Sound Storm Laboratories LoPro8 Installation

March 2014 – I installed this subwoofer in a 2014 Honda Accord Plug In using the stock radio and navigation system that came with the car. The subwoofer was placed under the passenger seat with a little room to spare as I wanted to keep everything as stealth as possible. This subwoofer has a built in amplifier and various controls for great bass and gives the music the extra punch it needs. I’m amazed this subwoofer doesn’t have a port but can still produce deep and strong bass levels for its size. I bought mine new from Amazon at $113. It’s near impossible to get to the back of the car radio without dismantling the entire dash so I chose not to do that and created an alternative to share.

Before you get started, safety first. Be sure you put electrical tap on all exposed speaker and power wires. Be sure you put electrical tape in any area where they might touch another wire or connector. Wrap electrical tape around wires where they might rub anything and expose bare wire later on. Don’t add power to the subwoofer until you’ve double checked your connections and ready to test.

For subwoofer power, I bought a 20 amp buss fuse holder at Home Depot and attached one end to the positive battery post. Use the battery in the engine, not in the trunk. Then open the passenger front door and there’s a plastic vertical panel next to the door hinge covering access to the quarter panel wheel well. I pushed a red 8 gauge wire through there to above the front right light assembly, then well above the radiator around the left light assembly to the battery. I attached the other side of the fuse holder to this wire. NO FUSE INSTALLED AT THIS TIME.
Passenger front seat – foot area. There is one horizontal panel just above where the feet would be. That pulls down. The kick panel is that horizontal panel you step over when you enter into the car. That pulls up. There’s a vertical panel just right of the feet and that pulls off.
The passenger door has a black rubber boot that feeds wires from the cabin. I made a small cut in the boot on the cabin side and fed the red power wire through the boot. I followed the existing wire harness along the kick panel and the wire comes up under the passenger seat. I patched the cut in the boot with some caulking. For the ground wire, I used black 8 gauge wire and attached it to the passenger seat mounting screws.
This subwoofer has a third connection that tells the subwoofer to turn on when the car is turned on. Otherwise the subwoofer would have power all the time and drain the battery. I took a 12 Volt cigarette lighter charge adapter and cut the end off the cord. I ran the 12 volt power side to the subwoofer Remote connection. Do not connect this to the Remote Level Control on the other side.

For speaker input, the subwoofer can use low end RCA cable input or high end speaker input. I chose the high end. At the passenger kick panel noted above, is a wire assembly. You’ll find a solid blue wire and solid orange wire, the rear right speaker. Splice in a 10 gauge speaker wire to these and route the rest under the passenger seat. I could not locate the left speaker wires so here’s my fix. I ran 10 gauge speaker wire from under the seat, to the back seat of the car, through one of the top child car seat anchor points to the left speaker. There, I put female spade connectors on the ends. About 2 inches back, I stripped the insulation off, and attached 3 inch leads with male connectors. I pulled the speaker connector off the speaker. I put the female connectors on the speaker and male connectors on the speaker connector.

At this time, from under the passenger seat, you should have a red power, black ground, 2 speaker wires, and a cigarette adapter line.

At the subwoofer… connect the speaker lines to the supplied connector. Be sure your polarity is correct. There is an extra ground wire on the connector, be sure to connect it to ground. Attach the red wire to power. Attach the black wire to ground. Be sure your polarity is correct here too. Go to the battery and install the fuse. Install the Remote Level power adjust cable and control. DO NOT CONNECT THE 12 VOLT CIGARETTE ADAPTER yet.
HINT: Be sure your speaker polarity is correct. Using a spare speaker, you can attach one line to the speaker and ground the other side. Turn on your car radio with low volume. If you hear speaker sound, then that is the positive line. No sound, and the speaker hook up is the negative side. Turn off the car power.

