Advice on replacing wireless mic setup in secondary school

[Remiel]

Hi Guys,

 

I was directed to this forum by a friend over at Edugeek.net. I have recently been employed as the IT/AV Technician at a high school, leaving me responsible for the hall sound and mic system. I have some knowledge of these from being involved with stage productions during my time at school, however that was a long time ago and I’m a bit stumped.

 

The current setup I have inherited is as follows -

 

Moss-Fet Electrovision ELV800 Amp

 

Pulse EQ216 Equalizer

 

S.Com Samson stereo Compressor

 

Soundcraft eFX12 Mixer

 

 

In regards to mics, the current setup is 6 JTS UHF PT-950B belt packs with an assortment of JTS CM-201 and unbranded lapel mics, most of which are broken beyond my ability to repair.

 

These are paired with 6 JTS UHF US-901D Receivers.

 

 

So here's my problem. I've been told that I need to replace the mics with a budget of between £2500 - £4000 (not set yet as they're still 'finding' the money). Essentially they want a price list for 5 - 6 new radio mic sets with interchangeable Lapel / headset mics for school events / productions respectively.

 

I've spent the last 3 days reading up on suitable mics and to be honest I’m none the wiser in regards to an effective and compatible set that aren’t so cheap they're not worth buying or far beyond the price range I’ve been set. I'm also concerned about running 6 wireless mics at the same time because according to my predecessor the current JTS lot have been nothing but trouble (I suspect through mistreatment). I've tried going down the road of rentals and although they were very successful, I just can’t sell the idea to SMT.

 

If anyone could offer some advice I would really appreciate it.

 

Many Thanks,

 

Matt

[WiLL]

The problem with looking at buying new radio mic sets at the moment is that there is still a lot of fuzziness regarding what is to happen in 2012 when the analogue radio freq's are sold off to digital tv. Most radio kit may well be in danger of being rendered useless. With that in mind I would use this as a way to sway your school bursar to hire for at least 2 years until the switchover, you'll get better kit when you need it, time to try different brands to see what you prefer without spending money on kit which mught prove useless in two years. Then when the switchover has happened and we all know where we stand, you will have a better idea of what to buy and school will know what they are buying will not be redundant.

SWorry if that is garbled, recovering from food poisoning over here.

[Alec]

In regards to mics, the current setup is 6 JTS UHF PT-950B belt packs with an assortment of JTS CM-201 and unbranded lapel mics, most of which are broken beyond my ability to repair.

 

So here's my problem. I've been told that I need to replace the mics with a budget of between £2500 - £4000 (not set yet as they're still 'finding' the money). Essentially they want a price list for 5 - 6 new radio mic sets with interchangeable Lapel / headset mics for school events / productions respectively.

 

I've spent the last 3 days reading up on suitable mics and to be honest I’m none the wiser in regards to an effective and compatible set that aren’t so cheap they're not worth buying or far beyond the price range I’ve been set. I'm also concerned about running 6 wireless mics at the same time because according to my predecessor the current JTS lot have been nothing but trouble (I suspect through mistreatment). I've tried going down the road of rentals and although they were very successful, I just can’t sell the idea to SMT.

 

Hmmm, nothing wrong with the JTS 900 range at all. Do you believe that it's the belt packs themselves which are broken? (they are pretty robust) or just the mics? Lapel mics can be considered a consumable and will frequently develop cable faults - especially in juvenile hands.

 

If it is just the mics, then these lapel mics from CPC are ideal replacements at a fiver each. The only shame is that you'll need to remove the 3 pin XLR that they come with and replace them with the 4 pin XLR on the original mics. That done, you'll be up and running.

 

Think there was a similar cheapie headset mic from CPC discussed at length elsewhere in BlueRoom.

 

Did you have trouble running all six systems simultaneously - may well be just poor frequency planning and intermodulation problems, which are easily fixed by retuning, along with any frequency licensing - all of which would need to be done with any new kit.

 

Assuming the transmitters and receivers are functioning correctly, you should be able to be back up and running with a full complement of lapel mics & headsets, with the spares that you *will* need - and all for under £200 and half an hour's soldering.

 

You *do* need to plan on replacing/repairing mics. If not, then you could spend any amount of money on a new system which, after less than a year's worth of active use would also be "broken" in the same way that your current system is.

 

And you won't be spending huge amounts on new radio kit that may have a limited lifespan depending on frequency re-allocations.

[Remiel]

Many thanks for the quick response Will! I'm aware of the 2012 business yes, I found it while searching the forum earlier today I completely understand and agree with you, it's by far the better option. However there are certain people above me who I wont risk naming on a public forum who essential 'know what they want' and that's new mics :) I've tried the rental option of 6 radio mics for the most recent production here from a local company called APAudio. I was extremely impressed with both the kit and the service, the whole lot was around £300 for the week. However I just cant convince people of this, although I will keep trying.

