Test Bench: Celestion CDX1-1742 1” Exit Pro Sound Compression Driver

For this month's Test Bench, Vance Dickason characterizes the CDX1-1742 from legendary UK Pro Sound OEM manufacturer Celestion. This driver joins the CDX family of ferrite motor compression drivers, and is designed for use with 1” throat horns, featuring a FEA-optimized ferrite magnet motor structure, and a proprietary next-generation “Sound Castle” soft diaphragm clamping assembly that reduces diaphragm mechanical stress and distortion. For this Test Bench, Celestion supplied the H1-9040P horn, with a 90° × 40° coverage pattern. This article was originally published in Voice Coil, May 2018.

Following the first test on the new Scan-Speak Ellipticor series, with the D3404/552000 tweeter, this edition of Test Bench focuses on the Scan-Speak Ellipticor 18WE/4542T00 midbass woofer. Like the D3404, the 18WE/4542T00 is a seriously feature rich transducer, which has a magnetically attached aluminum trim ring that can obviously be anodized a variety of colors besides black. For the cone assembly, Scan-Speak chose a rather stiff curvilinear profile back coated paper cone with an elliptical 45 mm × 35 mm convex paper dustcap. This article was originally published in Voice Coil, April 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.

In this Test Bench, Vance Dickason examines the Peerless by Tymphany DFM-2544R00-08 compression driver, which is part of the brand’s new three model compression driver series. The compression driver features a 1” throat exit diameter, but with a 1.75” titanium diaphragm and the same type of polyimide surround. The DFM-2544R00-08 is driven by a 44.4 mm diameter voice coil wound with aluminum wire on a TIL film non-conducting former. This article was originally published in Voice Coil, March 2018.

In this month's Test Bench, Vance Dickason examines a new 1" PEEK diaphragm compression driver from Precision Devices, the PD.CD1N. This is a unique design in Precision Devices' UL portfolio, using a PEEK diaphragm/surround material, which also incorporates a three-slot optimized phase plug design and a 44 mm (1.73”) diameter voice coil wound with copper-clad aluminum wire on a Kapton former. This article was published in Voice Coil, March 2018.

This month, I characterized a a 10” PA woofer from Wavecor, model WF259PA01. This is an interesting driver since, until now, Wavecor has been known mainly for its high-end home hi-fi drivers. However, the company has decided to expand its coverage in the loudspeaker market and has introduced a well-designed 10” OEM pro sound PA woofer. The WF259PA01 is for now available only as an 8 Ω model, and uses a very stiff flat black coated curvilinear paper cone. This article was originally published in Voice Coil, February 2018.

In this edition of Test Bench, I characterized a 1.4” titanium diaphragm compression driver from Precision Devices. The new driver from this prestigious UK Pro Sound OEM manufacturer is part of a seven model lineup of high-performance neodymium compression drivers. The PD.CD2N has a 50.8 mm (2”) throat diameter, with a radial neodymium magnet motor structure, an aluminum three-slot phase plug, and nominal 105 W (AES) rated power handling. This article was originally published in Voice Coil, February 2018.

For this month's Test Bench, Dickason characterizes a new 12” coaxial pro audio driver from B&C Speakers, a design typically applied in stage monitors, studio monitors, or distributed audio in large venues. B&C Speakers 12CXN88 is unique in that it uses a single neodymium magnet assembly for both the 12” woofer and the 1.3” throat exit compression driver. This article was originally published in Voice Coil, January 2018.

The driver for this month’s Test Bench explication comes from the UK. Volt sent the 12” RV3143 Studio Monitor woofer, which is probably the most uniquely designed woofer to come across my desk in a while — there is no frame on the back side of the driver! The Volt Radial Technology consists of a front-mounted eight-spoke proprietary cast aluminum frame that is mechanically coupled to both the back plate and to the top of the pole structure/phase plug, in contrast to a normal rear frame that is only coupled to the motor front plate. This article was originally published in Voice Coil, December 2017.

The driver for this month’s Test Bench explication came from a German OEM driver manufacturer and is from Eton’s home audio Orchestra line of drivers. I asked Eton to send a model from this line, the 4-512/C8/25 RP, mostly because of the unique cone. All of the cones in the Orchestra line are serrated paper cones, which is somewhat reminiscent of the orange sliced paper cones in the Scan-Speak Revelator line. This article was originally published in Voice Coil, December 2017.