In this blog post I compare the B&C DCX-464-16 against the Lamar M2-16 Field Coil Compression Driver.
For this comparison I'm using my own ES-290 Biradial wood horn which loads down to 300Hz. I am only looking at the midrange frequency spectrum for this test. The types of acoustical measurements chosen are intended to highlight the sound quality aspects for two channel music applications (audiophile).
I've CNC machined custom throat adapters for each compression driver to ensure a perfectly smooth throat transition. (see below)
Frequency Response & Distortion
Both drivers exhibit good frequency response results within the horn's bandwidth (300Hz-4kHz). The B&C shows plus/minus 1dB from 350Hz-2kHz. The Lamar shows plus/minus 2dB from 350Hz-3kHz.
Higher Sensitivity for B&C
With the test setup untouched I replaced the Lamar driver with the B&C and noticed significantly higher sensitivity with the B&C. B&C published 112.7dB sensitivity using a 4 volt test signal (1watt) and so it could be calculated that the Lamar is 104.7dB which puts in line with many other compression drivers.
Spectral Burst Decay
Below is the spectral burst decay results. Both drivers are free of any significant resonances even with the vertical scale extended down -35dB. In the end the B&C does show a cleaner result...one of the best I've observed.
Incrementally increasing the level by 5dB increments I then observed the distortion level until it reached a threshold of 1%. At 90dB the Lamar is getting uncomfortable in the 2kHz region. (see red arrow below)
By 95dB the Lamar was very close to my 1% distortion threshold. (See red arrow below)
I was too scared to attempt a 100dB sweep on the Lamar considering it's high cost. However the B&C continued to remain below 1% distortion at this SPL level (see red arrow below).
Off-Axis Polar Response
For interest's sake, below is the off-axis polar response for the ES-290 Biradial Wood Horn. This data is pulled from a previous blog post which can be found here.
Both drivers exhibited excellent results and would be well within my performance target for audiophile music applications.