 

What would be my best option in purchasing that the 2012 change would have the least impact on?

 

A concurrent post has been automatically merged from this point on.

 

There's also an issue I forgot to put in my OP, after testing the mics when I arrived, all belt packs appeared to still be in working order, I agree they do appear to be pretty rugged things. Out of the available lapel mics only 3 of the 6 worked. I managed to find a few spares in the drama dept; however while testing them I found that the mics tended to randomly cut out when used together, which is most likely due to intermod, right? I also found that the range did not appear to be the most reliable, is there a method of boosting the range of all 6 receivers?

 

As I'm sure you can all tell, I'm pretty new to this and have just had this kit thrust upon me. I'm an IT Tech primarily, this area just falls under the job description!

 

Unfortunately due to the fact that it evidently hasn't worked properly in some time, the leadership have come to the conclusion that it needs replacing.

[Alec]

There's also an issue I forgot to put in my OP, after testing the mics when I arrived, all belt packs appeared to still be in working order, I agree they do appear to be pretty rugged things. Out of the available lapel mics only 3 of the 6 worked. I managed to find a few spares in the drama dept; however while testing them I found that the mics tended to randomly cut out when used together, which is most likely due to intermod, right? I also found that the range did not appear to be the most reliable, is there a method of boosting the range of all 6 receivers?

 

OK, so intermod problems will be sorted out by retuning. I get fantastic range out of my 4 900 series systems. I do have the JTS antenna distribution unit, though, which tidies things up a lot, driving 4 receivers from one pair of antennae - as well as providing power to all 4 - so no more piles of power supplies. These are under £300 if I remember rightly.

 

As I'm sure you can all tell, I'm pretty new to this and have just had this kit thrust upon me. I'm an IT Tech primarily, this area just falls under the job description!

 

Unfortunately due to the fact that it evidently hasn't worked properly in some time, the leadership have come to the conclusion that it needs replacing.

 

So, from what you said earlier, you should be able to restore this system to full functionality with very little spend and time.

 

As it looks like it's just the mics that are broken, and the frequency spread that is wrong, yet there is no desire to perform the small amount of maintenance to fix the problem (and which would be reuired to keep any radio mic setup working), I would predict your £2.5-4k spend will result in an equally "broken" set of kit within a year of typical school use and you'll be back to where you started!

[Andrew C]

Your immediate problem will be that there is only space in the licence exempt band for four radios. This means that you are trying to squeeze them in too little bandwidth, or you are in a non-licensed band with at least two of the sets. If the latter, you could be getting interference from all sorts, and worse, interfering with other legit users of the spectrum. OFCOM would be unimpressed.

 

Can you tell us which frequencies you are trying to use?

 

And I'll add another voice for trying the CPC capsules before replacing anything else!

[Stan Hope-Streeter]

However there are certain people above me who I wont risk naming on a public forum who essential 'know what they want' and that's new mics ....... I've tried the rental option of 6 radio mics for the most recent production here from a local company called APAudio. I was extremely impressed with both the kit and the service, the whole lot was around £300 for the week. However I just cant convince people of this, although I will keep trying. .... As I'm sure you can all tell, I'm pretty new to this and have just had this kit thrust upon me. I'm an IT Tech primarily, this area just falls under the job description!

Unfortunately due to the fact that it evidently hasn't worked properly in some time, the leadership have come to the conclusion that it needs replacing.

 

 

Oh dear, here we go again...

 

You need to tell the ignorant fools in charge of your school that they will be wasting their (no, I mean OUR - TAXPAYERS') money.

Of course this needs to be done in a way which avoids them ending up feeling the idiots that they are.

 

They have to understand that:

 

- The whole kit will need replacing in two years' time, or they will face prosecution for using it. Especially if you have played by the rules and have licences, since the relevant authorities will Know Where You Live.

 

- The lapel-type mics need regular maintenance in use, and are a consumable not a capital cost item.

 

- Cheap (that's a relative term, I mean costing £500 or less per channel) radio mics will never perform to the inflated expectations of their users. Neither will expensive ones unless the rest of the audio system is of full professional quality and the operators suitably experienced.

 

- In the New Age Of Austerity, they are likely to face considerable public opprobrium if their mismanagement of scarce public funds somehow becomes public knowledge. Which might happen, say, if a parent happens to be a broadcast engineer and asks a few questions about the shiny new kit after next year's school Panto.

 

 

 

And YOU need to cover your posterior, or they will blame you in two years' time when you have to request the budget for replacement.

 

 

PS there was a very similar thread here about a week ago, see if you can find it.

[Alec]

PS there was a very similar thread here about a week ago, see if you can find it.

