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Hmm, not sure how to do that. I've seen the waterfall option on REW but haven't fiddled with it. I'll pull it up and look for the sweep option.



Tried the windshield, the dash, all around the speaker pods and the speaker itself. The only thing that's helped slightly is pressing hard on the metal surround of the speaker, but it was just a slight improvement. I swear it sounds like something's rattling around in the speaker or pod. Would the speaker wire vibrating in the pod be enough to cause a null that severe?
this is a room measurement but it should get you started. he also covers some stuff for the waterfall plot. Saves me from typing...
 

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Ya but you don't have to get too crazy with it. If these are out of site and you have enough clearance the outside could be done instead. Make sure its sealed up as well. The trick mentioned above is great for sealing the wire.
 

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The spectrogram might show this better but both are 3d plots. The show freq vs spl vs time. So when you play the sweep you expect the speaker to play the freq and stop. Any additional energy present after is cause by some type of resonance. Kinda like tapping on a sheet of metal and hearing the ring. Or like some musical instruments like symbols.
 

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If you're evaling a single driver you should mute the others. Once the issue is resolved you can bring back in the other drivers and make sure they're in phase.

Best you can do to those pods is deaden them, add some poly fill, and make sure the speaker and speaker wire are sealed up tight. You can try bringing the response down above 200 to reduce the null a bit.
 

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My question: will it harm a 4-channel amp if you only use two channels? I have these bridged at the moment, but I think it's making them mono (the literature with the amp was unclear on this) and I want to have independent driver volume control. I think this speaker bar is an open chamber between the two drivers, so there could be leakage between the two, but it doesn't seem like muting one channel is actually stopping each driver from firing.
You probably have the signal inputs mixed up. When you bridge the amp, the front channels combine and the rear two channels combine. So if you are using Front as the Left Midbass, and Rear as the Right Midbass, then the Front L/R input need to be the same (LT Midbass DSP >> Y adapter >> Front two RCAs).
 

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Measurements for the speaker bar alone.

View attachment 317900
Are you running these as a real three way? What are the Xover points for the mid range and sub? Why not cross these 80-200, subs 0-60, and mids 200+. The midrange and midbass xover should even out the bump in response around 250Hz. The midbass should have enough headroom to handle some EQ around the problem null at 170Hz.
 

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I would try the subs up to around 80Hz and have the overhead pods play 80 to around 200. From other threads discussing underseat midbass (rather than door midbass) folks tend to agree that playing the midbass higher than 150-200 Hz doesn't work as it impacts sound stage and localization. You're basically doing the same thing with the over head pods as the underseat midbass guys. Your 5.25s can take over above 150Hz easily.
 

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ehh, dont worry about that yet.. gain is just adjusting the relationship between input and output voltage of the amp. You're bridged to the woofers as well so just apply the appropriate amount of power and dont worry about what the gain knob is set to. You have more than enough power on hand regardless, I would think.
 

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Easy why to tell is to take near field measurements of individual drivers.

I'd guess <1000Hz or so would be cabin modes and >1000Hz is stuff like comb filtering from reflections. I'm just guessing at 1000Hz, not sure what the cutoff is actually.
 
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