[sparkymarky]

Hey guys, thought i might save some people a long road of trial and error.

So after instalingl a jl audio amp and 10" jl audio sub sometime ago and been playing with settings for about a year now (!) it finally sounds good with all types of music. I was struggling to find a nice balance between rap (snoop, bass etc), dance (kicks and bass), pop (highs and kicks) and some lets say easy listening laid back stuff (dire straits, quality needed between highs and lows).

Settings:

Head unit:
Hifi professional head unit set to max vol of 44 to utilise as much clean raw signal and power as poss. Amp gain (amp set to high input - tried low input but the fronts get too much power too quickly) set so that i am always using head unit at a minimum of head unit vol 40 to get the most power/signal quality out of the headunit before clipping) (and 40 is a decent sound level for constant listening without being overly loud - underseats given more power from the amp than the highs so that you get a good bass kick/thump but highs not taking away from the bass and not being too imposing with these hifi tweeters). Downside is that at initial radio turn which is always vol 29, it needs to be turned up to 35 for average vol, 39,39,40 for pretty loud listening and 44 for "tolerable loud for periods of great sounding bass and highs but after a while i turn it down from here as it gets too much - plenty loud for me" .- 44 sounds great with no mudiness at all using the below settings.
To further help the underseats gains were set with head unit at +2 bass so that if i need extra bass with certain songs i know i wont be sending too many volts as my max gains will have been done with the bass already at +2 on the head unit).
Head unit balance set to -1 to fade to right slightly. Could do with it being -3 to the right when sat in the drivers seat as ears pick up the left tweeter and door so much but i tried that and there is a big difference in measured voltage at the amp and would end up sending too much power/and thus bass to the left underseat when setting the voltage to get loud bass from the right underseat). -1 is enough to only be 0.5 volt of a difference down the back end at the amp input and allow your left ear to pick up the right door speakers more.

fronts: hifi tweeters and mids high passed around 200hz and given a max gain equivalent of 30 watts. Doesnt sound much but fronts go loud with little power and i dont want them drowing out the underseats- always better to turn down vol of highs than keep increasing the underseats vol.

underseats: hifi oem 8" "subs" bandpassed between 80-190hz using 2 channels of the amp above for the LP and also using an
audiocontrol 24xs to give it the HP.

sub: Jl audio 10" 300wrms

Amp: jl audio 4300. 4 channel. Crossed fairly high at 75hz but using a 24db cut. As the underseats are struggling around 80hz i crossed at 75hx expecting to have turn the crossover downwards later but i dont seem to get any directional bass from the boot which is good. I do get directional bass at anything above 80hz so 75hz seems the max for me. Adding the sub has mad a massive difference to the bass kick around 50-75 hz. Really underpinned the underseats. THUMP!

sub amp: alpine 300wrms

Been driving around recently with just fronts and underseats.
Since I added the bandpass and cut the lows to the underseats it REALLY cleaned up the sound. Removed the flappyness to the sound if you know what i mean. The underseats could be lived with on their own to be fair when listening to pop. no good for rap etc but pop with some well recorded kicks sound pretty darn good from the underseats. I am v impressed by the stock items once given good power and bandpassing.

That said, after a few weeks of driving with them thinking it sounded great, i did then think i was still lacking something, as i was constantly adjusting bass and treble on the headunit but not getting the desired sound still.

So i reconnected the sub. Previously running the sub i just set boost on the aftermarket alpine amp to zero and set the amps gain to 34v to give the 300wrms that the sub is rated at. That gave deep booming bass, overpowering in fact as it used the trunk to load itself. Drowned out the music quality. So, this time, as the underseats are cut @ 80hz i wanted to use the sub to help out around that frequency as well as do the low stuff. So this time i set the subs aftermarket alpine amps boost (50hz) to give the bass kick. I set the amp gain to the same 34v. But now obviously that 34v is reached sooner than when the boost was on zero. To put it another way, freqs either side of 50hz are getting up to 300wrms but the lower stuff is getting less, solving my problem of warbly bass down low as it now gets less power down there but more kick higher up.

The result:

All types of music sound great. I have the head unit always on +1 bass and if the recording is not great i go to +2, all the bass id ever need.
Treble: always -2 to remove the shrill of the hifi tweeter and expose the door mids more. I go up to -1 if recording or music type needs it.

And thats it. Thats all the adjustment i now need to do on the fly from the front. Up a bass or down a treble.


Conclusion:


Dont just low pass the underseats at say 200hz. Ensure you bandpass them so you get rid of the lows that they cant play. Really sorted out the bit of muddiness at volume.

Try and play your sub up a bit higher than the usual 50/60hz, boosting around 50 and setting max gain after. Unless you are hearing directional music from the back of course. In my case i dont hear it and the soundstage is definitely not being drawn toward the rear.

Finally happy with what is now a great sound. Kick bass is pounding and deep sub bass for rap is there in the right proportion. Not too intrusive just underpinning with deep bellows. Amazing for a 10" really. Highs are there in the right amount as they are getting less power and thus less vol than what i used to give them. This has exposed the underseat kicks. highs can be shrill hence the -2 treble but nowhere near as bad as when i was giving them more power. I do have components in the garage to go in, but as they are 4 ohms and the underseats 2 ohm it would mean a whole restart on setting everything up again probably. so am leaving them in their box for now.

[Guido S]

Hey SparkeyMarkey I don't understand a lot of what you've written so I'd like to pick your brain a bit about the details. Couldn't figure how to pm you but if you'd pm me maybe we could talk.

[sparkymarky]

Just looked and I can't find the pm either