Stanley
3rd Gear Poster
For the audio nerds and generally curious here, I figure I'd do a lengthy write up my system, but also some of the decision points involved, to help people that are putting together their own system.
Quick links to places with solid car audio info:
www.diymobileaudio.com
No everyday vehicle ever comes with a truly decent audio system: there's just no market for such a thing, not helped by the fact that most people think that more volume + more speakers is what indicates quality. As long as I've been buying vehicles, the first thing I do is upgrade the sound system. With the Bird (and the march of tech and having some actual funds for once), I have the chance to do things young me never could have dreamed of. There's definitely a few things I'd have done different if I was doing this from the start, but overall I'm very happy with how it all turned out.
HEAD UNIT
First thing to do was to rip out the old Premium Sound deck. To the surprise of my out-of-touch self, it was actually getting quite hard to find what I now know to be an old-style head unit: that is, single DIN, with text-only infographics. I absolutely hate modern displays in cars in general--the bright and cartoony colours, the "please fasten your seatbelts and don't run over orphans" warnings, the idea that you're reading a display off your line of sight while driving at all--but over and above that, I wanted a CD player to match the older style of the car, and an archaic-looking LED display with chunky segmented characters to match things like the clock, and I didn't want it to be the size of the moon. Luckily this guy, while just discontinued, was still in stock.
The Pioneer DEH-X8800BHS. It has Pandora and Spotify and Bluetooth and other things I don't care about, and even still has iPod support. What I actually use though is the front USB port on the far right, covered by the little door (under the "Mixtrax" label). It can read up to 32 gigs, so I bought an ultra-low-profile USB stick (so I don't accidentally brush it and break it off) and put all my music on there. The display has colour changing, so I switched it to green, where it matches the interior clock and temp display and general colour perfectly. It also has a 13-band EQ, which is nice because, while the vast majority of my tweaking is going to come from elsewhere, it's nice to be able to make larger-scale shifts on the fly to the system as a whole.
There are better decks of this type: the Pioneer DEX-P99RS is the ultimate along these lines, but long out of production and running around $1,500 nowadays (if you can even find one) and doesn't have front USB.
SOUND DEADENING
Most people start a system overhaul with their speakers, just like a lot of guys when they want more horsepower start with the engine. And just like ramping your engine to the nines without upgrading and reinforcing a host of other things to compensate is a terrible idea, the best start (or at least, the thing you want to make sure you do alongside a major stereo upgrade) is sound deadening. If you don't deaden, a lot of your bass response is just going to be wasted turning your car into an annoying-sounding rattlebox, when it isn't getting lost due to external noise.
This is the part where I learned a lot after having had it done: if I could go back I'd do a lot of this completely differently. While in hindsight I shouldn't be surprised, it turns out that not all deadening is created equal. Over and above that, it turns out that there's really more than one type of deadening, and if you want to do this really well, you want a multi-layer approach using the different types of material. Some absorbs vibration / resonance (especially key in the doors, to stop vibrations/buzzing that occur when you play your music loud and to not lose midbass response from your speakers, particular when the volume is high, because in a proper setup most of your bass is coming from the front doors). Some actually deadens sound like wind noise, road noise, etc. I had a simple all-in-one product added, which sort of does everything, but not as well as doing it right in layers. Don't get me wrong--it's still a massive improvement--but I wish I had done it better, and may go back and slap an extra layer of deadening over top somewhere down the road, at least on the doors and rear floors, which are the parts easy to access on the Bird.
I had the doors, front and rear floor, trunk lid, and roof done. The roof is often overlooked, but Second Skin makes a kit that fits under our headliner nicely and gives some additional heat protection as well.
www.secondskinaudio.com
I'm also going to look at doing the wheel wells, behind the fender guard, to cut down on road noise. Resonix is generally considered to make the best deadening in the business: I wish I knew about them before I started.
resonixsoundsolutions.com
AMPLIFIER/DSP
Another area I knew very little about, but in this case it worked out because at first I threw in only the most basic garbage amp I could find, just enough to power a simple set of cheap upgrade speakers. I got rid of both amp and speakers in time, but that time enabled me to figure out what I was really looking for.
One of the first things you need to do is figure out if you're doing a passive system, or an active one. Passive is generally set it and forget it, using physical crossovers (i.e. devices you install alongside your speakers) to manage the transition from the lows to highs. Active is done via software, and gives you tons more control but more things you need to fiddle with (and can screw up).
