Electric crossover recommendation

[grumpy]

Uh, yes, I know that, Dave

Doh... read the thread... just too quickly.
At least robertbartch got something out of it.

[robertbartsch]

BOPUTNAM:

So, if I use the xls/rca cable connector adaptor any balanced output/input will become an unbalanced input/output; right?

What exactly is the benefit of balanced input/outputs?



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IIRC, your amp, at least one of them, has balanced inputs? Why not adapt the pre-amp output, and be done with the RCA's...?

AVCables is one of my favorite sources for all sorts of stuff - best quality and good prices. They have all sorts of adapters. You should bookmark their site!

Here's their selection of female RCA adapters.

Here's their selection of male RCA adapters.
__________________
bo

[Ian Mackenzie]

BOPUTNAM:

So, if I use the xls/rca cable connector adaptor any balanced output/input will become an unbalanced input/output; right?

What exactly is the benefit of balanced input/outputs?



***********************

...

IIRC, your amp, at least one of them, has balanced inputs? Why not adapt the pre-amp output, and be done with the RCA's...?

AVCables is one of my favorite sources for all sorts of stuff - best quality and good prices. They have all sorts of adapters. You should bookmark their site!

Here's their selection of female RCA adapters.

Here's their selection of male RCA adapters.
__________________
bo

The benefit is common mode noise rejection over distance particularly low level signals like Mics feeding a desk. The problem is most active crossovers in the Pro sene usually if balanced jacks or XL connectors.

For domestic audio this is no benefit really for short cable runs and the additional balanced circuits can deteriorate the otherwise HiFi signal.

Balanced cables to not eliminate earth loops. Not all equipment offers true balanced operation either and some of the JBL electronics do not follow convention. So beware.

Normally the balanced to unbalanced output runs the hot pin (2) to the centre RCA and shield pin (1) to the outer sleeve of the RCA. Pin (3) is left floating.

Nornally unbalanced RCA to a balanced input has hot centre to pin (2) and the outer sleeve to pin (1). Pin (3) on the balanced input should be shorted to pin (1) to reduce noise.

[jblbgw_man]

Normally the balanced to unbalanced output runs the hot pin (2) to the centre RCA and shield pin (1) to the outer sleeve of the RCA. Pin (3) is left floating.

Nornally unbalanced RCA to a balanced input has hot centre to pin (2) and the outer sleeve to pin (1). Pin (3) on the balanced input should be shorted to pin (1) to reduce noise.

An additional variation of this is the servo balanced outputs where pin 2 (Hot +) goes to the center pin of the RCA and pin 3 (Cold -) (not pin 1) goes to the earth of the RCA, therefore isolating the groung from the source equipment

[robertbartsch]

I purchased a used DBX 223XL from Flee-Bay and I hope to use it in a two-way - bi-amp system.

My Denon 3300 receiver has pre-amp "out" and power amp "in" RCA cable jacks. My low freq amp will be a 200 watt per channel Adcom and I plan to use the Denon power amp (100 watts) that is built into the receiver as the high freq. amp.

So basically, the electronic crossover goes in between the single pre amp "out" jacks and the dual (twin) power amp "in" jacks; right?

Apparently, my 2 inch HF compression driver (JBL 2445) has a tendancy to roll off the HF material above 10HK, so will the DBX allow me to boost the material above this freq?

Thanks...

[jblbgw_man]

I purchased a used DBX 223XL from Flee-Bay and I hope to use it in a two-way - bi-amp system.

My Denon 3300 receiver has pre-amp "out" and power amp "in" RCA cable jacks. My low freq amp will be a 200 watt per channel Adcom and I plan to use the Denon power amp (100 watts) that is built into the receiver as the high freq. amp.

So basically, the electronic crossover goes in between the single pre amp "out" jacks and the dual (twin) power amp "in" jacks; right?

Apparently, my 2 inch HF compression driver (JBL 2445) has a tendancy to roll off the HF material above 10HK, so will the DBX allow me to boost the material above this freq?

Thanks...

Essentially YES .... but remember that your Dennon output level will be nominally -10dBu where as the nominal operating level of the 223XL is +4dBu, this may present as a higher than anticipated noise floor level from the 223XL as you will be operating typically 14 dB below the nominal operating level, therfore resulting in a 14dB lesser S/N figure than that that is published for this unit, so around -80dB instead of -94dB


These units are normal polarity convention so pin 2 is Hot + and pin 3 is Cold -. Using 2 conductor shielded cable, on the input to the 223XL connect the + of the RCA to pin 2 of the XLR and the RCA ground to pin 3 of the XLR, connect the shield of the cable to pin 3 of the XLR but do not connect it to the Dennon, leave it unterminated at the Dennon end. On the output of the 223XL take pin 2 to the RCA + centre pin, As I don’t believe the 223XL are servo balanced outputs, therefore connect the negative of the RCA to pin 3 of the XLR …… hey presto it should work with a good chance you won’t end up with a ground loop.

Now ……… Do we presume you are still using some sort of passive network feeding the 2445 to provide CD equalisation???

I will be interested in your thoughts of the 223XL …………. I found them to be rather harsh sounding beasts especially feeding a compression driver. I don't believe their design is high end at all.