Bass Mech

i think it is unlikely you'll get any better bass from replacing the front speakers. unless you can get a larger speaker in the door it's not worth messing with.
you really need something about 8 inches in a door to get any real mid bass and you need a dedicated amp to drive it.
you'll never get any lower than about 60hz in a configuration like that.
but if you wanted to spend the money and take the time to fabricate something it could be improved on a lot. but you would have to do some serious modification.

i think a better idea would be to install a digital signal processor such as the alpine or bit one and if you time align all 4 door speakers and the sub for a correct arrival time at the drivers seat you will have a lot more mid bass.
also if your going that far with the processor you'll need an aftermarket amp and then replace the speakers with something that can handle a little more wattage and designed to be used in an infinite baffle such as a JL audio ZR 650-CW driver.
so to your point this is the only suggestion i have but i don't think slapping a new speaker in the door itself is going to help. you need a lot more watts to drive it and it needs to be crossed over correctly.

i had a set of these in the 8" size in the front doors of my corvette and the bass was unbelievable, almost didn't need subwoofers! the kind of bass that makes your pant leg move and you can feel the "thwack" of a snare drum in your chest!
you won't get that out of a 6.5 but it is the best you can do without major modification.

but if you have gone this far, you might as well re tune the whole system. I've not played with the factory speakers but most are more than adequate to handle a little more power as long as it is crossed over at a point that is within the mechanical limits of the speakers.
i would probably run signal sweeps at a moderate volume listening for mechanical distortion and choose a crossover point that avoids it.
but if you were to replace all 4 with the JL components , add some power i think you could get a good deal more mid bass out of the system, having the ability to tune each speaker, send it the frequencies it can handle will allow you to literally dial up as much mid bass as you want.
i think the rest of the speakers in the car are adequate except the sub. we've already talked about that here.
the hardest part of any audio system is the bass and mid bass region.
i had a pair of 4" door speakers (also JL) in my vette that carried the entire midrange from 400z and up including a tweeter in the center and the sound was deafening! from just a 4" speaker!!
you don't need very much power for mids and highs in a car.
if it were me i would not even bother to lift a speaker grille on the factory system. i would get the processor and 8 channel amp tap into the factory amp plug and power everything up there.
if your planning to replace speakers anyway why not try them first, if you blow some up then replace them with something better. why make it more expensive and harder on yourself than it has to be?
i would be curious to see how many channels the factory amp actually is.
i bet several of the speakers are tied together in pairs.
i bet the doors and dash speakers are a single channel on each side. same for the rear doors and I'm not sure about the deck shelf speakers.

anyone have a wire schematic?

Loe

I'm planning to download the TIS soon for the amp harness. i'll post the entire wiring schematic if its on the TIS.

akshunj

You're off by about 367 mph

akshunj

I recommend any of you looking for a subwoofer take the time to listen to different subs and enclosures and understand how they affect the sound.

The sub/enclosure you are looking for will be much different if for example, you want your Techmaster PEB tracks to boom vs. if you want your Primus or Chilli Peppers to sound good.

I prefer the sound of a sealed enclosure over any ported configuration.

Loe

update on the base premium sound system (straight from the OEM amp label):

Door speakers are 4 ohm
Dash midrange are 4 ohm
Center channel is 5 ohm
Subwoofer is 2.5 ohm

to me, it looks like the stereo is roughly 35 watts X 6, 30 watts x 1, 53 watts X 1 = 293 watts.

Bass Mech

interesting you say that you prefer the sound of a sealed verses ported.
I'm curious why?

a sealed enclosure will have far greater mechanical distortion, is less efficient and has a much higher roll off or F3 than a ported configuration

but in the confines of this discussion and what the posters in this thread are mainly asking for is something that can handle the lower end of the subwoofer spectrum.

a sealed enclosure will usually roll off fairly flat in a vehicle and while that may win you points at the judging station with an RTA it sounds pretty awful.

most people like bass that can be felt in your gut and a correctly designed vented enclosure is a much better tool for that. you'll get nearly 2x the output at the 35-40 hz range with the same size woofer while still giving the tight accurate bass of a sealed box.
the fact is a correctly designed vented enclosure has almost no difference in sound above the tuned frequency as that of a sealed box.

building a sealed box is not only amateur in design but to me seems a waste of space as you get about half the usable frequency response and about 1/2 the output of a ported design.

