Wireless Question

[Nuisance]

I have a straightforward question about wireless systems for my band. If all of us are using the same Sennheiser wireless IEM systems, should we all select the same frequency band (A, B, C, etc.), using different groups or channels within that band, or should we choose different bands entirely?

My Sweetwater representative mentioned that it doesn't really matter, which makes sense given that we only have four members. However, when I research online, I’m seeing a strong recommendation for everyone to stay on the same band.

For those with expertise in this area, what's your take?

 

[drpepper]

As I understand it, you should use the same group/different channels. With analog transmission, each device actually affects 3 frequencies; one above and one below the frequency tuned to (there's math to figure out what they are). The preset frequencies within each group (in a group/channel matrix) are arranged to not interfere with each other.

Edit - Looks I I read you too quickly...if you're able to use completely different frequency bands and all have vacant ranges, I'm not sure why there would be a question, but if you have multiples in the same band, then what I said applies - start with the same group because the frequencies are arranged for that purpose

 

[Nuisance]

Correct. I am talking about the actual band the groups live in . I believe both Sennheiser and Shure label them A, B, C, and so on. The frequency ranges in each band are too far apart for it to have any effect IMHO, but because I'm asking each band member to invest in a wireless system, I want to make sure I'm getting this right (they are ready to buy, and asking me what band to get).

 

[Wasnex]

I believe the correct term is "group." A radio band is more like UHF and VHF. Per Shure, a Group is "a collection of pre-programmed, compatible frequencies," (within a band). The channels in each group are selected so that there is less chance of interference between channels.

Among the gear I have used, the intent is to run all gear in the same group.



The best choice of channels can vary from one location to the next. So ideally some sort of scanner is used to sample the local RF environment and identify which channels have conflicts and which appear to be free. A free channel can develop a conflict at any time though, so the need to change channels is not unusual. Sometimes when you change one channel, it causes a leap frog situation and you wind up having to change other channels. I believe this is because the frequency from your wireless units interact to some extent with other channels that are present in the local RF environment.

Some wireless system have built in scanners.

Here's an article on using a scanner:

Shure Tech Tip: Radio Frequency Scanners

A RF scanner is useful in any installation employing wireless mics if your wireless system lacks an onboard scanner. This post explains exactly how they work.

www.shure.com

 

[Wasnex]

Correct. I am talking about the actual band the groups live in . I believe both Sennheiser and Shure label them A, B, C, and so on. The frequency ranges in each band are too far apart for it to have any effect IMHO, but because I'm asking each band member to invest in a wireless system, I want to make sure I'm getting this right (they are ready to buy, and asking me what band to get).

AFAIK there is a geographic component to selecting which band you should use. AFAIK this is based on avoiding conflicts with powerful broadcasts in the local area. AFAIK, just because two systems are operating in different bands does not necessarily guarantee compatibility.

https://content-files.shure.com/KnowledgeBaseFiles/Frequency-Band-Chart.pdf

Wireless Frequency Finder

Wireless Frequency Finder.

www.shure.com

Tell Me About: Wireless Microphone Frequencies

Use this handy chart to keep track of the available frequencies for wireless microphone operation in the U.S.

www.shure.com

My knowledge on wireless is a bit stale. AFAIK @s0c9 stays fairly current on this stuff.
@s0c9

 

[drpepper]

Correct. I am talking about the actual band the groups live in . I believe both Sennheiser and Shure label them A, B, C, and so on. The frequency ranges in each band are too far apart for it to have any effect IMHO, but because I'm asking each band member to invest in a wireless system, I want to make sure I'm getting this right (they are ready to buy, and asking me what band to get).

Oh, you mean for buying gear...didn't read you that way. In that case it depends on the specific model and band options you’re looking at. If you’re not traveling all over, it’s worth checking your area on Sennheiser’s Frequency Finder to see what the situation looks like. Separate bands avoid overlap, sure—but you don’t want someone in your group to end up with a band that’s a bad fit for your local spectrum.

 

[s0c9]

Oh, you mean for buying gear...didn't read you that way. In that case it depends on the specific model and band options you’re looking at. If you’re not traveling all over, it’s worth checking your area on Sennheiser’s Frequency Finder to see what the situation looks like. Separate bands avoid overlap, sure—but you don’t want someone in your group to end up with a band that’s a bad fit for your local spectrum.

One can also read the Google doc in my signature.
The problem with choosing the wrong band for your ZIP Code/area is that you can potentially end up with a band that has no - or very few - open channels. So when you power up your unit, you are going to get interference, artifacts, and other annoying noise no matter the channel you choose. The user then tends to blame the unit, versus some basic knowledge of wireless availability that will prevent that from happening.
Check the Sennheiser and Shure links in my signature as well as the Google doc.

