Building a Mobile Listening Lab

Rear speakers, amplifier, and subwoofer

MLS — Mon, 09 Nov 2009 19:04:00 GMT

Now that the front door speakers were in -- and we could ably demonstrate the difference between the front aftermarket and rear factory speakers -- it was time to install the new rear speakers. Matt and I decided that this next phase would be big; not only would we be mounting JL Audio C2-650X full-range 6-1/2"s in the rear doors, but we would be installing JL's magnificent new HD 900/5 five-channel amplifier under the rear seats, adding a JL ProWedge 10" W7 boxed subwoofer, and wiring the whole system with Streetwires 12-gauge speaker wire. While threading the 12-gauge wire into the rear doors would prove to be challenging, the rest of the installation went quite smoothly -- thanks to the acres of room afforded the backseat area by GMC.

Choosing rear speakers
Since I do all of my listening from the front seats, and since our goal is to create a truly high-performance system without using top-of-the line components exclusively, we decided to put a set of mid-level, full-range speakers in the Yukon's rear doors. Since we went with JL Audio C2 components up front, it was a no-brainer to voice match the rear speakers as much as possible. A quick check of our installation database confirmed that the C2-650X models would fit.

At left, the Yukon's factory rear speaker; at right, the JL Audio C2-650X coaxial:

The larger magnet structure, better basket construction, and superior sealing of cone to basket flange give the impression that the speaker on the right will perform better when mounted in a door panel:

We knew we would have to run the speaker wire through the existing wire looming from the body of the vehicle into each door:

Exposing the flush-mounted wiring harness in the door jamb:

So we pull out the harness and discover that there's precious little room to run any additional wire, to say nothing of high-performance, 12-gauge speaker cable. Oops? Well, almost -- the brilliant Matt Freeman peeled back StreetWires' clear jacket and wrapped the positive and negative strands on either side of the plug, in the plastic grooves:

Major installation hurdle negotiated, the harness is once again in place and yes, we struggled (successfully) to wrap the looming back on top:

I should note that when screwing in the speakers, I had to be careful not to overtighten, as the bolt head seemed to stretch the speaker surround quite easily. Another small issue with the speaker design were the connecting posts -- they were thin and pliable and weren't stiff enough to scrape through some stray solder on the speaker wire's spade connectors, forcing me to re-attach new spade terminals. Neither of these were issues with the higher-end C2s up front. Relatively small concerns, as the speakers sound smooth and sweet in the back seat.

Choosing amplification
When we started this project at the beginning of the year, we didn't anticipate using JL's killer 5-channel amp, which wasn't to be on the market for several months. And we figured we'd be working slightly quicker than at the snail's pace into which we've seemed to settle. The original plan was to connect a four-channel amp to the main speaker system and use a mono or bridged-to-mono stereo amp for the subwoofer. By the time we were ready, however, the HD 900/5 was in house and seemed the perfect choice for our Hi-Fi 2.0 project. Audiophile-grade and Class D means efficient high-fidelity. These things run cool, never shut down, and control your speakers effortlessly. I’ve wanted one of these amplifiers ever since I heard them demoed at CES 2008 (Consumer Electronics Show – our industry’s biggest trade show, held in Las Vegas every January). JL had a Beetle wired up for true high-fidelity, and these amps were at the core of a mind-bogglingly accurate car audio system.

Amplification was the one gear category where we knew from the outset that we would go top of the line. That's because the power source is the heart of an audio system. When we later fired up the system, the difference the amp made was obvious; an amplifier is the force behind your speakers, similar to the way a musician ‘powers’ his or her instrument. We put the Keith Jarrett Trio’s latest disc “Yesterdays” in, and the tonal complexity, warmth, and level of detail was so pronounced it just made us laugh. I think the harmonic richness of Gary Peacock’s upright bass is what hit me first, followed quickly by the delicate sparkle of Jack DeJohnette’s ride cymbal dancing around Keith’s resonant Steinway articulations. You’re never really ready for that kind of experience in a car.

