Question  Questions


I'd like to thank all my site visitors and everyone who has taken the time to send me E-Mail.  A lot of people end up asking many of the same questions about my audio system and my car.  I've put this section together as an attempt to address some of these questions.  Be sure to check back periodically as I will continue to add to this section.

bluebull.gif (339 bytes) "I'm planning on building a subwoofer enclosure for my audio system.  Could you send me the measurements & specs for your box?"
 bluebull.gif (339 bytes) "I always see people face their subwoofer enclosures into the trunk.  Why did you face yours forward?"
 bluebull.gif (339 bytes) "I have a subwoofer system in my car and I hear rattles everywhere.  How did you get rid of yours?"
 bluebull.gif (339 bytes) "How do you find the best tweeter mounting location, and why did you mount yours behind the mirrors?"

bluebull.gif (339 bytes) "Why is your dyno horsepower less than what the car is rated at stock?"
 bluebull.gif (339 bytes) "How can I make my car faster?"
bluebull.gif (339 bytes) "I'm looking for a performance catalytic converter.  Where did you get yours?"

bluebull.gif (339 bytes)"How do I remove the rear hubs/bearings if they're badly rusted?"


Q: "I'm planning on building a subwoofer enclosure for my audio system.  Could you send me the measurements & specs for your box?"

I could give you the specs on my box, but they'd do you no good.  The box depends very very much on the model/brand of woofers you put in it and your musical tastes. As far as dimensions go, I built the box into the trunk and really don't have any written down or anything.  Trim panels cover everything so it's tough to measure.

Measure the inside of your trunk and figure out how much space you're willing to give up for the pursuit of better audio.  Depending on how detailed a box you're willing to build, figure out the rough internal volume.  Then compare that to recommended enclosure volumes for the subs you have or the subs you are considering buying . Typical requirements for most sub brands can usually be found on their manufacturers' websites.  I know that JL Audio has some great tutorials on box design and has a lot of recommendations for their subs.  I'm sure other manufacturers have the same. Or, you can ask your local car audio shop what designs/brands they've had the best results with and see if they agree with your listening tastes.

I built my box more than 5 years ago and subs needed quite a bit more air back then to give great performance.  (My box is 5 cubic feet which most would consider h-u-g-e).  Today's sub setups don't need nearly as much airspace which makes it easier to build a box into a given space and still have some trunk left.   Plus, you'd be amazed what two good quality tens will do these days in a small (but optimum) enclosure - give that setup some consideration because it usually performs well for the least amount of trouble/box size.  Building the enclosure to fit four tens like I did in our cars isn't an easy task.

When I built mine, I used the lightest wood that I could find - which kind of goes against most car audio logic.  Usually you want the heaviest densest wood so the box doesn't resonate and color the sound.  I used the lightweight wood, but made sure to internally brace the box every 6 to 8 inches to make it incredibly stiff.  I went through all this trouble so the box wasn't insanely heavy and didn't affect the car's mileage or performance.  When completed, my 5 cu ft box itself (both pieces - refer to the pics) probably weighs a hair less than 50 lbs.  After removing the interior trunk panels, carpet, spare tire, etc., the car gained around 75 lbs with the audio system (over stock) which wasn't bad.

"Q: I always see people face their subwoofer enclosures into the trunk.  Why did you face yours forward?"

The question I asked when I built my system was, 'Why does everyone face their subs into the trunk?'. 

When I built my system, I faced the subs into the car's interior for two reasons.

1)  All of the other speakers are in the car and that's where my ears are.  Facing the subs into the car instead of the trunk gives the bass better clarity and impact, at the expense of a bit of loudness.  If you build a quick generic box (or if your final box is small enough), you can face it both ways and judge which one you like best.  Facing the subs into the trunk takes advantage of the car's transfer function a bit better, but it also increases delay & arrival time which takes away from bass clarity & detail and how well the sub-bass seamlessly becomes a part of the music.  Most people face them backwards because they want it to be as loud as possible, and because they see that's what everyone else is doing.  If you take a look at some of the best competition vehicles, the subs are actually in the front of the car - like in the kickpanels, under the dash, or in the floor.  Since that wasn't an option for me, this worked out well.