 

The other thread is here - though, to be fair, that was about whether or not to purchase a wireless system. In this case, you already have a complete system that simply needs a small amount of maintenance - no more than you should be expecting to carry out on any professional installation.

[Andrew C]

There is quite a lot of on-topic info in this thread too.

[Pete Alcock]

Hi Remiel,

 

I run a dozen or so JTS mics of various types (not all at once I hasten to add), and they're incredibly robust. Mine are often on hire to schools. The mic capsules or headsets themselves are 9 times out of 10 the culprit, and they tend to fail where the cable enters the plug. This is usually because the youngsters wrap the mic round the pack after unsticking it from their cheek. Easy to fix with a fine soldering iron.

 

Core of cable goes to pin 2 of the plug. Screen of the cable goes to pins 3 & 4 linked. The CPS cheapie mics are excellent, and can be wired in this way. The plug is this Mini XLR socket

 

Regarding the choice of frequencies, I find this invaluable: Audio Technica Frequency Checker

 

Definitely worth trying to repair the kit rather than spend a lot on either new or hires (I'd say, anyway).

 

Pete.

[MarkPAman]

What everybody else has said abut fixing what you've got

 

But, as it's a school, if you don't spend this money on radio mics it will be spent be somebody else on laptops or books or something, so.....

 

Use the rest of the dosh to buy 2 good(ish) systems that are "2012 proof". Depending on your location, you may be able to use these now. When the changeover happens you'll be able to use 4 of your current mics (and have 2 spares) in the licence free band (channel 70) & the two new ones on channel 38

[timtheenchanteruk]

unless I am mistaken, there is no longer an ambiguity over 2012, we are moving down to 38. this may or may not be avaliable in your area now.

 

also, as far as I am aware (unless something has happened in the last 3 weeks), there is only trantec at the moment that have Ch 38 kit (apart form digital stuff £££), the new sennheiser is tunable down to after being sent back to them, but not out of the box (yet)

 

Id replace the mics, as said before to check the bodypacks (although the lot at my place destroyed 2 senn E300G2 packs in a week)

 

if it is decided by the powers that be, trantecs racked and ready stuff is good for its price, either the S4.4 (comes in about £3k for an 8 way) the S5.3 (around £5.5K for an 8 way) of the S5.5

 

the 4.4 is the budget end, but still performes well, downside it takes PP3s, the S5.x is essentially the same hardware, just programmed differently, metal cased, feels nice, not used them live though.

[revbobuk]

You can't get 8 channels of the s4.4 - the 4.4 will only give you 4 channels. You mean the s4.16 - and the s4.16 won't tune down to channel 38, as you rightly point out. So if the OP were to buy 8 channels of s4.16, then 4 of them would be useless after 2012.

[chelgrian]

also, as far as I am aware (unless something has happened in the last 3 weeks), there is only trantec at the moment that have Ch 38 kit (apart form digital stuff £££), the new sennheiser is tunable down to after being sent back to them, but not out of the box (yet)

 

Higher end Sennheisers starting with the 2000 series come in versions that cover the entirety of channel 38 however the snag is that you'd get about 2 channels for your L4K. The other option is that you *can* run 6 mics in channel 70 but *only* if they are all Sennheiser Evolution G3.

 

Read:

 

http://www.sennheiser.co.uk/uk/home_en.nsf...ases_rf_changes

 

I think the license exemption is a frequency range rather than a specific set of frequencies so I think it is legal to use this frequency combination in the UK.

 

Be aware that channel 70 is likely to become noisy in 2012, you'll probably be OK if you are in the middle of no where however if you are in a city centre channel 70 may become unusable.

[Remiel]

Many thanks to you all for the responses, they've been extremely enlightening!

 

I will discuss the issue of 2012 and the state of the current JTS belt packs and receivers with SMT tomorrow.

 

I've been looking at a UA-900 Antenna Distributor, however I'm aware they can only run 4 receivers each, would running 2 distributors be viable? Using these would alleviate another minor issue of lack of power sockets in the general area of the cage the sound gear is housed in. Also, if I was to use the antenna distributor with a set of 2 directional antennas, should I be looking at active or passive? To put it into perspective, the sound gear is located in a locked 12x12ft steel cage in the rear wing of the school hall stage. There is a 3ft stone wall between the current JTS receivers and the hall itself. I could run the antennas to pretty much anywhere around the stage itself though (hidden preferably).

 

In regards to replacing the microphones themselves, unfortunately soldering is not an option as the head has stated categorically that he doesn't want any 'home made gear'. I know a lot of you would be offended by that statement but I'm 100% sure any soldered mics, visible or not would bring down a world of hurt on me, especially if I need to do it for all replacements. In order to avoid soldering, should I just be looking for mics which come with a 4 pin mini XLR connections out of the box, if such things exist?

 

Once again, thank you all for your responses