Amplifier Review - Jensen JPA460
May 6, 2005
By Paul Sonoda
MSRP $159.95 USD
Back in the day, the Jensen Tri-axial 6” x 9” where the ones to have. In fact, Jensen was one of the only games in town. Jensen’s long history of performance has resulted in a value driven 4-channel power amplifier. Can this inexpensive amplifier live up to the reputation of the old school Jensen? Read on.
First Look
The Jensen JPA460 is a 4-channel Class B amplifier rated to deliver 60 watts per channel in to four channels. The JPA460 is capable of running in 4, 3 or 2-channel mode. It is even able to run “Tri-Mode” for a simulated 6-channel operation. Both the front and rear pair of channels includes independent variable high-pass and low-pass crossovers continuously variable from 40 Hz to 250 Hz. The JPA460 can accept either low-level RCA output of high-level speaker output. To pass signal to another amplifier, there are separate front and rear full range RCA outputs. The Jensen JPA460 amplifier is wrapped in a highly styled black powder coated cast aluminum heat sink.
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topA Closer Look
The Jensen JPA460 amplifier’s heat sink has overhangs that conceal connections and adjustments. On the connection side, the JPA460 is power connector is able to accept up to 4 gauge power and ground wire. The speaker connectors allow from a minimum recommended 16 gauge wire gauge up to 10 gauge wire. To protect the internal circuitry, The Jensen JPA460 included two 25 ampere ATO fuses for a total of 50 amps of current capacity.
On the signal side, the JPA460 has separate adjustment knobs for level, high-pass, low-pass and bass boost settings. The RCA outputs are capable of handling up to 8 Volts RMS. (More than most standard head units) To determine the output, both the front and rear channels can be independently selected to run high-pass, low-pass or full range. Even though there are independent adjustment pots for the high-pass and low-pass crossover, band-pass operation is not possible. Connecting RCA up to the JPA460 is selected by a center switch that allows for 2, 3 or 4 channel mode. This determines how to connect the RCAs to the amplifier. If you have an entry level head unit with only one pair of RCA outputs you will either need to use RCA adaptors or an extra RCA or adaptors to get signal to all the channels. To maximize bass performance, the JPA460 has a narrow “Q” boost filter that increases the output of the amplifier up to 18 dB at 45 Hz.
Installation
The installation of the Jensen JPA460 is pretty straight forwarded. The cast aluminum heat sink incorporates the mounting feet that are placed solidly in the four corners of the amplifier. The power and speaker connecters are well marked and easy-to-use. There are two 25 amp fuses that provide over current protection to the amplifier. The terminal screws on the connectors allow for a very secure connection. On the signal side, the JPA460 adjustments are well defined and easily understood. The controls are easily adjusted with a small flat blade screwdriver. There are two LED lights; one for power and other for indicating standby operation.
Manuals/Web Support
The owner’s manual provides adequate information about the amplifier, including basic installation, trouble shooting and a general discussion of amplifier features. There was little information on connecting the amplifier with only one set of RCA outputs. This is a common situation with lower price head units. For the best performance results, it is recommended that you have an authorized Jensen dealer perform the installation. I went to Jensen’s website, http://www.jensen.com, to learn more about the JPA460. A few navigation steps and I located the JPA460. There was basic information about the performance and features of the JPA460. There was no manual available for download at the time of the review.
Sound Q & Performance
This amplifier is one great value. At a retail price just under $160 bucks, the Jensen JPA460 delivered an impressive 79.1 watts x 4 into 4 ohms. At two ohms, the JPA460 delivered 98.7 watts x 4 into 2 ohms. When the amplifier was bridged into 2 channels, the Jensen amplifier delivered 197.4 watts per channel. That puts this amplifier at less than fifty cents a watt! Under all test, the JPA460 exceeded all its CEA-2006 power claims.
Under max usable power, I never blew the two 25 amp external fuses. The Jensen JPA460 delivers amplifier efficiency from what you would expect from a typical Class AB amplifier. At 4 ohms stereo operation, the JPA460 produced its power at 73.8% efficiency. Into 2 ohms stereo or 4 ohms bridged, the JPA460 returned an efficiency of 58.6% drawing a maximum 46.8 amps of current. When operating at one-third power, the Jensen amplifier between 30-35% efficient. Again, this is typical of a traditional Class AB amplifier.
The sound quality of the amplifier was quite good. The bass response was relatively tight and accurate. The sound quality of the mid to high frequency was definitely above average for an amplifier in this price category. Although slightly under its rated 100dBA signal-to-noise ratio, the JPA460 measured in at a respectable 97dBA. This amplifier delivers performance at a level significantly above its price point.
Summary
The Jensen JPA460 delivers quite good performance. Coupled with its full featured design, the JPA460 is one heck of a value. This amplifier would be a great choice for someone looking for an inexpensive amplifier to start building a system. This amplifier would do well to power a pair of component speakers and a single 4-ohm. One this is for sure, this Jensen JPA460 delivers the goods while being easy on your pocket book.
5
out of 5
3
out of 5
2
out of 5
