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Is this how a Subwoofer Crossover is supposed to work?

I bought two Starke SW12 subwoofers that I installed.  So far I'm not particularly happy with them.  They are way too loud even with the volume set almost to off.  More importantly, I'm having trouble integrating them into my system and I'm wondering if that is because their crossover setting is really functioning as I understand a crossover should. Attached please find measurements from Room Equalization Wizard with SPL graphs of the two subs (no speakers) taken at my listening position with the crossover set at 50 Hz, 90 Hz, and 130 Hz. Ignore the peaks and dips which I assume are due to room nodes.  All of those settings appear to actually have the same crossover point of 50 Hz. All that changes is the slope of the rolloff in sound levels. This isn't how I thought a properly designed crossover was supposed to work.  I thought the frequency the levels would start to roll off would change, i.e. flat to 50 hz then a sharp drop, flat to 90 hz then a sharp drop, etc. etc..  But Starke says this is how a subwoofer crossover is supposed to work.

https://www.dropbox.com/s/8x4cr32pagwg48i/Two%20Subs%20Different%20Crossover%20Points%20No%20Speaker...
Any experts on here with an opinion about this?  Is it possible to buy an inexpensive active crossover that I could use in place of what is built into these subs?
pinwa
erik_squires
15,662 posts
 
Hi OP,

You may also find the people and forums at DIYaudio to be more helpful. The forums let you post images in your discussion, and lots of speaker builders in the multi-way and subwoofer discussions for you to lean on.

You may also like the forums in the Room EQ Wizard discussions.

Best,

E
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timlub
2,039 posts
 
@pinwa
I don’t see anything that tells where your sub placement is.
To start, make sure that your subs are at least 3ft from any wall and make sure that your subs are not near each other. Starting here will help reduce any room boundry reinforcement from the corners. In fact stack some things in the corner to help break up standing wave.. Pulling them out in the room normally helps reduce peaks.  Next, turn your subs all the way down, bring one up a hair and measure. See where the peaks are. Turn this one down and check the other, measure and see where the peaks are.... Move them around checking independently trying to remove frequency peaks. Once you see that the peaks are down, bring them up together just slightly, measure and adjust as needed. This will all take some time and this is only a starting point. I hope this helps, Tim
audiokinesis
2,713 posts
 
Erik asked: "Then let me ask this question another way. Looking at the OP’s original data, have you ever seen 2 subs start out that poorly in a room?"

I’ve never measured two subs in a room. 

There may be significant room for improvement, but do not know how much of what we see in his curves is room interaction and how much is the subwoofers’ native response.

Pinwa asked, "my starting question, at its simplest, is really just whether or not subwoofer crossovers are supposed to behave the way the Starke crossover is behaving."

Your measurements look to me like they are in the ballpark for a variable-frequency second-order lowpass filter.

I can elaborate if you’d like.

Duke
erik_squires
15,662 posts
 
Erik asked: "Then let me ask this question another way. Looking at the OP’s original data, have you ever seen 2 subs start out that poorly in a room?"

I’ve never measured two subs in a room.

To my eyes, they should look a lot better than that, if configured well, but since I can't tell what is by design, and what is interference I think the OP would be well served by eliminating 1 major variable in his measurements. Plus, it’s fast, and cheap to do.


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