Reports of noticeable noise floor in ATW 1800 wireless system

[Collis Davis]

I have had an ATW (Audio Technica)-101U wireless system since 2002. As far as I can determine, there have never been any major issues with this system aside from the fact that the receiver is a battery hog.

Lately, I have been thinking of upgrading to the new ATW-1800 Series (with either dual or single channel operation). My principal reason for upgrading would be to take advantage of the dual channel feature of the ATW-1821 model. But I was surprised to read two out of three reviews (at B&H Photo Video) about the the ATW-1800 series that were quite critical. What follows is a quote of one of the negative reviews. The third review was 100% positive in its evaluation.

Audio-Technica | ATW-1821 - Dual Wireless Microphone | ATW-1821D

Once on the above web page, click on the "Reviews" tab.

"I tested this with another professional sound mixer in Los Angeles, and while we were both impressed with the price we were underwhelmed with the performance. Range and noise floor were our main issues. While it is probably fine for really low budget reality stuff, weddings etc, I could not stop obsessing on the noise floor. Also the noise would pump up a little bit while transmitting/receiving. With some tweaking of output levels etc we got it running pretty quiet but by then I could not stop obsessing about the noise.Keep in mind I am used to using a Zaxcom or Lectrosonic 411as a camera hop, so I am comparing it to systems that costwell over twice what this one does and have more powerful transmitters. But my final opinion would be that they got close but I wouldn't trust it for broadcast/film work where the sound quality would be scrutinized by post.

Expertise: Professional sound mixer for television/film "

Personally, I never encountered the noise floor problem before with the ATW-101U, so what's the story here?

I would appreciate hearing from any of you who have used the new ATW-1800 series wireless mike system, or, ideally, hearing from those who've used both models would be even better. Thanx for your take on this issue. Of course, there is a competing system out there by Azden, also a dual-channel system. How might this one compare to the ATW-1800?

Collis Davis

[Don Bloom]

I've been using the AT dual channel system since January now and YES there is a BIT of noise that sneaks in there but I have used the system for weddings, seminars and talking heads and frankly you don't even notice the noise. At least I didn't. To me it's so far down you just don't hear it. Neither have any of my clients and I don't mean just weddings. So from my view the noise thing isn't an issue. BTW I am not using the AT 839 mics that come with the bodypaks. Maybe thats' the difference but I doubt it.

As dor comparing to the Azden dual channel, it depends on which one. A freind of mine needed a dual channel and got the Azden 200 series. After a quick comparison I would have to say no it's not as good as the AT1800 both in features and sound BUT it's not a bad unit for the money. They also have the 320 series which is a new version and of course has more features but I have never compared the At to it.
Features about the AT I like a lot.
1) The Xmitters have a db level set
2) they also have built in line level
3) they work off of 2 AA batteries
4) the on/off switch is behind a sliding panel (no accidential off)
5)the receiver has a slide in case with a belt clip and open bottom to get to controls
6)each side of the receiver has a levels control on the bottom
7)setting channels o the receiver and xmitter is easy
8)the receiver runs on 6 AA batteries
9)the unit has 3 scan channels 'scan 1' 'scan 2' 'scan 3' which makes finding open freqs really easy
and finally,
10)the unit is in my mind well built and solid. While the body paks are not metal they seem to hold up to 'oops' moments. Mine have been dropped more than once and are still running just fine.
Anyway that's my opinion of the AT1800 DC unit. YMMV

Don

[Ty Ford]

"Reviews" that end up on sites are often posted by the competition to knock the competition. You get that when anyone can post a "review."

I review gear for a living. I reviewed the 1800 for Pro Audio Review when it came out.
Below is that review.

