Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Rob Spence]

 So, I did this wedding on Saturday. I had a total of 8ch of ULX J1 band in 2 cases, each with a Shure splitter/power supply and half wave antenna. Four mics for the reception band and other rack for the ceremony (though only used 2 ch for that).
After the ceremony we moved the second rack to the reception to provide mics for speeches and skits by the friends & family of the newlyweds. All frequencies coordinated for intermod. This was in the sticks so no likely outside interference (Verizon 1x available sorta).
I got surprised by the lighting folk using wireless DMX with their transmitter 2’ from my rack. One of my receivers had its rf indicator flickering to what looked like DMX on my lighted terminators when it’s mic was not on. There did not seem to be any interference when the mic was in use.

Ok, so much for painting the background.

It’s a wedding, so things must work so I bought a bunch of new 9v Duracells for the wireless.

During the 4 hr show I had to replace batteries on all the mics once and on one, twice. The power light on two mics turned red and we did quick swaps even though the battery status showed 2 bars (of 3).

Two of the swaps were with warehouse club batteries which I have had good experiences with in the past. They ran down too.

The nice thing about working with pro musicians is they can handle things like this and the audience never notices.

I use this set of mics several times a year on outdoor festivals and I usually get 4 or more hours of run time though we turn em off between acts since not every act uses all of them.

So, I was surprised by the consumption rate.

Any insights?




Sent from my iPad using Tapatalk Pro

[Luke Geis]

In my experience, 9v wireless products all have that problem. The 9v battery just doesn't have the capacity that the AA options do. The typical 9v battery has about the same capacity ( energy ) as a typical AA does. However, when you double the AA's up, you get double the energy capacity! Couple that with lithium energy densities and its no wonder a wireless pack can last 10 hours or more. 9v wireless systems suck; energy that is......

I am perhaps a bit braver than others, but I buy only lithium batteries for my wireless and I can get three whole days of show with one set of batteries if I keep the packs turned off when not in use. I can pretty much get a solid 10 hours of " on " time with the lithium batteries.

[brian maddox]

In my experience, 9v wireless products all have that problem. The 9v battery just doesn't have the capacity that the AA options do. The typical 9v battery has about the same capacity ( energy ) as a typical AA does. However, when you double the AA's up, you get double the energy capacity! Couple that with lithium energy densities and its no wonder a wireless pack can last 10 hours or more. 9v wireless systems suck; energy that is......

I am perhaps a bit braver than others, but I buy only lithium batteries for my wireless and I can get three whole days of show with one set of batteries if I keep the packs turned off when not in use. I can pretty much get a solid 10 hours of " on " time with the lithium batteries.

I switched to L-Ion 9V a few years ago because they have MORE capacity than an alkaline.  I'm still using the first set i bought.  They're at least 5 years old at this point.  They've never let me down.

[Jay Barracato]

I switched to L-Ion 9V a few years ago because they have MORE capacity than an alkaline.  I'm still using the first set i bought.  They're at least 5 years old at this point.  They've never let me down.

In a traditional regular carbon/zinc or alkaline battery, the 9v is built from 6 cells that are the same radius as a AAAA but slightly shorter in series. This means the amount of material available to react before the cell reaches equilibrium is less than an AA.

Sent from my Moto Z (2) using Tapatalk

[Brian Jojade]

The OP seems to indicate that the mics behaved differently at this particular event than normal.  Assuming he used the same type of battery as usual, advice to use different batteries could have given the same symptom, just different lengths of time.

It's quite possible that you had some bad batteries in your batch.  It happens.  When I had ULX systems, there was one event where I forgot to bring batteries (stupid Me) and had to go to the gas station and pick some up. They had Duracells, so I thought I was safe. They lasted just over an hour! Horrible.

I've used plenty of different types of batteries. Duracells gave me the best results with the most accurate meter readings.  Energizers seemed to show 'full' longer then the duracell, but once the meter dropped one bar, they gave up very quickly.  Rayovacs are great batteries if you've got a short event and want to save $$. They don't last nearly as long, but at half the price worked pretty well.

Since the transmitters are only transmitters, how noisy the RF environment shouldn't make a bit of difference in how the batteries perform.  Nor should the distance from the receivers.  What I did notice though is that the source volume would make a big difference in how long the batteries would last.  A mic on a podium that was left on would last much longer than one that was used by a lead singer screaming into the mic.  Additionally, the gain level of the mic would make a difference in battery life as well.  Turning down the gain on the transmitter seemed to increase battery life as well, although not by as much as keeping the mic in a quieter setting.

