I was able to fit my infinity 6.1's in the kick panels and a pair of JL 8w3's installed in the rear speaker locations. Its all powered by a jl 300/4 with the subs bridged on 3&4. My question is where to set the crossover points. I have the hp and lp at 80 now with 12db slope, but the front just seems to be screaming at me with all lows coming from behind. I have the tweets at 0db on infinity crossover. Should i be using the amps crossover function or the built in function on the alpine 9815. Also should I have some overlap on the settings.

The good news is the 6.1's sound much better than the 4in that use to be there. Those 8's hit pretty hard for only getting 75 watts each.

thanks in advance.

 

Hmm. Having messed around with the 9815 and getting frustrated I have a couple questions.

Door panels deadened? How do the 6's in the doors sound WITHOUT the 8's playing bass wise at 80hz? Can you go a bit lower without them sounding like crap? I would personally spend some time without the 8's on at all to see just how much I could get out of the 6's in the front for midbass and then add the 8's in.

I had my alpine at 90hz on 24db IIRC (I tuned that system 3 years ago and have left it alone) for both my sub and my midrange. The rest of it was handled passively from the Focal crossovers. The system was in a subaru with VERY shallow doors and lots of resonance, forced me to run the 6's in those doors a lot higher than I liked to. Then forced my bass to play too high ... anyways, I would set the Alpine 9815 on a steeper slope (at least 18db, pretty sure you can do that or 24) than your amps provide you, at about 80hz and see how it sounds, then try and sneak it down to around 70hz or maybe even 63hz ( think thats a stretch with a midbass/range playing up to around 3.5k) and see how it holds up. You have to do this with a CD that is a) recorded well and b) that YOU know well. I generally tune with the follow tracks (people are going to laugh heh)

Celion Dion (green disc early one) If you can have HER scream on your system, pretty much anyone can.
Warehouse disc from DMB ( I know every note, lots of instruments)
2pac All eyes on me (disc 1) couple good midbass/sub bass tracks
Korn Untouchables track 4/13 Decent male vocal range, good riffs

From there I mess around with tracks that THEY like to listen to .. and get it sounding how they like it (usually just some tweaking of the bass/highs)

Those 8's will sound nice I am sure and they will play up to around 90hz without sounding too muddy (benefit to small cones, faster). Just take your time and blend them in with the gain on the amp with your front stage and be careful not to let them overpower the front stage and you will be fine I am sure, just be patient.

The second hardest thing to do in a car (behind getting an ACCURATE soundstage) is getting quality midbass IMO. Not many cars outside of serious builds and/or competition cars have it. Road noise, exhaust noise, wind noise, tire noise, engine noise all generally fall in the midbass range (say 63hz up through around 300hz, some people call it up to 800hz) so there is a lot of things working against you when it comes to reproducing that range in a car.

Hope that helps, PM me if you want my number.

Summary, steeper slope via the 9815 for your midbass High pass and sub low pass.
Try and sneak the crossover point down a bit on your 6's to see if they will handle it. The steeper slope will help.
Set your front stage first, your 8's second. Subs should be blended, not overpower the music. (some people like crazy bass though)


Fej

 

little known fact about fej...he makes up all this stuff as he types.

 

Dayum Fej,
I couldn't agree with you more. I have some goofy azz discs I use that I'm VERY familiar with and have a good run of frequencies I'm trying to adjust. Got a few titles I normally keep in a different spot than my other cds. lol

I also agree on the midbass being a trouble spot. One of the reasons is the wavelength matching the inner dimensions of the vehicle causing resonance, which sounds like a distorted signal.
McIntosh Labs did a study on several auto interiors and found a big trouble spot ~150Hz because the wavelength matched the longest dimension of the interior.

And lastly, don't sweat Scottfx cuz he makes up some stuff too. I mean c'mon, who has a computer in their car anyhow?
Scott

 

Interesting info on the wavelength thing, thanks. I have never delved that far into the "science" of sound, always preferred to let those highly intelligent people with degrees in such things make generalities for the laypeople like myself to read and file away for later use I just know making solid midbass in a car is tough to do, as this system finally has a fair amount, which I have always lacked with a 2 way. Thanks again Scott

Fej

 

The 150-250 Hz rule is indeed true. Clarion's old hi-end units used to have a line called Audax. I owned two of these and they actually had a button for a notch filter at 180 Hz (if I remember correctly :o , it was in the late 80's).
As for poor mid-bass. If I read correctly, you have the 6.5" in the kicks. That does not leave them much of an enclosure. I know first hand since I'm using the same driver in my kicks AND doors. My door 6" does much better at putting out bass than the kick does even though they are the same drivers and are driven by the same wattage. The Infinity Perfect tweeters can rip your ears off if you want them too. I have mine attenuated (I have too since I have two on each side)

You can PM me...I could always use a "First Lady"

 

Man this is a rough crowd here all of a sudden, at least I don't have a qlogic box in MY ride

Fej

 

Set the slope to 24 at the amp and that helped a lot. Since they are mounted in the kicks, I don't think I will ever get the bass out of them like when they where mounted in the back enclosures. Still need to deaden the front of the car which I am in the process of doing. Just wanted to test the fitment and sound putting in system before I get the interior back in. I am closer to sounding how I want it now, and will fine tune when the new carpet and insulation is installed.

thanks

 

No prob 90 Glad it helped out.


Fej