K6JRF's Page
formerly W6FZC
ESSB Audio Techniques Page

(Sep 23, 2009)
This Review summarizes the results of audio tests of the Apex 215 microphone.

Apex 215 Ribbon Microphone Report
The Apex 215 is a Chinese made, dual-ribbon microphone. Experts say that the mic is "renamed" from the existing ShuaiYin SYR50 microphone. It is a dual motor mic and it doesn't require phantom power to operate. Street prices range from $129 to $246.

Passive ribbon mics traditionally have lower sensitivity than condenser designs so the use of a second ribbon, mounted side-by-side with the first, does raise the mic's sensitivity and output level. Apex 215 has an extended figure-8 polar pattern that makes it ideal for use on any number of sources including acoustic instruments and critical solo or harmony vocals.

This is how it's rated but in practice for use in a "ham" environment, it does not perform that well. This is due to the higher noise levels encountered b/c of shack 'noise' such as amplifiers and computers. In particular, the computer's fan noise is easily "heard" b/c the preamp gain must be increased by +5 to +10dB to compensate for the low sensitivity. And even then, you must be in front of the mic to get the full response.

However, this leads to other problems such as sudden transients that cause the ribbon to distort the captured sounds. The ribbon mic is extremely suspectible to this and care should be taken to protect the ribbon elements from sudden shocks and pops.

The Apex215 will easily handle SPL as high as 137dB, making them an ideal choice for close miked-voices, for example, but this type of operation leads to large pressure gradients (POPS) causing extreme distortion. In the MP3 test, you will hear some "warbling" that was produced by the mic b/c of this phenomena.

Apex 215 Ribbon Mic Specifications:
    Polar Pattern: Figure 8
    Frequency Response: 30Hz-18KHz
    Sensitivity: -53dB
    Impedance: 200 Ohms
    Recommended Load Impedance: >1000 Ohms
    Equivalent Noise Level: 17dB(A-Weighted)
    Max. SPL (for 1% THD @ 1000Hz; 137Db
    Dimensions (mm): 150 x 30 x 60
    Dimensions (in): 5.9 x 1.2 x 2.4
    Net Weight: 363g / 12.8oz

The "review" of this microphone is very short since it doesn't deserve even this little space that I HAVE to give it in order to say that it's chinese crap!

The output audio is only available if you are DIRECTLY in front of the mic. And the "sweet-spot" is ONLY available off the BACK of the mic! The construction is very cheap and, the final insult, the shock mount connector is too large so it doesn't mate with a standard boom threads. Also, the shockmount connector does not swivel so if you use a side-mounted-boom, the mic is edge-on to you. There is no provision for adjusting the mic's direction. So if a shock-mount is used, the mic's boom must be mounted directly behind it.

The audio MP3 below is an excerpt captured by NA1A, Duke on a Flex5000A. The "warbles" heard in the MP3 were produced by the mic(!) as was the frequency distortion.
This MP3 captures the fine audio from the Neumann TLM-103

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