SPEAKERS AND SUBS
Audiopipe APBP-12PRRD
By Paul Sonoda
Posted on Tuesday, Jun 1, 2004

It used to be that if you wanted a cool sub enclosure, you needed to find a high-end custom installer. This is still true today, there are other options. Several companies have created prefabricated (read already made) enclosures that are cool and zoomy. The Audiopipe APBP-12PRRD is one example. The question begs itself: Does the APBP-12PRRD compare to a custom fabricated enclosure? Read on.

First Look
The Audiopipe APBP-12PRRD is a dual 12-inch single reflex bandpass enclosure. According to Audiopipe, it’s fabricated from a high-grade MDF (Medium Density Fiberboard). The enclosure is a single reflex bandpass design. The front of the enclosure has a 1/4-inch clear Plexiglas cover that’s curved at the corners. This creates a cool display for the two 12-inch woofers mounted inside the enclosure. The APBP-12PRRD is finished in a nice automotive-grade gray carpet with the Audiopipe logo embroidered on the top of the enclosure.

Closer Look
The Audiopipe APBP-12PRRD has two dual 4-ohm voice coil woofers. The red metal cone woofers have bright red colored steel baskets. Mounted with the magnets visible, you see the zoomy cool chrome back plates. The woofers of the APBP-12PRRD are wired in parallel to two high-end, gold plated, 5-way binding posts located at each end of the enclosure. There are three different possible configurations: 2-ohm stereo, 1-ohm mono, and 4-ohm mono. Depending on your amplifier, you should be able to find a configuration to maximize the power to this bandpass enclosure.

One of the coolest features of the Audiopipe 12 is the integrated neon. The cool glow of the neon really highlights the chrome of the woofers inside the enclosure. Wiring the neon is easy with a speaker-type terminal cup for connection power.

Manuals/Web Support
The Audiopipe APBP-12BRRD did not have an owner’s manual. It did, however, come with a registration card for the one year warranty. Having an owner’s manual would have been beneficial to describe different wiring configurations. In search of more information, I went to Audiopipe’s Web site, www.audiopipe.com. On their site, I was able to view their 2004 catalog page and get the low-down about the APBP-12PRRD. While there was basic information about the Audiopipe bandpass, there was no wiring diagram. To be fair, wiring the APBP-12BRRD is not too difficult.

Installation
Installation of the Audiopipe APBP-12PRRD is simple. Due to its large size and weight (over 70 pounds), installation consisted of placing the enclosure in the back of my test vehicle. Make sure you go work out at the gym before lifting this enclosure. Connecting the APBP-12PRRD to my amplifier was a simple connection of speaker wires. To figure out how to maximize the power of my amplifier, I needed to use a multi-meter to measure the impedance at each woofer. I determined that it was 2 ohms at the 5-way binding post. If you’re unfamiliar with using an ohm meter, it’s recommended that you have an authorized Audiopipe dealer install the APBP-12PRRD.

After wiring the speaker connections, I connected a 12-volt output to the neon input.

Sound Q & Performance
I tested the enclosure facing forward, then backwards. Since all the output of the APBP-12PRRD comes out of the sides of the enclosure, the direction of the enclosure did not significantly affect the frequency response or performance of the enclosure.

I tested the APBP-12PRRD at 1 watt, 600 watts, and 1200 watts. The power used was based on my test amplifier’s ability to deliver undistorted power to the enclosure. While the power levels of 600 and 1200 watts are below the rated power of 750 and 1500 watts, the power output is close enough to provide a good reference for evaluation. I also measured the output of the amplifier on an oscilloscope while powering the APBP-12PRRD to ensure clean power for testing.

At 1-watt input, the lowest output was 95 dB with the peak output of 106.7 dB at 50 Hz. Next, I increased the power to 600 watts and repeated the test. The first thing I noticed was a difference in the frequency response — I’ve noticed this phenomenon before with other sealed bandpass enclosures. The lower frequency, 31.5 Hz, increased at a greater rate than the rest of the frequency range. There was almost a 10 dB gain at this frequency when compared to the rest of the frequency range.

When I increased the power to 1200 watts, the woofers of the APBP-12PRRD protested, but handled the power. At some frequencies, there was an audible rattle noise from the woofers. Overall, the output of the APBP-12PRRD increased. The maximum output increase of 2.1 dB occurred at 31.5 Hz. At both the 600-watt and 1200-watt power levels, the frequency response was relatively flat, between 30Hz and 60Hz. The overall increase in output was fairly linear between the 600-watt and 1200-watt reference levels. The peak SPL output was nearly 125 dB, which is about average of what you could expect for an enclosure of this size. The dip at 70 Hz is a frequency response aberration that’s a characteristic of my test vehicle and should not be viewed as a negative when looking at the performance of the APBP-12PRRD.

Summary
The Audiopipe APBP-12PRRD has cool looks, decent performance, and a great price. Does it compare with the custom enclosure that your high-end installer can provide? Now, that I’ve played with the APBP-12PRRD, I think it’s an "apples to oranges" comparison (nice copout). What you will get with the APBP-12PRRD is a solid, well constructed pre-fabricated enclosure that, with the neon turned on, will make the night cruiser very satisfied.