Setting up speakers/sub with a test CD and SPL meter
Oct 27, 2008 at 6:32 PM Thread Starter Post #1 of 6

earwicker7

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I recently purchased an SPL meter, as I needed to properly balance my Ergo AMT headphones (the factory levels were way off
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). I figure, now that I have one, I should break out my Stereophile Test CD and use the SPL meter to help better integrate the sub on my daughter's setup.

One thing that I don't like about her sub (Gallo TR-1) is that the crossover dial only has two numbers--50 on one end and 180 on the other. I don't know if the progression is logarithmic or linear, so I'm not exactly sure where to put the dial for 80, which is recommended by the company.

Is there a way to use the test CD and SPL meter to determine where the crossover should be set? One of the tracks on the CD is an 80Hz warble tone.

Also, there is a phase dial and volume dial. Any hints on how to dial these in correctly?
 
Oct 28, 2008 at 6:03 AM Post #2 of 6

Alpha 1 Omega

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for setting up a sub I usually put the sub where I am going to sit and put on a movie or some music that I know well and walk around the room till the sound sounds the best.

as for crossover that is a huge debate I prefer the turn it all the way up to the highest setting and let the receiver take over from there depending on the source like DD DTS and others..

hope that helps
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Oct 28, 2008 at 6:47 AM Post #3 of 6

Maxvla

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Ideally you want your sub to be crossed over just above the bottom end of your main speakers so they blend nicely. Take your main speaker specs, if they say 20-40hz I'd recommend ~80hz. If they say 40-60 I'd recommend 80-110. I really don't like subs left at their highest settings which are usually around 120-150hz. You start getting into mid-bass which will sound bloated.

But in the end set it however it sounds best. Those are just general rules. My speakers drop at 50hz and I ended up with 85hz on the crossover that sounded the most natural.
 
Oct 28, 2008 at 6:50 AM Post #4 of 6

JadeEast

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I read a very good article by Bob Katz about integrating subs.
"Accurately Set Up a Subwoofer with (Almost) No Test equipment" was the name but my bookmark is dead. Looks like it's in this pdf now.

http://www.ingelec.uns.edu.ar/pds280...tzArticles.pdf

It involved using pink noise to figure out crossover, phase and volume.
The pink noise changes in tone when the sub is out of alignment.
 
Oct 28, 2008 at 4:28 PM Post #5 of 6

earwicker7

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Thanks everyone!
 
Oct 30, 2008 at 3:27 AM Post #6 of 6

warpdriver

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Setting the crossover is tricky because very few crossover knobs are accurately marked anyway. And what's even worse is that they often affect the volume too, so you have to adjust both at the same time.

In this review of 5 subwoofers the reviewer measures the actual effect of the knobs and you can see that the crossover knobs vary in their accuracy and how much the volume is affected

Sound & Vision Magazine - Test Bench: Five Mid-Price Subwoofers

To set the knobs accurately, you have to use some kind of real time software analysis, and you can view the effect of changing each knob on the resulting frequency response. This way you can play with each of the settings and observe their effect in seconds. Something like http://www.hometheatershack.com/roomeq/ is indispensible. I use the SMS-1 which graphs the response on a TV screen, but I determined that the crossover of 80Hz was way better than 70Hz, and that I needed to invert the polarity, but also use a phase of 70 degrees. That allowed me to get my response within 3dB at 80Hz. If I had kept the phase at 0, I would have had a huge hole in my frequency response at 70Hz range.

Other than that, it's guesswork, and it's up to your ears to find the best blend of the sub to the main speakers. Matching the levels is easy enough with your test tone, but you'll have to trust your ears to find out which settings work the best and even then it's probably far from optimum.
 

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