Audio-Technica 1800 Series Dual Channel Camera-mount UHF Wireless System
Ty Ford
Sticking one wireless receiver on the back of a camera is fairly common for run and
gun. If you need two, Audio-Technica’s new 1800 Series Dual Channel Camera mount-
able UHF wireless system deserves a look. Although single receivers are available in
the series, the new ATW-R1820 dual channel receiver is a significant change in wireless
receiver technology.
RECEIVER FEATURES
The ATW-R1820 dual channel receiver contains two separate full diversity receivers.
That’s a total of four RF front ends in one case, all using the same two BNC-mounted
stub antennae. It also has an auto-scanner and onboard audio mixing features.
The receiver kit includes a snug cloth holster with a metal clip that can be used to attach
the receiver to a belt or to the back of a battery box. The bottom of the holster is open
but fitted with straps to allow the short mini-XLR to XLR cables included with the kit to
be attached to the receiver audio outputs. BEC group (Digital Video Camera Accessory - Wireless Receiver Holders - The BEC Group) also
makes a receiver box that locks onto various camera battery lugs into which the re-
ceiver fits.
The receiver weighs one pound six ounces when loaded with six AA batteries. While the
receiver case is metal, the battery door is plastic and detaches completely from the
body. That makes it one more thing to keep track of. Fortunately, six AA batteries pro-
vide nearly six hours in dual receiver mode and almost 10 hours in single receiver
mode, so battery changes shouldn’t be required as often. The receiver has a small, four
bar battery life display in its LCD window. The receiver also has an external power jack
to accept 12 V DC, 500 mA from a camera or other external source.
The top of the ATW-R1820 receiver hosts the two BNC antenna connections, power/
audio peak LEDs for each receiver, a power switch for internal/external power for one or
both receivers, controls for changing frequency and operating the auto-scanner and an-
tenna switching status lights.
The bottom of the two-channel receiver is relatively busy. There are two mini-XLR out-
puts, A and B and a switching matrix. You can send the output of receiver one to both
outputs, so it feeds both A and B mini-XLR outputs. You can route receiver one to output
A and receiver 2 to output B so each are on separate tracks for split track or stereo re-
cordings. You can route receiver one and two to MIX which makes a mono mix of both
channels available to both outputs. Two small pots on the bottom of the receiver are
used to adjust the levels of the individual outputs or create a two channel mono mix of
the two mics.
MIXING RECEIVERS TO OUTPUTS.
The receiver’s mixer allows some interesting possibilities. If receiver one‘s is set to out-
put A and receiver two is set to MIX, receiver one is audible on both outputs and re-
ceiver two is audible only on output B. If receiver one is set to Output A mix and receiver
two is set to Output B 2, receiver one is only on the left channel and receiver two is on
both A and B channels. Depending on how the receiver is mounted, you might want to
tape over the mixer controls after setting them to prevent accidental changes.
One of the features I like best about some of the AT receivers is the stereo mini jack
right on the receiver that lets you listen to the audio before it gets to the mixer or cam-
era. In this case, it let me sort out which mic was going to which output. There is also a
monitor level control which has plenty of gain to feed a set of headphones. There was a
difference in the audio between what my Sony MDR7506 heard from the stereo mini
jack directly from the receiver and the audio passed from the receiver’s balanced out-
puts to my Sound Devices 442 mixer. The main outs were clearer, making the receiver
mini jack output sound dull by comparison.
BODY-PACK TRANSMITTER FEATURES
The ATW-1801 body pack transmitter (and ATW-1802 plug on) each run on two AA bat-
teries, a departure from 9 VDC operation. The transmitters, as with the receiver, may be
ordered to operate on either of two frequency bands; 541.500 MHz-566.375 MHz or
655.500 MHz-680.375 MHz. There are a total of 996 frequencies per band in 25 kHz
increments. The phase lock loop system uses FM modulation with +/- 10 kHz deviation.
Each transmitter can be adjusted for 10 mW or 30 mW output. RF output obviously de-
termines battery life.
Both transmitters have LEDs that show green when powered up and red when powered
but muted. These LEDs blink to indicate low battery. There is also a small, four bar dis-
