working with sub bass

[Nakatomi]

Last Saturday I got myself plugged into a band pa. My initial sound check was to play some music I knew well, which needed some bass taken off. Fair enough I thought, so moved into my mic.

I usually have my mic just about flat, but that wasn't going to work. Oh no. For both mic channels I had to crank the baas down to almost nothing to avoid feedback and to be intelligible. Is this normal?

The sub was about 6 metres away in free space (it was actually against a fence which stops people falling down the stairway which leads to the castles dungeon.

I've never had a mic feed back on bass that easily and I've played on a lot of systems, even next to subs.

Do other sub users generally have to wang the mic bass nearly all the way down?

[CRAZY K]

Last Saturday I got myself plugged into a band pa. My initial sound check was to play some music I knew well, which needed some bass taken off. Fair enough I thought, so moved into my mic.

I usually have my mic just about flat, but that wasn't going to work. Oh no. For both mic channels I had to crank the baas down to almost nothing to avoid feedback and to be intelligible. Is this normal?

The sub was about 6 metres away in free space (it was actually against a fence which stops people falling down the stairway which leads to the castles dungeon.

I've never had a mic feed back on bass that easily and I've played on a lot of systems, even next to subs.

Do other sub users generally have to wang the mic bass nearly all the way down?

I use budget priced Peavy Subs with Pro 15 tops, although not much now, over 10 years in every conceivable location never had feedback worries even with plenty of bass on the mike and dont forget I work IN FRONT of the PA.

Had plenty of complaints from people a mile away though:rolleyes:

No doubt users of high end subs will be along soon to say differently ?

[Benny Smyth]

Never happened to me (I use a pair of RCF 905a subs).

[Nakatomi]

Maybe it was the room. The DJ pulpit is pretty much right in a corner, and corners are bad for bass nodes & stuff. Bass on the music channel.had to go down to maybe 10 o clock but the mic bass had to come down to like twenty five to which on that mixer is almost all off. My voice did sound lovely & rich though but I've never had to
Eq that aggressively before. Que sera I suppose.

And that was even after the sound guy had tweaked the PA so the music wasn't so boomy. Maybe it was all just too big for the room.

Still, it gave me a good idea how I could sound with 3 boxes. Loads of headroom and a lovely smooth bottom end.

[DJColsie]

The only trouble I've had is when sent up in a corner in a stone building with both subs and a "line dance" instructor wanted to plug in her £2.50 mobile head microphone. Nightmare. No problems otherwise.

[CRAZY K]

"line dance" instructor wanted to plug in her £2.50 mobile head microphone. Nightmare. No problems otherwise.

I bet that sounded total :Censored::Censored::Censored::Censored::Censored: :Censored:

[DJColsie]

I bet that sounded total :Censored::Censored::Censored::Censored::Censored: :Censored:

absolutely!

[Nakatomi]

The only trouble I've had is when sent up in a corner in a stone building with both subs and a "line dance" instructor wanted to plug in her £2.50 mobile head microphone. Nightmare. No problems otherwise.

Heheheh. I used to have bad bass feedback issues with my AT-73a headworn mic in clubs - I'd have had to take the bass so far down as to make it sound very tinny, so I didn't use it. Lord knows how bad a £2.50 mic would sound :lol:

[ukpartydj]

I do get bass feedback on my mic on occasion:
RCF 705as, RCF310a, Shure PG48.

I take out a fair bit of bass anyway as I think it's easier to understand without too much low end personally and I'd prefer to not sound like Barry White :)

[RobKennedy]

I always tend to knock some bass off the mic channel, interestingly when I turn up to a few regular venues where there is a mixer the mic channel always has the EQ turned down a bit on the treble and bass so it must be common !

That's generally not due to feedback though just to make it sound a bit better.

Feedback normally seems to happen to me when the client is making some type of speech, completely ignores my advice and casually wonders RIGHT in front of the speakers.

I'm always amazed I don't get more problems.

[Solitaire Events Ltd]

I do get bass feedback on my mic on occasion:
RCF 705as, RCF310a, Shure PG48.



With respect, you have a decent sound system with a £30 mic which is not going to deal with some frequencies than a more expensive quality mic.

[DJ Jules]

I've found it more of a problem with subs as bass tends to travel in all directions, whereas higher frequencies go forward. I've really only found it a big problem when I've been working on certain stages, or I've had a single sub under the booth (basically because I'm much closer to the sub than I am to the tops!!)

I've very, very occasionally found it when I've had two subs and I've been stood right in the middle of them - lower frequencies suffer from constructive and destructive interference much more than high - and remember bass travels in all directions - so you usually find you'll have a spot right between subs where you'll really feel the bass. If you get the distance from the subs to the wall spot on, you'll get further constructive interference at very specific frequencies which can really take you by surprise.

Generally though, yes, I EQ some of the lows out, and more when I have subs.

Julian

[ukpartydj]

With respect, you have a decent sound system with a £30 mic which is not going to deal with some frequencies than a more expensive quality mic.

My mistake it's actually a PG58 (not PGA48) which I believe cost me £50 years ago... I know the SM58 is the industry standard for lead vocals and I thought the PG58 was standard for backing vocals? Doesn't that mean they've gotta be pretty good?

[Solitaire Events Ltd]

My mistake it's actually a PG58 (not PGA48) which I believe cost me £50 years ago... I know the SM58 is the industry standard for lead vocals and I thought the PG58 was standard for backing vocals? Doesn't that mean they've gotta be pretty good?