2)  With no subs firing into the trunk, there are absolutely no rattles from the trunk.  I didn't have to apply a lot of Dynamat back there, which saved time, expense, and weight.  The front face of the box seals off the air inside the car from the air inside the trunk.  Instead of the subs having to move the air inside the trunk (as well as rattling a lot of metal and plastic), mine move the air inside the car.  And it sounds great - but your mileage may vary based upon your design, listening tastes, and system setup.

If you're building an SPL vehicle or you listen to rap and want to rattle your fillings out and annoy people like me when you drive by, then face the subs backward.  You will probably gain a bit of loudness.  If you really enjoy listening to a wide variety of music and value sound quality (the novelty of sheer loudness wears off quickly), try facing them forward.  I don't think I gave up much loudness in order to enjoy some incredible sound quality.  I listened with an enclosure facing both ways, and after making a comparison it was an easy decision to make.

"Q: I have a subwoofer system in my car and I hear rattles everywhere.  How did you get rid of yours?"

If you have subwoofers in your trunk you're in for a ton of rattles - especially if you have it facing backward.  You can spend all the money you want, but it will take a lot of time and effort on your part to get rid of those rattles.

There is one easy cure to get rid of most of them - face the box forward into the interior of the car and seal off the front of the sub box from the airspace of the trunk.  That's exactly what I did with my four 10s.  It works so well it's damn amazing.  I have minimal amounts of asphalt-backed mat in the trunk to help silence the few that I did experience.  Otherwise, you may just have to take absolutely everything out of there and find the rattles by trial and error.  Facing the sub(s) forward may be slightly quieter, but it will definitely sound more detailed with better clarity and much less boomy - but how your sub(s) sound is strictly a matter of personal preference.  By all means, facing your enclosure both ways is worth trying if you have a moveable box.

Some people cover absolutely every metal surface in the car with mat or deadening spray, but that gets expensive and heavy.  I knock on a panel with my knuckle.  If it rings or rattles, cover it with mat.  If it doesn't, leave it alone.  You may need to remove all of your tail lights and various plastic interior pieces and apply sticky-back felt or home weatherstrip foam to the parts that rattle against each other.

Other than the trunk, you may find other areas that make noise that you wouldn't really expect.

On my 94 SC2, there were rattle(s) from the underside from the exhaust shield.  Some of it I covered with asphalt-backed mat, other parts were made silent by wedging small wood blocks in strategic areas.  I admit, it looks a bit weird but it cured all the rattles.

A buddy of mine had a 92 SL2, and the noise was actually the rear seat backs rattling.  There is a metal pin that goes through a metal hole right where they pivot near the center of the car.  This was rattling and it took some crawling around under the car to realize that it wasn't coming from under the car, even though it sure sounded like it.  You can test this by sitting on top of the rear seats when they're in the down position and see if it cures the rattles.

I've taken quite a bit of the body and interior of my car apart, and I think that Saturns are built pretty well considering how many plastic interior panels there are.  Any car is going to have rattles when you put a subwoofer in the trunk and it will take quite a bit of work to get rid of them all.  But let me tell you, when you can have the audio system at a good volume and get out of the car and not hear one rattle - it's great.  People at every audio competition I attend can't believe it when I go through SPL (loudness) testing, I usually get a great score for the equipment I have in my car, and they can barely hear it outside.

You may want to read the newsgroup, or search it with Dejanews and the keywords 'dynamat' or 'rattles'.  You're sure to find lots of advice from people who've been thru it all.

Q: "How do you find the best tweeter mounting location, and why did you mount yours behind the mirrors?"

I tried the tweeters (surface-mounted with duct tape) in lots of different positions before deciding on where I did place them.  Here's my opinions on mounting locations and observed effects:

Extreme dash corners, firing upward near windshield - imaging was good, but stage was too narrow.  Path length equality (left to right) was the best it could be in this position (which is a very good thing), but again, I didn't like how narrow the stage was.