play in the LCD window of each transmitter that indicates battery life. The mute and
power can be locked either on or off. There is no noise when switching from mute to on.
Powering down the transmitters, however, does generate a small click. I also found
some situations in which there was enough RF in the air to allow some unpleasant
noise to escape the receiver even after the transmitters were turned off.
A small but readable LCD screen and can be toggled to show the status of the features
of each transmitter. When the transmitters’ SET buttons are pushed, the LCD becomes
backlit; enough to see in the dark. When in MUTE, “mute” in very small letters appears
on the transmitter’s LCD display. Both transmitters have sliding panels that cover the
adjustment controls to prevent accidental status changes. The panel on the plug-on
transmitter has a hole that allows you to turn the transmitter on and off, even when the
panel is closed.
The ATW-T1801 body-pack transmitter is slightly smaller than a box of Marlboros and
chews up a pair of AA alkaline cells in eight hours at low power and six hours at high
power. That specs out to 160 mA and 180 mA current consumption, respectively. The
body-pack has a switchable input with low-Z input for mic or high-Z musical instrument
pickups and also makes available a small bias voltage, but not enough for Phantom
Power. Input sensitivity is adjustable in four steps from -6 dB, 0 dB, + 6dB and +12 dB,
with a default of + 6 dB.
The antenna on the body-pack transmitter unscrews. The microphone connector is
spring loaded, locking, four-pin Hirose-type connector. Pulling the sliding outer shell of
the connector releases the lock. The spring clip for hooking the transmitter on a waist-
band or pocket is designed so that it can be reversed; allowing the mic to be mounted in
either of two vertical orientations. The transmitter case is made out of high impact plas-
tic. The battery hinged door is a little hard to get open if there are no batteries to pop the
lid.
PLUG-ON TRANSMITTER FEATURES
The ATW-T1802 plug-on transmitter duplicates the features of the body-pack transmitter
with a few exceptions. It provides 12 V DC Phantom Power, but doesn’t have a high im-
pedance instrument input option. The Audio-Technica AT 4073a worked very nicely with
the plug on. It’s high sensitivity may not be what you want in extremely high SPL envi-
ronments, but it feeds the plug on an impressive signal. A Sennheiser 421 dynamic mic,
while less sensitive, also worked well.
IN USE
The auto-scan feature on the receiver needs some work. Its first scan ended up in the
middle of a used NTSC channel in town with a transmitter about six miles away. At that
frequency, range was limited to about thirty feet. After checking a chart and choosing a
more open frequency, I walk tested both transmitters running high power (30 mW) with
the receiver in dual mode and got about 50 yards before taking soft hits on the plug-on
and 70 yards with the body mic. I did have some unusual range reduction problems on
a rainy day.
On subsequent days, I got more than 50 yards with the body mic and 30 yards with the
plug on with my body between the mics and the receiver with both transmitters and re-
ceivers working; about ten more yards when the antennae were in the clear. The plug
on, one day, went a good seventy yards when held vertically and in the clear.
Using two antennae for two full diversity receivers in the same box can be expected to
reduce range to some degree. It’s a simple trade off; some range for operational flexibil-
ity. So while you may not break any long distance reception records with the Audio-
Technica 1800 Series, partnering two diversity receivers and a mixer in one box does
give you a lot of operational power.
SUMMARY
Navigating the menus to make changes was easy after I had used the system a day or
so. For the ENG/EFP market, where having two channels of wireless strapped to the
camera is increasingly useful, the Audio-Technica 1800 Series brings a lot to the table,
especially at its price point of $1795. You may or may not want to use the mixer features
on the receiver, but having them does provide options. Audio-Technica sells the 1800
Series in three different sets; a receiver and two body mics, two plug-ons or a body mic
and a plug-on. The only things on my wish list would be a strapped pouch to hold every-
thing and, of course, 48 V Phantom Power for the plug-on.
Ty Ford is on special assignment from Radio World and Pro Audio Review. He may be
reached at www.tyford.com.
©*Copyright 2007 Technique, Inc. 8/07

