I am an audio newb, please learn me!

[gramicci101]

Originally Posted by Chimera

stock config has the dash as 2 4 ohms wired in parallel for 2 ohm load

The 3.5 and the tweeter? I thought they were two 4 ohm speakers with a crossover between them.

[Chimera]

Originally Posted by gramicci101

The 3.5 and the tweeter? I thought they were two 4 ohm speakers with a crossover between them.

if you look closely at the tweeter with it out, its connector takes input on the 2 middle pins and wires the directly out on the 2 outer which go to the 3.5
and each speaker has passive crossover caps on board the speaker as I recall. I don't have any of them in anymore, I could look when I get home, but that's what I recall.

edit: the full signal deff goes into the tweeter, I don't think it would be possible for them to have fit a crossover network on the back of the tweeter, I think it's a simple parallel setup

[gramicci101]

Originally Posted by Chimera

if you look closely at the tweeter with it out, its connector takes input on the 2 middle pins and wires the directly out on the 2 outer which go to the 3.5
and each speaker has passive crossover caps on board the speaker as I recall. I don't have any of them in anymore, I could look when I get home, but that's what I recall.

Ok, yeah. The two speakers don't play at the same time, so the head unit sees a 4 ohm load across the entire frequency range. The mid has a low pass filter and the tweeter has a high pass filter both set for their crossover point.

[keithr]

Originally Posted by Superchan

What I'm thinking is mounting those to the rear seats, so you could fold them into the cabin for more bass-ey-ness if desired, or if you need all your trunk space for some reason.

I would not do that. The vibrations from the sub(s) are going to go straight into seat back and the rear deck, which are going to rattle like all get-out. Also, folding them into the cabin is not going to produce more bass-ey-ness, it doesn't work that way. We won't get into sound wavelengths, but you don't want subs right behind your head. In our cars, you want your subs as far toward the back as you can reasonably get them.

Originally Posted by Superchan

From what I was told (Was told, I'm ignorant, grain of salt) 10's are capable of moving more air, thus creating more bass, however there's a higher chance of distortion or something. Completely dependent upon the quality of the speaker itself.

Ummmm.... no. If that was the case, nobody would use larger speakers for any sound quality competitions or in any high-end setup.

Yes, shitty speakers will likely sound shitty. But it has nothing to do with whether they're 8" or 10" diameter, it's because they're shitty.

Originally Posted by Superchan

I, personally, am not looking for rattle-my-door-hinges bass, but thump-my-chest-a-bit bass.

You should come to Phoenix and have a listen to my car. I think you'll be convinced that a single 10 is exactly what the doctor ordered.

Originally Posted by Superchan

I'm getting some recommendations on the 208's

While these are not at all bad speakers, my recommendation is that you take a step back and unprogram your brain that you must use 8" drivers.

Originally Posted by Superchan

Not really caring too much about a clean install, but I think my "stick it to the rear seat thing" idea is kinda cool.

You also don't want a big box potentially tipping over and/or sliding around in your trunk when you take a corner, or eating up what little usable trunk space we have to start with.. food for thought. That 208 setup is 37" wide by 13" tall by 8" deep. It would take some trial and measurements, but my instinct tells me you're going to get better sounding bass by standing it up and firing it toward the rear of the vehicle, which is going to make it very tip-prone unless you secure it down. If you lay it flat with it firing up, the sound is going to be different. Again, it would take some trial and measurements to really figure out what's best. Either way, it's a pretty big box to deal with.

Originally Posted by Superchan;

Budget is around $750, ish. The 208's + amp + controller would fit in that.

@Chimera mentioned a Stealthbox and NVX amp, which I've recommended that setup to a couple other people in other threads here.

http://www.pacificstereo.com/jl-audi...frs-10tw3.html

Click the green button that says "Sign up" and you'll get a 20% off coupon for your first order. That makes the Stealthbox $520.

http://www.sonicelectronix.com/item_...NVX-MVPA1.html

$160.

So, that's $680, which leaves you $70 for a wiring kit and any other miscellaneous items.

And that Stealthbox will produce exactly the kind of bass you've been describing. It will not rattle the car apart, it will not blow the windows out of the neighbors' houses, but it will add a solid, clean, low-end thump. It installs in the corner of the trunk and makes the most efficient use of space possible.

It *IS* capable of producing quite a surprising volume level of bass, so you'll want to be prepared to start hunting down rattles and vibrations in the car, which are the car's fault, not the sub. That's only a factor depending on your usage of the volume knob on the radio and the type of music you're listening to.

