Crossover question...

Polkaroo

Hey all, I need some advice...my RTIA7's claim to go down to 35 Hz. Should I set the crossover in the bass managment of my receiver to 35? Or maybe a bit higher like 40Hz or 50Hz? Same for my center and surrounds...Should I set the Xover to the lowest point as claimed in the specs? The Center is the CSIA6 and the surrounds are the RTIA3's. The Sub is the PSW505. Thanks...

ben62670

For music you probably want to set your mains at full range, and your sub at 60hz.
For movies set your mains to 60hz, and your sub to 80hz.
Also some don't like a sub with music.
These are not set in stone numbers, but just an idea where to start. They will work for most rooms, but you may want to play around with them to get them to where it sounds best. Toeing your speakers in a bit, and room placement mean a lot. Hopefully others with the RTI lineup will chime in.
Good luck with your system, and enjoy.
Ben

dorokusai

80hz.

kuntasensei

Polkaroo wrote: »

Hey all, I need some advice...my RTIA7's claim to go down to 35 Hz. Should I set the crossover in the bass managment of my receiver to 35? Or maybe a bit higher like 40Hz or 50Hz? Same for my center and surrounds...Should I set the Xover to the lowest point as claimed in the specs? The Center is the CSIA6 and the surrounds are the RTIA3's. The Sub is the PSW505. Thanks...

You never want to set the crossover the same as a speaker's rolloff point, since that will create a gap in the response over the range of the transition. Given the normal slope of digital crossovers, you want to allow about a half-octave transition above the speaker's -3dB point. That would be 52.5Hz, so I recommend using 50Hz. This will give it time to smoothly transition to the sub before the speaker's natural rolloff can create a gap in the frequency response. It will also offload deeper bass from the speaker to the sub, freeing up headroom on your receiver's amp section and giving you a cleaner sound. Because it's a gradual transition, you'll still get the directionality of the upper and mid bass.

Likewise, the CSiA6's -3db point is 55Hz, and a half-octave above that is 82.5Hz, making it perfect for a 80Hz crossover. The RTiA3's -3dB point is 50Hz, giving you 75Hz as a half-octave above, so 80Hz will work well for those as well though I would try 70Hz to maintain directionality of upper bass in the rear soundstage.

Turn the crossover on the sub itself all the way to its highest point and let the receiver handle all the bass management. This effectively gets the crossover circuitry out of the way and lowers the odds of circuit-induced delay throwing the subwoofer out of phase (i.e. throwing off the proper distance/delay setting). If your receiver has auto-detection of distances through an auto-setup routine (i.e. MCACC, Audyssey, etc.), the detection of the sub's acoustic distance normally comes closer to its physical distance if the crossover on the sub is out of the way. Also, if you receiver has a "LPF of LFE" setting (low pass filter of the LFE channel), set it to 120Hz to allow the full range of the LFE channel to pass to the subwoofer.

dorokusai

Blah blah, 80hz. There's no reason to even think that much about it.

kuntasensei

Sure there is. Different people hear directional bass at different levels. Your directionality may stop near 80Hz, someone else might hear directionally down to 60Hz. Matching the speaker's actual capability to the proper crossover point ensures that you maintain as much directionality as possible. It also can affect issues with phase alignment between the subwoofer and other speakers, since you might get phase cancellation at one crossover point that is alleviated by lowering it slightly. This is especially true of the center channel, where the quality of voices can be more noticeably affected by problems in the crossover range.

Also, it's not a brickwall filter - it's a crossover, so if the crossover point is 80Hz, bass begins to be gradually redirected well above that point (depending on the slope of the crossover). The crossover point is the point where the speaker and subwoofer are both reproducing the sound at roughly the same level, not a sudden transition. The lower you can set it, the less risk you have of localizing the bass to the subwoofer.

Polkaroo

Thankyou all I think I understand a bit better...I will experament and keep all this info in mind.