Wireless Mics 8 Channel

[gpjt]

Looking to replace our dated 8 channel Wireless Microphones (image) as they are giving all manner of feedback on most channels due to what i think are issues on the receivers etc. i believe that the ones we currently have are an old technology too.

 

Issues i'm having is finding a solution that has the antenna on the front, most are now on the back. I've also contacted the likes of gear2music, managed service and also other companies for quotes, but most aren't very much help.

 

Anyone done a similar replacement?

 

[Aprice]

We've worked with plenty of wireless systems, but the only ones we've found to be solid are Sennheiser or Sure. Both of which aren't cheap, even second hand G3 units still hold their value pretty well.

 

The antenna connections are usually on the back, but when they're put in cases there's usually a cable that brings the antenna to the front mounted on a 1U blank.

[Andycat]

My Sennheisers have leads out the back to allow extending your antennas, although mine go to a proper fixed antenna on the wall in the Hall

[AndrewPowell]

I'm an audio tech on touring music and theatre, outside of IT.

 

It isn't going to be cheap, but a proper wireless rack will be your way forward here. As mentioned in the previous reply, the antenna connections for any decent system are going to be on the back, but can be brought to the front with a rack panel. I would also suggest, if you go for something decent, you purchase a proper 'paddle' antenna, a splitter, and just have the one.

 

Personally, dependant on budget of course, Sennheiser's EW-D is the best bang for buck atm. Its digital, so does depend how busy your wifi etc is, but in general they're excellent. If you're looking to buy a ready to go rack, Mercury AV is a good place to start, but likely won't be the cheapest you can find.

The other option is to enquire with local hire companies, many will be refreshing old G3 stock to G4 or axient. They might be willing to sell a whole rack with all the bits needed.

 

 

I will say, that feedback is not caused by the Mic's. Feedback is a use issue, and even with the worlds best RF equipment, you'll get feedback. Feedback is caused by the mic picking up its own signal from the PA. That won't change no matter what mic you have.

 

Happy to offer advice on this one, its my wheelhouse

[gpjt]

Thanks @AndrewPowell thats really useful information!

 

As you can imagine in Primary Schools budgets are tight, but we'd certainly look at installing whatever is needed to ensure it's fit for purpose.

 

I did find these and presume it's a budget solution. We'd need 2 of them of course and do wonder if these would be any better than what we already have? That sort of pack would have most if not everything we need including the bodypacks etc.

Edited May 14, 2024 by gpjt

[PotNoodleTech]

You may have to replace them anyway as most of the older wireless mics as I understand it, are actually illegal as they operate on the wrong frequency's nowadays - I am not an expert but I do remember a load of kerfuffle about it a few years ago. Consult an expert to be sure as the last thing you want to do is save money by not replacing them only to get fined for more than the cost of new sure ones??

[howartp]

You may have to replace them anyway as most of the older wireless mics as I understand it, are actually illegal as they operate on the wrong frequency's nowadays - I am not an expert but I do remember a load of kerfuffle about it a few years ago. Consult an expert to be sure as the last thing you want to do is save money by not replacing them only to get fined for more than the cost of new sure ones??

Correct.

 

You can typically get 4 mics in the unlicensed channel 70 range (863.100-864.900).

 

For 8 in a primary school you will probably be looking at a channel 38 shared license (606.500 - 613.500) - which gives you up to about 12 mics depending on brand and spec.

 

If you're next door to someone else using the shared license you may need to go coordinated which prevents anyone else (legally) using your frequencies. We have 8 in Ch30 (542-550), plus 12 in Ch38.

 

General: https://www.ofcom.org.uk/manage-your-licence/radiocommunication-licences/pmse/pmse-technical-info/mics-monitors

Shared: https://www.ofcom.org.uk/manage-your-licence/radiocommunication-licences/pmse/pmse-technical-info/mics-monitors/shared

Coordinated: https://www.ofcom.org.uk/manage-your-licence/radiocommunication-licences/pmse/pmse-technical-info/mics-monitors/co-ordinated

[mavhc]

Its digital, so does depend how busy your wifi etc is

 

I assume that's because they're also using 2.4GHz?

 

You could probably only use 5GHz APs in the surrounding area to help

[Andrew_C]

Early (ish) digital systems didn't play nicely with data networks. They would stamp all over them until they submitted. I believe they are better now, but beware!

[dhicks]

they are giving all manner of feedback on most channels due to what i think are issues on the receivers etc.

 

As pointed out in a previous reply, do you actually mean "feedback" (generaly a whistling / screeching sound caused by getting the microphone too near the speakers) or something else? If you have a constant low-level buzz / hum (at around 50Hz) then that could be a power supply ("ground loop") / cable shielding issue.

 

For wireless mic frequencies, I find this guide quite handy:

 

https://www.canford.co.uk/TechZone/Article/UKLegalRadioMicFrequencies

 

We have a set of 4 Chord handheld / headset mics, bought about 10 years ago off Amazon, still going strong, now around £240:

 

https://www.amazon.co.uk/Chord-Wireless-Handheld-Microphone-System-Blue/dp/B00A692Q66/ref=sr_1_15

 

Those are on channel 70 frequencies (UHF 863.42MHz, 864.99MHz, 864.30MHz and 863.01MHz), 4 is about as many as you'll fit in that frequency band. Great for assemblies / every day use for when you don't want to use your best (more expensive / delicate) mics.

 

We also have a couple of (even cheaper, £30 each) mics on VHF 174.1MHz and 175MHz (also "channel 70", but completly different frequencies) - again, handy for pupils to use if you don't want them wandering off with the decent equipment.

 

We have a set of 8 Studio Spares own-brand receivers / mics on the 2.4GHz band, same as networking WiFi. They don't seem to have a problem with inteference, despite having WiFi access points throught the building.

 

All the above are license-free frequencies, for which equipment tends to be cheaper. It depends on your location as to whether you'll get interference from other users on particular frequencies, although we don't have too much of a problem and we're in central London. Cheaper wireless mic units don't tend to have a hige pick-up range anyway, which can be quite helpful in not picking up interference. We have recently found our two very cheap mics on the VHF frequencies have started getting more interference, so maybe avoid those.

 

Licensing mic frequencies isn't actually that expensive, I think a few hundred pounds per location per year depending on the frequencies you're wanting. We find having the license-free equipment above for day-to-day use works quite nicely, then you can save any more expensive equipment for productions, or hire it in as needed. The licensed-frequencies "pro" equipment will work alongside the cheaper stuff just fine, too, so if you are, say, doing a production where you have a dozen children with lead parts and the rest with smaller parts you can hire "pro" headsets for the main parts and give the other kit to the rest, which might keep your costs down a bit. I tend to find external people hired in to do sound / lights don't like working with cheaper equipment, though.

[Chris_Cook]

I'd also recommend the sennheiser. They do antenna distribution units which can reduce the number of antennas and psu sockets required.

 

The new digital ones are also really handy - you can change settings and mute on the beltpacks from your phone without interrupting the event.

 

It would be worth checking what frequency your current mics are on, as a number of years ago one band was removed from service. It might be that someone else is using that channel.

 

If you use one of the licensed channels then you get more mics simultaneously and less interference.

 

If you are getting proper feedback, then I would recommend checking any EQ settings on your sound desk or system controller (if present). If someone's boosted one of the frequencies that could cause this. You could also look up ringing out a sound system that might help set up your EQ to minimise feedback. Speaker and mic positioning are also really important for this.

[AndrewPowell]

As pointed out in a previous reply, do you actually mean "feedback"

 

This is probably the most important question. Before you spend any money, can you describe the actual issue you're having? It might be that we can help fix that. Do you use headsets, or handhelds?

 

The product you've linked, while newer and slightly better, certainly won't see a notable improvement, and imo isn't worth spending the money on.

[gpjt]

This is probably the most important question. Before you spend any money, can you describe the actual issue you're having? It might be that we can help fix that. Do you use headsets, or handhelds?

 

The product you've linked, while newer and slightly better, certainly won't see a notable improvement, and imo isn't worth spending the money on.

 

The current equipment has got to be at least 10 years old and the transmitters antenna are bent, broken etc. So much so that if i were to hold the antenna with my fingers while being used the feedback stops. I think they just need replacing with a more current setup. We use headsets for out end of year performance with anything up to 8x 10/11 year olds singing etc. I know we can get really technical with setups and the equipment can be whatever depending on what you want to spend, but we just want to get to the position where we can use the mics for what they are intended for and mic up the children during the performance.

 

Doesn't have to be local theater type standard, but better than what we already do.

Edited May 14, 2024 by gpjt

[Andrew_C]

Once a year?

 

Hire.

[gpjt]

Once a year?

 

Hire.

 

Thought about that too but they want them available for a good week before for rehearsals and quotes to hire for the amount of time their needed are running well into the price that i found in the link above.

[gpjt]

Any recommendations on a company midlands based to come out and do an audit? I had one quote of £900 which was ridiculous.

[russlp]

Novum are excellent: https://novuminstalls.co.uk/callouts-service-calls

[SamanthaD]

Just to add a few thoughts on everything already mentioned.

 

That many antenna bunched into a small space will more than likely cause issues. You've not extended them to their full length which doesn't help either. Antenna distribution will help massively.

From your reports it sounds like you may be using unlicensed frequencies caused by the changes in the frequency spectrum. Have a look at Ofcoms PMSE section (Program Making and Special Events) which covers microphone use for the letter of the law.

 

As others have said the free to use band Channel 70 covers 863 - 865 MHz. You can fit 4 frequencies on there comfortably, but it's a free for all. Channel 38 is the standard UK General paid for license and covers 606 - 614 MHz, but also gives you access to the "duplex gap" of 823 - 832 MHz. This isn't well known and not often mentioned as Channel 38 kit generally can't tune that high, but Channel 70 kit can go down to it. Worth looking at is it is often free. The final alternative for RF is using the "interleaved spectrum" which is the gaps between the TV stations, and is a location specific license agreed with Ofcom. We have 3 interleaved licenses, but these are on frequencies normal UK kit can't tune to so getting hold of the kit is a little more difficult. I've found this chart from Shure is really useful for visualising all of this.

 

In addition you have digital microphones such as Sennheiser EW-D, some work in the 1.9 GHz range (DECT frequencies), others in 2.4. Research before committing to a purchase!

 

Expect the Sennheiser G3/G4 secondhand market to be flooded soon as it goes end of life at the end of the year and companies will be making the jump to EW-DX. 8 systems with 2 ASA units (antenna splitters) and remote antennas might cost a few thousand now, but will last you a good while yet.

[AndrewPowell]

Whereabouts in the UK are you? I hire equipment, and for local schools, I do alot of deals for wireless mics. Usually i'd suggest hiring would be far the best value for once a year, but i also understand that schools can drop things on you very last minute. I also guess it depends on your definition of 'value'. To me, paying the extra once a year for the better, pro level equipment, is better than owning a dirt cheap set, but thats my opinion.

 

Honestly, I have a dim view of the really cheap sets, but then I also have to remember that your expectations are not the same as mine. My partners primary school has a 6 channel chord one that they love and then they add channels of better stuff from me when it really matters. It functions pretty damn well, and for a primary school is perfect.

 

One thing i will say, is I would stop using the word 'feedback' to describe your issue. It doesn't sound like the issue you're having is feedback.