Originally Posted by Superchan;

My friend is helping me install the wiring stuff, and he used to work at an audio shop. He told me to go with my own stuff originally rather than overpaying for someone to do a (probably) less than adequate job. Car stuff isn't huge in my area unless I want to drive a couple hours into missouri.

Well if he worked as an installer then he'll know about how to run your power wire, how to locate and install a good ground, fusing, etc.

If he ran the cash register...well... hopefully he picked up some knowledge by osmosis.

Originally Posted by Superchan

Would I remove that amp and replace them with the new one?

No, not right now. That amp is what makes your door speakers play.

Originally Posted by Superchan

The what Now?

The radio. "HU" is cool audio guy slang for Head Unit, aka receiver, aka deck, aka source unit, aka radio.

[wheelhaus]

There's a LOT to talk about if you're getting into car audio, but if you want to keep it simple for first steps then I'd also highly recommend the JL stealth box. One 10 or two 8's will be PLENTY unless you want to get loud. A single 10 moves more air than a single 8, so it can produce lower frequencies with less effort, but the same could be said for a 12, and a 15, and an 18... So you pick the size, power handling, and specs based on what fits your needs and the application. In this case, we have a tiny cabin and a small trunk, so a 10 is really your hard limit. A single 8 can do wonders in a small space. I have two 8's in individual sealed fiberglass enclosures driven by about 600 watts max RMS (dialed back of course), and it's more than I'll ever need, but I have headroom and the amp is never warm.

Good car audio is very subjective, everyone will have a different opinion of what's best. Having more bass is usually the first step. Most people jump in wanting WAY more than what they'll actually need, unless they're a teenager who wants to blow the glass out and piss off the neighbors.

Then, at some point you'll want better overall quality and go with an aftermarket amp for mid and high drivers, maybe upgrade the head unit, and add some sound deadening to help control rattles and resonances (that can add unwanted color to even low volume music).

Eventually some graduate to a really nice setup with additional sound deadening, a solid head unit with DSP (digital signal processing for better tuning, or a 3rd party DSP unit), with nice quality drivers all being driven individually for discreet adjustment of timing and frequency response. Most at this point will only use front component drivers with no rears for a clear "sound stage" and more accurate tuning. Once you get to this level you've begun to really appreciate good music on a system that's been adjusted to sound phenomenal.

[Superchan]

Noob question inbound

Where do I get a wiring kit?

[Chimera]

Originally Posted by Superchan

Noob question inbound

Where do I get a wiring kit?

amazon, or any stereo shop, your stereo installing friend should easily be able to provide one.

[gramicci101]

Any walk-in car audio shop, Amazon, Crutchfield, Sonic Electronix, all kinds of places.

Match the wiring kit to what your amp requires. If the amp only needs an 8ga power wire, don't buy one with a 0ga wire on the premise that bigger is better.

Also, make sure you even need a kit. If you're pulling signal from the door amp then you don't need RCAs. All I really needed was 15 ft of 12ga power wire and 2 ft of 12ga ground wire. I bought them singly for about $5 from a local shop, and then a couple of crimp connectors from Lowe's.

[keithr]

... I wouldn't tap any signals off the stock amp.

Garbage in = garbage out.

You don't need to take a processed, speaker-level signal off a factory amp and feed it into a good amp and a good sub if your head unit has RCA subwoofer output(s). It's a very small time investment to pull the radio out and run a proper RCA line-level input to your amp. You'll also get the added benefits of the subwoofer controls (on/off, level, whatever is there... I don't know I don't have an FR-S) on the head unit actually working. If you tap the factory amp, those controls won't work.

Chain, weakest link, you know the drill.

[gramicci101]

Originally Posted by keithr

... I wouldn't tap any signals off the stock amp.

I didn't have the option for RCAs, unfortunately. I ended up getting a male and female plug and harness for the rear amp, putting those together, and pulling signal off the signal from the radio before it got to the amp.

[keithr]

Originally Posted by gramicci101

I didn't have the option for RCAs, unfortunately. I ended up getting a male and female plug and harness for the rear amp, putting those together, and pulling signal off the signal from the radio before it got to the amp.

Yeah, I see that you drive a BRZ, like me.

Seems that although our HU was supposed to be "better" -- we didn't get some of the stuff that the FR-S got, like subwoofer RCAs on the HU. Instead we got eleventy billion harness plugs. Seriously, that's a lot of shit on the back of our radios.

