# Independent Review of the Cadence iA9



## JasonPaul (Jul 2, 2007)

*Cadence iA9 - Independent Review*

Here is a review that is going into PAS mag about the Cadence iA9 this spring.. 

CADENCE iA9HC Amplifier Review

By: Garry Springgay 

Up in the Northeast corner of the United States, in Howell, New Jersey to be exact, is where you’ll find the folks of Cadence Acoustics. Here a dedicated group of people have been turning out high performance products for over 18 years. The company has made a name for itself as an innovative brand, offering high performance but still very moderately priced products. Sold in over thirty countries worldwide, the company believes they have a new approach to the old ways of thinking about sound reproduction. 
A quick trip to their website; informed me that their motto is “Consistently louder! Consistently harder!”
When the UPS driver dropped off the latest in high performance Class D amplifiers from them, I was eager to check it out and see what was what.

The amp they sent is one of the new iA series of amplifiers, and is sold by Cadence retailers as well as authorized internet retailers, so finding one near you shouldn’t be a problem. Once out of the box, the iA9HC is heavy and gives the impression of being a solidly built product. Rated at 2000 watts into 1 ohm, the amplifier sells for about 500 bucks in the U.S. and slightly more in Canada, and comes with a 5 year warranty. 
The black anodized heatsink is finished in a classy brushed aluminum look, with the Cadence logo CNC machined into the top for great contrast. Measuring 16” x 9.25” x 2.5” it’s about in the middle of amplifier chassis sizes, and comes with a clear Lucite bottom cover, which lets you gaze at all the cool parts inside, if you’re into that sort of thing. And I am. 

Features:
Belying its low price, the iA9HC doesn’t skimp on features either. It comes with all the usual controls; gain, crossover adjustment, subsonic filter, bass EQ, and pass through RCA’s. 
But in addition to the “usual” features, there are a few other unique ones that will prove to be very useful in system building and tuning. The iA9HC can be “strapped” to another one in a Master/Slave configuration, or several of them can be daisy chained together and controlled by a single set of controls. Also, in addition to the ubiquitous Bass EQ control, the Cadence amp has a “Bass Focus” control which is used to apply very low frequency boost for sealed enclosure applications. Have a look at the graphs for a detailed look at how this is different, and cool!
There is also a diagnostic LED which will alert the user to a potential problem, and a 0-180° phase switch. A remote mount level control is also included, so you can change the sub level from the driver’s seat.
The nickel plated, solid brass cable connection terminals are large and beefy, as you’d expect on an amplifier capable of 2KW of power. The B+ and Ground terminals accept 1/0 gauge wire, and the speaker terminals provide dual connections for 8 gauge speaker cable. The wires are securely fastened with hex-head set screws. I took the clear bottom cover off, and poked around inside, and I was impressed with what I found, considering the very reasonable price of the amp.

Tech:
The power supply is the heart of any amplifier, particularly a big powerful Class D amp like this. The Cadence iA9HC is equipped with a pair of large toroidal transformers, and uses no less than 16 – 1000µF high speed, low ESR capacitors. Power supply switching and current delivery is taken care of by 12 large TO-247 case size HEXFETs. Devices of this type are typically capable of switching 50 amperes or more each, so there is no doubt that ample current will get delivered to the output stage. And speaking of the output stage, again I found abundant capacitance, with 4 large can 3300µF caps, and 8 more 470µF capacitors. The output devices are plentiful as well, with a total of 20 high current TO-220 case MOSFETs on hand to handle the toughest current loads. 
The rest of the inside of the amplifier is also worth talking about, as the same sort of attention to detail was applied to often overlooked components like the output filter stage, which is critical to properly remove the high frequency square wave carrier. From the signal control to the protection circuitry, the amp is well built using traditional through-hole components, and heavy gauge copper PCB traces on the double sided PCB. An anti-thump circuit uses a high current relay to open the circuit to the loudspeakers until the amp is fully on and ready to play, and eliminates turn on and off noises. Control pots and switches are good quality as well, and were placed well, with the pots in the center of the holes in the end plate, and straight. 

LISTENING
Connected to my 2 ohm reference system, I adjusted the crossover and set the bass EQ controls to flat. True to the claims, the amp does indeed turn on and off quietly, with no pops from the woofers. Beginning with some of my favorite drum recordings from the likes of Neil Peart, Ian Paice, Buddy Rich and Carmine Appice, I put the amp through the paces, listening at low levels for detail and later at very high volumes to see how much power it would really deliver. The overall sound from the Cadence amp was excellent, with very good control of the woofers and an obvious plethora of power. Moving on to some jazz and other tracks with acoustic bass, I also thought the amp had good timbre for a Class D design, and again the control and definition was excellent. 
Because I was using a sealed woofer system, I played with the Bass Focus control a bit, and I was really pleased with the warmth it can add, particularly if your woofer system is a little shy on cone area. But be warned, this control can overdrive a woofer if your system isn’t up to it, and should be used with some common sense. Thankfully the folks at Cadence obviously realized this as well, and limited the amount of boost available. 

PERFORMANCE/BENCH MEASUREMENTS
After my listening was done, it was time to move into the electronics test lab, and get the real performance numbers out of the amp. With published power ratings of 600, 1000, and 2000 watts at 4, 2, and 1 ohm respectively, I’m happy to report that the Cadence amp delivered power in excess of those numbers when fed with a 14.4V supply voltage. 
Other performance measurements were also excellent; the amp has very good S/N (signal to noise) performance as well as good overall efficiency. If you drive it to full power with a sinewave and a 1 ohm load, it can draw almost 200 amperes, so if those conditions sound like you, prepare your electrical system accordingly. With a musical signal however, the average current draw is much lower, and the efficient design helps keep the current draw down, and minimizes amplifier heating as well. After all the full power testing and measurements were made, the amp was barely warm. Crossover and subsonic filters performed as advertised both using -24dB/Oct slopes. Output impedance was exceptionally low for a Class D amplifier at 0.002 ohms (lower is better) which is a testament to the output filter design, and perhaps helps to explain the good definition and woofer control I noted.

CONCLUSION
When I first wrote the next sentence, I was going to say that the Cadence iA9HC is an excellent amplifier for the money. But with performance as good as or in some cases better than amplifiers costing twice as much, it’s simply an excellent amplifier, period. With a host of features that include a few really unique and useful ones, great sonics, and very good design and construction, if you’re in the market for a high power subwoofer amp, you owe it to yourself to give this powerhouse some serious consideration. I give it two thumbs up!

Cadence iA9


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## mvw2 (Oct 2, 2005)

Cool. I wouldn't really expect less then the best. Kudos.


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