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In the Forum: Audio Discussions
In the Thread: Learning to interpret RTA

Post Subject: Learning to interpret RTAPosted by zanon on: 6/10/2010

Hello:

I would like to ask this forum for advise.

I picked up a very simple and cheap RTA and decided to use it to listen to my speakers. It is 1/3 octave RTA, so I know Romy will say it is useless. It may not be very useful, but I start with nothing so I think of it as a first step.

I play pink noise from my stereo (2.1) and see a big hump in bass (also a dip from 125-500). I turn off the stereo and just play the subwoofer -- I see a big hump in bass only and nothing on the top. I play just the R and left channel, and I see relative flatness, except of course for the dip from 125-500.

This is my quandry. I am in a very large and open room, and without the subwoofer bass is truly in audible. The double bass opening from "So What" by Miles Davis really can hardly be heard. With the subwoofer, it is easy to hear, and I think very well integrated. I took great care to position the sub, time align it with RL channel, set the volume and phase correctly etc. so I get nice integrate bass extension but also you do not really know that a subwoofer is playing, the presentation is pretty seamless.

But it looks terrible and bloated in the RTA, while the "flatter" graph sounds thin.

Is this all an artefact of my cheap, low quality RTA and I'll see something dramatically different with more sophisticated measurement? Or is it that the bass is being lost in the large room, and this "extra" bass is what is needed to provide a better integration between low and high frequencies?

HF is very directional btw and the presentation does not "charge the room" as Paul S says, but instead sounds OK in a small sweeet spot.

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