SUV Audio Guide


May 13, 2000




After visiting many audio shops and searching online for info on upgrading my 1999 Tahoe's sound system, it is my firm belief that everyone out there seemed to have a different opinion about what I needed and should have. Confused and uneducated, I was really lost about what to buy and how much I should pay... THAT is why I decided to write this little guide for all those looking to replace your current stock system. (Note: This Epinion, although initially for SUV sound systems only, can be applied to all vehicles).

First, let me point out some differences between car and truck audio system layouts. With any full-size SUV, the one BIG BIG BIG difference is just that... it's big. Interior space in an SUV dwarfs even the biggest Cadillac because of the high ceilings and the lack of a enclosed trunk. This is good for storage and people moving but NOT good for creating a "sound stage" - the listening atmosphere. It is analogous to home theatre, where smaller rooms are generally easier to tune acoustics than a large room.

OK, now that I have addressed the issue of space, I will now mention the question that many people ask me when they hear my system... "How much did you pay?" Well, the fact of the matter is, with audio systems you get what you pay for. I am sure you have heard the stories of people actually spending MORE for the audio than for the car. That to me is just not logical, but to each his own, right? As for me... My system ran about $6,500... may sound like a lot of money but with an SUV, that figure is quite reasonable. HUH? What are you talking about? $6,500 is NOT reasonable at all... let me explain why.

When buying an audio system, you should really think about the type of music you listen to. Hip-hop, R&B, classical, pop, techno, etc... each can sound very different in the same automobile with the same system. Why? It all comes down to the acoustics of your car and your sound stage. In an SUV, music can sound very hollow because of the interior space. Sounds echo and depending where you are sitting, you might notice stereo separation. Stereo separation is the phenomenon where the sound entering your left ear is not at the same "phase" as your right. This can happen when the distance to the nearest sound source, such as a door speaker, to your left ear is not the same as the distance to your right ear. With SUVs being so wide, it is not uncommon for things to sound pretty funky with your stock sound system.

So how do you fix that aspect of your stock system? There is only really on way to do this which is to get a device to play around with "timing". Usually, a timing device, is a stand-alone unit that takes the output from your head unit (whether it be a cassette, CD, MD, or radio source) and electronically delays signals to each speaker to create a "stereo point". A good example of adding a delay to your music can be seen in home theatres. Ever wonder how you get that echo effect in Dolby Surround? Well, essentially, your receiver adds a delay to the rear speakers so that you hear the noise coming from the front faster than the rear... hence creating the illusion of an echo. Using the same sound manipulation technique , you can also setup a stereo point in your car... for the most part, the driver's ear is closer to the left speaker so by creating a little delay, you can "even out" the distance between the left and right speaker. Instead of having a stand-alone device, I opted to pay the extra money to get Sony's CDX-8850. This head unit incorporates a built in timing chip that allows for the stereo point to be centered in 7 positions: the driver's seat, the passenger's seat, the rear left passenger, the rear right passenger, front passengers, rear passengers or everyone.

Now that we have established a stereo point, what kind of speakers do you need to make that point worth listening to? Speakers also come in a variety of flavors. There are three main types that you can choose from: 2-way, 3-way, and component speakers. Some other types would be horns and subwoofers which can be added in to "complete" the overall sound stage. In case you don't know, components are multiple speakers that compliment each other. Usually consisting of a tweeter and a mid-range speaker, they can be equated to a home theatre bookshelf speaker with its separated tweeter and mid-range.

Components are used in high performance audio systems to create better sound separation between the high sounds and the low sounds. Also, if you have more than 4 speakers in your car, it is very likely that you have component speakers already. One the other hand, 2-way and 3-way speakers are just components in one enclosure... 2-way refers to a tweeter and mid-range combined into one speaker while 3-way adds an extra sub-mid-range speaker to the 2-way. ??? What's a tweeter, a mid-range, and a sub-mid-range speaker? Tweeters emit the high notes like cymbal crashes and high vocals. A mid-range emits sounds in the mid-vocal range such as human voices, and instruments. A sub-mid-range is a mix between a tweeter and a mid-range... personally, I can't hear the difference between a 2-way and a 3-way car speaker.

(Skip this paragraph if you don't want to read technical stuff.) More specifically, the human ear can hear frequencies between 20-20,000 hertz (Hz). Some people can also hear as low as 10-15Hz. and as high as 21,000 Hz. So what does that have to do with speakers? In order for you to hear sound from the speaker, it is given an electrical current that makes the speaker move back and forth to create the frequency at that particular point in time. So if you think about it, a speaker's job is just to move back and forth to the music (kinda like me when I am "trying" to dance...). So why are there so many types of speakers out there? The reason is simple... there is NO such thing as a single speaker that can accurately emit all the audible frequencies. There are some extremely high-grade speakers that can come close but those are just too expensive to even mention. That is why there are tweeters and woofers (woofers compromise all mid-range speakers and subwoofers). By combining all three, we cover the entire range of audible frequencies.

