Test Bench: Eminence SD28 Soft Dome Tweeter

Being primarily known as a pro sound driver OEM, with a great reputation for both guitar speakers and PA drivers, it may come as a surprise that this Eminence driver, the SD28, is a 1” soft dome tweeter — a staple of the home and car audio businesses. I should note however, that while Eminence has a rather large catalog of pro audio transducers, the company also produces drivers for home and car audio companies. This article was originally published in Voice Coil, January 2019

Voice Coil January 2019 is now available. This edition focuses on New Materials for Earphones and Headphones and also includes a valuable listing of Earphone and Headphone Manufacturers and a schedule of headphone-centric events for the year. In Acoustic Patents, James Croft looks at a new patent of a multilayer voice coil plate and flat speaker based on the same, while in this month's Test Bench Vance Dickason features a 1" compression driver from Radian Audio Engineering, and a 1" soft dome tweeter from Eminence. This is much more, now available in print and download.

BlieSMa was founded January 16, 2018, by Stas Malikov. The first product being released by BlieSMa is a 34 mm tweeter, the T34A-4. Available from May 2018, the T34A-4 is a 30 mm metal aluminum/magnesium alloy dome tweeter with a substantial feature set that includes extremely low moving mass, and a fully saturated neodymium motor with copper sleeve shorting ring. Particularly impressive is the T34A-4's extremely wide frequency range, going from 1.3 kHz to 35 kHz. This article was originally published in Voice Coil, June 2018.

This edition of Test Bench focuses on the Scan-Speak Ellipticor D3404/552000 dome neodymium motor tweeter. Overall, the D3404/552000 is like a big elongated 28 mm diameter tweeter. For a motor system, Scan-Speak basically scaled up their currently successful Air-Circ tweeter motor with 10 neodymium slugs and copper shorting rings and a titanium former. The big news is that this motor and diaphragm yield a 2.83 V/1 m sensitivity of 97 dB! This article was originally published in Voice Coil, April 2018.

BlieSMa, located in Blieskastel, Germany, was founded January 16, 2018 by Stas Malikov. Prior to starting BlieSMa, Malikov worked at Ultrasound Technologies, at Morel as a QC manager and a transducer engineer, and at Accuton as a production engineer for the last 8 years. The first product released by BlieSMa is the T34A, a 34 mm tweeter. Available since May 2018, the T34A is a metal aluminum/magnesium alloy dome tweeter.

The driver featured in this Test Bench is the new E0060-08/06 6.5 “King Coax” from SEAS. Recognized for several years for its high-performance coaxial midrange/tweeter drivers, SEAS developed this new driver at the request of a studio monitor customer who wanted a compact three-way monitor and asked SEAS to develop a midrange + tweeter coax. The King Coax received its name from the copper ring under the tweeter, which resembled the look of a crown. This article was originally published in Voice Coil, June 2017.

These Test Bench samples came from Germany. From Eton I received the 29HD2, its neodymium motor tweeter, with a fairly rich feature set that includes an aluminum faceplate, a 28 mm diameter magnesium diaphragm with a ceramic coating on both sides protected by a cosmetically attractive grill/phase plug, and driven by an aluminum former wound with round copper-clad aluminum wire (CCAW). This article was originally published in Voice Coil, April 2017.

For this Test Bench, SB Acoustics sent its new high-end Satori line neodymium 29 mm beryllium dome tweeter, the TW29BN. Features include a 29 mm wide surround beryllium diaphragm sourced from Materion, a non-reflective cast-aluminum rear cavity, a two-part aluminum faceplate with integrated mechanical decoupling, dual balanced compression chambers, a high-saturation neodymium ring type motor magnet with a T-shaped pole and dual copper cap shorting rings. This article was originally published in Voice Coil, February 2017.

Previewed at an exclusive event in Munich, in May 2017, Scan-Speak has now launched the first two drivers in its Ellipticor line, combining a series of design innovations such as elliptical voice coils, resulting in lower distortion, combined with higher SPL. The first two Ellipticor drivers released by the Danish brand include the D3404/552000 tweeter and the 18WE/4542T00, a 6.5” midwoofer.

The new Tang Band Speaker 25-2176S 1” dome tweeter features a 25 mm wide surround coated fabric diaphragm optimized for high-frequency cutoff above 20 kHz, a unique aluminum assembly that is both self-shielding and acts as a heatsink, a unique aluminum mounting ring for screw down mounting up to 0.5” mounting depth, ferrofluid voice coil cooling and resonance damping, plus gold-plated terminals. This article was originally published in Voice Coil, July 2016.