Hum?

basilh · Post by **basilh** » 4 Sep 2007 2:00 am

Lana, whomsoever told you this, really "Hung You Out To Dry", it is so so wrong.
A rubber bridge over the cables wouldn't make one iota of difference to induced hum or hum from an earth loop.
Neither for that matter would ANY form of shielding, there WAS a small feeback loop from the transmision back to the desk, that is apparent by the constant "Phase Change" on the continuity announcer's microphone (Yours)
You even complained about the level, saying about being in a cave !!.
Maybe they were even taking a feed from the net for monitoring purposes and "Inadvertently" routed it back to one of the 'active' busses.

Alan Brookes · Post by **Alan Brookes** » 4 Sep 2007 5:26 pm

Basil, you're flogging a dead horse...

Lana Rosselli · Post by **Lana Rosselli** » 5 Sep 2007 2:59 am

basilh, now that comment would have been far more beneficial than your previous comments. I thought it was our headphones that made me sound like I was in a cave. I know the engineers were recording on a lap top but not sure of their connection. That would have been something that I could have at posed as an issue. But with that said, in future remote broadcasts, I will keep that in mind.
I remembered from 2006 the issue we had with the base amp causing a hum. So that was the first thing I mentioned. And when the amp was muted (this year) the hum we heard went away. I was then told that amp had been isolated. We also had a problem with one player's guitar...

As for the 'ground loop' comment...that too was brought up - in exact terms.

I do have one question with regards to basil's last comment...if indeed this was the issue, would that have caused our headphones to cut in and out? I would - for lack of better terms - refer to this as a system overload. Equating it to too much on one circuit. So it may sound odd but I often need to find a similarity in order to understand new processes.

And by the way, I do commend you for your donation to Diabetes Research. I have held that cause close to my heart for many years. In fact, for the past four years organized Monsanto's corporate campaign (raising up to $75K) in addition to my own personal fundraising. Unfortunately I am not in a position to donate my personal year's earnings but have managed to collect close to $4K in donations per campaign. I tip my hat to you pence or penny!

All in all, thanks for the explanation.

Alan Brookes · Post by **Alan Brookes** » 5 Sep 2007 5:29 pm

Okay, you're both two good people, now kiss and make up.

As a diabetic, thanks to both of you for your efforts.

basilh · Post by **basilh** » 6 Sep 2007 12:09 am

You're right Alan,
Lana, the headphone problem was PROBABLY twofold,

1. It was probably some form of feedback on the 'Cue" circuit that caused the cave effect and

2. The cutting out could have a myriad of causes, but in order of probability (In THIS particular instance) they would be, op amp cutting out because of mismatch caused by taking too many feeds from the 'phones output, faulty 'phones level potentiometers (Switchcleaner cures this) Faulty jack on the headphones cord, faulty connection where the cord connects to the earpieces, faulty routing switch for the aux sends or the headphone routing selector.
My guess would be the first instance.

As for the charity work, Last year Bob and I raised over £125k that's a quarter of a million Dollars.
Last weekend we were on a show with Daniel O'Donnel and the Fri. and Sat. nights raised over £25k for Daniel's Romanian Orphans Fund.
I've been a close friend of Daniels since he started in the music business, I produced his first hit record.
Daniel is, like Bob an MBE, they both got presented with their honours from the Queen of England for their services to charities, and in Bob's case, also for his BROADCASTING work

Lana, I would have responded sooner but I was at the studios layng down the tracks for a Charity show to be aired by the BBC from the Rico Arena, featuring Bob and myself, Daniel O'Donnell and many guests.

You may ask "where is Basil" on these posters, well , I'm Bob's musical director and his band on stage, as well as his record producer and general factotum, and as such only occasionally do I even dare to grace the posters, BUT, I did when we did our last annual Birmingham Symphony Hall Concert.