I've got PG58s and they are very good for the price, but generally, a higher value mic will do the job better.

[ckpr2]

What ever happened to those devices you could buy for mic's that stopped feedback ?
I think they changed the phase of the signal so it is negative feedback instead of positive.

[CRAZY K]

What ever happened to those devices you could buy for mic's that stopped feedback ?
I think they changed the phase of the signal so it is negative feedback instead of positive.

Not sure but my modern box amps--Peavey ( now dead) and Yamaha both have anti feedback units and the JTS mikes seem to be very good for feedback so really should be no need to worry these days unless you get a venue with really bad acoustics.

[Nakatomi]

Ah yes. Feedback destroyers. Still apparently not used by pro sound engineers.

I'd much rather not have to work with another box.

[CRAZY K]

Ah yes. Feedback destroyers. Still apparently not used by pro sound engineers.

I'd much rather not have to work with another box.

As a musical entertainer working in a wide variety of locations from Barns and Marquees to Hotels and Village Halls using microphones, mini disc, I pod and sometimes a Cortex my new Yamaha Box Amp is perfect for me.:D

[ukpartydj]

I'm certainly no pro when it comes to feedback but my understanding was:

Make sure you're using a directional microphone (when I started out I used a non-directional mic which caused feedback all the time) I'm sure there are proper words for what I'm trying to say.
Point the microphone at your mouth and make sure that a speaker isn't facing you.
Place speakers further away.

Thinking about it I never get feedback from mid-high sounds when I speak only low and guess where the sub sits half the time ... right next to me! Maybe I should push it to one side!

As feedback destroyers simply eliminate certain frequencies I personally don't think the "quality of the mic" would be a factor as surely no mic will try to eliminate it's own sound?

Maybe I'm missing something :)

[Nakatomi]

Most mf/hf feedback is caused by reflections if the mic is directional enough & you're not on axis to the speaker.

Lf feedback is just well, picked up by the mic regardless because bass just isn't as directional. Longer wavelengths & all that.

I still had a good amount of bottom end from the mic side of the pa but it was a but on the tinny side for my taste.

[Solitaire Events Ltd]

Ah yes. Feedback destroyers. Still apparently not used by pro sound engineers.

.

Because all they do is take certain frequencies out.

[CRAZY K]

Because all they do is take certain frequencies out.

Dead right and the reality of that is that "experts" setting up sound systems (as happened to me when working with a bluegrass band) take out all the offending frequencies AND in the process leave the sound in no mans land---not enough bass generally.:rolleyes:

I was told that they spent ages getting the balance right to avoid feedback--I pointed out that there was no real bass and I couldnt work with it.

Sooo they turned the bass back up:D:D:D:D:D:D:D:D:D

[Nakatomi]

Because all they do is take certain frequencies out.

I know that feedback happens in a lot of cases because the frequency response of the room/venue is uneven in places, so using an EQ not only helps counteract feedback but helps stop unwanted peaks in the audio too. A feedback destroyer homes in on the root frequency of the feedback & puts a notch filter on it, which isn't the same thing.

Maybe my mics have both had big humps in their frequency response between 100-150Hz & I've just not noticed until now. A shame, but I'm planning on a mic upgrade soon anyway.

[DJIanScott]

I've been doing live PA work for years with various bands and solo artists, and there's simply no substitute for a decent mic. Instead of feedback destroyers and ambient room monitoring systems, I suggest a Shure Beta 58 mic. They're only about £120 and they have an extra 5 or 6 dB noise threshold from the normal SM58. Short of waving it a metre in front of the bass bins, I rarely get any feedback at all.

[CRAZY K]

I've been doing live PA work for years with various bands and solo artists, and there's simply no substitute for a decent mic. Instead of feedback destroyers and ambient room monitoring systems, I suggest a Shure Beta 58 mic. They're only about £120 and they have an extra 5 or 6 dB noise threshold from the normal SM58. Short of waving it a metre in front of the bass bins, I rarely get any feedback at all.

Agreed, to add to that, some amps have onboard feedback limiters-- my defunct Peavey Box Amp had that and so it appears does my new Yamaha Box Amp, if all else fails when using a full range speaker i just increase the speaker height by pushing them up in the air with the excellent hydraulic Ultimate Stands:D

[dicky]

I actually think it is a lot to do with the quality of the mic as well the abilities of the person to use the mic

Since I bought the Senheiser I really don't have any problems with feedback, compared to my previous 'budget' mics. I can move around the room using my mic with no issues.

It also doesn't fall apart after several gigs but that is another matter altogether :p

However when giving the same mic to various persons making speeches (and women seem to be worse for this than men for some reason) even standing next to me they can get it to scream and howl no problem!

Rich

[CRAZY K]

I actually think it is a lot to do with the quality of the mic as well the abilities of the person to use the mic

Since I bought the Senheiser I really don't have any problems with feedback, compared to my previous 'budget' mics. I can move around the room using my mic with no issues.

It also doesn't fall apart after several gigs but that is another matter altogether :p

However when giving the same mic to various persons making speeches (and women seem to be worse for this than men for some reason) even standing next to me they can get it to scream and howl no problem!

Rich

Sounds like they are standing in the wrong place and as you say not using them properly.

I would repeat again if you have any way of getting the speakers up high ( no idea of your set up allows this ) with telescopic stands I find this definitely helps, as i may have to tomorrow night in a very very small room --someones lounge in fact:D:D:D