Hollow / bad sounding midbass on certain songs

[ryyo]

Hello all.* I'm having a midbass issue that I'm hoping someone can point me in the right direction to correct.* My driver's side (left) only midbass sounds hollow (maybe distorted) but only on a few songs (seems to be mostly a few rock songs).* It is very apparent on Metallica's Enter Sandman.* Whatever it is, it doesn't appear to be making the same "bad" sound from the passenger's side midbass.* I confirmed this by putting my ears up to both speakers.

Other than the few songs where the midbass sounds bad, everything else sounds pretty good (to me) for the most part.* Everything seems to image where it should, at least to my untrained ears.* I listen to all types of music, and with most songs/tracks, the bass/midbass slams well out onto the center of the hood and sounds good.

About the install... In a 2015 F150, heading it up is a Kenwood DMX1057XR, which is connected to an Alpine H800.* The Alpine is responsible for all of the time alignment, crossovers, and some left/right eq and leveling.* There is some minor eq work being done by the Kenwood.* I just find it easier to eq with the Kenwood than using the RUX controller.* A JL 300/4 is connected to Audiofrog GB25's and GB10's that are mounted in pods on the A pillars.* A Sony XM GS4 provides about 140W to Audiofrog GS690's that are mounted in the doors.* And about the doors... all doors are sealed up to the most practical extent, but I have yet to apply CLD tiles to the outer door skin.* A JL 1000/1 powers a 12" Alpine Type R (I know this sub gets some flack, but I think I've got it sounding pretty good.* It's also getting replaced by a Stereo Integrity SQL12 hopefully sometime this week).* Crossovers are all 4th order and as follows.* Sub is low passed at 80hz, midbasses running from 80hz to 315hz, midranges from 315hz to 3200hz, and tweeters high passed at 3200hz.* I used Erin's time alignment calculator to set time alignment with the H800.

The odd thing is that I'm pretty sure the issue was present before I installed the GS690's.* Prior to that, I was running the factory speakers off of the Kenwood head unit's amp using the crossovers from the head unit, and I'm not sure if it was just the driver's side speaker or both sides (I didn't check at the time).

I know a frequency response graph would probably help for me to include, but unfortunately, I don't have a laptop.* All I have is AudioTool on my phone.* I'm thinking some of the eq I've applied on the Kenwood may be the issue, but if that were really the case, then I think I would hear the problem from the passenger's side midbass as well (since the problem was there prior to hooking up the midbasses to the H800 and the Kenwood is incapable of l/r eq).* I'll need to check again to make sure the bad sound wasn't also coming from the passenger's side though.*

If there's any problem frequencies that people could suggest for me to look at, or any other suggestions, it would be greatly appreciated.*

[BigAl205]

Stuff like this is going to take some troubleshooting. If you mute the right midbass, does the left still sound bad? If so, you might try swapping your RCA's temporarily at the amp to see if the weak midbass moves to the right. If it does, there's something in the signal chain...crossover, EQ issue, etc.

[jrwalte]

The left side door typically has a null somewhere in the 70-120 range too and it may just be some songs that exacerbate where your null is. You could try increasing your sub acoustical crossover to 100 instead of 80.

[ryyo]

Stuff like this is going to take some troubleshooting. If you mute the right midbass, does the left still sound bad? If so, you might try swapping your RCA's temporarily at the amp to see if the weak midbass moves to the right. If it does, there's something in the signal chain...crossover, EQ issue, etc.

Good ideas on the troubleshooting. I'll test those out hopefully this afternoon.

[ryyo]

The left side door typically has a null somewhere in the 70-120 range too and it may just be some songs that exacerbate where your null is. You could try increasing your sub acoustical crossover to 100 instead of 80.

I've messed around with crossover points and have increased the sub up to 100 before, but I haven't checked with that particular song to see if it helped. I'll adjust them again and see if it helps. This sound almost seems like it's something that will damage that midbass if I'm not careful and playing it too loudly. I know a RTA would help pinpoint the issue. I wish there were more people in my area that were really into car audio. I'd probably pay to get this fixed.

[jrwalte]

could be the null you compensated for in EQ by boosting too much, which giving it over to the sub would help. But like you say, without a RTA we're shooting in the dark.

[Jdunk54nl]

Even with a phone app, you can take screenshots of what you measured via your RTA app. Are you using just the built in microphone or the dayton phone microphone? Also some rta apps are way better than others.

Dayton phone mic:
https://www.parts-express.com/Dayton...ophone-390-810


I would ultimately suggest getting a cheap laptop (doesn't need much to run REW) and a microphone for it.

I always suggest (now anyway) getting an XLR microphone (dayton emm-6) and a interface like the motu m2 or focusrite 2i2 over USB microphones (I have three usb mics now and 90% of the time use my motu m4 and dayton emm6) just because you can do a lot more with the interface and xlr microphone that isn't possible currently with a usb microphone.

[Jdunk54nl]

Also, where are you located? There may be more people in your area than you think. If we know where that is, some people can probably suggest someone.

[ryyo]

Even with a phone app, you can take screenshots of what you measured via your RTA app. Are you using just the built in microphone or the dayton phone microphone? Also some rta apps are way better than others.

Dayton phone mic:
https://www.parts-express.com/Dayton...ophone-390-810


I would ultimately suggest getting a cheap laptop (doesn't need much to run REW) and a microphone for it.

I always suggest (now anyway) getting an XLR microphone (dayton emm-6) and a interface like the motu m2 or focusrite 2i2 over USB microphones (I have three usb mics now and 90% of the time use my motu m4 and dayton emm6) just because you can do a lot more with the interface and xlr microphone that isn't possible currently with a usb microphone.

I've got the Dayton mic, but I haven't calibrated it yet. When I used the AudioTool app to get a rough measurement, at the time I used the internal mic of my phone (LG V60). TBH, I really don't know much of what I'm doing with that app or any RTA for that matter. I used band limited pink noise to get spl levels at different frequencies, and adjusted the eq based on that.

[ryyo]

Also, where are you located? There may be more people in your area than you think. If we know where that is, some people can probably suggest someone.

I'm in Norfolk, VA.