In trying to tweak my new RL-i 10, I noticed that the sub is very peaky from about 40-50 Hz, much louder than at 60-80 Hz. What can I do to remedy this? I have a .6 foot box, with around 350-400 watts going to the sub.

The box is packed with polyfill.

Any suggestions would be appreciated. Thanks,

Dave

As suggested in email (but also for anyone else with similar concerns who may happen upon this thread ), ditch the polyfill and if you still want to flatten the response more, slug the box with a chunk of wood or something that will bring down your internal box volume to around 0.4 cu ft net.

Here's hoping you get your setup to where you want it!

Thanks Mike,

Listened to it a little more last night, and there is a definite improvement after removing the polyfill. It almost sounds like the 50Hz boost may be cabin gain. This with a test tone cd I made.

Anyway, of all the songs I listened to after removing the poly, only one CD sounded funky, and it sounds weird on my home setup also. Too much LOW on the kickdrum. It sounds nice on systems without subs, but with subs...it's crazy.

I'll goof with the eq some more to see what I can come up with.

OK, did some more messing around, found out that it is cabin gain. I tried blocking it down to .5 cubic feet, and it did help a little, but didn't sound 'right'.

I then opened the back hatch and used by SPL meter to test at about 1 footr...60 and 70Hz were actually louder than 40 and 50Hz in this situation...so it's my wagon causing the gain...

Anyway, it sound pretty darn good anyway, I just need a little less oomph on the 40-50Hz range. I'm thinking this EQ would be a good bet..the parametric eq on it would help me dial down my 50Hz mountain a bit.

http://www.eclipse-web.com/equalizer/index.html#21010

The parametric eq is variable between 25-100Hz. It also has a 5 band graphic eq, and can be had on ebay for about $150

Feedback will be appreciated.

My buddy Thilo Stompler (owner/engineer @ TC) uses a model very similar, if not that exact model in his car. Though I should note that he doesn't use it much for EQ as he does for basic sub-volume adjustment, nonetheless, it has been going strong for a long while and seems quite reliable.

Mike,

Have you seen cabin gain in that range? It is about 10 db louder in this frequency range

Typically cabin gain sets in at around 60-80 Hz and below. I can't be sure why you are experiencing the peak at 50 Hz, but you might also try moving your enclosure to different locations in the car since there could be cancellation issues at hand as well.

Actually, I did reverse the phase on the sub, it made a pretty big difference in the 60-80Hz range. I'll try moving it around a bit.

nice work mike