Hey guys, Im new to this forum but I joined in hopes that someone could help me out with my system before I take it to a shop and spend more money. I am driving a 2021 VW Jetta GLI S (no beats audio) and I decided since the factory speakers sound so good but have little sub bass that I wanted to install a sub into the car. Long story short the setup I have rn is good but the bass is lacking still. Almost sounds like I have a 6” sub instead of a high-power 10”.
Lets start from the battery and work our way back to the subwoofer so you have a clear idea of my system setup. I used a Shosche 1500W amp wiring kit from Walmart (which I assume is slightly higher than 4 gauge wire but is not OFC) to connect my factory battery to a 1-to-2 fuse block.
There is a fuse between my battery and the fuse block that came with the kit. From that fuse block I have wiring going to my Rockville Audio RXA-F1 (4 chan amp that produces 65x4 @ 4ohm and 95x4 @2ohm) which powers my front 2x door speakers which are wired to my factory tweeter location which I swapped with Skar TXT-1 tweeters (yes they are cheap but they work well for the price). The other exit of the “power fuse” block goes to my mono amp. I started with the Rockville RVA-M2 (rated for 440W RMS @2ohm). The mono amp powers my sub in a custom sealed box that used to house my now blown JL Audio 300W RMS sub (forgot the name) but now has a Skar VD10 D4 10” sub (rated for 500W RMS continuous). I had the problem with that amp still not giving enough unclipped power to my sub so I decided to take a leap of faith and purchase Rockville’s more more powerful and brand new Krypton-M3 (rated for 700W RMS @2ohm). I have a ground cable going from both amps to a 2-to-1 fuseblock and my ground is screwed underneath my carpet on the frame of the car with as much paint sanded off as I could.
However changing from the RVA to the Kyrpton somehow made my sub produce less sound. Its sounds better and definitely has a more balanced frequency range but it is not loud. My factory midbass speakers have more umph than my sub rn. Sound is sent via a 4 chan passive line-out converter that sends a 2 chan signal to my RXA-F1 amp which then sends signal to my Krypton-M3 (RCA from LOC to 4 chan amp and then RCA from 4 chan amp to mono amp).
On my factory radio I have the EQ set to +7 for highs +5 for mids and +9 for bass (range is -9 to +9) and when using bluetooth I have the volume strength set to minimum (other options are medium or maximum). On my phone I use Apple Music to stream HQ 192kps audio and the EQ in my settings is set to Hip-Hop since I listen to it more than anything else. So basically everything I have is set to as much bass as possible.
I used an oscilloscope to set the gains on all my amps and according to my oscilloscope my factory head-unit does not clip at max volume level so I set my gains at 90% volume. The 4 chan amp gain is set appx at 50-60% and the same is for the mono amp, anything higher starts to clip. On my 4 chan amp I am running in 2 chan mode with HPF set to around 1000hz since my factory mid-bass cant handle the bass with extra power above half volume. My mono amp has its “HPF” set to the minimum 15hz, bass EQ is set to +3db, and “PASS” is set around 100hz.
My sub is wired to 2ohm in a sealed enclosure (specifications are not known but I can find out if needed) and should definitely be getting more sound. When I first started my setup and only had the 4 chan amp, I bridged two channels on the amp to the sub which @4ohm gives 200W RMS but since it had a 2ohm load it overheated shortly after one song with intense bass. I have yet to hear my sub sound as loud and clear as when I had my system setup like that. Only reason I got the mono amp was to prevent my 4 chan from overheating while still giving the sub the power it wants.
I have yet to figure out a solution for my problem but I have a couple ideas that Im hesitant to give a shot at since it means, you guessed it, more work and taking the car apart again.
My first idea is to ditch the cheap passive line-out converter for a nice and shiny Audiocontrol LC2i. I assume itll be able to send a cleaner stronger voltage signal to my amps and the “Accubass” feature appears to be what I need to bring back the sub bass. However Im not sure if this will solve my problem or complicate it.
My second idea is to get a 5-10 Farad capacitor bank to ensure that my amps are recieving plenty of juice to power my speakers, however doing the math in my head I doubt it’s necessary unless I decide to get a larger sub or more subs.