(A note about the power wiring: Since we realized that we would be powering the entire system with this super-efficient, low-profile technological marvel, we realized that we wouldn't be needing the 1/0-gauge power wire coming off the battery into a distribution box with multiple fuses, outboard capacitor, etc, and running individual 4- or 8-gauge power leads to each amp. All we needed was one length of StreetWires 4-gauge to stretch between the battery and the amp. So, we disconnected and removed the StreetWires PowerStation capacitor, pulled the 1/0 cable we had used to pre-wire the vehicle, and ran the smaller wire in its place. Sure, that was a bit of a drag -- unnecessary step -- but at least it was easy. We simply tied the new wire to the old wire and pulled the new 4-gauge through as we removed the 1/0-gauge cable. Such are the vicissitudes of spending a year on a vehicle overhaul.)

Running RCA patch cable from the rear panel of the radio ...

... rightward behind the glove box ...

... down behind the right front kick panel ...

... along the floor trim ...

...and to the amp location, joining the power and speaker wiring (speaker wire not visible in this picture):

The controls are easy to access under the seat (and are nicely hidden behind an elegant, removable metal plate) and they give me total flexibility over each set of outputs. High- and low-pass selectable, continuously variable filters with adjustable slope, multiple channel configuration, input sensitivity, subsonic filter, etc.

Listening, evaluating, and making these kinds of adjustments is nothing but fun for me. It's like tuning a fine musical instrument.

Just after I made all the adjustments. Flip the seat down, turn on the stereo, and it's ready to pump:

Choosing a bass speaker
With respect to the subwoofer, I considered a few options. I gave very serious thought to replacing my front, between-seat console with a JL Audio Stealth Box, but ultimately decided against the idea as I would have lost my rear A/C ducts and front seat cup holders. The cup holders could have been remade with fiberglass, but sacrificing rear seat climate control was too steep a price to pay for low-frequency high fidelity. If this vehicle wasn't also the family road car, I would have done it in a heartbeat. A Stealthbox would have been a true hi-fi solution, as they're designed specifically for a vehicle's physical and acoustical environment, utilizing a high-end 10" W3v2 subwoofer in a super high-quality, handcrafted enclosure (which would be located in the listening area of the vehicle's cab).

So, what could be our great-sounding alternative? Matt and I explored the driver's side rear quarter panel factory subwoofer location to see if a stealthy replacement could be managed. We could have installed an entry-level 8" sub of some kind, but the results would have been less than ideal: moderately deep bass physically separated from our listening area. We decided to go with a high-quality loaded sub enclosure and position it right behind the rear seats. When I have passengers in the back, the woofer fires into the seat back; when I don't, I pull the seat back down and enjoy unobstructed low end. It takes time to gradually break in a new woofer, and this one sings a little sweeter with every passing day. I love it.

So, here again, we really are going top of the line with a JL Audio ProWedge: solid-as-a-rock cabinet construction loaded with the best subwoofer they make. From symphony music to slamming electronic beats, this woofer fills my enormous vehicle with bass energy -- and barely breaks a sweat doing it.

Note: while the picture below looks nice, it's not set up optimally. For safety, the enclosure should be secured to the floor. I've also discovered that if I position it in the middle of the left-hand seat back and turn it around to fire into the seat, the response tightens up considerably. And if no one's occupying the spot, the seat back can be folded down for greater clarity:

Next up: applying more Dynamat to previously untouched surfaces and Alpine IMPRINT [TM} signal processing. Stay tuned.

[Once again, installation photos were taken with Canon's versatile and fun EOS Digital Rebel XSi SLR camera]

Video: factory vs. aftermarket speakers

MLS — Mon, 14 Sep 2009 12:37:00 GMT

OK, so we finally got the video formatting worked out. It's very informal; Matt sat in the back seat with the Canon XSi camera capturing our back-to-front-and-back-again fading demo by moving the camera's built-in microphone forward and backward along with the fades. We're listening for sonic improvements (detail, tone quality, dimensionality) when we fade to the JL Audio components up front from the stock GM speakers in the back. Check it out and see if you can hear the difference.