A DSP is a Digital Signal Processor, used to create an active setup. You can buy a DSP separately from your amp and plug it in, or do what I did and buy a two-in-one amp and DSP combo. Unlike a lot of combo items, there's no compromise / loss of quality if you buy the right one, and then you have fewer boxes and wires to deal with. A DSP allows you a degree of control over your sound that no deck can give you: EQ for each individual speaker with dozens of bands per, crossovers, time/distance alignment, high and lowpass filtering per speaker, db control per speaker, special effects like subharmonic enhancement, etc etc. You plug a laptop in and manage everything via their software. The deck's own settings thus become very secondary. I went with this beauty:
www.audiotec-fischer.de
The P Six has lots of power, and lots of control. My only regret is that it's not 8-channel. Helix sells an 8-channel with DSP, but it's notably weaker in output, and I was able to make what I wanted work with just six physical channels, after a bit of messing about. I had to get a little 2-channel amp for the rear speakers, then slave that to the P Six, but otherwise it all came together nicely. This is the rear amp:
I can't emphasis how tiny this thing is. 1.34" x 3.35" x 4.33", and yet 170 watts per channel. It's incredible, and will fit anywhere, basically an overstuffed cigarette packet. Both amps sit under the passenger seat.
SPEAKERS
This was the hardest part by far. Not just to figure out what speakers in general I wanted, but whether to go with a two-way setup or a three-way, and then from there, where to mount this stuff in the car.
Two-way would be woofer in the doors, and then either a tweeter or a wideband up higher somewhere to cover the rest of the range. You don't need fancy software for that: a lot of companies sell matching two-way speaker systems with passive crossovers designed just for them. A three-way would be woofer, midrange, and tweeter. A three-way, if set up correctly, is always better, but is also more expensive and harder to configure properly (it's actually easy to make a bad-sounding system this way) and requires an extra set of speakers, also with the need to be mounted up high. You pretty much always manage a three-way system actively, i.e. with a DSP.
Woofers
Starting with the doors. The Bird has 5x7/6x8 mounts, which is not really supported in higher-end audio. You can buy okay speakers in those sizes, certainly big improvements over stock (here's one from Audiofrog) but the best stuff is round and anywhere from 6" to 8". Our door mounts will handle up to 6.5" without any issue, needing nothing more than a cheap plastic adapter to make it fit. I wanted to get an 8" there, but the way the inside door mounts are molded with their curves on either side makes that largely impossible (I gather there's some guys on SCCOA who finagled some kind of custom mounting and door molding to make it happen, but I didn't want to mess with that myself without the detail of exactly how they did it). So I picked these, which have an excellent reputation for midbass delivery:
stereointegrity.com
Instead of the stock setup where the door tries (poorly) to play everything in the full hearing range--20 Hz to 20,000 Hz--these are only capable of covering from 65 Hz to 8,000 Hz. And from there you cut that further, down to almost nothing: I have mine playing from just 65 to 350 Hz. A woofer is there not to handle your deep bass but your midbass, the remaining low-end tones that your subwoofer isn't pumping out.
It seems like such drastic cuts would be crippling these. Why do it then? Directionality.
Most sound is directional. The higher the frequency, the more our ears tend to zoom in on precisely where it's coming from, and thus the harder it is to get that omnidirectional illusion, where the audio just seems to be "coming at you" as you'd expect and sounds right. Only on a small part of the low end do we have a hard time sensing the direction: at 20 to 80 Hz (broadly, the subwoofer range) it's impossible for the average person to tell (which is why subs get stuck in the trunk and facing backwards: you can't tell, so long as you get the time alignment right, and there's actually benefits to being able to put it back there that I won't get into).
The chart above shows speaker size ("Diameter"), and then the directionality of that speaker as the frequency range from it climbs ("Pattern": the ever-shrinking blue circles at the top of the image, as you move from left to right). The sound doesn't have any real directionality in the green zone, whereas by the time you get to the red, it's coming out like a beam instead of a broad wave (hence the term "beaming"). If the beam isn't pointing right at your ears, you can always tell where the sound is coming from and you're losing audio information. Beaming is bad; we want to avoid that. The last bit in particular is why having all your speakers in the door tends to sound so poor: you're losing the high end because a lot of it is beaming into your legs instead of reaching your ears.
This is the main advantage of having a three-way setup vs a two-way: you can make each speaker focus a more narrow area where it performs best, rather than trying to do too much, but also have it so that each is playing in the frequency range best suited for its size and delivering a more omnidrectional sound.