 

[Nuisance]

One can also read the Google doc in my signature.
The problem with choosing the wrong band for your ZIP Code/area is that you can potentially end up with a band that has no - or very few - open channels. So when you power up your unit, you are going to get interference, artifacts, and other annoying noise no matter the channel you choose. The user then tends to blame the unit, versus some basic knowledge of wireless availability that will prevent that from happening.
Check the Sennheiser and Shure links in my signature as well as the Google doc.

Thanks. I see no Google doc link link in your signature......but would love to read it if you would like to add it here.

Nevertheless, I tried the Sennhesier tool, but either it wasn't working or I'm not smart enought to figure out how to use it.

 

[cfortner]

If you buy 4 lines (Sennheiser, Shure, etc.) in the same, to your location compatible band, use the four lines in one group with different frequencies of this group.

 

[s0c9]

Thanks. I see no Google doc link link in your signature......but would love to read it if you would like to add it here.

Nevertheless, I tried the Sennhesier tool, but either it wasn't working or I'm not smart enought to figure out how to use it.

It's there.. I assure you.. "Band WIRELESS for BEGINNERS" ??

 

[Wayward Son]

I have the analog Sennheiser eW G4 system. Sennheiser uses the terminology “Banks”, to refer to a predefined set of “Free” Channels (each Channel representing a single frequency center). I say frequency “center” because as drpepper suggests, any given frequency actually includes adjacent frequencies above and below the center. In my system, it appears that frequency centers are no closer than 0.400MHz apart—minimum. But there isn’t any precise interval—and is a Sennheiser engineering consideration way beyond me.

Sounds like you already understand that you would keep all your players in the same “Bank” (of separated frequencies)(I believe Shure refers to “Banks” as “Groups”). This is not strictly required—particularly because you have only 4 members, and you are likely to end up with many available frequencies (my system has 20 Banks—almost each of which has 15 Free Channels) where I play (not congested). Keeping in the same Bank is efficient though, because at a gig, if any one player is is getting interference, you simply move them to a Free Channel within the same Bank. That is, you are only keeping track of (Guitar/Ch.1), (Bass/Ch.2), (Keys/Ch.3) and (Drums/Ch.4)—NOT (Guitar/470.100 MHz), Bass (471.050 MHz), etc. So when the Keys player needs to switch, simply move them to Channel 5 in the same Bank—and it’s already (theoretically) far enough away from everyone else to avoid interference. Quick/easy adjustment under pressure.

The above assumes you have the SAME system. With my Sennheiser system, there ARE overlapping channel frequencies across different Banks—so again, the simplest solution is to stay in the same Bank. As Wasnex suggested, the specific frequency Sennheiser identifies as Bank 1/Channel 1 does not necessarily equal that specific frequency for Shure Group 1/Channel. So if you all end up with different systems (Sennheiser, Shure, Audio Technica, etc), you WILL want to pay attention to specific frequencies and making sure they are spread out.

One last thing…also as Wasnex alluded…WHERE you live may make a difference in which part of the larger Band would be least crowded (best suited), regionally. For example, the Sennheiser system I have, optimized for my geographic region, is specified as “A1”. But the same Sennheiser system, optimized for Billings, MT might be a different set of Banks/Frequencies with a designation of “G”. And again, Shure, AT—May use different letters. Your rep shout be able to sort that out for you.

 

[el murdoque]

I have a straightforward question about wireless systems for my band. If all of us are using the same Sennheiser wireless IEM systems, should we all select the same frequency band (A, B, C, etc.), using different groups or channels within that band, or should we choose different bands entirely?

My Sweetwater representative mentioned that it doesn't really matter, which makes sense given that we only have four members. However, when I research online, I’m seeing a strong recommendation for everyone to stay on the same band.

For those with expertise in this area, what's your take?

Advantage: Any body pack will work with any sender you use. That might help with troubleshooting or other problems.

Disadvantage: Should you play in a very noisy environment (noisy as in lots of interference), there might be a limited number of noiseless frequencies, and you might have to deal with one or more of you having to deal with background noise.
AFAIK both the Shure PSM 300 series and the Sennheiser G4 will work with at least 10 units running in the same band.

I'm using a Shure system - that has this function where you just press a button and the unit scans the frequency range available and settles on the frequency with the least interference. I seldom have to use that function - only when my IEMs have background noise.
This highly depends on the area you're in, and what else is transmitting in or close to the venues you play.

 

[DJWhitJr]

Agreed with previous posters. You should buy the units transmitting in the same frequency band and all band members should be using the same group/bank to avoid intermodulation.

If you want to go wireless then I would encourage you to check out the AudioTechnica ATW-3255. It covers the entire frequency spectrum from 470mhz to 608mhz so you should be able to find an open frequency anywhere you go in the US.

Scott Uhl on YouTube has some good informational videos that may help you out.