(Please visit the site to view this media)

Installing the front door speakers

MLS — Mon, 27 Jul 2009 17:04:00 GMT

In keeping with our goal of achieving high-fidelity sound without springing for the “high end” (JL Audio ZR series, Polk Audio Signature Reference, the crazy-good Focal Utopia Be, etc) we chose to install a set of the brand-new JL Audio C2 650 components in the Yukon’s front doors. For now, we’ll be powering them with the Alpine CDA-9887’s 18 watts RMS per channel.

Scoping out the mounting locations
Matt and I started on the driver’s side and quickly discovered that installing the new speaker system would require a minimal amount of customization. Pulling off the door panel and looking at the factory speakers, we realized that the tweeter was part and parcel with its mount. Removing it just left a big hole – far too big to accommodate the flush-mount adaptor that comes with the C2s. The factory woofer was snapped in place via mounting tabs at the top and bottom of the speaker. This mounting configuration would, of course, hold true for the passenger side door, so we now had a better idea of the scope of this part of the project.

Mounting the drivers
We marked the woofers’ mounting hole locations in the door frames and drilled through with an 1/8” drill bit. We would also be placing Boom Mat acoustic baffles in the opening, but they don't need mounting holes -- their foam construction allows for easy drilling anywhere on the baffle lip. The cavity behind the door frame was spacious – clearly enough to hold the woofer and the crossover network. The large opening for the factory tweeter/bracket, on the other hand, needed to be adapted down for the C2 dome. Before fabricating something, though, we worked with the factory bracket to make sure there wasn’t some sort of way to keep using it – either by cutting out the built-in tweeter and replacing it with the new one, or by surface mounting (2-side tape? Velcro™?) the tweeter on top of the factory tweeter, as it looked like it would still fit under the door grille easily. I thought the surface mounting idea was pretty clever until Matt astutely pointed out that there would be no easy way to route the wires back behind the door panel. Drilling into the plastic factory mount probably would not have been a successful experiment. Likewise, cutting out the plastic factory tweeter would have likely resulted in a mess. So fabricating a mounting bracket was beginning to look like the best solution. But how? Clearly, whatever material we used, we’d have to affix it to the door panel plastic somehow. Hmm. I looked around our installation bay, my eye catching the open box of Dynamat next to the truck. Eureka, the solution was apparent in my mind’s eye. Stretch a piece of it across the back of the opening, cut an “x” into it, push in the C2 tweeter’s surface mount cup, reinforce with more Dynamat if necessary, and violà: a secure mount.

Placing the crossover
Rather than simply tossing the crossover network into the bottom of the door cavity, we were inspired by our Dynamat tweeter mounting trick to do the essentially the same thing here. In this case it would be a simple matter of cutting into the Dynamat that we had already installed into the door many weeks previously, placing the crossover and reinforcing with some additional Dynamat. This would allow for a solid, easily accessible mount and minimize the lengths of speaker wire we’d need to add to the factory wiring.

Connecting and routing the wires
The Crutchfield-provided speaker wiring harness was helpful in giving us a snap-in connection to the Yukon’s speaker wiring system, but we were on our own making the rest of the connections. I cut off the harnesses’ speaker-side ends and crimp/soldered male spade connectors in their place. “Crimp/soldered,” you ask? Well, yeah. I don’t completely trust a crimp connection that’s going to live in an in-motion, difficult-to-access location; yet I certainly wasn’t about to solder connections directly into a crossover device or onto speaker terminals that I might want to remove in the future. So I crimped on the spade ends, but reinforced those connections with a little solder inside the metal sleeves that house the bare wire.

The C2s don’t come with any speaker wire, so I grabbed some from our installation bay and cut four pieces just long enough to reach the speaker locations without being taut or bunching up in the door cavities. Again, male spades on the crossover side, but females for the woofers and males for the tweeters. The tweeters had short lengths of wire already soldered onto contact points – rather than actual wire terminals – on the side of their housings. Unfortunately, one of those contacts had come loose in shipping, and we were faced with having to reconnect a wire with no actual terminal to use. We really didn’t want to take the time to send the tweeter back to JL Audio for an exchange, so Matt decided to join me at the soldering bench and solve the problem by soldering the wire directly back on to the lump of JL factory solder. The connection held.

