Beginning REW, Problems

[Jason_Nolan]

Hello,

I'm brand new to this and having some problems. I would like to measure the response from my Definitive Technologies Trinity subwoofer with an 80hz crossover. I also own BP3000TL's, which is giving me some problems. I would love to use them both at full range, but at times I notice that I'm having cancellations and it hurts the response, and at times it seems to help the bass response when I don't have the 3000's crossed over. Confusing, at least for me. I'm sure it has something to do with standing waves, but I can only be subjective at this point. Which is why I choose to download REW. I have a digital radio shack meter and I also have an ECM8000 behringer mic, but I don't have the mixer to connect between the soundcard and the MIC, so I'm going to use the RS mic for now. The sound card is the cheap soundblaster USB external.

On to my problems. I first posted about getting an inverted perfect response, which I know couldn't be right. I figured out by reading I didn't calibrate my soundcard. So I've did that, or attempted to, but still no luck. Wayne asked me to start this new forum, so here it is. Any help is greatly appreciated to help my obsession with this.

Thank you,

Jason

[brucek]

I would love to use them both at full range

A poor idea. Bass management works, and it should be used. It passes frequencies that cause modal resonances (resulting in peaks and dips) to a subwoofer. The subwoofer can be moved to an optimum position to get a smooth response. Then the subwoofer can be equalized with a parametric equalizer to remove any remaining peaks.

Full range is just asking for trouble.

I have a digital radio shack meter and I also have an ECM8000 behringer mic, but I don't have the mixer to connect between the soundcard and the MIC, so I'm going to use the RS mic for now

For subwoofer and any measurements below about 3KHz, the Radio Shack meter is fine. If you want to do full range tests, you'll require a preamp.

The sound card is the cheap soundblaster USB external.

It's perfect.

So, what are your problems with taking a measure of your subwoofer?

brucek

[Jason_Nolan]

Thanks for your input, I'm sorry to have wasted your time. I finally figured it out.

I do realize bass management works and it's easier to control a sub easier than the sub plus the subs in my towers and center. It's depressing to learn though after spending the extra money on towers with 18's and a center with a 10. Maybe it's possible...probably not though.

Thanks,

Jason

[Jason_Nolan]

I don't have any room treatment yet, would that help to allow me use atleast my towers as full range? I thought the more subs you had the better?

[brucek]

Room treatment will not help much in the under 100Hz region, where modal resonance is a problem. To affect the peaks and dips caused in this frequency range you normally use subwoofer positioning to obtain the smoothest response, and then add equalization to finish the job if needed.

This is one of the problems with towers that have intergral subwoofers.

Multiple subs usually adds difficulty, but can be useful to balance off against each other at troublesome frequencies. It can be tricky to pull off in some rooms though. A single capable sub is your best bet.

brucek

[Jason_Nolan]

OK, thanks for your reply. Last night I took your advice and set everything to small with an 80Hz crossover. It is over all the smoothest and deepest sound I could get. I think you're right with the set classing and causing nulls. So, I ordered a Behringer FBQ2496 from Musicians friend or Prosound, cant remember. I should get it next week. I was curious though, after you take a measurement and load in a house curve, how do you manipulate the Behringer to reflect what you want it to do. I've saw some people say something about MIDI, but my sound card does not have a MIDI out. Is it possible to do manually, or is this difficult? I plan on reading up on it more, but any information is always welcome!

Thanks,

Jason

[brucek]

how do you manipulate the Behringer to reflect what you want it to do.

REW recommends filters to enter into the equalizer after you run the Find Filters and Optimize routine.

You can enter those filters by hand or through a Midi cable (USB to Midi). Personally, I always enter the filters by hand into the BFD front panel. It only takes a second.

Be sure to read the Connections Basics thread

brucek

[Jason_Nolan]

I got the BFD today or FBQ, whatever. I plan on hooking it up this weekend. I hope I made the right choice over the 1124, it seems like it may have had a little more flexibility?