Is this how a Subwoofer Crossover is supposed to work?

geared4me I use the volume controls on the R8 to get the rough level and then the volume control on the DAC to fine tune.  The DAC doesn't have any amplification.  The DAC Volume Control only reduces volume.  BUT it turns out having the Subs hooked up with the DAC's Balanced Outputs runs about 7 dB hotter than if you hook them up via RCA.  So that is where the problem with the sub running too loud probably starts since the R8 only accepts RCA inputs and only has speaker level outputs.

Pinwa 

I think that the biggest problem could be how you are running the setup control wise. If you are sending the dac signal directly to the subs and controlling the speaker volume with the amp. I suggest you try setting the amp to one set level maybe a bit over 50% and leaving it there all the time. Then dialbin the subs and use the volume control on the dac exclusively. Yoy will need to split the rca output of the dac to send to the subs and amp so the are both seeing the same output voltage. 

This will save you possible headaches. It seems like how you are currently running them, you are basically trying to set them up everything you change the volume level on the amp. 

Looking at the initial graphs it also seems like some of the issue is room gain below 50hz too. What was the spl you did the measurements at? I am asking as I have a room gain of about 10db @30hz in my space.

Hey OP,

Don’t be so upset about the Klipsch yet! See the dip around 28 Hz? This is a typical close mic measurement of a ported speaker. This is normal. Ideally you also close-mic the port, and sum the two together which is somewhat complicated math to do right. For more on this, see D’Appolito’s work, Testing Loudspeakers. 

As you move the mic away from the sub, the rear port contributions will come into play, but so will the room. Unfortunately this is how we have to do it to get quasi-anechoic measurements of ported speakers.

Next, you are right, the Starke is pretty flat, but the crossover is not doing what normally you’d expect. The THX standard, which many try to match, is a 4th order low pass filter for the sub. This helps match with a main sealed speaker that has a 2nd order high pass applied. As Duke has previously noted (and looked through the messy data) this looks somewhere between a 1st and 2nd order low pass filter.

Instead of changing the crossover frequency, you are changing the slope, and in all cases you are left with a rather low Q factor for the filter. A bad thing, meaning the filter’s effects are visible almost down to 20 Hz no matter what the setting is.

So while I like the speaker curves overall, the built-in crossover is a coarse beast. Definitely get a miniDSP and leave the sub’s crossover "wide open." You’ll be able to not only execute a 4th order low pass filter at any Hz, but you’ll be able to clean up some of the anomalies and add millisecond level delay to the sub, allowing you to perfectly phase match with your mains.

Also, please note how much better this is than your original measurements. Now that you can see how well it does, you know what to shoot for. :)




Best,

E