User Guide

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100Hz (the 12 o’clock position).
When using the ampliers for component speakers or coaxial, you will want to set the CROSSOVER MODE switch to HIGH PASS. The HPF control knob adjusts the high pass frequencies
between 60Hz and 1.2KHz. Do not attach tweeters directly to the amplier even in the high pass mode without a secondary passive crossover to protect them.
Audio Preamp Input
The dB Series ampliers feature RCA pre amp inputs. Run RCA cables from your sound source to the inputs of the amplier. We suggest the use of high quality shielded RCA patch cords
to help reduce and eliminate unwanted electrical noise to your system. Use good quality RCA interconnect cables. Cheaper cables usually have poor shielding that can cause interference
pickup.
Be sure to run the RCA cables on the opposite side of the vehicle that you used to carry the power and ground leads of the amplier.
Using The Built-In Low Pass Electronic Crossover
All the dB Series ampliers feature 12dB per octave fully adjustable low-pass and high pass electronic crossovers.
For Low Pass sub woofer systems, set the CROSSOVER MODE switch to LOW PASS. Now the knob marked LPF will control the low pass frequencies depending on the model anywhere
from 50Hz to 250Hz. A frequent error made is setting the low pass frequency too low, especially when using vented sub woofer enclosures. We recommend that for most installations you
do not set the frequency knob lower than 80–100Hz (the 12 o’clock position).
When using the ampliers for component speakers or co-axials, you will want to set the CROSSOVER MODE switch to HIGH PASS. The HPF control knob adjusts the high pass
frequencies between 60Hz – 1.2KHz (dB25, dB45) or 15Hz – 4KHz (dB55). Do not attach tweeters directly to the amplier, (even in the high pass mode) without a secondary passive
crossover to protect them.
Subsonic Filtering
For sub woofer installations with a passive LP crossover, you can set the amplier’s CROSSOVER MODE selector to HIGH PASS while setting the HPF knob from the lowest setting to
50Hz, this will act as SUBSONIC FILTER for all signals below that setting. This is especially useful for vented enclosures where the port tuning frequency falls below the sub woofer tuning
frequency to protect against sub woofer unloading.