Updating a School's PA

[Alex Kenivel]

I've been tasked with minor upgrades to a school auditorium sound system.

The school my wife works at has an assembly coming up and teachers need to be able to run audio from their laptops.
I went over a few weeks ago for a quick inspection of what they have: small off-brand passive speakers mounted on either side of the stage and a rack fridge containing 1 Shure wireless mic receiver, 1 Listen (brand) cheap IEM transmitter (fools who were playing around with it last ended up leaving batteries in all of the receivers and they're all corroded) one Dennon dual tape deck player/recorder, a CD player, large rack drawer, an archaic powered rack mixer with only two XLR inputs (the rest are hard wired) that somehow has the power section bypassed, into an older QSC Crown power amp.

All of the Upstream devices are taking up every connection to the mixer even the cheap IEM transmitter that has an auxiliary input. Only two teachers know how to (barely) work the gear including my wife so no one else really touches it. The tape player, IEM transmitter, and CD player haven't been touched in years.

I'm tasked with a short-term and a long-term solution for getting teachers on stage and up and running with their laptops.

I've already figured out a short-term solution: laptop to 3.5mm aux cable into a 1/4" adapter into the Shure receiver Aux input - teachers wont be able to stand at the front of the stage and present with their laptops but it will do for some music during the performance. It Won't Be stereo so they will only hear one side of the feed through both speakers but that's good enough for them. The signal will piggyback onto channel one of the mixer along with the microphone audio so they'll control levels from the laptop.

Long-term solution I'm still trying to figure out. Ideally they'd want to connect Bluetooth to the mixer to be able to present from the front of the stage and project their display onto the view screen. I'm thinking about discarding the CD player, the tape player and the mixer and replacing all of that with a small mixer with Bluetooth capabilities. There are a bunch of them on Amazon but most of them look really cheap and are only powered via USB Jacks.

Does anyone know of any quality bluetooth-able mixers with actual power adapter (not USB-C) for this purpose? The few mixers I'm looking at include:

Harbinger LV8 8-Channel Analog Mixer with Bluetooth
Pyle PMXU68BT

There are a bunch more mixers on Amazon but most of them are either USB powered or reveiws aren't goos re: BT audio.

The Pyle I mentioned was top of my list but as of now they are sold out. Don't need it right away but if I can present the school's Principal with viable options today I could likely get a mixer installed Thursday before Friday's event - not a huge deal if it doesn't happen right away - but the principal is leaving after this year and new principals don't like to spend money.

Or should I ge an outboard BT receiver and a mixer w/o BT capabilities?

 

[Alex Kenivel]

Went back at a better time with no children present to rig up the temp solution and check out the rig a little more thoroughly.

Their rack currently:

The Crown clips extremely easy - got things down to "announcement" level where it was the happiest using music and a volunteer singer (my daughter) with minimal audible clipping through their little Atlas Strategy speakers.

The assembly on Friday went better than any they had before. When kids came back to school from mass quarantine each teacher was given a lapelle mic and a lunchbox speaker for speaking with volume while wearing masks in the classroom. This is what they relied on for music playback this whole time so everyone was happy to have some quality (to them) playback for performers this time.

I gave the lead teacher options in different price brackets to upgrade their current system. I didn't even divulge the upper tier details (new speakers, etc) because I know that will be out of their budget.

 

[Alex Kenivel]

All of the items came in for the mixer upgrade: the Pyle mixer I mentioned above, a few short XLR cables, Y cable, cable ties, and a Phenyx Pro PTU-52 Wireless microphone (two mics/two channels).

I ripped out the old wiring - - mostly hand wired/RCA and the old powered mixer, dual tape deck and CD player, cleaned the shit out of the inside of the rolling rack and installed the new pieces.

