That damn laatch55
- Thread starter Apap1
- Start date
- Joined
- Oct 15, 2014
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- 3,419
- Tagline
- ---not quite right
My shop system has been active bi-amped since it’s inception. Has the house system bi-amped then tri-amped but was having some noise issues so it’s all apart rn. Have some isolation transformers to get wired up for running balanced/unbalanced gear to try, also tried a DSP and still had some noise/hiss so I’m looking at cleaning up my mess of AC and signal cables next. Also going to rewire Tim, my half WOPL 700/1 as there is some area for improvement in my grounding and wire routing as that amount is a tad noisy compared to Linda. My full WOPL 400/1. Active multi-amping sure frees up a metric fuck ton of power and headroom though!
Talk about a rabbit hole eh !
I found that directly coupling the drivers to the amps brought out some "Idle hiss" that the passive crossover would have taken care of....
So, in trying to match the drivers for efficiency and impedance, and protect the compression drivers from any "turn on/off" DC
I built a attenuator / protection interface to go between the 2245's and the 2405's.
Essentially reduced the idle current / hiss and then adjusted the gain to compensate. A series parallel ckt using non inductive resistors match the impedance to the 8 ohm 2035's and a decent quality protection cap matched to the intended crossover point is in series to take care of any DC that might make its way to the diagrams.
2405's @ 110 db - 16 ohm
2445's @ 111db - 16 ohm
2242's @ 99 db - 8 ohm
2035's @ 98 db - 8 ohm
Rabbit hole..... This is one BIG rabbit........
The DSP allows real time tinkering.... Warning.... This may be bad !
I recently spent hours calibrating everything to the Harmon house curve and hated it ! It lacked the Bass and "crispness" my system can turn out....
I went back with the Umik 1 and REW and started over...
I ended up "boosting both ends Bass / Treble, 200 Hz and down & 3,000 Hz and up. (ish)
By the time you read this I may have changed everything... again.....
M
I found that directly coupling the drivers to the amps brought out some "Idle hiss" that the passive crossover would have taken care of....
So, in trying to match the drivers for efficiency and impedance, and protect the compression drivers from any "turn on/off" DC
I built a attenuator / protection interface to go between the 2245's and the 2405's.
Essentially reduced the idle current / hiss and then adjusted the gain to compensate. A series parallel ckt using non inductive resistors match the impedance to the 8 ohm 2035's and a decent quality protection cap matched to the intended crossover point is in series to take care of any DC that might make its way to the diagrams.
2405's @ 110 db - 16 ohm
2445's @ 111db - 16 ohm
2242's @ 99 db - 8 ohm
2035's @ 98 db - 8 ohm
Rabbit hole..... This is one BIG rabbit........
The DSP allows real time tinkering.... Warning.... This may be bad !
I recently spent hours calibrating everything to the Harmon house curve and hated it ! It lacked the Bass and "crispness" my system can turn out....
I went back with the Umik 1 and REW and started over...
I ended up "boosting both ends Bass / Treble, 200 Hz and down & 3,000 Hz and up. (ish)
By the time you read this I may have changed everything... again.....
M
