CAD M177 & M179

US mic manufacturers CAD move in on the affordable end of the market with two new large‑diaphragm models, one of which offers multi‑pattern functionality. Hugh Robjohns evaluates the M177 and M179.

Although CAD Professional Microphones may not have the cachet in professional studios of some of the established European microphone manufacturers, I have always found them to offer remarkably good value for money, usually equalling the sound quality of microphones costing at least a hundred pounds more. The new M177 cardioid and M179 multi‑pattern microphones are no exception to this rule.

A lot of the budget condenser mics available today are manufactured in the Far East, almost regardless of whose badge appears on the body. It is worth noting, then, that CAD construct their own Optema capsule designs in a special clean‑room facility within their factory in Ohio in the USA, and install them in microphones manufactured entirely on site.

CAD first came to prominence in the 1990s with their E‑series Equitek range of studio condensers (reviewed in SOS June 1997), designed specifically to meet the needs and budgets of a rapidly expanding project studio market. The company's microphone range also includes high‑end valve designs including the VSM, VX2 (reviewed in SOS August 1999 and SOS September 2000 respectively). There are hand‑held vocal mics and dedicated percussion mics as well, and the inevitable line of contractor and installation microphones.

Components & Design

The new range is priced aggressively to compete with badged microphones manufactured in the Far East. CAD hope to influence the market with the M‑series in much the same way as they did with the original Equitek, offering high‑quality, rugged and long‑lasting microphones at very attractive prices.

These new models share the same capsule elements as the original Equitek E300 (now superseded by the E350). This is an externally biased unit with a gold‑sputtered 1.1‑inch diaphragm, available in both single and dual‑sided versions. In the M177, a single‑pattern version is configured for fixed‑cardioid operation, whereas the M179 employs a dual capsule to provide a continuously variable polar pattern from omni, through cardioid, and on to figure‑of‑eight.

The fixed‑cardioid CAD M177.The M177 and M179 both employ much more sophisticated electronics than the Equitek series, which is how the performance gains have been achieved. The head amplifiers employ high‑speed, low‑noise operational amplifiers rather than discrete FET designs. These op amps are laser‑trimmed for accuracy and provide plenty of gain, allowing high levels of negative‑feedback to improve linearity. A new all‑discrete internal power circuit has also been developed which has resulted in lower self‑noise and consequently a wider dynamic range.

The specifications are certainly impressive, with a noise floor which compares favourably with many high‑end mics. At 11dBA, these mics are 3dB quieter than the AKG C414, 1dB quieter than the Neumann U87 and only 1dB noisier than a Sennheiser MKH80 — impressive company indeed! The distortion figures are equally splendid (under 0.15 percent), and the design also boasts a frequency response of 10Hz to 20kHz.

The response plots supplied with both mics exhibit a set of mild wobbles at the high end, between 3kHz and 15kHz, and a response which remains remarkably flat down to 10Hz, with no sign of a low‑end roll‑off! Overall, the response appears to remain within ±3dB throughout the whole range — the HF wobbles being the only area which nears those limits. A very mild (under 2dB) mid‑range depression, centred on 900Hz, can also be seen on both charts. The mics provide a high output level of 15mV/Pa, and a dynamic range of 133dB. With the pad switched in they can tolerate peak levels of an ear‑destroying 143dBA.

Mechanics

The mechanics of the microphone have received as much attention as the electronics, resulting in a rugged construction which should prove resilient even to the abuse of a life on the road. The body has that very fashionable 'slightly squashed tube' appearance, with a dual‑layer wire mesh grille protecting the capsule. A U‑shaped chassis runs around the outside of the mic, supporting the capsule at the top and the two charcoal‑grey side panels, which are held in place by four accessible screws. The three‑pin XLR connector at the base of the mic has a threaded perimeter to which is fixed the stand adapter.

The multi‑pattern CAD M179.Both the M177 and M179 are supplied in very impressive foam‑lined flightcases and are accompanied by a frequency response plot, a warranty card, and a brochure detailing various operational and technical aspects of the particular model. The stand adaptor is fixed semi‑permanently to the mic, with a 5/8‑inch thread size and no European 3/8‑inch adapter, not even a cheap plastic one.

With a frequency response which is still going strong at 10Hz, mechanical vibration reaching the mic is a serious problem, and the internal shockmounting, although good, is no match for a decent suspension cradle. It seems a shame to have designed a cost‑effective mic with such a phenomenal response, only to ship it with a rigid stand adaptor which will not allow it to perform to its full potential. Personally, I would have preferred the money lavished on the flightcase to have been put towards a decent cradle.

Unfortunately, not only is a suspension mount not supplied with the mic, but CAD don't even mention the option of one in their accessories lists. However, fitting such a device — should CAD or some other third party design one — would be very simple, as the standard mounting can be removed easily via the knurled nut at the base of the mic. The only drawback here is that the serial number label is glued onto the (easily removable) stand adapter — so much for security then...

Four screws release the panels from both sides of the body, providing superb access to the internal electronics. These are housed on a single circuit board mainly stuffed with surface‑mount components, supported solidly between the mic's chassis rails. The capsule is mounted in rubber supports to provide a degree of shockmounting, and is protected by an internal pop screen.