For a 6" speaker (my door speakers are 6.5"--close enough), you thus want to stay around 1,130 Hz and lower (though it's not precise to the Hz or anything). Since a proper crossover filter doesn't actually shut off the sound at whatever frequency you set it at, but only starts slowly but steadily dropping it off, you want to cut early. My crossover filter that cuts in at 350 Hz only means that the dropoff starts there: only at 700 Hz is there no signal coming from the speaker (if you cut it off 100% at your filter point, it sounds incredibly artificial).
Overall, every bit the woofers now play is in the green zone and thus, despite them being down in the doors, my ear can't tell that the sounds they're playing are coming from around my feet: the sound seems to be coming right at me just like the vocals and other elements from my higher-mounted speakers.
Midrange
These pickup where the woofer leaves off, and form a bridge between the woofer and the tweeter. Your general mids come out of these: a lot of guitar, a lot of the vocals (don't confuse midrange with midbass). They tend to be anywhere from 2.5" to 4". I went with these:
www.audiofrog.com
One of the great things about the Bird is its small A-pillars, giving great sight lines. The only real downside to that is that it makes putting speaker mounts directly in them annoying. It's a common spot for modern vehicles, since modern A-pillars are the size of the moon, but in our cars it would look ugly. As midrange speakers are more directional than woofers (and because you want to keep them as close to your tweeters as you can), there's not a lot of options if I'm going to skip the A-pillars. They need to be up high. That left me dash mounts, where the speaker is lying flat and firing up into the windshield.
As a 2.5" speaker, they're nice and small. Like the woofers, while they can cover a broad range (150 Hz – 16 kHz), we're only going to use a small part of that for directionality reasons. Midranges start to cut in at exactly the spot your woofer's filter starts cutting it out, and taper off around 2,500 to 4,000 Hz, depending on your setup and speaker size (with the smaller the speaker, the higher you can go). The human ear is also really, really sensitive to midrange audio, so if you have a three-way setup it's common to do what's called underlapping, where you deliberately cross over a bit early between the midrange and the tweeter, before the tweeter fully kicks in, so that both the midrange and the tweeter aren't double-blasting you with the same range of mids tha tyour ears really zoom in on.
Tweeter
Tweeters are going to play everything else, the vast bulk of the audio range (~2,500 Hz to 20,000 Hz), and need to be small to best capture those high frequencies: 1" is typical. But if you look at the chart I posted earlier, you see it's pretty much impossible to avoid beaming at the frequency range tweeters play at. That's why getting the tweeter physically mounted up high and pointed at your ears is so important in a way that no other speaker cares about (and why all-in-one coaxial speaker setups down low in the doors suffer so badly by comparison): otherwise it ruins your soundstage. I went with the matching tweeters from Audiofrog, designed specially to complement the GB25s:
www.audiofrog.com
These went in the pillars, in side mounts rather than molded into the pillar directly. There's a company out of Germany that sells custom-made aluminum pods for them on Ebay. Here's what the two look like in the car:
Rear
None of this includes the rear speakers, which are generally treated as anywhere from a luxury / afterthought to outright bad. The reason is that they need to be handled carefully to not shift the soundstage to the rear: you want the audio to sound like its consistently coming from in front of you, and rear speakers can mess with that (and also give you more audio overlaps/nulls that make tuning your overall setup harder). A lot of high-end systems thus just skip the rears altogether. However, I've come to realise that, properly set up, I like the additional depth they give to the sound: what is known as rear fill. So I threw in a set of JL Audio C3s, where they're more than good enough.
www.jlaudio.com
Typically you have the rears not playing much in the way of bass (~250 Hz cutoff down low) and only playing up to 3,000 Hz or so, after which you apply a lowpass filter (since again, the higher the frequency of sound, the more directional it is). Then you raise the volume on the rear speakers a couple notches at a time, until the point your ears starts telling you that there's sound coming from behind you--until directionality pulling the soundstage to the rear kicks in--when you then dial it back down a notch. You want the rears to be invisible, contributing in a way that you can't pick out unless you mute them, when you suddenly notice how weak your sound is without them. The nice thing about having a DSP is that at a keystroke you can shut off speakers, so you can get an immediate sense of what not having X or Y part of your system playing does to the overall sound.