Pet peeve: whoever’s making speaker wire without marking or color coding the strands so one can easily discern positive from negative at each end, this camper was not happy. ; )

The sound
Upon completing the driver’s side installation, we let the stereo play for a little while as we cleaned up the installation bay (we saved the passenger side door for another day). We had both front doors open and the difference in sound quality when we walked around the back of the truck was astounding. It was as if there were two different stereos playing. Walking left to right revealed a diminishing in presence, detail and tone. We knew we were definitely on the way to a major sonic upgrade. In the next couple of days, I will post a video a video demo to give you a sense of the overall improvement once we finished the passenger side.

Photo Gallery (Taken with Canon's hot EOS Digital Rebel XSi SLR camera)

Passenger side door woofer opening. Note our wiring harness (connected to factory wiring plug) with new spade ends, ready for connection to the crossover:

Matt (well, arms & torso, anyway) with baffle and JL Audio C2 650 woofer:

Matt drilling holes into door frame after using the speaker to mark hole positions:

Back of door panel view of tweeter mounting hole covered by a piece of Dynamat:

C2 650 tweeter with equipped wire connected via spade connectors to extra speaker wire (soon to be attached to the crossover):

Front of door panel view of tweeter mounted into the Dynamat strip:

The spot directly behind the dangling black connector is where we would cut through the Dynamat to mount the crossover:

Crossover mounted into Dynamat below the woofer:

Securing the woofer in place:

Closeup of the mounting area:

Dynamat installation and pre-wiring for amplifiers

MLS — Thu, 07 May 2009 16:57:00 GMT

So a couple of weeks ago we made some major headway on the project. Matt Freeman, our mobile electronics catalog editor and Michael Richardson, Crutchfield mobile installer extraordinaire, and I spent a day double-lining each door with Dynamat Xtreme and routing the 1/0 Streetwires Ultra Flow power cable into the truck.

Double-lining the doors might sound like overkill, but by clamping down on the vibrations of the actual skin of the vehicle, you're really taking a serious bite out of road noise. Couple that with a solid sonic barrier on the interior panel (and covered gaps in the framing) and you add the benefits of increased isolation from external noise, reduction/elimination of internal buzzing and rattling, and better sound damping within the cab.

Instant luxury car
The difference was immediately apparent upon climbing into the front seat at the end of a pleasant day's work. Before we even turned on the stereo, we could "hear" the quiet. It felt like being in a professional recording studio. I popped in a disc of some of our final and near-final mixes. For the first time I could hear bass guitar articulations previously inaudible. The upper midrange was much more sculpted and clean, thanks to the reduction in reflections and reverberations. I turned the key. Engine noise was no problem; I could still hear everything clearly, without notching up the modest volume level, allowing Matt and I to share thoughts - in conversational tones -- about what we were hearing.

The GMC Yukon became a Lincoln Navigator. Stereo or no stereo, I highly recommend an application of Dynamat to transform your ride to a dead-quiet one. I wish I had taken a before/after dB reading. I have no doubt we'd have seen at least a 3 dB difference.

Prewiring for the amplifier installation
Michael found a location high and to the right of the brake master cylinder with plenty of surface area into which he could drill a hole big enough to accommodate the garden hose-sized power cable we ran from the battery to the rear of the truck. The original plan was to put both planned amplifiers (a 4-channel for the 2 sets of speakers and a sub amp) in the cavernous space under the rear bench seats. However, Michael astutely demonstrated how the rear seats fold collapse down and fold forward, giving me a Chevy Suburban-like cargo area. Given the potential need to haul music gear, I'm sold on the idea of keeping the floor clear.