Bass Mech

that is pretty much what i expected. i think for advertising reasons they add up the wattage of each speaker.
it also means the amplifier has no power supply. just like bose they change the impedance of the speaker coils to get the desired wattage. this means if you connected a 4 ohm woofer to the factory amp you would get only 35 watts from it.

so what does the schematic show? what speakers are tied together? there are 6 channels driving speakers 1 center and 1 sub

the good news is this makes for a fairly easy upgrade. assuming the 6 channels are the front door and dash, the rear door 6.5 and tweet and the rear deck speakers that makes 3 channels x2 for left and right.
then you got a sub and a center.
here is that i would buy if it were me..
i would get the alpine PXA-H800 and run 4 preamp signals from the factory HU into it. then use all 8 channels, front, rear, rear deck and sub with center channel
connect those outputs to a JL xd 6 channel amp and a JL xd 3 channel amp.
run 4 of the 6 channels to the front pair, rear pair and use 1 of the remaining for the center (leave the 6th channel unused) and run the 3 channel 1 pair to the rear deck and power the sub with the sub channel.
or you can get an 8 channel and a mono block either way you end up buying 2 amps.
i would then be able to crossover the fronts rears and deck at a high pass filter starting at about 150 hz same for rear and deck about 400 and up.
then 400 and up for the center.
subwoofer at 100 and below.
all these just as starting points to get close.
i would run the setup wizard and let it self adjust and tweak it from there.
this arrangement would make the factory stereo louder than anyone needs and enough bass depending on your sub even for the most ambitious bass head.

or if you don't want a processor you could just amplify everything using high level convertors right out of the factory amp and into your aftermarket amps. use the crossovers on the amps to set frequencies. but you would want to get the JL cleansweep first to level out the factory signal first.

Loe

no wiring schematic on the amp...I'm curious as well.

I installed my subwoofer tonight tapping into the rear speakers @ speaker level inputs (full range signal). It does not sound good, the subwoofer "rolls" off around 70hz no matter where I set the crossover point (the speaker/amp combo is advertised as 37hz as the lowest it'll play). It'll only play lower frequencies (albeit very very softly) if I turn up the dB on the amp (12dB @ 45hz "bass boost" function). The bass is weak and only sounds good when I stick my head in the trunk.

I'm going to try to tap into the subwoofer line (which should be crossed-over at the OEM amp), but the speaker-level input on the aftermarket amp is looking for L/R inputs, whereas the OEM amp wires are MONO. I'll have to connect two wires to the +/- of the OEM subwoofer line and see how it sounds.

If not, then i'll get an inexpensive PAC SNI-35 LOC (great reviews on amazon and very inexpensive at $11-$13)

Bass Mech

Loe what amp and sub are you using?

Loe

Don't judge me... LOL (got it for $40 total package with discounts, MSRP is $149) Rockville RVB8.1A 8" powered sub with a class AB amp 200watts RMS/300 watt pea (CEA rating). This is my first aftermarket stereo system of any kind so I'm still learning as I go and an inexpensive one is a good starting point. It has L/R high/ and MONO low inputs. I'm really thinking the the rear speaker-level (post amp) inputs are not good and may just tap into the subwoofer ine post amp. I know some have tapped into the rear @ speaker-levels, but that is to hook up an LOC.

akshunj

The ported enclosure is more efficient, yes. This often (not always) comes at the expense of increased size.

Yes there's a chance of some mechanical distortion due to larger xmax involved with a sealed enclosure, but a ported enclosure is not without it's drawbacks; port whistling, "boomy" response in the higher freqs.

Like I said in my earlier post I suggest people listen to the different types of enclosures and understand how they affect the sound. The different types of enclosures sound different listening to the same music.

I think my Techmaster PEB vs Primus analogy is a good one.