Mid-door, 3 inches above woofer in door and right under dash overhang -  Imaging was OK, until anyone sat in the car who was not short.  Legs got in the way and BAM, there goes your highs on one side.  One tweeter was always too close to a listener's ears, and path lengths from the tweeter on one side of the car to the other were more unequal than I wanted.  Plus, the steering column/wheel was in the way of the passenger having a clear ear path to the driver's side tweeter.  I did not try the tweeters in any arrangement that put them closer to the passengers than mid door, even though I've seen people do it.  I would think that would again throw balance and imaging way off, since the listener would have one tweeter 1 foot from him and the other 4 feet.  I suppose you can compensate with proper level adjustment and time alignment processing, but it's unlikely that the sound could be 'fixed' and made acceptable for both listening positions.

Kickpanel - the worst observed position (weird, huh - considering how everyone extolls kickpanel mounting).  Legs and feet get in the way and adversely affect tweeter output.  There just isn't enough room down there in our cars for feet, much less a clear unobstructed path to both passengers' ears.

Top of dash, on top of corner vent panels near side windows facing upward - instrument cluster was in the way of the driver's tweeter path to the passenger's ear.  Steering wheel didn't help either.

They sounded best behind the mirrors the way I have them now.   There is one metal brace under there that came out easily with a dremel.  The driver's mirror control is now zip-tied inside the door (mirror can currently be aimed by hand), and the panel was easily modified for tweeter placement with the correct size hole saw.  The mounting job was time-consuming but relatively easy.  Each tweeter's grille was removed, covered with cloth, and fit into the hole saw opening.  Behind that opening, wire and fiberglass hold the tweeter at an angle so that it faces across the car toward the opposite listener.

With this setup and position, tweeter level & balance needed to be tweaked.  But, after quite a bit of tuning (and EQing each side independently with an RTA measuring from the driver's seat) it sounds great.  The soundstage is very good, and the center is DEAD ON.  I was surprised - since that damn gauge cluster hump in the dash affects sound quite a bit, not to mention the steering column and wheel on that side.

An additional note on this positioning - It is correct that ideally the woofer and tweeter should be mounted in as close proximity to each other as possible.  In my case, they are less than 1 foot apart and the tweeter & woofer are on the same vertical plane - neither is further from me on a given side.  This arrangement in my car produces no ill effects audibly.  Time alignment could probably be improved, but again, I doubt that any corrections there would be audible to anyone but the most critical listener.

Of course with this mounting arrangement there are some drawbacks.  If a person sits in the passenger seat, he doesn't hear much of the driver's side tweeter at all.  In fact, I don't even let people sit on that side to listen - I put them in the driver's seat.  In the old days (5 years ago or so), IASCA competitions used to judge from both seats and average the scores.  In recent years, they concentrate on the driver's sound and score that only.

I could have set it up to sound good from the absolute center of the car (like many people do), but nobody sits there!  After ruling that out, I had a choice remaining - make it sound good for both people, or make it sound great for the driver.  The latter was the path that I took.

In judging, I always get excellent scores for the center image - often people ask about or look for a center channel speaker.  Again, proper level matching between right and left tweeter as heard by the driver was the key.  I don't believe that an excellent soundstage or image can be produced in our cars for both front seat passengers.  Even with a time-alignment processor & EQ - you're still faced with the 'good in both seats, or excellent in one' decision.

"Why is your dyno horsepower less than what the car is rated at stock?"

The 124 horsepower rating for our cars (DOHC motor) by the factory is measured at the crankshaft with an engine dyno before the engine goes into the car.  If you subtract typical driveline losses (friction between parts, turning all the gears in the trans, turning the flywheel, axles, power steering pump, alternator, pullies, wheels, tires, etc...) from that number, you'll find that most FWD cars will 'lose' about 15 percent of their power before it reaches the pavement.  RWD cars have losses as well, but I don't know what percentage offhand.

A chassis dyno measures actual horsepower output to the ground at the wheels after all the losses.  Suddenly, your Saturn's factory rating of 124 horsepower is actually more like 100 - 110.  In fact, if you can look at the dyno chart from my '92 from when it was completely stock, you can that it made about 100 horsepower to the ground.  Among the Saturn Performance Club members that regularly dyno, we've got several hundred dyno runs logged.  The horsepower numbers for both of my cars with their respective level of modifications are consistent with other members who have similiar cars.

I encourage you to do a net search on 'dyno' to read more about the subject.  You can also take a look at the following links:  

SPS's dyno testing
Kelley's SC2 dyno results
Al's SL2 dyno results

Q: "How can I make my car faster?"