I moved the Listen monitor system down next to the Shure wireless mic receiver and Dual-Locked the Pyle receiver on top of it. Dual locked the mixer onto the top of the drawer and used the foam from the mixer packaging to make a nice landing space for the microphones

Then I moved the rack to the other side of the stage next to the lighting controls and redid the cabling to the speakers. The speaker cable for the adjacent speaker had been run across the back of the stage to the other side, but the lead was on the floor so of course it was covered by all kinds of junk along the way. There was a ton of junk back there - old covid tests, boxes upon boxes of child masks, a giant broken ladder, an AV cart from the 90s, large rolling bulletin boards - it was a fucking mess that I had to toss around while hanging up cable ties to get the cables off the ground but it all got done.

While I was back there with all of the junk I found doors to the rack fridge so I put them back on.

Before the speaker cables were all wrapped together and bunched up on the ground. Now there's enough space to pull the rack out a few feet and get behind it if needed. There's also a ton more coiled up speaker cable inside.

 

[Alex Kenivel]

Pyle PMXU68BT -

Kind of flimsy. I can wiggle the knobs and the connected PCB and other knobs wiggle along with it. There is no Gain or Channel knob, just a single Volume and a peak indicator. I think they are just gain knobs. Everything works as expected. Bluetooth works well even at a distance. Does the job.

Phenyx Pro PTU-52

The school already had a Shure QLXD-4 so that's what I'm comparing these to. The Phenyx microphones pick up the rattles from noises inside the mic enclosure when you smack the handle, to me it sounds like the battery Springs. The Shure felt solid when struck with my hand and produced no noise.

The range on the Shure is better and the connection is stronger. The antenna are sticking straight back and exhibit no dropping out when walking all around the cafeteria area. With the Phenyx as soon as I moved side stage out of view of the rack the signal started dropping out but then came back on when standing in the middle of the cafeteria in view of the rack. It probably won't be a problem for anyone on stage.

The sound quality is very good on the Phenyx, very much like the Shure. The Phenyx mics have dedicated buttons for volume and when you tap the power switch it mutes the mic. The Shure has an on/off switch and an awkward thin joystick encoder to navigate the menu.

Something is up with their power amp, the input clips like a mofo and the fans don't come on at all. The speakers aren't great either but we'll see how they get along with it.

 

[la szum]

Went back at a better time with no children present to rig up the temp solution and check out the rig a little more thoroughly.

Their rack currently:
View attachment 6497View attachment 6498
The Crown clips extremely easy - got things down to "announcement" level where it was the happiest using music and a volunteer singer (my daughter) with minimal audible clipping through their little Atlas Strategy speakers.

The assembly on Friday went better than any they had before. When kids came back to school from mass quarantine each teacher was given a lapelle mic and a lunchbox speaker for speaking with volume while wearing masks in the classroom. This is what they relied on for music playback this whole time so everyone was happy to have some quality (to them) playback for performers this time.

I gave the lead teacher options in different price brackets to upgrade their current system. I didn't even divulge the upper tier details (new speakers, etc) because I know that will be out of their budget.

Well, hello 1990. Denon is tasty.

 

[TSJMajesty]

How does their current gear sound in the auditorium?

 

[Alex Kenivel]

How does their current gear sound in the auditorium?

Sounds good until you reach the clipping threshold. Shouting into one of the mics will sound crispy but normal voice and singing sounds okay as long as they don't screw up the gain staging I have in place. Thinking about creating a little informational page that will live inside the door describing what the knobs are doing for people who don't know better

 

[gearJunkie]

Sounds good until you reach the clipping threshold. Shouting into one of the mics will sound crispy but normal voice and singing sounds okay as long as they don't screw up the gain staging I have in place. Thinking about creating a little informational page that will live inside the door describing what the knobs are doing for people who don't know better

Maybe an inexpensive compressor/limiter could help Tame Shouting Teachers.

Not a bad band name

 

[Alex Kenivel]

Maybe an inexpensive compressor/limiter could help Tame Shouting Teachers.

If they want to expand their budget for anything I'd aim at the power amp first. That thing sucks