In Voice Coil July 2026, Mike Klasco shares his knowledge and contact list of suppliers of adhesives, coatings, sealants, high-tech thin films, converters, and dispensing equipment for the loudspeaker industry. And Vance Dickason characterizes the NERO-5CCN125D 5” Pro Midrange from SB Audience, the 121XR-X8 12” Pro Sound Woofer from REDCATT, and the EC30MP-4 Ceramic Dome Tweeter from Dayton Audio. Three very different solutions in Test Bench.

Half-way through its edition year, Voice Coil July 2026 is now available and brings a whole lot of information to loudspeaker professionals. In Industry News & Developments, Vance Dickason highlights two vendor options in measurement microphones from Z-Tech in China and Roga Instruments in Germany. As he explains, “Mike Klasco and I have been writing about measurement microphones for several years, and all the world players that have US distribution are featured in the Loudspeaker Industry Sourcebook. However, I have recently encountered two precision measurement microphone companies that manufacture extensive product lines…”. Z-Tech is an abbreviation for Zhengtian Technology Co., Ltd., was founded in 2006 and manufactures a comprehensive line of measurement microphones and acoustic accessories. Roga Instruments, a small company located in Nentershausen, Rheinland-Pfalz, Germany was founded in 2004 and offers an extensive line of measurement microphones and a wide variety of acoustic and vibration test equipment and accessories.

For this month’s issue, Mike Klasco updates the industry’s resource list of suppliers for key “gooey” products required by the loudspeaker industry. Adhesives, Coatings, Sealants, High-Tech Thin Films, Converters, and Dispensing Equipment, all are included in this month’s Voice Coil Directory, with valuable contextualization provided by the experienced Menlo Scientific team. In the different sections of this directory, Voice Coil readers will also find profiles for several surface enhancing treatments, from diaphragm damping, resisting UV, hydrophobic (water), oleophobic (oils and sweat), corrosion, detergents, and anti-microbial treatments. Always a valuable resource with updated perspectives of the most relevant companies.

Jumping directly on Vance Dickason’s Test Bench characterizations of the industry’s latest and most interesting speaker drivers, this July issue details three very different solutions. 



Starting with the NERO-5CCN125D 5” Pro Midrange from SB Acoustic’s pro sound brand SB Audience. The new driver from SB Audience’s premium high-performance NERO line stands out for the closed-back design, which offers the option of removing the rear cavity and using a custom back box. The rear cavity of the NERO-5CCN125D is constructed of cast aluminum and filled with acoustic damping material. Otherwise, the cast-aluminum frame is completely open below the spider mounting shelf for cooling, connecting to the neodymium ring magnet motor assembly with eight double spokes. The cone assembly of the NERO-5CCN125D midrange consists of a curvilinear inverted single piece “bowl” shaped injection molded carbon fiber cone and corresponding dust cap with a narrow inverted roll coated cloth surround, with the remaining compliance coming from a 3” diameter flat cloth spider (damper) with constant height waves. Driving the cone assembly is a 1.5” diameter voice coil wound with copper-clad aluminum wire (CCAW) on a nonconducting fiber glass vented former.
 


The second Test Bench for this month is on the 121XR-X8 12” Pro Sound Woofer from REDCATT, a strong OEM/ODM manufacturer of both pro sound and home audio transducers. After Voice Coil measured its ultra-thin 12” subwoofer – affectionately known as “Twiggy” – REDCATT sent Voice Coil the 121XR-X8, a rather innovative new 12” pro sound woofer. Details of the REDCATT 121XR-X8 8Ω design are rather extensive and include a patented radially charged neodymium magnet structure with a unique cooling system. Another highly unique aspect of this radially charged underhung motor structure is an active shorting ring. This “active” shorting/demodulation ring takes the form of a secondary winding that is inset into the inner gap area of the return cup. This copper wire wound secondary winding is connected in parallel to the main voice coil, with a two wire lead that goes from the main push-button terminals, up the side of the neodymium motor return cup, and disappears down the cooling channel at the top of the return cup.


The third characterization for this month is of the EC30MP-4 Ceramic Dome Tweeter from Dayton Audio. Voice Coil Test Bench has featured several 30mm tweeters over the past few years but this is the first one from Dayton Audio. The Epique EC30MP-4 (MP is Dayton’s model designator for “matched pair”) features an aluminum dome coated with a vapor-deposited ceramic. Suspended by a narrow coated cloth surround (Fs=700Hz), this tweeter features a voice coil wound with round copper wire on a Kapton former, powered by a large Y35 ferrite magnet that includes a copper-clad pole piece (shorting ring) that exhausts into an injection-molded plastic damped rear cavity. The aluminum faceplate features six mounting holes plus a metal grill to protect the ceramic diaphragm. Voice coil tinsel leads connect to gold-plated Faston-type terminals located on opposite sides of the tweeter motor. Sensitivity is rated at 92.5dB @ 2.83V/1m, while RMS power handling is rated at 80W – substantial for a home audio tweeter.

As always, this issue is complemented with a selection of new product launches and highlights of interest for loudspeaker professionals, in the Industry Watch section. 

 



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