Axiom Home Page Forums General Discussion Technical Questions Graph testing again, I'm confused, so is mojo :)

Ok, since I received my new 80's and 600 I thought I would do some more room freq response testing. Mojo had recently asked me if I was getting anything out of my 80's at the lower freq's using the test CD. To be honest, when I had my 60's, I'm not sure I monitored the woofers.

So today I've been doing a little testing using the Realtraps CD. To remind everyone, it starts at 10hz and goes up to 300hz in 1hz increments every 10 seconds. The result is a pretty good graph.

Here is where I'm confused. On my Denon I have my 80's set to "small" with an 80hz crossover. I would think as I approached the 80hz tones my 80's would start to kick in or blend with the sub. As I get to the higher freq's, the 600 would fade out and the sound would be just coming from the 80's.

Why the heck are my 80's drivers moving then at the lower freq's? 20, 30, 40, etc... the woofers are moving in and out like crazy, I think the midrange woofers are even seeing a little action. This makes no sense unless I don't understand the crossover setting and setting the mains to small?

Any ideas, this makes no sense.

Upon reading the instructions for the realtraps CD, I see one thing I was doing wrong. It says to run the pink noise test that comes with the cd and turn the master volume to 70dB from the listening position. Of course, this is after you have already calibrated you speakers to match using other methods. I have everything calibrated to 75dB.

Now that I have bumped down the master volume I'm going to try again. I still don't understand why the 80's would be active at those lower tests with an 80hz crossover and "small" setting.


Back to try again..

I am puzzled by your (and Mojo's) experience as well. I wonder if the slope of the cross-over is low, such as 12 or 6dB/octave, instead of the usual 24dB/octave. In this sceneraio, M80s are still in business at 40Hz, playing 6-12dB lower in effort. Is there a way you can adjust or see what the cross-over slope is?
John

I just got done jotting down the results after adjusting the master volume to 70dB, man what a difference. I'll run upstairs and plug them into my spreadsheet and try to post a graph soon...

Even at 20hz the woofers on my 80's were moving. I'm confused.

My 4806 has LFE + mains in the setup options if that's what you are referring to.

On my Denon 2805 if I set my mains to large in the speaker setup menu, this opens up another option where I have the options such as LFE + Main. However, when they are on "small" this option does not exist.

I'm not aware of any other option I've come across in the Denon when the mains are set to small...

Here is the graph I created tonight. In this graph I'm comparing the results from when I had m60's and an ep500 to my current setup of m80's and an ep600.

The results are pretty similar. I think I have the sub running a little hot and I'm sure if I could figure out why the 80's are going way below the 80hz crossover, that may change things. I've also included a graph of my room with no treatments back when I had the 60's and 500.

Looks like I've missed some good action over the last hour .

At least I know I'm not nuts! Or maybe Randy and I are both nuts .

We need others (with non-Denon amps) to try this. Maybe it's our amps.

Even if there is a problem with the Denon LFE cross-over circuit and it's letting all the lows through to the M80s, I am totally shocked that the M80s would even respond at 10 Hz.

By the way, as I've posted before, I, like Randy, have the M80s set to small and have only LFE set (not LFE + main). Randy, on my Denon 2105 I have the "LFE + main" option even when I set my fronts to small.

Why is this happening???