Gain voltage

**valhallax** · June 5th, 2011, 10:13 AM

ok, so we're having problems with various guitarists and their 4/12 cabs beaming through the stage, overcoming the pa, where we just turn everything else up and the cab mic for the guitar off. how can this be? we're running 210 cabs with dual driver 1003 horns, and 511b's up top for the high end. ive surmised a gain structure problem in the mix. i would like to hook up a dvm to the input side of the amp and check if we're getting enough gain to the admitabely cheap rmx 1450 amps for mid range. what voltage am i looking for. also.. a mackie sr40 board, where the trim pots are turned nowhere near max and the mics just scream feedback. onyx preamps any good? anyway, im just a playback guy and helping my buddy out with sr work has me at a loss. plugging in a mp3 player for fill between bands and everything is loud and clear. currently set up in a 40x60 room, should deafen folks..no? OldGuy, wish you were here , montana is awsome this time of year, anytime of year actually.

**bfish** · June 5th, 2011, 06:45 PM

Here's a good primer;

Setting Sound System Level Controls

**bowtie427ss** · June 6th, 2011, 07:26 AM

ok, so we're having problems with various guitarists and their 4/12 cabs beaming through the stage, overcoming the pa, where we just turn everything else up and the cab mic for the guitar off. how can this be?

I would ask: is it their 4/12 cabinets, or their megawatt heads and unwillingness to play at a reasonable level?

The problem may be as simple as you don't have an engineer or tech willing(possessing the intestinal fortitude) to slap your guitarist in the head while simultaneously telling him to "turn the #$%& down!" One of the most frustrating things with amateur bands/musicians is getting them to establish and respect a reasonable stage volume.

o.. a mackie sr40 board, where the trim pots are turned nowhere near max and the mics just scream feedback

Pricepoint gear is usually made with pricepoint parts, you really cannot expect much linearity from an 18 cent trim pot. If the mixer sounds good otherwise, higher grade, more linear responding pots can be installed as an upgrade. This mod alone has turned a couple peavey mixers into admirable performers for me in the past. It's a labor intensive project, but well worth it in the long run for a console that's going to continue to go to "work" for you.

Just my .02...................

**Panomaniac** · June 6th, 2011, 09:51 AM

Originally Posted by bowtie427ss

One of the most frustrating things with amateur bands/musicians is getting them to establish and respect a reasonable stage volume.

Ain't it the truth!

**Altec Best** · June 6th, 2011, 11:24 AM

Originally Posted by bowtie427ss

I would ask: is it their 4/12 cabinets, or their megawatt heads and unwillingness to play at a reasonable level?

Agreed !

Originally Posted by Panomaniac

Ain't it the truth!

+2, Hey John, you have 210 cabs with dual driver 1003's and 511B's on top of that in only a 60' x 40' room.That could be Overkill. IMHO

Personally I think A7's or A5's would fit the bill for that paticular sized room.Your right about Montana ,especially on a nice clear night. "Big Sky Country" great place for a telescope.To do a little Astronomy !

**valhallax** · June 6th, 2011, 03:10 PM

anyway, a db meter shows 106db's cranked, and it begins to clip the mid amps. wired parallel with a pair of 421's perside, thus my thinking signal problems to the amps. using a 3 way crossover with altec 8500 crossovers between the 210 cabs and the 1003's. the lows set at 10, the mids set at 7, and the highs set at 3. its a rane 23b. is there a table of input voltage somewhere that shows how many watts / volt at such and such ohms? it would appear we're seeing about a watts of power to the speakers?
altec best..there is no such thing as overkill, hehehe