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jblnovice
05-03-2020, 08:49 AM
first time user. active XO help? Upgrade suggestions please. Long list of system at end. I cannibalized the drivers out of MR 835 to build OB speakers. First time with OB. So these are actively tri amped with a behringer cx3400 crossover. Pictures included. 3/4 in baffle 48h x 16w. So it starts to get strange here. Love the sound. added planar super twt. The amp I'm using is crestron 16 channel bridged. I got the amp at goodwill 20 bucks. Read it could be bridged for 8 ch/200 watts. Built by ATI and I rigged a trigger to bypass crestron control. So I have balanced running out of behringer into single ended inputs on amp. made cables from balanced to rca. Then 200 watts to jbl 2032H (15in woof), 200 watts to jbl -M209-8 (8in mid), 200 watts tp jbl 2418 H (horn compression twt 1 in.) and generic planar twt from madisound piggy backed off twt. I have caps across the tweeters so I dont blow them. After measuring and blending it sounds really good. I am using a velodyne hgs-18 I got for $350 for low bass because of OB. Made a wiring harness out of supra cable hook up wire from madisound. My problem is my background noise is to high. I can hear hiss at seat when music not playing. My guess the xo or maybe the way its bridged? everything sounds great. So my questions are what would you do for upgrade? Get better active analog crossover? Considered digital xo but considering ease of my inputs on current set up list. Better JBL drivers? Better 6 ch. balance input amp? I'm using a lexicon mc-12 b in 2 channel mode running balanced gotham cables to crossover and subwoofer. I have 6 different input options which is why lexicon. I have full analog pass through on turntable and sacd/dvd audio. sorry if this is too much information. Just dont want to answer as many possible questions.

this is what I am using
denon dvd 3910 analog through put to lexicon for sacd, also use digital out to paradigm pw-link for anthem arc room control digital out into lexicon
luxman turntable into vincent phono stage into analog through put on lexicon
paradigm pw-link for streaming tidal/amazon hd music digital out into lexicon
LG v30 phone analog output to lexicon with analog through put for MQA off tidal. -Don't laugh It sounds really good, never thought a phone could be a source after 25 years of playing audio fool.
Two other digital inputs into lexicon.

Lexicon MC-12b balance out L/R full range to behringer
Lexicon MC-12b balanced out L/R subwoofer to velodyne using lexicon sub XO to blend to main speakers OB

sometimes use different set up just running rca outputs of lexicon to homemade ss amp into Kef LS50 speakers and piggy back off amp to 2 stereo subs boston acoustics sbr 1000 powered subwoofer 10in with 2 passives and 500 watt amp.

Main question is how to quiet XO or what do I upgrade amp, xo, drivers, anything else) Pictures included
I have homemade room treatments on all reflective surfaces windows, ceiling, 1st reflection points, etc. please dont say turntable. I only put it there when playing vinyl
room 19.5 ft long, 13 ft wide, 8ft high , have anthem arc room correction built in to paradigm pw-link that I use for room correction on digital.

thanks, I dont know what I'm doing so I hope the photos show up

grumpy
05-03-2020, 03:34 PM
Which driver is the hiss coming from?... thinking you could pad the 2418... a lot, and just increase the drive to compensate.

Robh3606
05-03-2020, 05:26 PM
Have you played with the gain structure at all?? I have some driver actively padded to keep the noise down

Rob:)

jblnovice
05-03-2020, 06:14 PM
Have you played with the gain structure at all?? I have some driver actively padded to keep the noise down

Rob:)
Yeah I actually made some progress right after I posted this. I played with input level and found I could increase gain pass zero and gaining volume in the hiss but when I went below 0 it stayed the same. I ended up lowering all my levels by -5 db which was max I could do. I was still getting noise. I borrowed a balanced amp and went balanced out xo to balance input on amp and lowered it some more. What I realized was I probably need a 6 channel balanced amp to drive all the stages. I cant hear hiss from my seat but I can hear it 1-2 ft from the tweeter. So basically what I figured out it that the behringer adds its own level of noise but I get another set of noise added from bridging the crestron amp. I managed to decrease overall noise level. If I want to reduce it to where I can not hear it from the seat I can bet a 6 ch balanced amp. I am still getting noise from the berhinger though so I would have to find a quieter 3 way active analog crossover. I can make it tolerable just by swithching amp but that will be an additional purchase.

Mr. Widget
05-03-2020, 09:07 PM
Do you hear the hiss from the Crestron amp with the input disconnected? If you do, then changing amps is called for... I expect the hiss from the amp alone will be negligible. If this is the case, and adjusting the gain structure doesn’t solve your noise issue and/or padding down the tweeters doesn't solve the problem then you need to replace the crossover.

I have a triamped system with 110dB (1w/1m) horns and drivers with no padding and there is almost zero noise... with my ear in the horn there is barely perceptible noise. Padding the driver a few dB would eliminate even that, but luckily I don’t listen with my ear in the horn. :D



Widget

jblwolf
05-04-2020, 12:05 AM
I agree 100% with MR.W.l have used the same crossover you are using for 2yrs and I replaced a rane 23 xover with lasted 15yrs til it got noisy.with good hifi amps your rig will rock that is after you have fine tuned it.one issue I found is setting the delay for the low and mid with are adjusted to spec.on some recording I have to make adjustments.nice rig Wolf