Lana Rosselli · Post by **Lana Rosselli** » 6 Sep 2007 3:59 am

Thank you! With that I can eliminate a couple of possibles- narrowing the quest!!! I wonder if it would be possible to have a dedicated feed or find an alternative to feeding directly off the sound board. Of course doing that would require us to have our own sound board to get the mix correct - right?

Congrats!!! That had to be pretty cool getting an award from the Queen. But then again, seeing a kid finally get 'the pump' and being able to normalize their childhood somewhat is quite rewarding as well. In the four years I ran the corporate campaign, we raised $265K. Unfortunately my work load has caused me to step down as the campaign lead but not my participation. I hope some day soon elet transplants will be as common as penicillin!

Thanks again!

basilh · Post by **basilh** » 6 Sep 2007 6:06 am

Lana, if you ran a RADIO link from the main auditorium soundboard, say via the headphone out to a dedicated 'in-ear monitor system, and then fed the output to your console, you would then eliminate all possibilities of a ground loop at YOUR end, then, any hum would be the responsibility of the PA crew ..and as a bonus you'd have the ability to listen to the main out via another in-ear receiver as well as monitoring your own desk out via conventional means.

BTW In-Ear systems are quite economically priced and you wouldn't need the top of the range "State of the Art" ones, most of the systems are pretty adequate for what I suggest.
You don't need to go tho the expense of molded earpieces, ordinary headphones will plug directly into the normal receivers.

Congrats on the $256K, you know that all we can do is help a little, BUT, a little here and a little there EVENTUALLY adds up to something substantial, our COMMON goal.

Bill Ferguson · Post by **Bill Ferguson** » 6 Sep 2007 10:03 am

To clarify the way the system was connected.
We were ALL on the same leg of the circuit.
We had no hum in the sound system.
We do hook up a separate mixer to feed audio to SteelRadio.com. This is my job and my equipment and it is the best money can buy.
Varying levels are exactly what comes off the stage. We cannot and will not attempt to set every level the same. Remember, we are mixing 24 channels of sound down to 2 channels while sitting in a "Live" room. You can only imagine how loud we have to run our headphones.

There was NO hum in my output to SteelRadio.com. The hum was picked up from something in the hotel. It was not present all the time. However it was still there when we disconnected our mixer from SteelRadio.com. We tried the grounding change to no avail.

The cables on the floor did not cause the hum. This is just something that was told to Lana in the heat of the moment.

The entire crew, including Lana, did a superb job for this broadcast.

We are constantly striving to improve the broadcast, but you have to understand no matter how good the equipment, we don't get to remix or in other words "no 2nd. chance".

I will put mine and my staff (all volunteers by the way" up against anyone.
I have CD's of the entire show (no hum from the same output) and they are GOOD.

Bill Ferguson

Earnest Bovine · Post by **Earnest Bovine** » 6 Sep 2007 2:41 pm

Bill Ferguson wrote: The hum ... was not present all the time.

For what it's worth, I'm pretty sure that the hum was there all the time, always at the same level. When the music got loud, it would mask the hum, so we didn't hear it during the loudest parts of the broadcast.

Earnest Bovine · Post by **Earnest Bovine** » 6 Sep 2007 2:43 pm

Where was the A-to-D converter?

Jim Sliff · Post by **Jim Sliff** » 6 Sep 2007 9:14 pm

I agree completely with Doug's assessment - I could always hear some level of hum during quiet portions - during louder music it was masked, but if there was a momentary rest in a piece the hum would jump. It was always present, and you could also identify it with long sustained notes with weird oscillations - the hum waveform fighting the waveform of the note.

Jim Sliff · Post by **Jim Sliff** » 12 Oct 2007 4:47 am

I just noticed - they sure let this thread die, didn't they?

I guess qualified advice isn't really desireable for some unknown reason.

Alan Brookes · Post by **Alan Brookes** » 12 Oct 2007 11:09 am

You want to heat up the argument again ?

admin · Post by **b0b** » 13 Oct 2007 10:14 am

The show is over. No point in trying to solve a problem that doesn't exist anymore. Next year when they set it up again the wiring will almost certainly be different.

Closed.