Unfortunately, there is no easy or cheap way to get a serious power increase out of our cars.  15 to 20 horsepower is a good estimate (for a dual cam) with all the usual bolt-ons (header, intake, exhaust, etc.).  Porting/polishing the head & bumping the compression (via decking or new pistons) would be the next step to improve upon that - but either won't give you more than about 10 hp additional.

The largest gain for the buck is nitrous oxide, but a 50-hp shot is probably the limit on an engine with stock internals and a minimally-modified fuel system (and may only gain .5 - 1 second in the quarter and less than that in zero to 60 time).  You can find several owners running nitrous on my links page.  There are risks though - most of the people I've come across who have run nitrous have been through more than one motor.

I've heard of people working on installing aftermarket engine management systems as well as turbos.  If done correctly (and properly tuned), that's where the real power lies. You can also find links to people building turbo systems on my links page.

Since it's so tough to get the car to go significantly faster in a straight line, consider making it faster in the corners.  A great set of tires, new sway bars, bushings, springs - these cars sure can be fun on a winding road.  After all, happiness isn't always a straight line.  You can also consider getting more seat time.  Autocross, road course lapping sessions, and the drag strip are a great place to make yourself a better driver and work toward getting the most out of what you already have.  There will always be faster cars than yours, so do whatever you can to get the most enjoyment out of the one you already own.  To find track events in your area, take a look at .

Q: "I'm looking for a performance catalytic converter.  Where did you get yours?"

I ordered mine directly from Random Technology.  When I bought it, Random didn't make a direct fit for our cars (however, they now do offer a direct-fit for Saturn), but they did offer 3 universal sizes/styles which they'll put whatever ends on you like .  If I recall correctly, the cheapest & smallest universal runs around $150.  I bought the largest & best universal that they offered (we have a lot of room for the cat under the car) and they put ends on for it to mate up to the HS header and Borla exhaust.  The total job ran a bit more than I wanted to spend on a cat, but I didn't want the stock cat to be a bottleneck between the upgraded exhaust & header.  Check out their website - they've got a lot of good tech info & dyno charts.

Dynomax and Walker offer some universals as well, check in Jegs and Summit Racing catalogs.  The only problem is that they'd be a pain in the ass to attatch with 'generic' sized ends.  You could also check with local muffler shops, as many will have replacement converters (and performance models as well) in stock if you'd rather not go thru the custom order hassle.

If you do install the cat yourself, a tip - buy a band clamp to use from the cat to the header/manifold downpipe.  The inlet of the random cat is way thick to try to crimp onto the pipe and form a good seal with normal exhaust clamps.   Most better auto parts store or exhaust shops have band clamps.  Or, you could just weld it for the best possible seal.

Q: "How do I remove the rear hubs/bearings if they're badly rusted?"

On a track-driven vehicle, rear hubs/bearings wear out and need to be replaced quite often.  Or, if a person needs to do suspension work or install rear wheel spacers, the hub assembly may have to be removed and reused.  If you have reuse in mind, whacking the rusted-on hub with a huge hammer might not be very good for the health of the bearings it contains.  If you'd rather not solve this problem with a hammer, I've found another way to do it that requires less swearing.   Keep in mind, this process can only be used if your car has rear disc brakes.   You may be able do do something similiar with drum brakes - use your creativity to figure it out.

Use penetrant on the area of the hub where it contacts the knuckle.  Don't just get it from one side, squirt it from the other side too and use a lot of it.  From here on in, here's what works for me:  I run a bolt through one of the access holes in the spinning part of the hub (between the wheel studs), and then put several washers and a nut on it between the hub access hole and the knuckle. I spin the nut toward me until it is snug and touches the back of the round spinning part of the hub.  Then I put a wrench on that nut and crank on that sucker.  It forces the hub away from the knuckle with leverage and works pretty well. You'll hear a huge BANG and it will come right off. You may want to be careful in case it flies off - you don't want to get whacked in the noggin with those wheel studs.

You can see a pictures of the process here:  HUB1, HUB2.

Tip: buy the largest bolt that will fit through that hole in the hub, or get one made from a harder steel (grade 5 or grade 8). The cheap-o carriage bolt I used (shown in my picture) bent from the force of cranking on the nut.


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