Sorry about the long first post but I figured it would be better to go into as much detail to ensure there are no questions. Let me know what you think and if you have anymore questions please ask away.
Thank you
Lets start from the battery and work our way back to the subwoofer so you have a clear idea of my system setup. I used a Shosche 1500W amp wiring kit from Walmart (which I assume is slightly higher than 4 gauge wire but is not OFC) to connect my factory battery to a 1-to-2 fuse block.
There is a fuse between my battery and the fuse block that came with the kit. From that fuse block I have wiring going to my Rockville Audio RXA-F1 (4 chan amp that produces 65x4 @ 4ohm and 95x4 @2ohm) which powers my front 2x door speakers which are wired to my factory tweeter location which I swapped with Skar TXT-1 tweeters (yes they are cheap but they work well for the price). The other exit of the “power fuse” block goes to my mono amp. I started with the Rockville RVA-M2 (rated for 440W RMS @2ohm). The mono amp powers my sub in a custom sealed box that used to house my now blown JL Audio 300W RMS sub (forgot the name) but now has a Skar VD10 D4 10” sub (rated for 500W RMS continuous). I had the problem with that amp still not giving enough unclipped power to my sub so I decided to take a leap of faith and purchase Rockville’s more more powerful and brand new Krypton-M3 (rated for 700W RMS @2ohm). I have a ground cable going from both amps to a 2-to-1 fuseblock and my ground is screwed underneath my carpet on the frame of the car with as much paint sanded off as I could.
However changing from the RVA to the Kyrpton somehow made my sub produce less sound. Its sounds better and definitely has a more balanced frequency range but it is not loud. My factory midbass speakers have more umph than my sub rn. Sound is sent via a 4 chan passive line-out converter that sends a 2 chan signal to my RXA-F1 amp which then sends signal to my Krypton-M3 (RCA from LOC to 4 chan amp and then RCA from 4 chan amp to mono amp).
On my factory radio I have the EQ set to +7 for highs +5 for mids and +9 for bass (range is -9 to +9) and when using bluetooth I have the volume strength set to minimum (other options are medium or maximum). On my phone I use Apple Music to stream HQ 192kps audio and the EQ in my settings is set to Hip-Hop since I listen to it more than anything else. So basically everything I have is set to as much bass as possible.
I used an oscilloscope to set the gains on all my amps and according to my oscilloscope my factory head-unit does not clip at max volume level so I set my gains at 90% volume. The 4 chan amp gain is set appx at 50-60% and the same is for the mono amp, anything higher starts to clip. On my 4 chan amp I am running in 2 chan mode with HPF set to around 1000hz since my factory mid-bass cant handle the bass with extra power above half volume. My mono amp has its “HPF” set to the minimum 15hz, bass EQ is set to +3db, and “PASS” is set around 100hz.
My sub is wired to 2ohm in a sealed enclosure (specifications are not known but I can find out if needed) and should definitely be getting more sound. When I first started my setup and only had the 4 chan amp, I bridged two channels on the amp to the sub which @4ohm gives 200W RMS but since it had a 2ohm load it overheated shortly after one song with intense bass. I have yet to hear my sub sound as loud and clear as when I had my system setup like that. Only reason I got the mono amp was to prevent my 4 chan from overheating while still giving the sub the power it wants.
I have yet to figure out a solution for my problem but I have a couple ideas that Im hesitant to give a shot at since it means, you guessed it, more work and taking the car apart again.
My first idea is to ditch the cheap passive line-out converter for a nice and shiny Audiocontrol LC2i. I assume itll be able to send a cleaner stronger voltage signal to my amps and the “Accubass” feature appears to be what I need to bring back the sub bass. However Im not sure if this will solve my problem or complicate it.
My second idea is to get a 5-10 Farad capacitor bank to ensure that my amps are recieving plenty of juice to power my speakers, however doing the math in my head I doubt it’s necessary unless I decide to get a larger sub or more subs.
Sorry about the long first post but I figured it would be better to go into as much detail to ensure there are no questions. Let me know what you think and if you have anymore questions please ask away.
Thank you