Both models include 20dB pad and 100Hz high‑pass filter slide switches on the body — chunky designs which are easy to use without having to put your fingers through a pencil‑sharpener first! The M179 also includes a thumbwheel to select the polar pattern, with a centre‑detent at the cardioid position. In all there are five marked patterns: omni, wide cardioid, cardioid, hypercardioid, and figure‑of‑eight. Notches in the wheel's circumference provide a further four identifiable intermediate positions and changing pattern does not create any clicks or pops, just the expected smooth transition in ambient pickup.

The M177 and M179 require phantom power between 24V and 48V (although some CAD literature suggests they can accommodate 52V supplies as well), but with a whopping 8mA supply current! This is well over twice what most other condenser mics require. The Sennheiser MKH80 and AKG C414 require only 3mA and the Neumann U87 a mere 0.8mA, for example. High supply current can cause problems in badly designed equipment, or where poor‑quality mic cables are being used, because of voltage losses. If a lot of current is drawn from a poor phantom power supply, its output voltage is likely to sag below the nominal 48V, making it more likely that the microphones will lack headroom and suffer transient distortion. It is also possible that, even if the CAD mics don't suffer as the phantom voltage droops, other mics powered from the same supply may be affected — something to watch out for when using a full complement of mics on a mixer with a small power supply. Also, the inherent resistance of mic cables means that the greater the current flowing, the more phantom voltage is lost in the cable itself, with the same end results.

Although I didn't experience any obvious problems testing these mics with a range of mic preamps with internal phantom supplies, I was careful to use good‑quality mic cables and to keep cable runs as short as possible. In general I would be very wary of using large numbers of high‑current mics together, powered from the same supply, or at the ends of long cable runs.

Listening Tests

I remember being impressed with CAD's Equitek range of mics, when I first came across them many years ago, for their remarkable performance at surprisingly modest prices. The M‑series is the same story all over again, but with technical performance approaching the best that is possible in this new millennium. Taking the M177 first, the retail price of this fixed‑cardioid design is below that of the AKG C3000, yet it outperforms models such as the Beyer MCE90 and Audio Technica AT4033A costing significantly more. Similarly, the M179 costs less than the AKG C4000, Audio Technica AT4050 or Rode NT2, yet is, at the very least, their equal. Only the AKG is quieter and none has as flat or extended a frequency response.

However, it is interesting to note that most of the mics mentioned here are supplied (as standard) with suspension cradle mounts, or can be fitted with them as optional accessories — a factor which may well give some of these models a quality edge in some practical applications. Moreover, the CAD high‑pass filters here are too gentle and turn over too high up to provide effective relief from rumble, although thet are helpful in taming proximity effect when necessary. Some consoles will offer facilities better suited to the removal of subsonic rubbish, but I worry that few users will even be aware of the considerable amount of LF that might be swimming around behind their mixes. Believe me, these mics are quite able to resolve frequencies below 20Hz, whether arriving through the air or the microphone body, even if your nearfield monitors can't do anything about it!

I found both the M177 and M179 to be extremely good microphones, able to capture a high degree of detail in complex material, presenting it naturally and, more importantly, with neutrality.

I found both the M177 and M179 to be extremely good microphones, able to capture a high degree of detail in complex material (using my favourite 12‑string guitar test), presenting it naturally and, more importantly, with neutrality. Although these mics exhibited a subtle character (at least compared with my reference Sennheiser MKH‑series mics) — mainly, I suspect, because of the inherent characteristics of their large diaphragms — it is musically complementary and never proved to be a problem.

Like all large‑diaphragm mics, I found the M‑series to work well particularly on voices, both singing and spoken, as well as a very broad range of acoustic instruments. The proximity effect was quite pronounced with very close working, perhaps a little more than on some other designs, but I found placing a separate pop shield a few inches away from the mic to keep the vocalist in the right place produced some superbly detailed and well‑balanced tracks. With its high SPL capability, the mic was also quite happy in front of amplifiers, although its low noise floor was obviously wasted in this application.

The M177 cardioid pattern is well‑defined, with a usable frontal pickup out to around 45 degrees. Above about 8kHz this response narrows towards a tight hypercardioid shape, as any similarly‑sized capsule would. The continuously variable M179 is a joy to use — no clicks or pops as the pattern is changed and the ability to fine tune the amount and colour of ambience captured in a live environment. As with any large‑diaphragm mic, the omni pattern is rather closer to a figure‑of‑eight above about 8kHz, but the figure‑of‑eight position retains good width in both lobes up to around 12kHz before it narrows.

There are relatively few continuously variable‑pattern mics around and certainly none at this price level, as far as I am aware. It is almost worth buying a couple of M179s for this facility alone, but the mic also stands on its own merits as an extremely low‑cost jack‑of‑all‑trades. It may not be the ultimate master, but it certainly makes an excellent deputy!

The only real downsides for me are the susceptibility to stand vibration and a concern about the high phantom current draw. Both would make me reticent to use these mics for live stage use (although CAD list this area amongst their applications). In the studio, where solid floors are the norm, the M‑series proved excellent. They stood up remarkably well against high‑end studio standards, even bettering some of the more venerable classics, at least in terms of noise. Provided these mics are used intelligently, they are capable of a performance which goes way beyond that expected at their respective UK prices, and are therefore worthy of serious consideration.