Selenium D3500Ti-Nd High Frequency Driver
By Mark Amundson
With the quality going up and the cost going down on rare earth magnetic materials, more Low and High Frequency Drivers are employing Neodymium as the magnetic motor. The main advantages of Neodymium over conventional magnet materials like Ceramic (Ferrite) and Aluminum-Nickel-Cobalt (Alnico) are twice to five times the remnant magnetic flux, which is the force the voice coil repels against to move the air. By using Neodymium, speaker designers can proportionally shrink the size of the magnet pole faces and motor assembly. While the assembly size and some component costs also shrink, it is believed that the Neodymium material is more expensive; leading to an equivalent to slightly more expensive driver. I received from Selenium USA their new D3500Ti-Nd driver, a spare titanium diaphragm and a couple of 2-inch throat horns to road test with. Having plenty of Neodymium HF drivers before, I was slightly surprised the large size (5.43" diameter by 4.09" deep) driver assembly. But the 7.5-pound weight confirmed to me that the motor assembly was indeed Neodymium, with much of the rest of the aluminum encasement for cooling and ease of mounting in the 4-inch bolt pattern.
The Selenium D3500Ti-Nd, as the name suggests, has a 3-inch diameter titanium diaphragm and Neodymium motor. With its 2-inch exit, it offers modest compression, and the diaphragm mass is lower than typical 4-inch titanium diaphragms with 2-inch exits. This means to me that the lower mass offers extended high frequency response comparatively. But the small voice coil diameter could mean smaller power handling.
Looking at the D3500Ti-Nd specifications, the 500Hz to 25kHz (-10dB) and estimated 800Hz to 15kHz (+/-3dB) frequency responses show both the power of the motor and the lightweight diaphragm combination. The 75-watt continuous and 150-watt program power ratings confirm my lower but moderate power handling expectations. However, the 8-ohm nominal impedance and 111dB SPL sensitivity at 1-watt, 1 meter tell me this is truly a professional driver and hits the sweet-spot middle for two-way applications and even high SPL three-way applications.
In the Box
Though a little tough to road test, I did dig up a "proprietary" monitor wedge and re-cut the baffle board to take the D3500Ti-Nd plus the HL14-50 mid-throw horn for a 45- by 45-degree pattern. I left everything in a bi-amp state on NL4 connectors, and first checked with pink noise and a RTA the frequency response. The response matched up with Selenium's plot and proved to be very flat in the 1200Hz to 15kHz range; that surprised me, as not many horn/driver combinations can boast that smooth of a passband. Of course all bets are off if I put a constant directivity horn on the D3500Ti-Nd, but the rolloff would likely be smooth, even in the tricky lower presence frequencies.
Out on the gigs, I just dialed up 1200Hz on the active crossover and dropped gain on the D3500Ti-Nd and horn until sensitivity matched the LF driver (about -10dB). As expected, the smoothness and moderate power handling sounded great, and try as I may, I could not torture the voice coil to destruction. In general, the vocal mics were the weak link in feedback rejection. While I do not make it a habit to replace HF drivers, I certainly will make Selenium's Neodymium drivers a top candidate for proprietary speaker designs, as well as upgrades to existing speakers.
What it is: Professional Mid to High Frequency Driver
Who it's for: Users with need for smooth response 2-inch throat drivers with cost and weight as considerations
Pros: Easy to use, smooth and extended
frequency response, large throat
Cons: Large body, moderate power handling for a 2-inch throat driver
How much: Selenium D3500Ti-Nd $382.99 MSRP
Mic-Mute Automatic Microphone Switch
By Jamie Rio
Here's the scenario: you've got a loud guitar player who also sings backups on your stage. When he is in front of his mic, your mix is perfect. As soon as he steps away from his mic, you pick up a lot of extra guitar in your mix and it all turns to crap. Or you have a drummer who sings, and his always on, hot vocal mic is making the drum mix sound like snot. The thought of muting these mics at the appropriate time is daunting–especially if you have never mixed the band before and you are shooting from the hip as it is. Well, here's the solution. It's a small device (about the size of a cigarette lighter) that plugs in between your mic and mic cable. It incorporates an electronic eye that controls an automatic mute switch. When the eye sees your smiling face the switch turns on. When it doesn't, the switch turns off. It's simple and amazingly effective. The distance that the eye sees is adjustable and the on/off effect is noiseless.
I used it with a loud guitar player and with a drummer. With the drummer it was great, as he never really varies the distance from his pie-hole to the mic. With minimal adjustment for distance, I got what I needed: vocals when he was singing and dead air when he wasn't. It worked okay with the guitarist, but he has a tendency to "work" the mic–pulling back when he is really pushing for a high note. This generally works well and I don't have to overly compress the vocal because he actually has mic technique. But the Mic-Mute does not take technique into account and the mute kicked in a few times when he pulled back. A little adjustment of the distance control should have helped, but I wasn't getting it.