Bass Mech

I've never built a ported box which a port velocity high enough to get port noise. And as for size you can always go down 1 size smaller driver and still get more output than sealed configuration in the same amount of space.
Your right though, people should listen to both and assuming the ported box was built correctly there should be no comparison, a ported box always wins by a mile.
The reason you see so many sealed boxes is because most stereo shops lack the talent or necessary skills to build anything but a 6 sided wooden box with a big hole in it to mount a sub. They are quick, cheap and to the average guy getting a system for the first time will be a far sight better than the factory stuff. This design makes a decent amount of profit for the shop.

Verses having someone with some skills make the overall system better with some real audio skills. Smaller subs, using less watts and a better overall outcome.
The good shops and the smart consumers shop this way.
The rest go to best buy for a cheap quick bump in the trunk solution

Bass Mech

are you kidding me? Dude!!!!



Umm ok at first glance ill give the benefit of doubt here. it is a ported box, but i would give it 30% chance it's actually tuned to anything near what it should be.
do me a favor. measure the dimensions of the box subtracting about 3 inches width to accommodate the amplifier cubby on the side.
measure the top and bottom depth, add them up and divide by 2 to give me the final depth
and give me the height.

now give me the diameter of the port and stick a measure tape into the port and tell me the length.
let's start off with that.

just looking at the picture and knowing its an 8" here is my guess.
i bet the box is about 10 inches wide internally, and about 10 inches high internally and about 8" deep that comes to about .5 cu ft internal volume. i am going to bet that port is about 2.5 inches or larger.
i don't have my box design software in front of me but i am going to bet at 2.5" diameter in that size bot the port needs to be about 12 inches long to be tuned anywhere near 45hz which would be just about ideal. usually 45-47 hz is the butter zone. anything higher than that and the sub will not only lack bottom end, but become unloaded in that box and if you play low freq bass notes the sub will go way beyond xmax and make a lot of noise.

will it make bass? sure will it sound much better than stock? if it were a 10"-12" i would say definitely in an 8" with only 200 watts in a questionably tuned box? hmmm it might be close!

good thing you only have 40 bux into it.
let me give you a little lesson in car audio..
rule number 1.
NEVER buy anything you think might need to be upgraded in the future! USED car audio has horrible resale value!
there is no worse feeling than spending money to have less than stellar results!
rule #2 you can always turn the bass down!
in other words your always better off to overshoot your needs a little than to come up short.

if you had a small hatch back that sub might be just enough (assuming it's worth a damn) but in a trunk? dunno..

for reference i had 2 ported 8" subs in my corvette. people that sat in it swore i had a pair of 12's but that was (2) 8's in a hatchback. a hatch back by design just about doubles the output.
2 8" subs have about the same cone area as a 13" single sub.

if i were building a box for the IS it would either be a single ported 10 or if you really want bass a pair of 10's ported to fit up against the seat backs facing rear. with a large rectangular hole in the middle to match the ski passthrough.
leave the passthrough open and about 500-600 watts and you'll have enough bass to **** off 2 neighborhoods!

if you want PM me with your number, we should talk on the phone.

Loe

thanks for the input....I ended up getting a passive LOC and it cleaned up the sound. I have note had time to adjust the gain setting on the LOC yet. but for now, the sub makes an appropriate amount of bass only when you seal up the port hole, otherwise its uncontrolled and distorts in all but midbass notes (and even then its boomy). With the box sealed, its a night / day difference in bass response in the low end, but it still rolls off below 50hz. The wires it came with is really good though. Yes, ill get a more reputable system soon like a JBL powered subwoofer. If I paid full price for this, I would demand a refund. But at $40, it supplements the base system fine; it will not shake windows, but fills where the OEM sub doesn't. Will send you a PM shortly.

Bass Mech

Yep that's a dead giveaway it's not tuned at all. I hate when companies buy crap like that from China and market it to people with false hope.
The good news is your already 80% there to a solution since you already have power, ground, signal to the trunk. Replacing what you have with a real amp and sub is as easy as a few connections.