So now I'm thinking about putting amplification in the rear quarter panel storage area. There isn't room for two amps, though, so I'll either have to find a spot for a second amp elsewhere or rethink the need for two amps. (I really want a stealthy installation.) It's possible I could get a 4-channel amp to drive the front components and the subwoofer, while relying on the Alpine CDA-9887 head unit's internal power for the rear door speakers.

I'm open to suggestions.

(Oh, and thanks to Jason, a loyal customer who contacted me with some great ideas from his Tahoe installation and generous offer of service manual info. I'll be in touch.)

Pictures from the day:

Super-installer Michael Richardson is so smooth with the
knife that he applies Dynamat with left-to right readability,
no visible seams, and an absolute minimum of wrinkles
(above). He readily acknowledges that no one will see
his perfect work once the door panels are re-hung, but
for him it’s a higher calling. (While I was satisfied with
my own work, rest assured I won’t be posting any
pictures of it.)

The same door with the panel back on, before re-attaching
the sail panel. Michael’s super-clean work is again apparent.

The inside of the Yukon’s left front door panel. You can
see the cut-out for the woofer (mounted in the door frame)
and the actual tweeter mounted in the panel itself.

This picture demonstrates the way we cut pieces of Dynamat
Xtreme to fit within the bracing. We also have a Dynamat hoodliner
we'll add later.

Here’s the right rear door with the panel removed, just
prior to an application of Dynamat. Note the factory
whizzer cone speaker with fabric stretched across the driver.

I took that speaker out in order to fully cover the factory
opening in the door frame (at Michael Richardson’s
excellent suggestion). I was then able to cut a hole
for the speaker in the Dynamat itself and drop the
speaker back in, thus ensuring a solid seal behind
the speaker. No noise or air is getting around that thing
now. Can’t wait to put some “real” speakers in there soon.

Remember I mentioned double lining? The left rear door
was the first one we did – before deciding to double line.
Therefore, I had to piece the material in behind what I had
previously installed – to cover pretty much the entire skin
of the door (ouch). Oops, I said I wasn’t going to show you
my work …

We chose to route the power wire straight back from the
battery to the firewall on the right-hand side of the engine
compartment.

Ultra Flow cable feeding into the vehicle’s cab via a hole
drilled into the firewall.

The cable comes through on the driver’s side.

Laying the Foundation, Part 3

MLS — Tue, 27 Jan 2009 00:02:00 GMT

Now that the receiver's in and the iPod is hooked up (see my first two posts for the full scoop), what about equalization and other signal processing for the system?

While I wait to deploy what is likely the ultimate in customizable equalization for a car - Alpine's IMPRINT^TM sound tuning system -- the CDA-9887 by itself provides solid parametric and graphic equalizer options. Parametric EQs are always welcome audiophile tools, as they allow precise adjustment of specific tones with minimal effect on surrounding frequencies. I use ‘em in the studio to, for example, filter out line noise from a guitar amp without changing the tonal character of the guitar. They're also great for tightening up a "boomy" sound, or even to add resonance to a brittle sound. Piano's left-hand bass line buried in the mix? A little parametric dab'll do ya.

The built-in graphic EQ features 10 factory-assigned and six user-programmable presets. The ones from Alpine are named by musical genre, and I had fun scrolling through all of them. That kind of thing is not really my bag; but it was instructive to hear the various colorizations of the sound, as they suggested possible approaches we could take with our mixes. At the very least, I have to give Alpine props for the naming of the presets; they certainly seem apt. As to the user-configurable presets, my buddy Jeff, a car audio/video buyer here and a savvy listener, took it upon himself to subtly sculpt out some upper midrange resonance, elevate the mid-bass and add a touch of top-end sparkle. Voilà, another flavor. Too bad this thing won't allow the user to title their presets or I'd name it after him.

My favorite signal processing feature from Alpine -- and a true hi-fidelity enhancement -- has to be Time Correction. At home, the listener can painstakingly optimize speaker placement, plop herself down in the room's "sweet spot," center close her eyes and hear a musical ensemble magically and accurately align itself in front of her. Vocalist in the center, drummer directly behind, guitar to the left, bass to the right, horns in the back and to the right, etc.

