it seemed a little noisy when idling. The ambient hiss contains computer noise mixed with the hiss you would expect. If used in a setting with crowd noise or other ambient hash from fans, guitar amps, etc., the speaker hiss will be masked. The low end is represented well enough, so the SRM450s can handle most applications, especially when only vocals are run through them. However, shows with a full band would need a subwoofer for added impact. Mackie pairs the SRM1850 subwoofer for cases like this, designed as a match for the SRM450.

At a rehearsal, I set up a pair of SRM450s on speaker stands facing the band. The singer’s mic was plugged into Channel 1 of Speaker 1. I then took a 30-foot mic cable from the Thru output of Speaker 1, a second SRM450. I adjusted the volume on each and away we went. The sound was loud and clear out of both SRM450s.

For another setup, the singer’s mic was plugged into Channel 1 of Speaker 1 and the guitar player’s vocal microphone was plugged into Channel 1 of Speaker 2. I set the Thru switch to CH1 on both speakers, so only Channel 1 would pass through to the other speaker. I used two 30-foot XLR cables from Speaker 1’s Thru into Speaker 2’s Channel 2 input and then from Speaker 2’s Thru to Speaker 1’s Channel 2 input. Now the guitar player who is closer to Speaker 2 can then adjust how loud he is in Speaker 2 by turning up his mic in Channel 1, and the singer’s feed in Speaker 2 by adjusting the Channel 2 volume. The singer can also adjust separately his or her own singing volume using Channel 1’s gain control and the guitarist’s vocal volume with Channel 2.

It sounds more convoluted than it really is, but now both performers have their own mix with no outboard equipment needed. Conversely, if both the singer and guitarist vocal mics were plugged into a single SRM450 and then the signal was mixed and sent to a second SRM450, the two speakers would share a single mix. But through various routing schemes, separate mixes at each of the two speakers are possible.  

Are They Good?

The SRM450 is a fantastic speaker for smaller P.A. applications. They are light, loud and sound very good. It’s a feature-rich product that should be at the top of the list for anyone who uses a portable P.A. system. I’m really impressed.

Tim Dolbear is an Audio Engineer and Producer at Eclectica Studios in Austin, Texas.

Product Summary



PRICE:  $629 (each)

PROS: Good-sounding, feature-rich, built-in mixer, daisy-chain multiple units, Feedback Destroyer, very portable.

CONS: Feedback Destroyer missed low notes ringing out, no phantom power for XLR inputs.

Try This

If you’re looking for better bass response, place your integrated speaker (woofer and tweeter) on the ground instead of on a speaker stand pole. While the pole will get them up above the crowd and throw better to the back of the room, coupling with the floor will add more boost for your bottom end. It’s a trade-off, but depending on your application, placing them on the floor may be a better solution.