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Sub Cross Over Help

Need a little help from you guys running subs. Let me start off with what I have. Power amp, Krel FPB400 CX, KCT pre amp, Bryston CD player, B&W 804s's with a Rel R328 sub. I've been doing a lot of research and reading and learned a great deal from you guys on this site. As of right now I have the sub crossed over at 40hz. The sub is next to the left speaker 18 inches from the corner and 8 inches from the back wall. The speakers are 10 ft apart and a fot from the back wall with my 55 inch plasma TV in the center. My listening distance is 10 ft from the speakers and the room size is 17 x 14. I've used a RTA with a 40hz tone to match the sub with my full range speakers. Everything seems to sound extremely well. The imaging and sound stage is superb. Only thing I've noticed depending on the music I play. I sometimes have to turn down the gain on the sub by 5 clicks, which I'm sure is normal. The gain on the sub sits at 16 clicks from zero. Let me know what you guys think and what I can do to improve my system if any. Please let me know.
dancer
dancer OP
56 posts
 
Thanks guys for your help on this. Timlub It the nail on the head. I did move the sub out of the corner witch did help. I dont have so much Bondry boost like I did. The X over is at 35hz. The only thing I notice is when I play hard rock like Rush Then I go to play something like Yellow or something that has a lot of low Bass in It. I will have to turn down the gain a little. I'm still playing with things to see If I can get better. I'm trying to get the sub to play good bass at the right gain. No matter what disc I play. Something tells me this is very hard to accomplish. As it stands right now the sub blends in extremely well with my 804's. Much better then it did before when the sub was in the corner. Any other advise would be helpful. Thanks
phasecorrect's avatar
phasecorrect
2,013 posts
 
If u have to turn down the gain then the sub is too loud to begin with...a common problem...most people turn up the sub until they can hear it which by then it loses its omnidirectional capabilities...if u can locate where the sub is then its too loud...u can spl match if needed...but I tend to calibrate a few decimals lower for optimum match...hope this helps
hevac1
812 posts
 
Dancer,

The fact that when you changed your subs location and it helped, you may want to try this for sub location. This is how I placed my subs.
Pick some music with lots of bass or the Yellow album you were talking about. Set your systems volume at the level you like to listen at. Turn your system off and put your sub where you normally sit. Disconnect your main speakers and turn your system back on. Get on your hands and knees, crawl around the room until you find the location where the bass sounds the best to you. Put your sub in that location and reconnect your main speaker, then listen. You still may have to make adjustments but the bass should be more uniformed.
You do need an SPL meter to get the volume correct at all speakers to start as Kal said.
I myself do not like subsonic bass when I listen to 2 channel music so I have a crossover to deal with the differences in bass between 2 channel and movie surround sound.
Enjoy
lewinskih01
910 posts
 
Glad to see it worked for you. I have a similar situation and also have 804S and Rel sub (but a Storm III). I suggest looking into what Kal (Kr4) mentioned briefly: "having an appropriate high-pass filter for the main speakers is very useful". I know I am, and I'm also looking into DSPeaker 8033.

Kal: which high-pass filter would you recommend? The "less components in the chain, the better" credo kind of draws me away from adding a filter, but clearly you must have found something good.
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