Why sacrifice space for bass?
by SCRM Garage
Tyler Dirden, One of the most realistic Honda CRX Del Sol owners we’ve come across, looks for the affordable and realistic solution to what he wants & needs, posts about it and is quite well known on the HondaTech forums.
To begin, I started with a goal of “least intrusive” enclosure. Bass tubes and boxes are way to intrusive for a car this small and take up alot of usable space. The interior has remained entacted and unaltered for a very clean and modest look.
The enclosure began life as a 20 gallon air tank with a 14″ diameter. This is the largest diameter that can be used without major rear subframe rework. The sub enclosure fits underneath the spare tire which is only raised 2.5″ for this particular installation. The enclosure was meticulously designed to preform with this sub and has the exact reccomended sealed enclosure volume of .8 cubic feet. This sub was chosen for it’s excelent reviews on Amazon and youtube. It also has a very small enclosure size requirement as stated above.
In the pictures below you will see the type of fabrication needed and COMMITMENT that you must have as you are altering the car permanently.
After the tank/enclosure volume is calculated fabrication begins by trimming the end off of the air tank and a small section off the other end. I used a 3″ cut off wheel which took a long time and effort. A plasma cutter would make a very good and fast cut here if you have one. The opening for the sub was cut out of the end of the short section and measured carefully for trimming and forming. The edge for the sub was hand formed with a large dolley and hammer by slowly rolling the edge over to form the speaker mounting flange. You must cut small slots as seen in the rolled egde to make the edge roll flat. I carefully divided the circumfrence of the hole by the speaker mounting holes and came up with an accurate slot placement. This takes time, don’t be in a rush. The final edge can be ground very flat and even when the roll is accomplished.
A hole was marked directly from the tank section in the spare tire well in the exact location (direct center) and cut out with a 3″ cut off wheel. The edges of the trunk ARE NOT level, flat or ready in ANY way to accept the sub flange. I used a floor jack and a large metal block for a stationary dolley under the flange and a regular hammer to form the trunk floor to a perfect flat, round feciever flange. This is simple if you take your time and don’t get hammer crazy.
It was determined that a 3.5″ protrusion underneath the car would be the maximum without becoming the lowest point of contact. I set this enclosure in at 3″ below the spare tire well and it looks fantastic. Making the flange to mount it with was difficult with a cut off wheel but turned out excellent here. The flange is 1/8″ thick steel, like the tank/sub enclosure and is much thicker than the cars metal. The rear of the enclosure has two long fingers that extend from it that tie in the rear tow loop/bumper brace to the rear subframe suspension forward of it. This effectively makes a very strong connection between the two and a SOLID foundation for BASS production without unwanted resonation (buzzing, rattles). I spent about 20 hours building it after everything was designed correctly and sourced parts for the build. 20 ss bolts and lock nuts are used to mount the enclosure here.
The finished enclosure will be rubberized on the inside for dampening. The round shape will not produce harmfull harmonics on the back side of the sub that boxes generally do. The round sub enclosure promotes clean compression and de-compression of the sub structure. The spare tire here is a 15″ rim that will sit nicely on the top of the sub and doubles as a grill! With only a 2.5″ raise of the spare, some jumper cables etc., can be stored underneath if properly secured.
You may be thinking that just because I went through all this trouble I would give a biased review; wrong. I will tell you the truth. Without this sub for the last 6 months, I really thought my forward system was loud (mid/highs) and was craving bottom which it never delivered. Even though the doors have massive 6.5″ mid woofers by Lanzar which took a very long time to get into the door without interfering with the window; they have no rear sealed enclosure to bring out the bass they could make. They have like 5 lbs magnets on each one. Again very loud but not much bass.
When I got this sub up and going for the first time on low settings (nothing on the levels are maxed) I don’t abuse amps, this changed the whole dynamic. It is scary how much bass a single 12″ sub can produce in the proper sized enclosure. It will bumb a kick drum on rock music sooo sweet and clean. It will pound a boom boom from bass favorites that is clean and undistorted. It hits the entire car out well and without rattles from handles and stuff in doors that buzz. The sub is solidly mounted to the floorpan and rear SUBframe (haha) of the DelSol and produces great bass in the seat of your pants. Subs mounted in the trunck don’t have that fuzzy cabin bass like some love because it gets dampened a bit but ALL the solid hits come through without a hitch and resonance bass too.
I am going to have to install more mid and highs up front to get the ballance of really loud and clear I want. I really like to immerse myself in a big song and dissapear into the noise for a moment, like soo loud you can’t be distracted by anything in life until the volume drops. A cocoon of sound, concert level and clean. I will give more updates with the next amp and forward equipment. This has been a very rewarding install and worth every moment to me. The few people that have seen it so far are blown away at the spare tire location. At first when the bass was low, the spare tire rested well on the edge of the sub shell. But when I bumped it up the tire bounced! I mean bounced and moved around. I had to raise it off the sub shell a half inch or so with a pool noodle to keep it put. This full size spare weighs 22 lbs and it was bouncing around. It stays put now and is dampened by the foam support underneath. It also makes a very clean grill to protect the sub that looks great.
The big ass hole in the dash is for the future air ride accesories and active crossover unit. I will fab a nice pocket out for the regulators and gauges etc and make a cover that will keep it sorta low key like the SRS bag that was there once.