Subwoofer
I used to think the only reason that you got a sub was if you were the kind of obnoxious asshole that liked to blast deep house out of a shitbox CRX at volumes high enough to rattle fillings in neighbouring postal codes. As I don't listen to that sort of thing, I never even considered a sub for most of my life. But eventually I realised that my car setup was lacking depth in a way my home theatre setup wasn't. After speaking to some people, the verdict was universal: I needed a sub. I grabbed this JL Audio beast, which fits nicely in the trunk without getting too much in the way of access through the fold-down seats I had installed:
www.jlaudio.com
The difference was enormous, giving the punch to the toms, really bringing out the drone in deep organ and synth sounds, and giving an overall feeling of depth to the whole setup. If anything I found it a bit much, even at the right volume overall, but the DSP lets you get really surgical with stuff like this: I dropped a part of its frequency range in the 40 Hz area so that anything with strong kick drums didn't sound like Godzilla marauding nearby. Almost no one would ever do something like that to their sub, but hey, that's what making the system your own is all about. I like the deep tones, but not the punch.
As an aside, I thought about getting some underseat subwoofers as well. They're generally crap at being actual subwoofers and no one would actually recommend them for that purpose, but they're small and do a good job of essentially being superwoofers, adding more depth to your midbass range (and they're better than nothing if you have no room/dollars for a real subwoofer). But my driver seat has the power adjustments and my passenger seat already has two amps under it, so room would be an issue no matter how low-profile they are unless I went to the footwells, and in any case I had to stretch things to fit in the rear speakers: there's just not enough channels on the P Six to make it work the way I'd like.
If you want a sub (or two), there's a guy out there who makes sub enclosures especially for our gen of Birds:
netaudio.com
TUNING
So, I had all my components, quality stuff, properly installed. The result was ... solidly meh. I mean, it was hard to make all that gear sound bad, but it definitely wasn't anywhere near as much of a step up from my old setup as I had imagined. The reason, as I was to learn, was that I'd tuned my old setup to within an inch of its life over the course of a year of listening, making up for its weaknesses, while this wasn't tuned at all. Nothing was really in balance with one another, and more parts meant more things I could (and did) do wrong.
Fortunately my city has an authorised Helix dealer, which meant much more than the fact that they had the gear for sale. They also knew the ins and outs of the DSP and the complicated software that controls it, and also had all the tools needed to do a full tune.
A shop with a proper tuning setup will set up a mic on the driver's seat, wrapped around the headrest, and then pump various noise files over the stereo to calibrate everything. So instead of a general audio setup for the car, they're aiming to make things sound best for the driver over on the left (passengers can deal). This testing also reveals what sort of nulls and echoes your particular car setup has: say, your centre console and speaker position is combining to create a noticeable dip in the 350 Hz range, so we'll boost that a bit, and you've got too much of X because of reverberations over here so we drop that range a touch. They also take measurements of how far each speaker is from this driver position, and in turn calibrate the signal from each through the software so that the sound is reaching that position at about the same time (what is known as time alignment). Cars are awful sound environments in a lot of ways, but one of the big elements to this is that you're sitting much closer to some speakers than others, rather than having a nice central position where all the audio is symmetrically framed around you. The resulting time adjustment is only in milliseconds, but makes a clear difference.
In the end a tune is unlikely to sound "right" for you unless you're hanging out at the shop while they're doing it and are steadily involved in the process, because we all have our own preferences (and deafness levels), but it's a solid baseline for you to take over from and make your own subtle tweaks, as opposed to how I was where nothing I did sounded right because I was so far from that baseline that I couldn't even get close to a sound I liked.
____
That's a wrap. I hope there's more than just myself that finds this sort of thing interesting.
Quick links to places with solid car audio info:
DIYMobileAudio.com Car Stereo Forum
A forum community dedicated to all mobile audio enthusiasts. Come join the discussion about capacitors, amplifiers, subwoofers, marine and automotive audio, troubleshooting, and more!
No everyday vehicle ever comes with a truly decent audio system: there's just no market for such a thing, not helped by the fact that most people think that more volume + more speakers is what indicates quality. As long as I've been buying vehicles, the first thing I do is upgrade the sound system. With the Bird (and the march of tech and having some actual funds for once), I have the chance to do things young me never could have dreamed of. There's definitely a few things I'd have done different if I was doing this from the start, but overall I'm very happy with how it all turned out.
HEAD UNIT
First thing to do was to rip out the old Premium Sound deck. To the surprise of my out-of-touch self, it was actually getting quite hard to find what I now know to be an old-style head unit: that is, single DIN, with text-only infographics. I absolutely hate modern displays in cars in general--the bright and cartoony colours, the "please fasten your seatbelts and don't run over orphans" warnings, the idea that you're reading a display off your line of sight while driving at all--but over and above that, I wanted a CD player to match the older style of the car, and an archaic-looking LED display with chunky segmented characters to match things like the clock, and I didn't want it to be the size of the moon. Luckily this guy, while just discontinued, was still in stock.