(Image courtesy of Alpine Electronics of America)

In the car, the speakers can only be placed in designated locations determined by auto engineers as low-priority, low-cost considerations. The listener - unless he is an 8-year-old child or Labrador retriever commandeering the middle of the rear seat -- has to sit at the extreme left or right directly in front of a single speaker. To address this problem, Time Correction delays the signal to the speaker closest to the listener, fooling the brain into thinking the sound is traveling a greater distance - equal to the distance of the farthest speaker.

To set it up, all you need is a tape measure or Jeff's incredible ability to visually gauge distances to within an inch. Sit in your listening position and measure the distances to all the speakers. Subtract the distances to all but the farthest speaker from the farthest distance, divide by the speed of sound at 20°C (it's in the manual); the resultant times are the time correction values for the various speakers in your car. And what's even more amazing is that you can store all of those values in memory, so everyone in the car can be in the sweet spot. Not at the same time, of course; now that would be some seriously cutting-edge technology.

So, in terms of sound quality, it seems that our Alpine stereo and iPod nano combination is doing the trick. I should probably even mention Alpine's cool Blackout Mode feature, which you can set to cut energy from the lights and display after 5 seconds of non-use of the stereo. Meaning, the machine winks out when you're not touching it, thereby diverting power to the audio section for even better sound.

Now what's the next step? Speaker replacement, I'm thinking. I have provisions for 6-1/2" component speakers in the front doors and 6-1/2" full-range speakers for the rear doors. We'll put those in and see how they sound, powered by the 18 watts RMS that the CDA-9887 cranks out into four speakers.

Thoughts? Comments? Suggestions? Let's hear 'em.

Thanks for reading, and don't forget to get your groove on.

Laying the Foundation, Part 2

MLS — Mon, 26 Jan 2009 23:26:00 GMT

So, what effect did replacing my Yukon's factory radio with the Alpine have on the rest of the factory system? (See Part 1 for background.) It really notched it up, no kidding. Fatter bass, more dimensionality and presence. The kinds of things you'd associate with a cleaner signal path and better amplification -- all vastly superior in the aftermarket head unit. Although I did discover that this particular Yukon's factory system contains outboard amplification (not the well-known Delco/Bose® system, which would have required an OEM interface adapter in order to use the CDA-9887). That means that the factory system is re-amplifying the signal (as well as noise and distortions) coming off of the new receiver's speaker outputs. To my way of thinking, it's a testament to the cleanliness of the Alpine's audio circuitry that there was still such a dramatic improvement in sound quality.

I've been using my iPod nano quite a bit with this new rig. Typically, I'll load in my tunes as lossless 16-bit .wav files (homey doesn't do lossy file formats when engaging in critical listening) and navigate them with the 9887. (Note: I have to downconvert my 24-bit mixes in iTunes, because the nano won't play them. I assume it won't be long before Apple releases upgraded firmware that will accommodate even higher resolution files.) The CDA-9887's iPod navigation system is so impressive for a car stereo, it's worth mentioning here. Just as when I use my iPod by itself, I can browse by Playlist, Artist, Album, Song, Podcast, Genre, and Composer. If I want to, I can scan my full library and access songs directly; I can even skip over dozens of them at a time with a cool feature called Percentage Search.

From a sound quality perspective, hooking up the iPod with the Alpine Control Interface cable allows the nano to feed digital information directly to the Alpine's high-end digital-to-analog converter -- bypassing its own DAC and its relatively noisy internal headphone amp -- for smoother, more nuanced sound. Essentially my iPod functions as a fully controllable external hard drive that I can load down with large .wav or .aiff files and still have room for a big chunk of my iTunes collection.

Not that I listen for pure enjoyment much in the car. Mostly, I use my commuting time to listen to our CD-under-construction in order to make mixing decisions. By the time I get back into the studio for another crack at a mix, I have a pretty good idea of what needs to be done. If I really need to concentrate, there are a couple of nice parks I drive to, where I switch off the engine and settle back and listen. Sometimes, these moments even trigger ideas for changes to arrangements and/or orchestrations.

