Is this how a Subwoofer Crossover is supposed to work?

Hi 8th-note

I have to take some issue with your statements, as I don't think they are in evidence yet:

2. You purchased two subwoofers which cost $350 each and weigh 40 lbs. to supplement the bass of a pair of full size, full range, highly regarded $4500 speakers that reportedly compete with speakers costing 10 times their price.

I think you are far too focused on cost here. Admittedly, I'd have bought a Hsu or SVS, but integration is going to be a much more important step here than worrying about not spending enough money.

3. If the Moabs go anywhere near 20 hz you don't need subwoofers. If pipe organ is your favorite type of music and you are missing the 16hz notes then you could spend several thousand dollars on a sub that would not only go that deep but was equipped with a high quality crossover that included a very low cutoff point. Wilson makes a sub for $40,000 that accomplishes this purpose.

Woah, nope, totally disagree with this entire statement.  Subs bring a lot more to the table than a spec. The ability to relocate them, to equalize them, and to limit the bass required by your main amp and speakers are big deals.  Done perfectly, you bring a lot more power and dynamic range to the system than you would have otherwise, and reduction in distortion.  Also, this is a giant PITA to do well, as this thread will attest to.

4. The subwoofers you bought are accentuating the frequencies that your Moabs are already putting out. They are doing nothing constructive.

We have not seen evidence of this, yet. So far all we have see is the sub response, and that the sub is too loud.  However, yes, the future of this system should be correctly integrating the sub with the main speakers.  One step at a time.

OP:  I just noticed that your main speakers are ported.  I am going to suggest you plug them before attempting to integrate with the subs.

Pinwa, I will put this to you straight. You have a fundamental misunderstanding of how your system works and how to incorporate a subwoofer into it. You can take a million measurements but you will not achieve your goal with the way you are trying to set this up. The volume control that turns the sound to your speakers up and down must also be the one turning the sound to your subs up and down. You can not send a fixed level signal from your dac to the subs while adjusting the speaker volume from your integrated amp and ever expect them to be at the proper level to blend. Due to the kind of integrated amp you are using you have bought the wrong subwoofers.

You can not send a fixed level signal from your dac to the subs while adjusting the speaker volume from your integrated amp and ever expect them to be at the proper level to blend.

yes you can. you just adjust the sub every time you adjust the volume. 

kenjit, I sincerely hope to meet you one day.

Hello Pinwa,

Imo the close-miced curve of the Starke provides a lot of useful information. Now you can tell what was room interaction and what was native to the subwoofer, and it is much easier to tell what the crossover is doing. Good job!!

I think the close-miced curve on the Klipsh is giving you an incomplete and therefore misleading picture. From that curve I’d assume it has a port or passive radiator tuned to about 26 Hz.

If so, getting a representative frequency response curve becomes vastly more complicated. You ALSO need to close-mic the port or passive radiator and SPLICE that curve with the woofer’s curve, adjusting for the relative RADIATING AREAS of the woofer cone and the port or passive radiator. You also have to take into account the relative phase rotation between the two and I don’t know how to do that math - I’d have to use a computer program.

In other words, close-micing ONLY the woofer of a vented box DOES NOT give a complete and accurate representation of what the system is doing.

I suggest simply assuming that the Klipsch is competently designed, rather than doing more measurements plus a ton of math.

Also, pay attention to what geared4life is telling you. If his analysis is correct (and I think it is), your system configuration is not allowing you to adjust the level of the subwoofers with the same volume control that you are using for your main speakers.

Duke