But why upgrade your speakers? For the most part, your stock speakers, even if you have bought an upgraded audio package from your dealer, the speakers are just made of weather treated paper. There are a few exceptions such as the Infinity sound system in the Jeep Grand Cherokee Limited, where the speakers ARE in fact high quality. In such cars, you might just opt to get a new head unit and/or more powerful amplifiers.

In my Tahoe, the stock "top of the line" audio system that I purchased came with treated paper speakers (I wasn't surprised). Paper is not a good material at all for sound reproduction. To get accurate and clear sound, the speaker should be made of extremely rigid material. Soft flexible material, such as paper, will bend and maybe even rip if too much power is applied to them... that is why stock speakers are replaced so much. Also, soft materials bend as they move so the sound won't be accurately reproduced. Conversely, aftermarket speakers are made up of synthetic material such as copolymers (similar to plastic), graphite, metal and even quartz. These materials are extremely stiff and can handle any abusive power you wish to subject them to plus they are not
susceptible to flexing.

My Tahoe, with it's stock 8 speaker setup, I opted to get A/D/S 3-series components in the front and rear and two 12" Boston Pro subwoofers enclosed in a sealed box in the back. I decided to disconnect the rear roof speakers because with two Boston Pro subwoofers that size, you'd have to be Superman to hear the rear speakers. These speakers and the subwoofers are competition level speakers, as I am an audiophile but, you should understand that THE MOST IMPORTANT factor in choosing the speaker is your taste in music!! If you like light music, small speakers will suffice... conversely, if you like to play your system so people four blocks away can hear, get big, powerful speakers. I also do not recommend buying speakers by the specs (range, wattage, etc.) alone. Speakers from different manufacturers may have the same features but they can sound VERY different from one another. I strongly advise that you go to an mobile audio retailer (or any place that sells speakers) and demo the speakers that you were thinking of buying.

Do I really need a subwoofer? No. If you listen to classical or light music where bass is relatively small, you will be fine with a decent component or 2-way speaker setup with large woofers (4x6 or 6x9). If you're taste in music is a little "harder", I really recommend you get a subwoofer. In SUVs, the space (here I go again...) works at a GREAT disadvantage. The way that subwoofers work is that they push and pull the air to create the compression waves that make the low frequency sounds... "boom boom". In an SUV, like a Tahoe, to move that much air, you will need big subwoofers. I originally tried out a single 10" subwoofer in my truck... 10 seconds later, after I stopped laughing, I put in two 10" subs. Much better bass but still not enough... so there I was installing my two 12" subs. Two 12" subs should suffice for anyone out to buy a well rounded and balanced system for your SUV... you have components to replay the mid to high frequencies and a sub to kick in the low frequencies.

With aftermarket speakers, it is rare that you will have enough power to drive them using your stock head unit's tiny internal amplifier. As with speakers, there are many types of amplifiers that you can buy. To make a long story short, always choose an amplifier with low total harmonic distortion (THD), and power that matches your speaker's RMS power rating. Why? Amplifiers with low THDs will prevent bad signals from damaging your speakers at any volume. Also, underpowering and/or overpowering your speakers eventually will lead to their destruction. Always remember that more power equals a louder system overall... I am using two Soundstream amplifiers; one drives my door speakers and the other drives my two subwoofers for a total of about 2000 watts. You probably won't need this much power but it is always nice to be able to expand your system later on.

I also recommend either getting an amplifier with a built in crossover or buying a separate crossover device. What for? Think about sending a low frequency signal to your tweeter... POP... speaker is dead. A crossover basically is a filtering device which breaks down the incoming signal, from your head unit, into sectioned signals: Low, mid and high. Lows go to the subs, mids go to the mid-range speakers, while the highs are sent to your tweeters. Not enough money to get the crossover? You can also get inline signal filters, which when connected to your speaker, allows only certain frequencies to get through. They are cheap and easy to install but they are not adjustable... unless you remove them and put a different filter in.

What about an equalizer (EQ)? Do I need one? Although not really needed, I just recommend one to further tweak your system for your specific car. As I mentioned earlier, if I were to put my system in any other SUV, it will sound distorted and unbalanced (either too much bass or too much treble). An equalizer allows the user to also match the music to his/her preferences... want more bass? want more treble? Usually, equalizers are integrated into your head unit (the little dials that say "bass" and "treble" do NOT count...) and consist of multiple sliders that correspond to a certain frequency range (if you didn't already, you might wanna look back at the paragraph that you might have skipped over up top regarding frequencies). Basically by moving each slider you boost or retard a specific frequency range... if you want more bass, you would boost the lower frequencies... if you want more vocals, you would boost the mid frequencies... if you want more highs, you would want to boost the higher frequencies.