On the LoPro8, set the controls like gain, boost, etc to very low. Be gentle when turning. Turn full clockwise. Then turn full counter clockwise. Then turn clockwise about a quarter turn, about a 3 o’clock position. Do this to all 4. Do the same for the Remote Level Control. Power on the car. Power on the radio. Turn the radio volume to low. Now connect the cigarette adapter and look for a green light to show on the subwoofer. Look and smell for smoke and sparks and shut down immediately if you see these. Put on your favorite song on the radio and turn the volume up to just above where you can hear it. Adjust the Remote Level Control, volume of the radio, and the Gain first in small steps. Then fine tune using the other adjustments. For a few days, I placed my subwoofer on a box and kept in on the floor in the back seat until I could adjust the subwoofer settings just right for me.

Before putting the unit under the seat, double check that your connections are tight but don’t overtighten where you’ll break something. Be sure to use electrical tape where you see exposed wires. There is a vent under the seat. I used a curved strip of aluminum foil to deflect the air around the subwoofer. When you push the subwoofer under the seat, don’t bind or pinch the wires. If the music still sounds good, and you don’t see or smell sparks or smoke in the car or engine, you can put back the panels you removed.

The LoPro8 packs some good bass and extra punch to the Honda radio. I can see the rear view mirror vibrate when I have the volume up about 25; it goes to 40. Sometimes I like to play the music loudly and the LoPro8 is a great unit for the size and I am very pleased.

Update April 24, 2014… The Honda radio has 2 microphones that listen to the noise in the car as it goes faster. At around 40 mph, rough roads, or windows down and cars rushing by, it causes the subwoofer to sound off on its own. I haven’t tried disconnecting the microphones yet. I believe there are 2 in the car supposedly to adjust the sound of the music as the road noise increases. Secondly, the cigarette lighter adapter used to power on the subwoofer may need to be adjusted to something under 12 volts as it causes a slight pop on the subwoofer when the power is turned off. An easy fix with an in line resistor. For now, I unplug it before turning off the car and no pops so far.

 

thanks for sharing.

a few comments:

a good sub/amp combo will have an "auto turn-on" feature that eliminates the need for the remote wire and cigarette lighter adapter. these products will also have a soft turn on/off feature to prevent pops.

you get a pop because the cigarette lighter turns off after the head unit - meaning the sub amp is still on when the source is turned off. it's not an issue of too much voltage, but a properly sized resistor to ground can help pull the voltage down faster.

instead of either of those options, you can buy a good quality line output converter that accepts speaker level inputs and has RCA outputs and an auto turn-on feature. I recommend the David Navone Engineering products.

yes, the active noise cancelling (ANC) system is going to cause issues with the sub. there are several bypass options listed on this forum. ideally, you'd use some small relays to bypass the mics when the sub was on but have the ability to use them when the sub is off - i.e. add a switch in the cabin that does both - fairly easy but requires running wire to each mic and to the sub amp.

the description for setting controls needs some work.

Input Gain should be matched to the maximum level you expect to use on the head unit. this is usually determined by the point of audible distortion of the factory system. the actual term for this is input sensitivity and the dial adjust from 6V input (minimum setting) to 0.2V input (maximum setting). to determine where to set yours, you can use a volt meter to measure AC voltage on the LOC RCA outputs or speaker level inputs using test tones being played through the head unit. sadly, since the SSL doesn't include a voltage scale, you are roughly guessing.

Subsonic filter can be set to minimum if the sub can handle low frequencies. it's essentially just a high pass filter normally reserved for ported enclosures but in this case it's more to protect the sub since it's not designed to handle very low frequencies. Set this to taste.

Bass Boost is best used in conjunction with the head unit bass EQ. you can turn the bass setting down on the head unit and turn bass boost up on the amp to allow the factory speakers to play more cleanly while the sub handles the lows.

the low pass filter is adjustable up to 150Hz and usually you want around 80-100Hz but the actual setting depends on where the stock speakers start to lose bass response.

 

Where are the pictures?