The repeat play feature comes in very handy when evaluating mixes; I might need to listen to a track repeatedly over many drives (it's probably best I travel alone, huh?). I find Shuffle to be a very useful playback mode, as well. Hearing our compositions in random order gives me an idea as to how well the tunes stand on their own, without dependency upon what precedes or follows them. Alas, an artist can't assume that listeners will be hearing a group of songs as an interdependent work of art these days. It's a good thing Abbey Road came out in 1969.

Laying the Foundation, Part 1

MLS — Mon, 26 Jan 2009 15:18:00 GMT

As you might have read in Crutchfield's Winter/Spring 2009 catalog (read article), I'm in the midst of a piece-by-piece overhaul of the factory sound system in my 2002 Yukon. While I have owned a few cars in my time, and have been a car audio hobbyist since high school, I can safely say that I've not been faced with a project remotely like this one. See, the thing is that I've never had a car with a body bigger than that needed to house a 2.4 liter, 4 cylinder engine. Anyone reading this who knows me is likely to be more than a little surprised that I'm driving something about the size of a studio apartment. As it turns out, my folks got a new truck and I got the fantastic deal only their child could get. And truth be told, I'm digging the comfort level and the surprisingly quiet ride. Even my anti-SUV, environmentalist children have found a way to grudgingly appreciate the leather seats, generous leg room, and plethora of reading lights. While the factory stereo sounded better than I thought it would, it wasn't nearly good enough to feed my music obsession.

I'm a musician in my other life, and at the moment my band, Soko, is working on a new album. (I still use that term; why not? "Album" doesn't mean "vinyl," either.) So for the next few months, I'll focus on my own music every time I find myself around a playback device. In addition to my home studio, I'll be listening to our works-in-progress on my home stereo, my iPod®, my daughter's boom box, my friend's high-end system, and any other piece of gear I can hijack. Since I do most of my music listening in the car, it's a no-brainer that I'll need to outfit the Yukon with the best possible gear I can afford.

The first step in the upgrade process was to replace the factory in-dash radio/CD player with an Alpine CDA-9887. In addition to its ace iPod control capability, I chose the Alpine for its high-fidelity characteristics: 24-bit Burr-Brown digital-to-analog converter for more detailed and lifelike sonic resolution, sophisticated onboard signal processing, and --- what I'm particularly excited about -- the ability to add their KTX-100EQ IMPRINT^TM sound-tuning kit. IMPRINT is a super-powerful equalization technology that corrects your system's performance to compensate for your vehicle's specific acoustical anomalies. (Trust me, your car didn't roll of the assembly line engineered to have the sonic sensitivity of a concert hall.) While I'm tempted to try out the KTX-100 right now -- it's sitting on my desk, looking at me -- I'm going to hold off and wait to complete the full installation of the new system before fully tweaking it. After all, part of the goal of this blog is to share with you the incremental sonic improvements I'll be making as I add speakers, amplifiers, subwoofers, acoustical treatments to the doors and side panels, and an improved power generation system.

Installing the new receiver was a snap. Removing the dash trim was simple matter of releasing some plastic clips, and out it came. And taking out the radio was even easier; all I had to do was press a single retaining clip and it slid right out. Didn't need to touch the screwdrivers and wrenches I had laid out beside me. Crutchfield's included installation kit centered the radio in GMC's 1-1/2-sized factory opening and trimmed it out nicely. I had already wired the 9887's wiring harness to our included GMC harness, so making all necessary power and speaker connections was similarly easy: connect a single plug to a jack. Connecting a new radio to the antenna in General Motors cars requires a simple plug adapter, so I did that, too. I also connected Alpine's iPod control cable to a pigtail jack hanging off the back of the new radio, and dropped the cable down to the glove box directly in front of the passenger seat. Piece of cake -- now I'll be able to operate my nano from the stereo and enjoy the best possible fidelity.