The Pioneer DEH-X8800BHS. It has Pandora and Spotify and Bluetooth and other things I don't care about, and even still has iPod support. What I actually use though is the front USB port on the far right, covered by the little door (under the "Mixtrax" label). It can read up to 32 gigs, so I bought an ultra-low-profile USB stick (so I don't accidentally brush it and break it off) and put all my music on there. The display has colour changing, so I switched it to green, where it matches the interior clock and temp display and general colour perfectly. It also has a 13-band EQ, which is nice because, while the vast majority of my tweaking is going to come from elsewhere, it's nice to be able to make larger-scale shifts on the fly to the system as a whole.
There are better decks of this type: the Pioneer DEX-P99RS is the ultimate along these lines, but long out of production and running around $1,500 nowadays (if you can even find one) and doesn't have front USB.
SOUND DEADENING
Most people start a system overhaul with their speakers, just like a lot of guys when they want more horsepower start with the engine. And just like ramping your engine to the nines without upgrading and reinforcing a host of other things to compensate is a terrible idea, the best start (or at least, the thing you want to make sure you do alongside a major stereo upgrade) is sound deadening. If you don't deaden, a lot of your bass response is just going to be wasted turning your car into an annoying-sounding rattlebox, when it isn't getting lost due to external noise.
This is the part where I learned a lot after having had it done: if I could go back I'd do a lot of this completely differently. While in hindsight I shouldn't be surprised, it turns out that not all deadening is created equal. Over and above that, it turns out that there's really more than one type of deadening, and if you want to do this really well, you want a multi-layer approach using the different types of material. Some absorbs vibration / resonance (especially key in the doors, to stop vibrations/buzzing that occur when you play your music loud and to not lose midbass response from your speakers, particular when the volume is high, because in a proper setup most of your bass is coming from the front doors). Some actually deadens sound like wind noise, road noise, etc. I had a simple all-in-one product added, which sort of does everything, but not as well as doing it right in layers. Don't get me wrong--it's still a massive improvement--but I wish I had done it better, and may go back and slap an extra layer of deadening over top somewhere down the road, at least on the doors and rear floors, which are the parts easy to access on the Bird.
I had the doors, front and rear floor, trunk lid, and roof done. The roof is often overlooked, but Second Skin makes a kit that fits under our headliner nicely and gives some additional heat protection as well.
Roof Insulation Kit
We'll outfit you with the best soundproofing materials to use above the car headliner fabric. Insulate yourself from the sun's heat and absorb unwanted noise.
www.secondskinaudio.com
I'm also going to look at doing the wheel wells, behind the fender guard, to cut down on road noise. Resonix is generally considered to make the best deadening in the business: I wish I knew about them before I started.
How To Sound Deaden Your Car Doors - The Right Way!
Here at ResoNix Sound Solutions, it's no secret that end-result performance is our main priority. It's also no secret that there is a lot of misinformation, poor advice, and marketing disguised as guidance that plagues the automotive sound treatment groups, threads, and discussions. The point of...
resonixsoundsolutions.com
AMPLIFIER/DSP
Another area I knew very little about, but in this case it worked out because at first I threw in only the most basic garbage amp I could find, just enough to power a simple set of cheap upgrade speakers. I got rid of both amp and speakers in time, but that time enabled me to figure out what I was really looking for.
One of the first things you need to do is figure out if you're doing a passive system, or an active one. Passive is generally set it and forget it, using physical crossovers (i.e. devices you install alongside your speakers) to manage the transition from the lows to highs. Active is done via software, and gives you tons more control but more things you need to fiddle with (and can screw up).
A DSP is a Digital Signal Processor, used to create an active setup. You can buy a DSP separately from your amp and plug it in, or do what I did and buy a two-in-one amp and DSP combo. Unlike a lot of combo items, there's no compromise / loss of quality if you buy the right one, and then you have fewer boxes and wires to deal with. A DSP allows you a degree of control over your sound that no deck can give you: EQ for each individual speaker with dozens of bands per, crossovers, time/distance alignment, high and lowpass filtering per speaker, db control per speaker, special effects like subharmonic enhancement, etc etc. You plug a laptop in and manage everything via their software. The deck's own settings thus become very secondary. I went with this beauty:
HELIX P SIX DSP ULTIMATE
6-channel High-Res amplifier with integrated, digital 12-channel signal processor | 6 x 120 Watts @ 4 Ω
www.audiotec-fischer.de
The P Six has lots of power, and lots of control. My only regret is that it's not 8-channel. Helix sells an 8-channel with DSP, but it's notably weaker in output, and I was able to make what I wanted work with just six physical channels, after a bit of messing about. I had to get a little 2-channel amp for the rear speakers, then slave that to the P Six, but otherwise it all came together nicely. This is the rear amp:
I can't emphasis how tiny this thing is. 1.34" x 3.35" x 4.33", and yet 170 watts per channel. It's incredible, and will fit anywhere, basically an overstuffed cigarette packet. Both amps sit under the passenger seat.
