New Head Unit issues

[EmpiricalApe]

I just took out my cheap-ish boss audio bv755b headunit and replaced it with a JVC KW-M780BT. I havent retuned my gains for the amp yet to accomodate for the higher pre amp voltage(4v). Sooo, if anything the bass should be at least somewhat louder, right? But it isn't. The bass sounds slightly dirty to me now, and the amp clips around 30% lower on the bass knob than the boss stereo, but doesn't really seem to be as loud at the same point on the boss audio HU with 2 Volt preamp. The sub also puts out a quiet buzzing sound with nothing playing. I'm using Android Auto vs Bluetooth, which I had been using previously. Any ideas?

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[JohnPD]

I have the same head unit, and had no issues before I installed an amplifier. There’s subwoofer and bass settings in the menu’s, and crossover settings for speakers and a subwoofer. There’s also gain settings for each. Maybe something isn’t adjusted right. You can even select the speaker and subwoofer size.

 

[huberoy123 10+ year member]

I just took out my cheap-ish boss audio bv755b headunit and replaced it with a JVC KW-M780BT. I havent retuned my gains for the amp yet to accomodate for the higher pre amp voltage(4v). Sooo, if anything the bass should be at least somewhat louder, right? But it isn't. The bass sounds slightly dirty to me now, and the amp clips around 30% lower on the bass knob than the boss stereo, but doesn't really seem to be as loud at the same point on the boss audio HU with 2 Volt preamp. I'm using Android Auto vs Bluetooth, which I had been using previously. Any ideas?

First step is to set your gains for the amp. If the problem persists, check the settings on your head unit.

 

[EmpiricalApe]

First step is to set your gains for the amp. If the problem persists, check the settings on your head unit.

but to properly do that, don't I need to first set a maximum clean volume from the headunit? I tried setting the gains for the amp today, and you could clearly see the sub moving irregularly and i had the headunit at 22/40.

 

[EmpiricalApe]

I have the same head unit, and had no issues before I installed an amplifier. There’s subwoofer and bass settings in the menu’s, and crossover settings for speakers and a subwoofer. There’s also gain settings for each. Maybe something isn’t adjusted right. You can even select the speaker and subwoofer size.

I had all the eq's flat except the cross overs for the lower door speakers. I had a sharp downward curve from 70hz. Could that possibly be the issue? I tried setting my amp gains earlier today, I had the head unit at 22/40 (I did a test by ear and the audio sounded distorted after 22) and you could clearly see the subwoofer moving irregularly on a 40 hz test tone at high and low gains.

 

[Firewalker]

There should be a subwoofer setting for turning it off and on. Sometimes there is even a sub level adustment on the head unit where you can go - or + with it. Mine is set at 0 but I can go up as high as +9 or -9 iirc.

 

[EmpiricalApe]

There should be a subwoofer setting for turning it off and on. Sometimes there is even a sub level adustment on the head unit where you can go - or + with it. Mine is set at 0 but I can go up as high as +9 or -9 iirc.

I have am external amp for the subwoofer so I have all of that set to 0

 

[EmpiricalApe]

First step is to set your gains for the amp. If the problem persists, check the settings on your head unit.

the sub puts out a very quiet but noticeable buzz with nothing playing that it didn't do before with the old stereo. I played around and none of the audio settings on the headunit affected the buzzing.

 

[JohnPD]

There should be a subwoofer setting for turning it off and on. Sometimes there is even a sub level adustment on the head unit where you can go - or + with it. Mine is set at 0 but I can go up as high as +9 or -9 iirc.

There is. You can set the subwoofer to none, and if you set it to on you can then set the volume level

 

[Firewalker]

Check the head unit subwoofer settings that is what we are referring to. There is also settings to adjust how far each speaker is from you, along with subwoofer delay settings as well. Check the user manual page 42 and on for audio settings. It shows on page 42 that there is a subwoofer setting you can adjust up and down.

User manual JVC KW-M780BT (English - 76 pages)

Manual JVC KW-M780BT. View the JVC KW-M780BT manual for free or ask your question to other JVC KW-M780BT owners.

www.manua.ls

 

[EmpiricalApe]

Check the head unit subwoofer settings that is what we are referring to. There is also settings to adjust how far each speaker is from you, along with subwoofer delay settings as well. Check the user manual page 42 and on for audio settings. It shows on page 42 that there is a subwoofer setting you can adjust up and down.

User manual JVC KW-M780BT (English - 76 pages)

Manual JVC KW-M780BT. View the JVC KW-M780BT manual for free or ask your question to other JVC KW-M780BT owners.

www.manua.ls

yeah I have all the subwoofer eq and cross overs set to none or flat

 

[audiobaun 5,000+ posts]

Another thing to be considered as far as the Buzzing Noise you Now hear from the a better made more quality HU of 4v rather than 2v is a better signal. that buzzing has prob been a factor from day one of the amp install of a POOR Ground on the amplifier/amplifiers. Where do you have your amps grounded, and what too. What Model and Brand of amps? Supply wiring and ground wire size used? It may benefit to relocate your Ground

 

[EmpiricalApe]

Another thing to be considered as far as the Buzzing Noise you Now hear from the a better made more quality HU of 4v rather than 2v is a better signal. that buzzing has prob been a factor from day one of the amp install of a POOR Ground on the amplifier/amplifiers. Where do you have your amps grounded, and what too. What Model and Brand of amps? Supply wiring and ground wire size used? It may benefit to relocate your Ground

I'm using a Sundown SFB 3000D, I have all 0 guage power ofc and grounds, as well as 0 guage ofc big 3. My ground for the amp is bolted to a bracket on the metal bracing on the sides of the trunk. Also, long story short, slid my car and it threw the box to the back of my trunk, slicing the rcas to the amp. I spliced on and soldered some new rca tips on, but it's just wrapped in a bunch of electrical tape. I made that repair before I switched head units and i didn't any change in sound, but as you said with the higher pre amp, could that be the issue that I've just started to hear? I also spliced into the ground of the headunit to ground my voltage meter. (Same thing on the last HU) Im going to mess around with that later today and see if it caused a ground loop issue that I'm just able to hear now.

 

[EmpiricalApe]

Another thing to be considered as far as the Buzzing Noise you Now hear from the a better made more quality HU of 4v rather than 2v is a better signal. that buzzing has prob been a factor from day one of the amp install of a POOR Ground on the amplifier/amplifiers. Where do you have your amps grounded, and what too. What Model and Brand of amps? Supply wiring and ground wire size used? It may benefit to relocate your Ground

ok I think I figured it out... I unplugged the rcas and plugged in another set just strung outside the car to the trunk, and there was no buzz or anything, so I assume the issue is interference through the rcas from the power cable that it's ran with

 

[audiobaun 5,000+ posts]

I'm using a Sundown SFB 3000D, I have all 0 guage power ofc and grounds, as well as 0 guage ofc big 3. My ground for the amp is bolted to a bracket on the metal bracing on the sides of the trunk. Also, long story short, slid my car and it threw the box to the back of my trunk, slicing the rcas to the amp. I spliced on and soldered some new rca tips on, but it's just wrapped in a bunch of electrical tape. I made that repair before I switched head units and i didn't any change in sound, but as you said with the higher pre amp, could that be the issue that I've just started to hear? I also spliced into the ground of the headunit to ground my voltage meter. (Same thing on the last HU) Im going to mess around with that later today and see if it caused a ground loop issue that I'm just able to hear now.

Well that changes things up. LOL. Splicing RCAs. Ya, that could be it. Its not easy to splice them back to where they once were within great standards. Worth a shot though.LOL. but ya. Id change the RCAs too if they got damaged.