DavePallant

Are the antenna/receivers far from the transmitters? Are you able to try operating the receivers alongside and close to the area where the mics are used to see if it is a combination of distance and interference? With supplied antennas on the back of the receivers the system might be running out of steam after 30 or 40 feet. If having the receivers close helps then that might indicate a couple of antennas and amplifiers could be used. The receivers might allow two antennas to be daisy chained down several receivers as opposed to just using the rabbit ears on the back of each unit. Which Thomann systems did you get? I'm assuming something like the t.bone Free solo twin. Similar to cedd above I've had less problems with my 823-832MHz sennheiser wireless channels than my 606-612MHz "GB" systems in terms of interference.

You should not mix banks because the frequencies within each bank are calculated with no other banks in use. For example using banks 1 and 2 in the table further up (bank 1 is channel 38, bank 2 is channel 39) will mean that the sidebands from Bank 1 might interfere with Bank 2. You need to choose a single bank where you can get the number of frequencies you need. For example if you need 16 then you could use bank 6, 7, 8, 9 or 13 or 14 all of which have more than 12 frequencies. Alternatively finding some E band systems (823-832MHz and 865ish MHz) might be easier.

I've looked at rechargables in the past but even just using 16 channels of Sennheiser it's 32 batteries. To keep my sanity I would need to recharge them all simultaneously and with a matinee and evening show there is not enough time between shows to recharge so for safety I would need two sets of batteries. Then overnight I might need to recharge two sets of batteries if I have matinees Friday and Saturday. On shows where I might be using 24 channels then we're up to 48 batteries per show and 96 needed to be kept track of and not mixed up. If I were to go for it then 48 batteries in chargers plus 48 more batteries would be around £600 whereas I'm in the different situation from the original poster of being able to charge for the batteries I use which is usually around £60 for a week of rehearsals and shows.

Does it need Microphone inputs or just line level?

I would go for the Sennheiser XSW 2-CI1-GB which has an instrument cable for bass or guitar and then source headsets from ebay or CPC depending on just how expendable you expect them to be. The XSW 2-Ci1-GB is around £330 at the moment. Also the XSW2 allows 12 channels in the GB channel while XSW1 allows just 10. I've used 12 regularly with no issues. I dont know why this is the way it is apart from quality of external antennas versus internal pcb antennas on the XSW1.

At one point I purchased a similar 2 channel 863-865MHz unit made by Citronic to make up numbers of channels and was very disappointed with pops and crackles and dropouts over the same distance as the rest of my system. I ended up using it a couple of times and then sold it. At the time I had 12 channels of Sennheiser XSW-2 channel 38 which have been largely faultless in various theatres at front of house or side of the stage. They now cost about £330 for a beltpack system which is mainly designed for musicians but is still fine for amdram. I still use them alongside my main Sennheiser G4 systems (because amdram groups can never have enough channels) and there is absolutely nothing to hear as a difference between the two systems. There is a cheaper XSW-1 range which I have never tried but they have internal antennas rather than the standard setup of a pair of posable diversity antennas.

The bay auction site shows SimplySound2010 selling them. Search for the part number ELUM105 and check that the description shows 3 pin DMX. You could also message them on that site to check they really are the 3 pin ones.

Would you be able to plug the Sennheiser transmitters into this? https://www.thomann.de/gb/millenium_pp2b.htm Phantom power on two channels of mic.

A little bit of the James Bond about a good foam case.

I bought a couple of cases from a company called pcb_soldering on ebay which have either cubed foam or solid foam. Ebay item 234915080248 is an example. Interesting the solid foam was the easiest to deal with and I've put 8 pencil mics in a thin case and a bunch of larger condenser mics in a deeper case. They are not the strongest in terms of taking hard knocks but they protect the mics well. I think someone else on here mentioned a band turning up with a Dewalt tower of drawers that contained all their mics. Sounded like a good idea but I cart stuff in an estate car so a little too bulky for me!

It should be. They are quite cheap but an order might be expensive. Rapid do 6x6mm tact switches £1.70 for ten but post on top will cost. Similarly CPC or Farnell. CPC have 6mm tact switches by Multicomp Pro e.g. SW02471 for 11p each and you can always make up an order value with their 100 off AA batteries!

This is a classic 6mm square tact switch. It through hole pcb rather than surface mount which I think the mic has but the guts are the same and it is a 4.5mm disc the same as your photos. They come with different length actuators which is why this one is longer than your example.

The four little plastic lumps on the corners of the switch casing make me think of switches like the Alps SKHW tactile switches. Alps switches are widely copied as well so could be the same pattern of shape and size. You can check if the body of the switch is 6mm square. Difficult to tell size from the photo. https://uk.farnell.com/alps-alpine/skhwala010/tactile-switch-0-05a-12vdc-th/dp/3261809?ost=skhw If the switch is smaller than 6mm square then alps have some other tact switches that might replace it.

Looks like those systems use what are effectively UK TV Channels 24 all the way up to 30. Most places around the UK they will be used for repeater TV stations if not for the main transmitters like Winter Hill and Sutton Coldfield. You could interfere with TV reception close to where you use them and on the other hand get interfered with if there is a TV repeater nearby. (Apart from it being illegal if you dont have a site licence). Incredibly wasteful in terms of radio bandwidth. The Sennheiser A band which is in that frequency area can fit several dozen channels into that bandwidth. Not sure you would even be allowed to get a site licence for a device that used 6 TV bands just to get 4 audio signals across a room! Dave

Thomann do stereo combiners which look like they are transformer decoupled. https://www.thomann.de/gb/millenium_sml_21.htm You would need four of them to go with your 8 channel splitter so it does get a little expensive. Dave