SPEAKERS
This was the hardest part by far. Not just to figure out what speakers in general I wanted, but whether to go with a two-way setup or a three-way, and then from there, where to mount this stuff in the car.
Two-way would be woofer in the doors, and then either a tweeter or a wideband up higher somewhere to cover the rest of the range. You don't need fancy software for that: a lot of companies sell matching two-way speaker systems with passive crossovers designed just for them. A three-way would be woofer, midrange, and tweeter. A three-way, if set up correctly, is always better, but is also more expensive and harder to configure properly (it's actually easy to make a bad-sounding system this way) and requires an extra set of speakers, also with the need to be mounted up high. You pretty much always manage a three-way system actively, i.e. with a DSP.
Woofers
Starting with the doors. The Bird has 5x7/6x8 mounts, which is not really supported in higher-end audio. You can buy okay speakers in those sizes, certainly big improvements over stock (here's one from Audiofrog) but the best stuff is round and anywhere from 6" to 8". Our door mounts will handle up to 6.5" without any issue, needing nothing more than a cheap plastic adapter to make it fit. I wanted to get an 8" there, but the way the inside door mounts are molded with their curves on either side makes that largely impossible (I gather there's some guys on SCCOA who finagled some kind of custom mounting and door molding to make it happen, but I didn't want to mess with that myself without the detail of exactly how they did it). So I picked these, which have an excellent reputation for midbass delivery:
TM65 mkIV Midbass – StereoIntegrity.com
stereointegrity.com
Instead of the stock setup where the door tries (poorly) to play everything in the full hearing range--20 Hz to 20,000 Hz--these are only capable of covering from 65 Hz to 8,000 Hz. And from there you cut that further, down to almost nothing: I have mine playing from just 65 to 350 Hz. A woofer is there not to handle your deep bass but your midbass, the remaining low-end tones that your subwoofer isn't pumping out.
It seems like such drastic cuts would be crippling these. Why do it then? Directionality.
Most sound is directional. The higher the frequency, the more our ears tend to zoom in on precisely where it's coming from, and thus the harder it is to get that omnidirectional illusion, where the audio just seems to be "coming at you" as you'd expect and sounds right. Only on a small part of the low end do we have a hard time sensing the direction: at 20 to 80 Hz (broadly, the subwoofer range) it's impossible for the average person to tell (which is why subs get stuck in the trunk and facing backwards: you can't tell, so long as you get the time alignment right, and there's actually benefits to being able to put it back there that I won't get into).
The chart above shows speaker size ("Diameter"), and then the directionality of that speaker as the frequency range from it climbs ("Pattern": the ever-shrinking blue circles at the top of the image, as you move from left to right). The sound doesn't have any real directionality in the green zone, whereas by the time you get to the red, it's coming out like a beam instead of a broad wave (hence the term "beaming"). If the beam isn't pointing right at your ears, you can always tell where the sound is coming from and you're losing audio information. Beaming is bad; we want to avoid that. The last bit in particular is why having all your speakers in the door tends to sound so poor: you're losing the high end because a lot of it is beaming into your legs instead of reaching your ears.
This is the main advantage of having a three-way setup vs a two-way: you can make each speaker focus a more narrow area where it performs best, rather than trying to do too much, but also have it so that each is playing in the frequency range best suited for its size and delivering a more omnidrectional sound.
For a 6" speaker (my door speakers are 6.5"--close enough), you thus want to stay around 1,130 Hz and lower (though it's not precise to the Hz or anything). Since a proper crossover filter doesn't actually shut off the sound at whatever frequency you set it at, but only starts slowly but steadily dropping it off, you want to cut early. My crossover filter that cuts in at 350 Hz only means that the dropoff starts there: only at 700 Hz is there no signal coming from the speaker (if you cut it off 100% at your filter point, it sounds incredibly artificial).
