Woofer Baffle Comparison Test

For many years I've used the XTC foam speaker baffles (with windows cut-out) for my door speaker water shields. Recently from another post I learned about the NVX silicone baffles, they looked nice and other users claimed the XTC baffles had a negative effect on sound (even with cut-outs), so I figured I'd give them a go. Thought it would be fun to actually measure and listen to both for comparison, to try to determine if there was actually any difference betweeen them.

I made an attempt to make consistent measurements between the old XTC and new NVX baffles, forgive me as I'm fairly new to REW and measurement mics so if I goofed, well, shit. I used a pink noise file from REW, had to convert to mp3 for my OEM stereo to be able to read it from the SD card (no line input option and bluetooth sucks). Set for 1/6 RTA, 50 averages. I chose a fixed mic position (headrest) to try to keep the comparison as consistent as possible:
Attachment 9791

Car is a 2018 VW Golf Sportwagen, woofers are in factory locations with 1" HDPE rings. Centre console definitely creates some cancellation. I set the woofers for a 60hz 24LR high-pass, no low-pass. No eq. Time-alignment set by measured distance.

Old, windowed XTC baffle:
Attachment 9792

New NVX baffle. One thing I don't like, they don't go very deep. Basket and back of cone are covered, but magnet is exposed:
Attachment 9793

However, there is no restriction directly behind the cone:
Attachment 9794

They also come with Egg-crate style closed cell foam adhesive pads. I'm not sure how much back-wave deflection these actually do but what the hell, I put them in the doors:
Attachment 9795

They have a nice collar and flare in front of the woofer to try to seal to the door grille. My doors have a small collar built-in, when I test fit it the NVX baffle fit over-top of the factory one (larger diameter):
Attachment 9796Attachment 9797

So, on to measurements. I wasn't expecting much difference but there actually is some, not sure how much could be attributed to measurement inconsistency? I didn't use any smoothing on these:
Attachment 9788Attachment 9789Attachment 9790

As for subjective listening, again I wasn't expecting anything. But there is one very noticeable difference (and I swear it's not my imagination), which is mid-bass impact. With the old XTC baffles, the woofers would play mid-bass frequencies but that was it, there wasn't much punch from them. With the NVX baffles, I was actually getting some kick-drum chest thwack out of them which surprised me. Maybe the collar is more efficiently coupling the woofer to the cabin?

I had decided to start from scratch with my tune anyway, and based on what I measured and heard I'm glad I waited until after switching baffles before putting much time into the new one.

I'm interested to hear what some of the more knowledgeable folks here think about this.

The measurements are interesting. I never did measurements; however, like you, I could hear the difference. I used the cut-out foam style or no baffle for years. No foam baffle was definitely better. I started using sections of flexible plastic attached to the top half of the cutout as a drip guard because it sounded so much better than the XTC foam. I recently used the Metra version of these and it was much deeper and extended past the magnet. I really liked the overall sound of the install and may use the baffle more in the future. Thank you for the work you put in.

Nice work. Separating the back wave from the front wave is important. If you did anything like seal over some open holes in the door frame with CLD while you had the door card off for the NVX version then it would make a difference. Also sealing off the cavity better than before so that the front wave doesn’t get between the door card and door frame would also make a difference.