Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Debbie Dunkley]

I just ordered the Samson S 3 way crossover as a spare for my PA. I usually use the DRPA but I wanted a back-up. I chose it because of some really good reviews I'd heard and the fact it has some nice extras such as limiters, low frequency roll off, mono sum, cd eq..... Also, I like knobs as opposed to digital buttons and menus - bit easier to adjust in a live situation. I'll play with it a bit when it arrives but I have a question if anyone can help me. The manual shows example hookups for 2 way stereo, 3 way stereo and 4 way mono. I run the PA system 3 way usually use mono out from desk and then stereo outs at the crossover so I can feed the amps left and right. I use the sub amps in bridge mode one per side so I cannot use the 'Y' function. I cannot find anything in the manual or online that indicates I will be able to feed just one channel of the crossover and take 2 channels to each of the amps. It looks like I can only use left and right inputs for stereo to get left and right outputs or left input for mono (single channel) outputs. What do you think??? If this cannot be done, it is no big deal if I have to use left and right out from the desk. Using mono is one less cable and frees up one of the returns on the snake....

[Greg_Cameron]

If you want to use the left & right outputs of the crossover for independent control, you could simply Y the inputs to the crossover from the mono return line. There's nothing wrong with that.

[Debbie Dunkley]

If you want to use the left & right outputs of the crossover for independent control, you could simply Y the inputs to the crossover from the mono return line. There's nothing wrong with that.
[/quote)



I can? That's good news. I know for certain applications Y connectors and cables are not considered OK so I didn't think of that. Thank you!!

[Greg_Cameron]

can? That's good news. I know for certain applications Y connectors and cables are not considered OK so I didn't think of that. Thank you!!

Generally speaking, it's usually ok to Y a single output to two or more identical or similar inputs. It is generally not ok to Y two outputs to a single input. The goal is to maintain an input impedance to output impedance ratio of at least 10:1. Balance inputs are usually on the order of >10k ohms.  In the case of the Sampson S3, the input impedance is spec'd at >15k ohms. Balanced outputs are often in the neighborhood of 100 ohms. So the ratio of of driving that single input from a 100 ohm output would be > 150:1. Just like speakers, every time you double the number of identical boxes, the impedance of the total load is halved. So if you drive both crossover inputs from the mono output, the total input impedance is now at ~7.5k ohms (75:1). Let say you wanted to drive 4 inputs. That would make the load 3.75k ohms. 8 inputs, ~1.86k ohms. 16 inputs, ~938 ohms. Which is just slightly under your minimum 10:1 ratio which would probably still be fine.

[Debbie Dunkley]

Generally speaking, it's usually ok to Y a single output to two or more identical or similar inputs. It is generally not ok to Y two outputs to a single input. The goal is to maintain an input impedance to output impedance ratio of at least 10:1. Balance inputs are usually on the order of >10k ohms.  In the case of the Sampson S3, the input impedance is spec'd at >15k ohms. Balanced outputs are often in the neighborhood of 100 ohms. So the ratio of of driving that single input from a 100 ohm output would be > 150:1. Just like speakers, every time you double the number of identical boxes, the impedance of the total load is halved. So if you drive both crossover inputs from the mono output, the total input impedance is now at ~7.5k ohms (75:1). Let say you wanted to drive 4 inputs. That would make the load 3.75k ohms. 8 inputs, ~1.86k ohms. 16 inputs, ~938 ohms. Which is just slightly under your minimum 10:1 ratio which would probably still be fine.

Thanks for the extra info Greg. Good information to know. I was wondering if I could use a small mic splitter style box instead of a Y cable which might be a bit more reliable in the long run and runs about $30.

[ProSoundWeb Community]