[TomBoisseau]

My church has a bunch of ULX systems.  Although I'm not really very involved with the sound there, I can tell you that the run time that they are getting is about what you quoted.

Also, I used to do sound at the Chic-fil-a headquarter south of Atlanta.  If I remember corectly, they had a bunch of the ULX systems in their install.  I seem to recall, that's about right for that model.

I'm sure someone else with more expericance with the ULX series can tell you better.

Tom

[Cailen Waddell]

I have found ULX battery draw proportional to the volume of noise the mic is transmitting.  Maybe this is anecdotal and bullshit in how mics work... but a loud concert I get under 4 hours on a 58 handheld.  A quiet lecture with a 58 handheld on a podium, around 8 hours. 


Sent from my iPhone using Tapatalk

[Luke Geis]

^^^^^^^^^

You are correct. The more sound it transmits the faster it draws the battery.

[Keith Broughton]

Rob, did you test the used batteries to see if they were low or did you rely on the battery meter on the RF gear?

[Rob Spence]

Rob, did you test the used batteries to see if they were low or did you rely on the battery meter on the RF gear?

Didn’t test em. It was a wedding, no time. Just pulled suspects and replaced. I didn’t bring the suspects home.
I should have.


Sent from my iPad using Tapatalk Pro

[Justin Goodman]

^^^^^^^^^

You are correct. The more sound it transmits the faster it draws the battery.

Can somebody explain how this works?  I'm not doubting that it's correct, just curious why it's the case.  My understanding of FM modulation is that output amplitude should be pretty constant (vs AM).  I can see the "work" of modulating the frequency with "content" potentially requiring some power, maybe?  But it doesn't seem like it would be tremendously different?

[Rob Spence]

I switched to L-Ion 9V a few years ago because they have MORE capacity than an alkaline.  I'm still using the first set i bought.  They're at least 5 years old at this point.  They've never let me down.

Any particular brand?

Charger?



Sent from my iPad using Tapatalk Pro

[Andrew Broughton]

I switched to L-Ion 9V a few years ago because they have MORE capacity than an alkaline.  I'm still using the first set i bought.  They're at least 5 years old at this point.  They've never let me down.

The other thing people don't realize about rechargeables is that they can be MORE reliable than Alkalines. If you've used that particular rechargeable battery before, you already know how long it will last when fully charged. An alkaline can be DOA out of the box, or have lower capacity than expected because IT's THE FIRST TIME YOU'VE EVER USED IT. It has no history or track record. You're just gambling that it will work.
There are no real advantages to non-rechargables except convenience. For professional, critical situations, KNOWN rechargeables are the right way to go.

[Jason Glass]

Can somebody explain how this works?  I'm not doubting that it's correct, just curious why it's the case.  My understanding of FM modulation is that output amplitude should be pretty constant (vs AM).  I can see the "work" of modulating the frequency with "content" potentially requiring some power, maybe?  But it doesn't seem like it would be tremendously different?

A wireless microphone transmitter carries a whole lot more circuitry than just the radio portion.  How that circuitry handles the audio portion is crucial in how rapidly the electrical current is consumed.

Sent from my mobile phone using Tapatalk

[Luke Geis]

There is a companding circuit in the microphone among several other monitoring circuits. It is sending all kinds of data to the receiver. The pilot tone, the audio signal, battery usage info etc. When actual audio is passing through it has to modulate that data and transmit it. Even running in hi or low power mode is a factor in battery life. Simply, the more information that is transmitted the shorter the battery life.

[William Schnake]

Rob, I can't answer your questions directly however, we own several ULX/P with both handheld 58/Beta 58a and body packs.  We always use Duracell Pro-cell 9 volt batteries.  We consistently get 6 - 8 hours regardless of which mic system we are using.  We have only had two of the Duracell Pro-cells not work in the past 5 years or so.  We go through between 800 and 1,000 per year.

Bill

[Luke Geis]

I have come across several bad batches of Duracell Pro-Cell batteries. How or why is beyond me, but I have been let down by them more than a couple times over the years. I would say at least 3-4 times in the last 15 years.

[ProSoundWeb Community]