[Collis Davis]

Don & Ty:

Well, your two evaluations of the ATW-1800 series certainly dispel any doubts I had based on those two reviews posted at B&H. You may be right that these "unauthorized" reviews may be intended to bad-mouth the competiton. Something to consider when reading these type of reviews.

Anyway, I am happy to learn of the myriad of new features over that of ATW-101U series of days of old. Certainly one concern of mine was Ty's report of the life of ordinary alkaline batteries for the receiver which is considerably longer than that of the 101U receiver. Might not this performance be improved with some of the higher amperage re-charegeable batteries instead of alkalines?

Since I own an AT-4073a short shotgun, I was gratified to learn that it works well with the plug-on transmitter as it requires phantom powering, but I am in agreement with Ty that including 48v phantom powering would be an attractive added feature. Hey, I am sold on what I've read thus far.

What are my chances of selling my ATW-101U system in the classifieds? Paid $720 for the system from the Equipment Emporium way back in 2002.

Thanks so much for your infomative comments.

Collis

[Ty Ford]

Colin,

I have two AT 101 and really like them. They are not perfect, but they have served me very well. They don't deliver the sound that an Audio Ltd. wireless does, but the cost difference is pretty staggering.

For battery life, think about getting a link for the receiver so it used camera power.

Regards,

Ty Ford

[Collis Davis]

Ty,

I am one step ahead of you re. powering the receiver another way.

My approach now is to power both my Canon XL-1S and the receiver from a battery belt. You know when the voltage wanes in the 101 receiver, reception falters as well and you begin to experience dropouts in your signal. With either the battery belt or AC powering, dropouts are never an issue.

Collis

[Ty Ford]

That'll work. I use a rechargeable battery for a portable DVD player for my 442 mixer. I can run it for days.

Regards,

Ty Ford

[Steve House]

Originally Posted by Ty Ford

That'll work. I use a rechargeable battery for a portable DVD player for my 442 mixer. I can run it for days.

Regards,

Ty Ford

What battery do you use? Looking at NP-1s and they're pretty pricey - would love to find a cheaper solution.

[Ty Ford]

http://www.batterygeek.net/Batteryge...atterygeek.htm

Price has gone up since I got mine, but you may not need this much jiuce. The only problem I found was that if it took a static discharge hit on a dry day. I'd have to briefly plug in the charger to reboot the internal breaker. When I told them about that, they said they'd look into fixing that with a simpler reset.

Regards,

Ty Ford

[Marco Leavitt]

Sheesh, comparing this system to Zaxcom and Lectrosonic just isn't fair. As far as noise, you need to be careful with the settings, or it can be quite noisy. I usually set the transmitter's gain all the way up unless there is yelling. Also, I find setting the output knob fairly high up (about two thirds) gives me the best s/n ratio. I've found the noise level to be pretty similar to Sennheiser G2 system.

[Sean McCormick]

Hi Ty,

Could the afore-mentioned battery you use work with a BDS? What would be needed if so?

I'm very interested in the thought of using an alternative to NP-1s for my 442/R4-Pro/Lectro stuff...

Thx,

Sean

Originally Posted by Ty Ford

Batterygeek.net: universal laptop battery, external laptop battery, macbook battery, macbook pro battery, universal laptop battery pack, External laptop Battery Pack

Price has gone up since I got mine, but you may not need this much jiuce. The only problem I found was that if it took a static discharge hit on a dry day. I'd have to briefly plug in the charger to reboot the internal breaker. When I told them about that, they said they'd look into fixing that with a simpler reset.

Regards,

Ty Ford

[Don Palomaki]

Some update information to a very old thread;

Ran a couple quick tests on an AT-1800 single channel received with a ATW-1802T plug-in transmitter.

Not clear (to me at least) from the docuemtnation but the transmitter gain setting refers to the relative gain of the transmitter/receiver as a system. For example, at 0 dB gain on the transmitter, the output voltage of the receiver (at max receiver volume setting) will be nominally equal the voltage input to the transmitter (subject of course to effects if the impedance of the source and destination). So 10 mV in gives 10 mV output. Simple.

The manual says the receiver power light will blink if the input signal is too hot. On my sytem that happened when the input to the transmitter was about 0.5 volts ( -6 dBV). and the transmitter gain was set to 0 dB.

At that point, with the transmitter muted the noise output of the receiver measured about -85 dBV (some of this could have been test lead dress and my environment - we are talking 56 microvolts here). The batteries I used were COSTCO Alkalines AA with about 1 hour of use on them.

With this receiver/transmitter in my test environment the noise floor was about 79 dB below maximum output, better than plain old FM without companding,

For best signal to noise in the output I would say to use the highest transmitter gain you can without clipping (blinking power light on the receiver. Then use the output level control on the receiver to match that level to your recorder/camcorder/amp.

Example:
If using an AT875 short shotgun with a output rated at -30 dBV at 94 dB sound pressure level (SPL)
In a venu expected to reach 100 dB SPL
The mic output will reach about -24 dBV
And you want 12 dB headroom in the audio.
Then plan for an input of -12 dBV
SInce the AT1800 system maxes out at -6 dBV
You could use +6dB transmitter gain to maximize your S/N and retain the head room you want in the wireless system

And the transmitter's phantom power does successfully power mics rated for 11 volts.