New Audio Build... Missing Low End Bass

For you folks that kept the factory head unit, are you missing out on some of the low end bass?

I have the 2016 Entune (non JBL) head unit, AudioControl LC7i,

$407 Alpine MRV-V500 Five Channel Power Amplifier

Alpine MRV-V500 (60x4 + 250x1) and an Image Dynamics 10v3 in a ********* box. The sub is wired to 2 ohms which should be pulling 250 watts RMS out of the amp.

I’ve had this same sub and box since it was installed in my 2010 Tacoma. Back then, I had an aftermarket head unit and a different mono amp (Alpine MRD-M500) on it. It sounded great and really hit all the notes. When I completed the install into my new 2016 DC, I was very pleased. It all sounded really good, but some of the songs that used to have good low end bass now sound like they have very little bass.

I’ve tried adjusting the accubass on the LC7i and summing the rear outputs. I’ve tried adjusting my gains and crossover points on my amp. I’m currently setup below the NOM gain, have my LP filter at 120hz and bass EQ set to +10 (controlled through bass knob). I usually have the head unit around volume 30 and don’t go past 45. The bass level on the head unit is set to the middle.
I used a bass tone generator app and noticed a severe cutoff in volume starting around 45 – 49hz. The woofer cone is barely moving compared to 50hz (which was very loud).

Any ideas on what else I could try? Is my amp too small for the woofer? Bad ground? I used 4 gauge wiring. Any way to test that I’m getting the full range of sound out of my equipment?

 

Maybe this is one of those factory head units which protects the speakers by keeping the mean & nasty bass away? I know some head units do this, but no idea about this one. Kinda sounds like it. Try a different input like an Ipod/mp3 player and see what happens.

 

I had to fiddle a lot with my LC2i settings to get some good sound. What exactly are your settings set at on the unit?

 

I'll try hooking up my phone directly to the sub inputs and see if it does any better with the tone generator this evening. Hoping its not the head unit as I really like it.

On the LC7i, all 3 channels are set to mid level as well as the accubass level and threshold. I briefly played with the adjustments but didn't notice much difference in the missing low end. I'll get more thorough with it.

 

@Mr Marv Please read OP

 

Thanks for all of the suggestions. I hooked up directly to the amp and have good clean bass down past 30hz. I'm going to pull the seat out so I can get to my LC7i controls in a bit. I doubt there is much it can do, but I'll crank on all the knobs.

Assuming it is the head unit, do I have any options? Would a signal processor restore the filtered out bass?

 

Ok, so I turned the accubass threshold level on the LC7i and didn't notice a difference until I went past the level marker to the very end of how far the knob turns. It finally kicked in and sounded like the bass was hitting lower. I'm not sure if it's just my unit, but there was a rather long delay from the time I adjusted the threshold to actually hearing the difference. I assume that's why I didn't catch it in my initial setup.

I listened to a song or two and the low end sounded better, but the higher notes were almost too loud. I'm going to tackle it again tomorrow with a fresh set of ears but it sounds like I'm headed in the right direction.

Thanks all for your help.

 

You have any good pics of your build?

 

If you have pulled from the rear speakers, maybe try the front as I think they run a flatter, fuller signal, from what I have read. I have mine going from the fronts and it sounds great, just factory speakers everywhere else powered from the factory HU. It's not going to win any competitions but it sounds clean, full and present. My go-to for setting levels is always AIC - unplugged, Peter Gabriel - Shaking The Tree (sledgehammer), Blackstar - Definition, and Deftones - around the fur. Then I put on Nickel Creek to tweak high end and make sure the system isn't too boomy; the low end on an acoustic guitar will get boxy quickly if the EQ isn't right...

 

the sound maybe different for the songs because your new truck has a different resonant sound frequency than your old one. Meaning certain tones will sound louder than others. If your truck sounds loud around 50hz then that maybe close to your new resonant sound frequency.

Also you have your crossover for your sub pretty high. Mine is set at 80hz currently, also if your door speakers are running full range then its possible that your sub is out of phase with your door speakers causing you to lose some bass at lower frequencies.

If you have a multi meter you can run a 50hz test tone at 75% head unit volume. Your gain should be set around 22.3- 22.4 volts coming out of your amps speaker channel.

Formula used to set gains on amps...

• 250w x 2ohm = 500 (wanted wattage x speaker load = x)
• square root of 500 = 22.36067...... (square root of x = V)

This will make sure you do not push too much watts to your subs at 75% head unit volume. This is nice because it leaves a bit of overhead room for lower volume songs.

 

Sorry, no good pics as everything is tucked away under the seat. I was, however, pretty pleased with the way my bass knob turned out. I also gutted my garage door clicker and soldered a momentary switch to the contacts. Now I can just press the button to the left of the bass knob to open the garage.

 

I assume the LC7i is using the rear. I could split the fronts and see how that sounds. Thanks for the tuning recommendations. I haven't heard any of them, but I'll give em a shot.

I though about both the acoustics of the new cab and the phasing. Placing my hand directly on the cone and feeling the dramatic cutoff should signal that it's not necessarily the resonance. It's not that I can't hear the bass, it's that its playing at a muted volume. I double checked the wiring of the woofer, but it wouldn't hurt to switch the phase. Thanks for the gain setting tips. I'll give them a shot this weekend.


Overall I'm pretty happy with the progress so far. Hopefully I can find some time to tweak it without the neighbors posting noise complaints on the subdivision facebook page

 

Your subs are under your seats too?

 

So turning the accubass threshold completely off fixed the issue? You're not the first person to have issues with setting up the accubass on the LC7i.

 

And I agree with the above mentioning the 120hz is too high of an x-over point for subs. That right there will likely give you the "higher notes" issue you described...

 

sub'd for the mounted amp pics.

 

Its been a while, but I finally have the bass I expected. Adjusting the accubass and levels got me a little closer to where I wanted to be, but the bass was still very shallow. I decided to remove the LC7i completely. I used the high level input of my amp and finally have the deep bass I expected.

Pretty sure there was an issue with my LC7i as nothing I tweaked would get it to work correctly. Good to know its not an issue with the 2016 headunits.

 

I've said it plenty. there is no bass limiting in the non-JBL head units in our trucks. glad you got it figured out, now sell that LC7i !

 

My LC2i was hard to get right. The Accubass should be all the way off as @SlowComa666 stated isn't needed. The threshold dial on the side I have on mine set all the way up. Then the other two adjustment knobs are just set at like 25%. Sounds good now.

 

sub'd as I am in currently in the process of ordering parts to upgrade my system in my '17 DC and there is a lot of good info in here and I'm using some of the same parts.