Bottom line is that for singers who are right up on the mic all the time, the Mic-Mute works wonders for cleaning up the mix. It also works on phantom power, so don't worry about batteries. This is a great little tool. Everybody should have a couple in their toolbox. Manufactured in Germany, in the U.S. it is distributed by Sunnybrook Electronics (www.micmute.com).
What it is: Small individual mic mute
Who it's for: Sound guys and bands who want more control over their mixes
Pros: It turns a mic on and off when you want
Cons: Doesn't always work with mic technique. Either on or off (no subtleties)
How Much: MSRP $300
Cerwin Vega Vision VIS-153 3-way Speaker System
By Jamie Rio
My very first pair of real P.A. speakers were Cerwin Vegas. I can't remember the model number, but they were two-way boxes with a 15 and a horn. I bought them used in 1980 because I had heard that Cerwin Vegas really pumped out the bass and could take a lot of abuse. Which, by the way, was true. I beat the hell out of them for five years and they never let me down. However, during the '80s this reputation for pounding low end soon made Cerwin Vegas a favorite for DJs. This probably wasn't a bad thing for Cerwin Vega, but by the time I got into the live sound biz in the mid-'90s, I never considered, nor did the companies I worked for, using them for FOH gear. Well, Cerwin Vega would like to change that, and is making a strong play for live sound companies and bands with their Vision Series.
The Gear
I am reviewing the Vision VIS-153, one of five models available in the Vision series. I immediately liked the look of these boxes. Now, to some, that may not be important, but I am a visual kind of guy and I want my gear to look good. Besides the looks, they are well made cabinets: 18mm multi-ply birch, a super-tough black polyurethane coat, beefy grille, nice handles and ATM certified fly-ware. Each box is loaded with one 15-inch woofer in a cast aluminum frame with a 3-inch voice coil. A 75mm titanium compression driver pushing sound through a proprietary horn with a 2-inch throat that handles the mid frequencies. The horn features non-planar walls, eliminating sharp edges that can cause distortion. A 44mm titanium driver coupled via a 1-inch throat to an elliptical horn, which offers superior dispersion and a more natural sound, brings high frequencies to you. You plug into the box through two Neutrik connectors. The box can be run full range or bi-amped, stand alone or be arrayed or augmented with a subwoofer. Each Vision cabinet has an impedance of eight ohms and can handle 700 watts (1,400 watts peak). Cerwin Vega claims it will produce an ear-splitting SPL of 133dB. All this, and the whole package weighs in at just 90 pounds.
The Shows
The biggest challenge when reviewing gear is finding the right venue. I am only working with two cabinets and no subs. So the gig needs to fit the gear. At any rate, I found the perfect setting. A small club near my home asked me to bring in a system for a two-night stand. Each night featured a different group. I got to the club early for the first night's performance and set up the speakers in full range mode. I used a small board, 31-band stereo graphic and a power amp that delivered 1,000 watts to each box. Programmed music sounds great through the Visions. If I were a DJ, I would only need a couple of subs and I could really rock the house. But I'm not a DJ; I'm a FOH guy. So I set up the band when they arrived.
My basic strategy working with a rock group in a small venue is to use the Front of House speakers to amplify the vocals and support the instruments on stage. What I mean is, I use the stage mix as part of the house mix. Basically, I put mics on the kick drum and snare, guitar amp, a direct for the keys and of course mics for the vocals. The guitar player had plenty of horsepower, so I just fattened him up in the room. The keys were a little underpowered, so I gave the player a separate keyboard monitor mix and filled in out front with the Cerwin Vegas. I let the bass do his thing on stage (without my amplification) and of course I put the vocals on top of it all. Once I got it dialed in, I think the word that best describes the Cerwin Vegas is natural. Basically, my guitar and keyboard stage sound and amplified sound were the same. That's about as good as it gets for a sound guy. And of course, the players want the room to hear their tone the way they hear their tone. The vocals had plenty of headroom and everybody was happy.
The next night featured an R&B band with a three-instrument horn section. Obviously more challenging, but the speakers handled the additional frequencies without putting up a fuss. I must mention that during the second night's sound check I used a much smaller amp for the Vision speakers–only 200 watts per box–and they really didn't like that. They definitely perform better when you pump in some muscle. So back to the big amp I went and all was well. Once again, the word natural comes to mind with these speakers. They are definitely smooth, even at high decibels. All in, I enjoyed working with the Cerwin Vegas. They made it easy to reproduce the different bands' sounds, and that's what makes the whole thing fun for a guy like me.
What is it: Passive three-way speaker
Who is it for: Musicians and sound companies (could work as install gear)
Pros: Handsome, clear, defined sound
Cons: I don't get to keep them
How Much: $2,000 MSRP