Overall, every bit the woofers now play is in the green zone and thus, despite them being down in the doors, my ear can't tell that the sounds they're playing are coming from around my feet: the sound seems to be coming right at me just like the vocals and other elements from my higher-mounted speakers.
Midrange
These pickup where the woofer leaves off, and form a bridge between the woofer and the tweeter. Your general mids come out of these: a lot of guitar, a lot of the vocals (don't confuse midrange with midbass). They tend to be anywhere from 2.5" to 4". I went with these:
GB25 2-1/2” (63 MM) AUDIOPHILE GRADE AUTOMOTIVE LOUDSPEAKER - Audiofrog
Overview Features Technical Details Downloads Overview Designed as a dedicated midrange driver for special applications in 3-way systems, the GB25 is optimized for enclosures as small as 0.2 liters (2-1/2” […]
www.audiofrog.com
One of the great things about the Bird is its small A-pillars, giving great sight lines. The only real downside to that is that it makes putting speaker mounts directly in them annoying. It's a common spot for modern vehicles, since modern A-pillars are the size of the moon, but in our cars it would look ugly. As midrange speakers are more directional than woofers (and because you want to keep them as close to your tweeters as you can), there's not a lot of options if I'm going to skip the A-pillars. They need to be up high. That left me dash mounts, where the speaker is lying flat and firing up into the windshield.
As a 2.5" speaker, they're nice and small. Like the woofers, while they can cover a broad range (150 Hz – 16 kHz), we're only going to use a small part of that for directionality reasons. Midranges start to cut in at exactly the spot your woofer's filter starts cutting it out, and taper off around 2,500 to 4,000 Hz, depending on your setup and speaker size (with the smaller the speaker, the higher you can go). The human ear is also really, really sensitive to midrange audio, so if you have a three-way setup it's common to do what's called underlapping, where you deliberately cross over a bit early between the midrange and the tweeter, before the tweeter fully kicks in, so that both the midrange and the tweeter aren't double-blasting you with the same range of mids tha tyour ears really zoom in on.
Tweeter
Tweeters are going to play everything else, the vast bulk of the audio range (~2,500 Hz to 20,000 Hz), and need to be small to best capture those high frequencies: 1" is typical. But if you look at the chart I posted earlier, you see it's pretty much impossible to avoid beaming at the frequency range tweeters play at. That's why getting the tweeter physically mounted up high and pointed at your ears is so important in a way that no other speaker cares about (and why all-in-one coaxial speaker setups down low in the doors suffer so badly by comparison): otherwise it ruins your soundstage. I went with the matching tweeters from Audiofrog, designed specially to complement the GB25s:
GB10 1" (25 MM) AUDIOPHILE GRADE AUTOMOTIVE TWEETER - Audiofrog
Overview Features Technical Details Downloads Overview Designed for installation in factory or custom locations, the GB10 1” tweeter provides low distortion audiophile-grade performance with extended high frequency response. The unique […]
www.audiofrog.com
These went in the pillars, in side mounts rather than molded into the pillar directly. There's a company out of Germany that sells custom-made aluminum pods for them on Ebay. Here's what the two look like in the car:
Rear
None of this includes the rear speakers, which are generally treated as anywhere from a luxury / afterthought to outright bad. The reason is that they need to be handled carefully to not shift the soundstage to the rear: you want the audio to sound like its consistently coming from in front of you, and rear speakers can mess with that (and also give you more audio overlaps/nulls that make tuning your overall setup harder). A lot of high-end systems thus just skip the rears altogether. However, I've come to realise that, properly set up, I like the additional depth they give to the sound: what is known as rear fill. So I threw in a set of JL Audio C3s, where they're more than good enough.
C3-570
2-Way Convertible Component / Coaxial System: 5 x 7 / 6 x 8-inch (125 x 180 mm) Woofer, 1-inch (25 mm) Silk Dome Tweeter There are times when an installation calls for a separate woofer and tweeter and other times when a coaxial is the better approach. With the Evolution® C3 Convertible...
www.jlaudio.com
Typically you have the rears not playing much in the way of bass (~250 Hz cutoff down low) and only playing up to 3,000 Hz or so, after which you apply a lowpass filter (since again, the higher the frequency of sound, the more directional it is). Then you raise the volume on the rear speakers a couple notches at a time, until the point your ears starts telling you that there's sound coming from behind you--until directionality pulling the soundstage to the rear kicks in--when you then dial it back down a notch. You want the rears to be invisible, contributing in a way that you can't pick out unless you mute them, when you suddenly notice how weak your sound is without them. The nice thing about having a DSP is that at a keystroke you can shut off speakers, so you can get an immediate sense of what not having X or Y part of your system playing does to the overall sound.