What's next? The head unit (music source). I can go on and on but I will try to keep this short. I have a Sony CDX-8850, as mentioned before, from which I send a 4V signal to my amplifiers. It has digital signal processing (DSP), which adds echo effects and can simulate "Live" field effects (like being at a concert). THE most coolest thing about this head unit is its "Wide" field effect. When enabled, the sound can actually manipulated so it sounds like the speakers are wider apart... this can really make a small car feel larger (well... with an SUV, how wide do you want to be?? - Think Hummer). With a built in EQ and advanced sound processing, this is the best head unit that I have ever owned BUT, since this is not a review on the CDX-8850, let me just leave it at that... :)

But which one should I buy and what features should I look for? It is your choice as to what kind of head unit you buy and what medium you will use - cassette, CD, MD, and now DVD. My system is CD only... 11 CDs total - one CD in the head unit and a 10-disc CD changer. First, match your head unit to your ergonomics... Big buttons, little buttons, dials, the display, and security (like detachable face plates) are just some of the superficial aspects that you should consider when choosing a head unit.

As for the guts of the head unit, choose one that matches your dream system. If you want competition-level sound, spend the money and get a head unit like Sony's CDX-90. If you don't use your sound system that much, don't waste money on features like DSP or high power speaker line outputs. If you are the average person, you should concentrate on a balance between price and performance. What am I getting at? Be an educated buyer and research yourself. I think you know yourself better than I do. The only safe thing that I can say is that you should view the head unit as the heart and brain of your sound system, so care should be taken to choose the right one.

Finally (at last!), these components are useless unless you connect them together (duh?). Let me just say I was QUITE surprised when I looked at the receipt for wiring (power, and speaker). No one ever told me that wiring everything together would cost me $200 alone... For the average upgrader, with under 1,000 watts running within the system, you can definately expect to spend less than I did (by at least $100) but with systems over 1,000 watts, watts you MUST wire your system with 0 (yes, ZERO) gauge power wires and grounds... these wires are about an inch in diameter and really (REALLY!) suck your batteries dry without hesitation. Things to consider with a lot of power also include making sure your car can support the amount of juice that you pull from the alternator and/or battery.

In all vehicles, the moment your motor started, ALL accessories (like the power windows, power locks, radio...) are powered by the alternator. The alternator is basically a mini-generator which, when turning, creates electricity (I will spare you with the details on how electricity is generated as you are probably on your 4th or 5th cigarette by now reading this novel...).

In SUV's the alternator is already beefy, as manufaturers know that SUV's require more juice than your sister's Geo Metro. Well to tell you the truth, beefy wasn't beefy enough for my system... when the bass hit hard, EVERY light on my Tahoe (interior and exterior) would dim. Kinda cool... if you were in a dance club... NOT in a car as it became impossible to drive at night with my radio on. Options? There were three: Get a capacitor (cap), get a new alternator, or add another battery. Option one was too difficult to install and getting a new alternator would set me back $250 (with installation). So option three it was. Adding a new battery to a GM truck is so EASY. Why? In late model GM truck engine bays (other manufaturers may have this too but I am not too sure...), there is a second battery mounting area!! It was easy as dropping the new battery in (I highly recommend Optima Spiral-Cell batteries - they last longer) and wiring up a relay switch, which turns the second battery on only when the key is in the ignition. No more light dimming problems and no worries that any other electrical device in my car wasn't getting enough power. On a side note, adding a second battery wasn't only for the stereo as I found out one morning after I left my interior lights on... I was just about to call a tow truck when I realized that I had two batteries. I jumped myself...cool. :)

Moving on... High quality speaker wires are also a must for any aftermarket system. The signals to your amplifiers (or speakers if you don't have an amplifier) are sensitive to electromagnetic fields (EMFs). The most apparent sign of EMF contamination is a high pitched background noise, coming from your speakers, when the engine is on and/or accelerating. EMFs can also come from the power lines running within your vehicle. To prevent noise from entering into the signal, you should invest in some high quality shielded speaker wires. Also, for high power speakers you should also get thick gauge wires so there is minimum resistance for the high powered signal to transmit through.

Upgrading my SUV's audio system was a long and expensive process (sadly, it's still not over as I want to add some LCD TV's in the back to shut up any backseat drivers). Originally, I walked into my local stereo shop thinking that I would spend about $2,000 (like my friend who upgraded his Acura Integra's sound system). *sigh* Obviously I was underestimating. I didn't take into account the amount of space that my SUV's system had to fill with sound. Overall it was a learning experience with a lot of setbacks and mistakes. I initially decided to do the whole upgrade myself in my garage but after estimating the time I'd waste pulling my Tahoe apart, I felt it was worth getting the system put in professionally. In addition, don't worry if your initial product choices don't satisfy your needs. I went through 5 head units (3 Sony, 1 Alpine, 1 Panasonic), 6 different amplifiers (each more powerful than its predecessor) and 3 subwoofer boxes before I was happy.

Lastly, as hinted before, a system should not judged by how pretty it is or how powerful it is... The perfect system is balanced, where no component overrides any other and all the components work together to give you the sound that you want to hear. My system does just that, which is the reason why I can justify $6,500 as reasonable. Still disagree with me? Read the entire thing over again. Repeat if necessary :) Just kidding.

Thanks for reading my Epinion and feel free to leave all questions and comments (good or bad) you want.



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