Suggestion needed for taming my Sub

[bcycle]

Hi,

Working out the last few kinks on my homemade sub. It sounds great but is a little boomy when playing music in a normal stereo mode. I'm running the pre outs from my receiver to it's amp input (all line level connections). I have the sub's high pass filter set to it's lowest frequency of 40hz. I DO NOT have the signal going back from the sub from the receiver yet. (I'm not sure if I can do that with my Yamaha RXV2500). In theory, the high pass filter should cleanly separate signals above 40hz and send them to my speakers which are good down to about 32 Hz or so. I haven't done this yet because I fear there will be considerable degradation to my main front speakers due to the fact that I would be running them through the sub's $117.00 Chinese manufactured plate amp and a fair amount of cable instead.

Can anyone suggest some sort of variable low pass filter that I can connect to the sub so it doesn't produce frequencies above XX? If there's something out there, I'm pretty sure I can better match my sub to my mains. Any other suggestions?

Thanks,

Greg

 

[mtrycrafts]

Hi,

Working out the last few kinks on my homemade sub. It sounds great but is a little boomy when playing music in a normal stereo mode.
Thanks,

Greg

You most likely have room issues that needs attention for the low frequency response. If you are using the sub 40Hz and below, the other speaker will also contribute to the low frequency issues too.

Until you carefully measure the in room response of your system at the listening position, who know what may help outside of some bass traps.

 

[MDS]

I'm running the pre outs from my receiver to it's amp input (all line level connections). I have the sub's high pass filter set to it's lowest frequency of 40hz. I DO NOT have the signal going back from the sub from the receiver yet. (I'm not sure if I can do that with my Yamaha RXV2500).

If you are using a receiver and its subwoofer pre-out you should not be running the front speakers off the sub. You should be connecting the speakers to the receiver.

If your line-level input on the sub does not bypass its xover, you should turn it up to its highest level not the lowest level and set the xover frequency in the receiver. Set the front speakers to Small and Subwoofer=Yes in the receiver setup menus. Then you have both the high-pass and low-pass set correctly and don't need an external xover.

 

[AVRat]

For starters, the x-over control on the sub amp is low-pass not high-pass. The high-pass to the outputs is probably fixed at 80 Hz. Since I don't have a manual, I don't know the specifics of the amp. To run in "Pure Audio" off the Yammie, I'd run speaker level connections to the sub then to your speakers with about a 80 Hz x-over on the sub. Set the mains to large with no sub in the receiver.

 

[bcycle]

If you are using a receiver and its subwoofer pre-out you should not be running the front speakers off the sub. You should be connecting the speakers to the receiver.

If your line-level input on the sub does not bypass its xover, you should turn it up to its highest level not the lowest level and set the xover frequency in the receiver. Set the front speakers to Small and Subwoofer=Yes in the receiver setup menus. Then you have both the high-pass and low-pass set correctly and don't need an external xover.

Thanks MDS,

Believe it or not, I have the sub connected to a passive line level a/b box. I'm feeding the signal from the Yamaha's Pre-out to the A input and the Yamaha's Sub out to B input. The Box feeds right/left signal to the Sub's input. The hitch with my receiver is that Sub pre out on the Yamaha only sends a signal when in surround mode. The purpose of the a/b box is so I can listen to the receiver in "Pure Direct" mode whereby it bypasses signal processing etc., and actually does sound better for stereo listening. But that's where I have a little extra bass "bump" so I'm wondering the best way to smooth that out. I imagine the crossover on the plate amp (Parts Express SA240) will do the trick if I take it's line level outs back into the receiver after the sub amp's xover, but I think the signal degradation will offset a smoother transition from sub to main speakers. Your thoughts?

Greg

 

[j_garcia]

No, that won't work. As AVRat mentioned, the high pass from the sub on nearly all subs is FIXED (adjusting the sub's x-over does not affect it), so you won't gain anything from feeding it back into the receiver.

Have you tried various positions within the room and have you run a response curve of just the sub and the sub coupled with your mains?