I was happy to yank that horrible BRZ HU out. I'm 10,000% happier with my Pioneer 4000NEX.

[babydriver]

Originally Posted by Superchan

From what I was told (Was told, I'm ignorant, grain of salt) 10's are capable of moving more air, thus creating more bass, however there's a higher chance of distortion or something.

Actually, and this is counterintuitive, the size of the speaker is not that important. What is important is how much air it can move and what its low resonant frequency is.

What is missing in the concept as you describe it is the amount of excursion that the loudspeaker can achieve. A larger diameter speaker does not have to move as far to "push" the same amount of air but many 15" or even 18" woofers barely move at all. A 10" woofer can move the same amount of air, but must have much greater excursion to achieve the same volume level.

You can accomplish the same thing with two smaller speakers that can push an equivalent amount of air, and they have less mass individually than the bigger diameter speaker. That is an advantage because lower mass usually means less distortion at a given volume level.

Another thing that you can do is use a subwoofer amp with a smaller, long excursion speaker (designed to take the punishment) and have the amp internally equalized to increase the output (by way of greater excursion) the lower the pitch goes. This is what my home theater Klipsch subwoofer does; it is less than 12" on a side as a result, yet makes really wonderful bass.

A large speaker is simpler and less complex to work into a system and often is more efficient. BUT, and this is important, the speaker cannot go much lower than its F(0), its resonant frequency. This number should be given as a specification along with power handling, frequency response, Xmax (excursion) and efficiency (in dB).

Porting and other enclosure tricks are designed to get the speaker response closer to its F(0) but even there you really can't go lower than F(0). If you equalize the bass to go below F(0) then you MUST use a sealed cabinet (not ported) or the excursion will get out of control very quickly.

This is not as straightforward as it seems, but there are some good books on speaker building out there and they all apply to car speakers too. It's just that the "enclosures" are sometimes a bit different (read: interior space of a door or a trunk).

This website can provide some good information that also applies to cars:

http://www.loudspeakerdesign.co.uk/

If you want to build an enclosure, I suggest that you start with an infinite baffle (sealed) box. They are easier to make. If you want to get adventurous, you might try a ported cabinet.

Software is available free at this site:

http://www.speakerbuilding.com/software/

I have used LspCAD Lite myself and it is an excellent product. Free!

The main thing is to have fun and learn something new! Don't be afraid to dive in.

[keithr]

Originally Posted by babydriver

If you want to build an enclosure, I suggest that you start with an infinite baffle (sealed) box.

As a point of clarification, IB and sealed are technically not the same thing.

IB are usually not perfectly sealed (air-tight), hence the baffle is, by definition, infinite. Like, a trunk, or behind a seat.

Sealed boxes are, as the name implies, sealed airspace, therefore the baffle space is, by definition, finite.

It's pedantic, yes, but if you're going to shoot the firehose of speaker box design information at the poor chap, it's worth noting.

[babydriver]

Originally Posted by Chimera

if you look closely at the tweeter with it out, its connector takes input on the 2 middle pins and wires the directly out on the 2 outer which go to the 3.5
and each speaker has passive crossover caps on board the speaker as I recall. I don't have any of them in anymore, I could look when I get home, but that's what I recall.

edit: the full signal deff goes into the tweeter, I don't think it would be possible for them to have fit a crossover network on the back of the tweeter, I think it's a simple parallel setup

Actually, without even looking, I can guess that the tweeters have a crossover cap in series and the woofer has either an inductor coil in series or nothing. The purpose of the crossover cap is to keep the low frequencies out of the tweeter, which can't stand the excessive excursion. Running full range on the tweeter would simply break the voice coil due to excessive excursion.

The woofer doesn't need this, but may have an inductor in series to roll off the top frequency. A capacitor in line (series) with the woofer would block all low frequencies and defeat the purpose of the woofer altogether.

Neither of these is usually very large on a tiny speaker like the stock one, so fine gauge wire in the inductor is OK to keep down the size of the coil. An electrolytic cap on the tweeter is pretty much standard practice. An inductor and a capacitor together form a first-order passive crossover.

The impedance will not be a constant 4 ohms, but will vary widely with frequency and rise as the frequency does in the tweeter. If the speaker's impedance drops much below two ohms in the bass region, most amps are likely to blow up their output ICs due to excessive current. However, if each speaker (woofer and tweeter) are 4 ohms, then the "driven" load is considered to be 4 ohms also, parallel or not.