(2) 6.5 inch subwoofer under dash install questions

    Yep, inside your box, you're going to only run 3 short (<1') wires:

    1. From the Red inside box connector to the Positive of speaker #1
    2. From the Black inside box connector to the Negative of speaker #2
    3. From the Negative of Speaker #1 to the Positive of speaker #2.

    Then you will only have the 1 pair of long wires (Pos & Neg) going from wherever your amp is to the speaker box connection red and black ports (red = pos & black = neg).


    If you get it working and you still don't hear the bass you want, turn up the gain on the amp at little bit at a time until you like it.


    Gain.JPG

    Your Memphis 16-PRX300.1 amp can output 190W to a 4 ohm speaker load or 300W to a 2 ohm speaker load. Your Memphis 15-PRX6D2 speakers are 2 ohm impedance speakers, so if they are wired in parallel inside the box (both negative terminals on the speakers connected to the negative terminal going back to the amp and both positive speaker terminals connected to the enclosure's positive connection to the amp) the amp will see a 1 ohm load and may shut down to protect itself. Try wiring the speakers in series using the chart chavey2 showed above. The amp will see this as a 4 ohm load and will output 190W and should drive both subs.


    To get max power from your amp, you need two 4 ohm subs wired in parallel so the amp sees a 2 ohm load and outputs at its max power level of 300W. Since the subs will be exposed to weather, look for subs that do not have a paper cone for maximum durability.


    A little cheaper approach would be to wire only one of your subs enclosure's internal connector connecting to the amp and leaving the second sub to work a s a passive woofer. The 2 ohm load of a just one sub will cause the amp to output at max power, but you run the risk of damaging the wired woofer if you exceed its rated power level.


    To get the maximum possible sound level from both the subs and the amp, replace the current subs with the highest sensitivity 4 ohm subs you can find at a price you're comfortable with. Ideally, each sub should be rated to handle at least 150W RMS power so that when wired in parallel, the amp will see a load of 2 ohms and produce 300W max output with each sub handling one-half of the power (150W). As I wrote earlier, at the same power level, a sub rated at 85 dB will sound twice as loud as a sub rated at 82dB. 88dB-rated subs will sound even louder compared to your 82 dB subs. Unfortunately, the higher the sensitivity, the more expensive the sub.


    Still another low-cost alternative is to use some music normalizing software such as MP3Gain (free) (https://www.howtogeek.com/howt…volume-of-your-mp3-files/) to modify the music so it is louder. Some folks do not like to re-normalize the sound level of their music for a variety of reasons, but I routinely re-normalize my MP3s to around 89-92 dB) so that I get louder music at the same or reduced volume settings, making the music easier to hear in high-noise environments like the Slingshot. Personally, I prefer Ashampoo's Music Studio 7 (currently available for $21 as a download) which offers flexibility in what it can do. You can find more info here - https://www.ashampoo.com/en/us…a-software/music-studio-7.


    I use a Clarion XC2410 amp which produces 50W per channel at 4 ohms, but 75W per channel at 2 ohms, so I just replaced my Roskford Fosgate 4 ohm speakers About $35/pr on Amazon with JBL 2 ohm speakers (about $135/pr on Amazon) that also offer a sensitivity rating 95 dB. This should allow me to get more power from my amp and the higher sensitivity of the speakers should produce significantly higher sound levels to maximize my music enjoyment. The JBL Stadium GTO620 I bought speakers are rated from 45-25KHz and should also offer a significant improvement in terms of their lowest frequency performance and help with producing as loud a sound level possible, but they're only rated for 75W RMS power, so you'd need to use your gain resistor control to reduce the input to your amp to avoid blowing the speakers from too much power. Again, using speakers with a rated power level below what your amp can produce does mean you risk damaging the speakers, so keep in mind you risk damage to the speakers if you do.

    OK. Thanks to all your info the install worked. I’m up and running now but just realized it’s not completely plug-and-play. Several adjustments that can be made underneath the Memphis faceplate. The only thing I was able to figure out was the Low pass filter...read that subwoofer should be in the 80-100hz range so I adjusted that. Obviously the control knob on the remote box I can use remotely to increase or decrease the level of bass once my passenger seat is reinstalled which is where the amp is mounted. How about the other dials. Was reading and got kind of confusing. Don’t want the amp to work too hard and possibly overheat. Sensitivity seemed to have the most effect on the thump of the bass

    Here's two amplifier setup articles, which should hopefully make your amp instructions more understandable -


    https://www.crutchfield.com/S-…ar/subwoofers/tuning.html - This article doesn't require any fancy equipment and is aimed at the average user and should work well for most folks.


    https://knowledge.sonicelectro…ier-gains-and-bass-boost/ - This article is for more advanced users.


    Good Luck!