Crossover freq for Illusion Audio C3CX

So I recently installed some Illusion Audio C3CX 3" coaxials in the stock dash speaker locations in my 2018 Dodge Challenger (comes with 3.5" speakers stock). I'm trying to figure out the best high-pass frequency for these little gems...

The manufacturer states this:

- Recommended high pass electronic xover: 250 Hz 12 dB Linkwitz-Riley

Now that seems a little low to me (for a 3" driver)? I have 6x9 midbass speakers in the doors and these C3CX speakers in the dash. I used to run my old coaxials at 450hz, so I started with that for the C3CX speakers as well. However, I always felt that the sound from the dash speakers sounded "treble'y" (for lack of a better word) at higher volumes (aka "harsh" or "thin" or "overwhelming"). These C3CX speakers seem much better (I don't have to dig a huge hole between 2k and 4k anymore to avoid "harshness" at higher volumes like I did with "lesser" speakers), but I still felt that they didn't "mesh" with the 6x9 door midbass speakers as well as they should.

So I tried setting the door <-> dash crossover to 275hz, 24dB slopes and so far I think they sound better like that (seem to blend better with the door midbass speakers) - and they even have a noticeably better sound while playing pink noise while taking individual speaker measurements (much more balanced sound - not so "treble'y").

So - any input on an appropriate crossover frequency for these C3CX speakers? I just worry that anything under 300hz could be problematic for such a small speaker at higher powers, even though the manufacturer *does* recommend 250hz 12dB slopes...

Thoughts?

Thank you!

Ugh.... I think I just found out if 275hz/24dB is too low for the C3CX... Recently after playing them that low at louder volumes, I noticed a faint vibration/rattle/static sound coming from the passenger C3CX. Was hoping it was just some sort of vibration-related issue with the dash plastic or speaker baffle, but unfortunately, it seems to be coming from the "woofer" itself (NOT the tweeter). First ever speaker that I've "blown" (at least I'm assuming that it's physically damaged). Mainly happens at louder volumes with lower frequencies.

I guess I'll contact the manufacturer to see if it's worth sending to them for repair or what. They were brand new when I bought them, but I bought them off Ebay, so no warranty (I did get them for a great price, at least).

Unreal. MFG does recommend 250hz/12dB crossover though, so I don't understand why it couldn't handle 275/24dB - and it's not like I sent tons of power to it - or clipped them...

I run mine at 400 or 450, tweet at 4700 iirc.

Sorry to hear you may have torched one. :(

Quote:

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Originally Posted by bnae38

I run mine at 400 or 450, tweet at 4700 iirc.

Sorry to hear you may have torched one. :(

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Yeah, that's what I originally ran mine at as well - 450hz. I was experimenting with other crossover freqs and figured that 275hz/24dB would be fine based on the manufacturer recommendation of 250hz/12dB. I was trying to get a "fuller" sound coming from the dash speakers.

I just reconnected the speaker and set it to 400hz/24dB and no more noise. What's strange is that the other speaker has no issue at 275hz/24dB though, so that leads me to believe there *is* an issue with the one speaker - it should be able to handle 275hz/24dB according to the manufacturer.

I'll leave it at 400hz/24dB for now. May just replace them with some Hybrid L3SE widerange speakers instead. Or maybe I'll just keep the C3CX's since they seem to fine again at 400hz. Although, I'm always going to be listening for that funky noise now... ;-)