Feel free to ask questions. I'll do my best to answer.

Tuesday, November 6, 2012

Sound Audyssey

Since I nursed my bass issue back to health, I decided to have another go round with Audyssey and see where it could lead me.  I did a basic 3 measurement calibration at ear level for each seat on my couch.

My prior bass graphs:
Black Lines are the most recent

So after Audyssey did it's thing, my listening couch graph(s) look like this:

Not bad, but a significant hole centered at 68Hz and audibly a little bass shy.  That's not exactly acceptable to me.  SO I did a little fiddling with it to see what I could come up with using the unit's EQ.  Check it out:
So the hole moved up a few Hz and filled in a bit.  Here's the 1/6octave smoothed (for clarity) overlay:

Oh, I restored the treble back to the speaker's natural response.

The receiver's default setting uses Audyssey's Dynamic Volume.  So I took measurements of it's default setting as well:

Some other Audyssey settings with Dynamic Volume engaged:

The Black lines bypass Audyssey on the left/right channels

You can see that even though the microphone was in a very close position on all 5 measurements (each one had the microphone position marked), the measurements are significantly different above the modal/transition zone(s).  Just more eveidence that there is no ideal "room curve".  So calibrating above the transition zone seems futile.

Monday, November 5, 2012

Bass, The Final Frontier

In my previous bass experiments, Multisub and Fast Bass, I was tried to replicate others experiments using a simplified, Dan "The Man" method with better success using the multisub.  Since that time, my two cheaper and older subs have died so I'm down to three.

Looking at the data from my multisub experiment, the first sub didn't add much to the response, and the fourth and fifth left the response looking nearly the same.

Compared to the nearfield, fast bass subs, the response looked pretty good:

The sound difference matched that graph more than any of the other Time Response views.

So with my three subs, I placed the subs where the second, third, and right in between the fourth and fifth placement.  The response came out similar:
Black lines are with 3 subs placed to approximate the 5 multisubs placement.
The lack of deep bass is due to the cheaper subs actually having a deeper response.


Friday, November 2, 2012

Requested Bass Experiment

Well, a forum member requested a bass experiment where I would keep the mic in exactly the same position and hit the power on my subs one by one and do some CSDs of the results.  I obliged, but I'll just show the extreme cases.  There's nothing else to see really.  It will give you an idea of the changes you can expect.

That's a wrap.

Dry (fast) Bass...

After reading this:  http://mehlau.net/audio/dual_nearfield_sub/ I wanted to try some nearfield subwoofing myself.  In my previous multisub bass experiment, I was able to smooth out my bass response by using five subs in a somewhat random fashion.  Well one of those subs died on me(the fifth one added) during some hardcore Willy Nelson listening.  So I had to change the set up and I came across Mr. Mehlau's experiment.  It was interesting to me that the fourth and fifth sub added were the closest to the listening position--right behind the couch.  It was suggested that I should see what the fifth sub's response was, so in this experiment, I decided to use three subs directly behind my couch.  

I had just purchased a Marantz HT pre that has Audyssey MultEQXT and I wanted to see if I could duplicate Mr. Mehlau's success with it.  Note that he has the upgraded '32' version of Audyssey.

Okay, enough talk.

 Frequency wise, the 5 sub set up was a significant improvement:
The time domain would slightly favor the nearfield subs in general:

Note the absolute level below 50Hz 

Inevitably I'm going to be asked which "sounds better"?  Well, I hate to disappoint, but the frequency graph says it all.  I don't hear any difference in the bass 'speed'. All I hear is less deep bass.  That said, if I could have it all (deep, flat, and dry bass) I would just to make sure I have the best possible.  I think this also shows a good argument for the '32' version of Audyssey.  Maybe I'm wrong however, but all of Mr. Mehlau's responses look better than mine.