M-Audio Transit and REW... a success!

**kjgarrison** · **06-21-09, 11:59 AM**

I have just read through this thread, and as a builder of an IB myself I am very interested in the problems encountered and solutions offered here.

I have taken a few preliminary REW measurements of my IB alone and noticed that it does have what I didn't previously realize to be a feature of IBs, namely higher frequencies with basically minimal fall off up to 200, even 250.

I'll be posting my own thread and asking for help when I get all the "settings" figured out, or maybe even to get the settings figured out.

But for this particular thread, I have a dumb question. Why is anything the IB does above the crossover selected in the AVR an issue? I'll risk a dumb answer and take a stab at answering my own question, too (just came to me as I was typing.) Is the reason that the AVR assumes a "typical" (and steeper) rolloff as would be expected with ordinary subwoofers, but instead gets full performance from the IB all the way up to ... who knows 250hz, resulting in an excess summation of IB and mains? If this is correct then are crossovers with IB subwoofers only half effective and half way like having LFE+Mains selected?

**jagman** · **06-22-09, 01:08 AM**

I can't answer your question because I just don't know. You're answer seems reasonable.

**brucek** · **06-22-09, 08:06 AM**

Quote:

Why is anything the IB does above the crossover selected in the AVR an issue?

I don't understand the question. An IB is no different than any other sub. The object is for the sub to track a target level that corresponds to the output of the receivers crossover setting. The room causes the sub to misbehave in that regard, so EQ is added. Why do you feel an IB is any different?

brucek

**kjgarrison** · **06-22-09, 07:33 PM**

Quote:

brucek wrote:

I don't understand the question. An IB is no different than any other sub. The object is for the sub to track a target level that corresponds to the output of the receivers crossover setting. The room causes the sub to misbehave in that regard, so EQ is added. Why do you feel an IB is any different?

brucek

Wayne said it .. maybe in post 16 ?

**brucek** · **06-22-09, 08:00 PM**

Quote:

Wayne said it .. maybe in post 16 ?

You've mis-understood what his point was, along with all the other people who were trying to tell the OP that an IB, like a sealed sub may require low end EQ gain. This isn't gain thrown at a modal dip, but EQ for the bottom end. The OP decided that the answer was to drive the overall gain 30dB high, and then cut everything but the bottom end. A poor decision.

IB's, like any sub should track the crossover that the bass management crossover provides.

brucek

**kjgarrison** · **06-22-09, 10:22 PM**

I surely did misunderstand. Thanks for the clarification. Of course it makes sense that the IB basically has to follow the -24dB/octave rolloff of the AVR's bass management system. (I'm assuming 24, since that is what my AVR does.)

You can tell I'm a noob.

But I'm working on it.

Thank you.

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