Subwoofer
I used to think the only reason that you got a sub was if you were the kind of obnoxious asshole that liked to blast deep house out of a shitbox CRX at volumes high enough to rattle fillings in neighbouring postal codes. As I don't listen to that sort of thing, I never even considered a sub for most of my life. But eventually I realised that my car setup was lacking depth in a way my home theatre setup wasn't. After speaking to some people, the verdict was universal: I needed a sub. I grabbed this JL Audio beast, which fits nicely in the trunk without getting too much in the way of access through the fold-down seats I had installed:
HO110-W6v3
Enclosed Subwoofer System with Single 10W6v3-D4 Subwoofer, Dark Gray / Black Carpet (600 W, 2 Ω) - Ported Enclosure JL Audio's High Output Enclosures are designed to deliver the ultimate high-performance bass experience with a rare combination of superb sound quality and awesome output. In the...
www.jlaudio.com
The difference was enormous, giving the punch to the toms, really bringing out the drone in deep organ and synth sounds, and giving an overall feeling of depth to the whole setup. If anything I found it a bit much, even at the right volume overall, but the DSP lets you get really surgical with stuff like this: I dropped a part of its frequency range in the 40 Hz area so that anything with strong kick drums didn't sound like Godzilla marauding nearby. Almost no one would ever do something like that to their sub, but hey, that's what making the system your own is all about. I like the deep tones, but not the punch.
As an aside, I thought about getting some underseat subwoofers as well. They're generally crap at being actual subwoofers and no one would actually recommend them for that purpose, but they're small and do a good job of essentially being superwoofers, adding more depth to your midbass range (and they're better than nothing if you have no room/dollars for a real subwoofer). But my driver seat has the power adjustments and my passenger seat already has two amps under it, so room would be an issue no matter how low-profile they are unless I went to the footwells, and in any case I had to stretch things to fit in the rear speakers: there's just not enough channels on the P Six to make it work the way I'd like.
If you want a sub (or two), there's a guy out there who makes sub enclosures especially for our gen of Birds:
Ford Thunderbird Sub Box Ford Thunderbird Subwoofer Box
Ford Thunderbird Sub Box Ford Thunderbird Subwoofer Box Thunderbird Sub Box Thunderbird Subwoofer Box Ford Thunderbird Sub Box Ford Thunderbird Subwoofer
netaudio.com
TUNING
So, I had all my components, quality stuff, properly installed. The result was ... solidly meh. I mean, it was hard to make all that gear sound bad, but it definitely wasn't anywhere near as much of a step up from my old setup as I had imagined. The reason, as I was to learn, was that I'd tuned my old setup to within an inch of its life over the course of a year of listening, making up for its weaknesses, while this wasn't tuned at all. Nothing was really in balance with one another, and more parts meant more things I could (and did) do wrong.
Fortunately my city has an authorised Helix dealer, which meant much more than the fact that they had the gear for sale. They also knew the ins and outs of the DSP and the complicated software that controls it, and also had all the tools needed to do a full tune.
A shop with a proper tuning setup will set up a mic on the driver's seat, wrapped around the headrest, and then pump various noise files over the stereo to calibrate everything. So instead of a general audio setup for the car, they're aiming to make things sound best for the driver over on the left (passengers can deal). This testing also reveals what sort of nulls and echoes your particular car setup has: say, your centre console and speaker position is combining to create a noticeable dip in the 350 Hz range, so we'll boost that a bit, and you've got too much of X because of reverberations over here so we drop that range a touch. They also take measurements of how far each speaker is from this driver position, and in turn calibrate the signal from each through the software so that the sound is reaching that position at about the same time (what is known as time alignment). Cars are awful sound environments in a lot of ways, but one of the big elements to this is that you're sitting much closer to some speakers than others, rather than having a nice central position where all the audio is symmetrically framed around you. The resulting time adjustment is only in milliseconds, but makes a clear difference.
In the end a tune is unlikely to sound "right" for you unless you're hanging out at the shop while they're doing it and are steadily involved in the process, because we all have our own preferences (and deafness levels), but it's a solid baseline for you to take over from and make your own subtle tweaks, as opposed to how I was where nothing I did sounded right because I was so far from that baseline that I couldn't even get close to a sound I liked.
____
That's a wrap. I hope there's more than just myself that finds this sort of thing interesting.
Last edited:
