wireless microphone system - advice please!

[bilikate]

Has anyone used the 4 x Headset UHF 4 Channel Wireless Microphone System from Electro supplies? Can't find any reviews or info anywhere and am a little nervous that it will fall to bits! Wanted to buy 3 sets to give me 12 mics. Thanks.

[Bobbsy]

If it's THIS ONE I can't comment on the quality but note that the frequencies span UHF Channels 46-49 so would require expensive individual licences for use (and your ability to get such a licence depends on your location).

 

The only licence free frequencies are a few in part of Channel 70 and some on the VHF band. Gear on Channel 38 needs a licence but it's a relatively inexpensive, easy to get one. All the rest require site coordination.

 

Wouldn't touch it myself.

[Stuart91]

It certainly looks too good to be true.

 

Problems with intermodulation increase exponentially as you add channels. I'll be astounded if three of these systems can run twelve channels simultaneously. It's most likely that you will have a train wreck of drop-outs and interference.

[peterskine]

It certainly looks too good to be true.

 

Problems with intermodulation increase exponentially as you add channels. I'll be astounded if three of these systems can run twelve channels simultaneously. It's most likely that you will have a train wreck of drop-outs and interference.

 

A quick calculation with IMD shows it can be done with these 3rd, 5th, and triple beat IMD free

674.075

674.625

675.350

678.525

679.450

681.550

682.325

686.850

688.325

688.775

691.075

692.500

693.550

694.925

 

If you only calculate 3rd order which is sufficient for Mics you can get 27 frequencies.

[Lamplighter]

I think someone in Ofcom/ArqivaPSME would have a heart attack if you applied for those 12 channels.

Brian

[Simon Lewis]

Has anyone used the 4 x Headset UHF 4 Channel Wireless Microphone System from Electro supplies? Can't find any reviews or info anywhere and am a little nervous that it will fall to bits! Wanted to buy 3 sets to give me 12 mics. Thanks.

 

As others have pointed out, licencing this system may be problematic, so a phone call to Arquiva to discuss this would be sensible before you order anything. I believe that if you follow Pete's frequency range, your licence (if available) is likely to be around £336 per annum. However, if you can get the licences sorted, this supplier seems to be selling the same system £300 cheaper ;-)

[Bobbsy]

The OP doesn't seem to have been back since the first post.

 

However, I just had a look at the web site for the OP's theatre company and it refers to UK tours. That being the case, the frequencies would be un-licenceable (and likely unusable) in quite a few UK locations due to high powered digital TV transmitters on the same frequencies.

[Stuart91]

A quick calculation with IMD shows it can be done with these 3rd, 5th, and triple beat IMD free

 

Hi Pete,

 

I know a little about your professional background, so I'm not going to pick a fight over this. ;)

 

However whilst I don't doubt that it would be possible to get those frequencies working together with professional level kit and suitable aerials, the OP is (was?) looking at a DJ level piece of gear that's clearly been designed to hit a price point. I'd have worries about the bandwidth each system takes up, and how accurate the receivers actually are. I've come across budget kit (from reputable brands) that couldn't run multiple systems on clear, coordinated frequencies.

 

Whilst running the twelve frequencies is theoretically possible, is it really advisable?

[peterskine]

The OP doesn't seem to have been back since the first post.

 

However, I just had a look at the web site for the OP's theatre company and it refers to UK tours. That being the case, the frequencies would be un-licenceable (and likely unusable) in quite a few UK locations due to high powered digital TV transmitters on the same frequencies.

 

I don't know that equipment either so it could be a dud. I was only pointing out in response to the question that finding enough IM free freqs within that band was not hard not taking into account any DTV in the area which was not the issue.

[Bobbsy]

Just to say that I'm always a bit leery of doing a professional calculation of IMD free frequencies on cheap gear--the RF filtering is often pretty rubbish with the transmitters "splattering" over a much wider bandwidth than they're supposed to.

 

In any case, I'd think the licensing issues should be a deal breaker even before we get into a debate about whether or not a 12 channel frequency plan can be found.

[paulears]

I think the facts that it's not in our conventional band and of dubious technical quality makes the intermod problem a big risk. If you need to use lots of channels then if you cannot afford the standard makes, then you should rent. Multiple cheapo systems still cost quite a lot of money, so there's a lot more risk. For one or two I'd personally risk it but not when you need multichannel stable systems.