2x Otops + 2x T60 slims + Crown xTi4000

[Grant Bunter]

Re EQing,
I think what is trying to be said here about EQing is: (somebody will correct me if I'm wrong)

Look at the SPL chart(s) for your cab(s)
Draw a line roughly in the middle (ie average response). This line = 0.
Adjust your EQ at each point (eg 100hz, 500Hz, 1K, 5K etc) to be the mirror image of the SPL chart (so if it kinda looks like minus three on the SPL chart make it plus three on the EQ and vice versa) at that frequency.
If you used an RTA after this you would essentially see a flat line, or nearly.

Have a listen to your system then. Being flat it should go a bit harder...

[metaverse]

thanks again Greg,

I forgot to add that I was only running 1 single TRS to XLR cable into the input of the AMP. Would this still work or would I need to add a second cable going into the channel 2 input as well ??




@ itsnew2me - Thank you... I'm just about to go to sleep but I kinda think I got it ... The thing thats throwing me off is the part where you say "if you used an RTA you would see a flat line".

So the short end of it is eq up or down so that the graph mirrors the SPL chart ???

[Gregory East]

1 input works on mine A +B go to both channels. Maybe it is down on signal doing it that way but volume hasn't been a problem.

[Gregory East]

Re eq, you make up for the less sensitive frequencies by boosting them, and citing the more sensitive ones so as to do the same amount of boosting as cutting.

Then when you rta the result is no more eq is needed because you got the system into flat response already. Then you can use another eq unit to make adjustments for each venue.

If you have time during or after the show you can make another setting superimposing your house eq onto the base eq and save it for the venue. Then you only need to tweak for the audience and material but your basic room is all set when you plug in.

[metaverse]

Thanks Greg

[metaverse]

Re eq, you make up for the less sensitive frequencies by boosting them, and citing the more sensitive ones so as to do the same amount of boosting as cutting.

Then when you rta the result is no more eq is needed because you got the system into flat response already. Then you can use another eq unit to make adjustments for each venue.

If you have time during or after the show you can make another setting superimposing your house eq onto the base eq and save it for the venue. Then you only need to tweak for the audience and material but your basic room is all set when you plug in.

Ok , so when you say :

"citing the more sensitive ones so as to do the same amount of boosting as cutting"

- Do you mean to bring down the more sensitive peaks to the average db response as seen on the SPL chart ??

[Tom Smit]

Yes, that's right. And where the cab is less sensitive, then boost by the amount of db to raise it back to the '0' line.

[Gregory East]

Yep.

[metaverse]

O.k. I think i'm almost there ...

So in these cases here :






The "0" line or "average sensitivity" would be ??

Otop_12" is 107db and the T60_15" is 100db ??

[Gregory East]

You'll be crossing over at 100Hz and getting big sub action there so I would look at average of 102 and 110 for the tops.

Eq'ing the subs flat is matter of personal taste. The bass drops where you need the lows tend to be alone in the mix from what I gather so you might get away with not sacrificing heavy hitiing 80hz in order to have appreciable 30Hz. Not my bag really, you'll get a heap of different opinions on that.

[Tom Smit]

My tendency would be to pull the "0" line down just a touch more than that so that there would be a bit more headroom.
On the other hand, the OTop looks quite flat. So, just a nudge up at 150 and 1200hz would save a bunch of proceesing power and bring everything up to about 108db.
That being said, you'd need about 4 T60s to reach equal loudness. That or, really hold back the OTop.
concerning the T60, I would probably shoot for an average of 98db.

[Gregory East]

I would flatten them independently and adjust for the sensitivity issue on the front panel control. This saves having to redo the eq when you have more subs etc. You can also bake in compensation with the bandpass level setting.

[metaverse]

thanks Greg and Tom ... lots to digest here ... ill post back with progress later on ...

[metaverse]

You'll be crossing over at 100Hz and getting big sub action there so I would look at average of 102 and 110 for the tops.

Eq'ing the subs flat is matter of personal taste. The bass drops where you need the lows tend to be alone in the mix from what I gather so you might get away with not sacrificing heavy hitiing 80hz in order to have appreciable 30Hz. Not my bag really, you'll get a heap of different opinions on that.

Can you elaborate a little on this ... I lost you around "the bass drops where you need the lows".

Are you saying to drop the eq sensitivity at 80hz ???


And later when you say to "flatten them independently" i'm assuming you mean one channel at a time ???

[netwerks]

Anyone know what -6dB is worth for volts from a overdriven XTi4000? Not too much hopefully.

Use a multimeter. There is also a thread around here that has what the max voltage, -3db -6db and -12db settings should be translated into volts.