For years, Crown has built the industry-standard I-Tech series: greatsounding amplifiers featuring onboard DSP processing. Offering advantages such as improved signal-to-noise ratio and optimized gain structure, Crown raised the bar with the introduction of its proprietary Class I amplifier technology.
Now, with the introduction of the I-Tech HD, Crown has once again raised the bar, this time with the assistance of another Harmanowned company, BSS Audio, to supply the DSP processing.
The Crown I-Tech HD is available in the following models: the IT5000HD, the I-T9000HD, and the I-T12000HD. I-T5000HD offers two channels of 2,500W at 4 ohms or 4,000W at 4 ohms bridged; the IT9000HD offers two channels of 3,500W at 4 ohms or 5,600W at 4 ohms bridged; and the I-T12000HD offers two channels of 4,500W at 4 ohms or 7,500W at 4 ohms bridged. The I-T12000HD was used for the review.
The I-Tech HD is a Class I amplifier; Crown holds the patent for the Class I, also known as Class BCA (Balanced Current Amplifier). One of the great features of a Class I amp is that it can handle low impedance loads. For instance, in Stereo mode, the I-T12000HD can run at a 1-, 2-, 4-, 8-, or 16-ohm load; in Bridged mode, the amp can run at 2, 4, or 8 ohms. As it is built, the I-Tech HD amp can run more efficiently, and longer, than non-Class I amplifiers. Instead of turning energy sent back to the amplifier from the speaker into heat, the Class I will recycle this energy back into the amp and cycle. [Associated information on the I-Tech HD and Class I amplifier technology can be found at www.crownaudio.com. — Ed.]
The next-generation OmniDriveHD DSP engine within each I-Tech HD, developed in conjunction with BSS and JBL, offers proprietary FIR filter technology for "significantly improved midrange clarity and dramatically improved off-axis response," says Crown. Other new features within the I-Tech HD include LevelMax limiter technology, which links Peak, Thermal, and RMS limiters for a smoother response and more SPL. Standard input options include CobraNet, AES/EBU and analog XLR. The front-panel LCD display can access full amp diagnostics and menu-based system setup while a handy USB slot can be used to quickly load presets into the amp on the fly and without a computer.
The Crown I-Tech HD's features allow it to be very easy to program and use. Case in point is the USB port on the front panel of the amplifier. Simply insert a thumb drive with your processor settings, upload 'em, and use 'em. That's it — it's that easy and that user-friendly. However, I did find a down side to the feature, for Mac users, at least; if the need arises to quickly dial in some basic crossover settings — for instance, for a last-minute add-on to the show, or because of an equipment failure — you must use HiQnet System Architect Software on a Windows computer (no Mac) to create settings. [According to a Crown representative, "It is possible to run System Architect on a Macintosh computer, but it is not possible to run it as a Mac application. To run System Architect, one can either use BootCamp and start the computer in Windows, which is running Windows on the Macintosh hardware, or use a virtualization software solution. The virtualization software, typically either Parallels or VMWare Fusion, allows one to run Windows without having to leave the Macintosh operating system. One of the software team members at Crown runs all three of these solutions on his personal MacBook Pro, so we are confident that it works." — Ed.]
Let me digress by saying that HiQnet System Architect is very easy to use: just click, drag, and drop to set up your "system" with Harman components, then open each component to configure. I did not have to consult any manual or online help to create a setting for our EAW SB850 subwoofers. I found System Architect much easier to navigate than the BSS Omnidrive that I am accustomed to using.
The I-Tech HD's inputs are selectable between analog and AES/EBU. My testing, due to this being our only amplifier capable of digital inputs, was done with the analog XLR inputs. There is also an option for sending digital AES/EBU with analog backup in case of failure.
The front-panel controls of the amplifier access some very cool and interesting features. Some worthy of mention are continuous load monitoring and voltage monitoring readouts, signal generator, and spectrum sweep set up for any bandwidth; results can be monitored on your PC using the System Architect software. Due to only having one amplifier for testing, I did not fully explore the I-Tech HD's comprehensive networking capabilities.
In addition to using the I-Tech HD in the field with great results, I decided to do an amp shootout in our shop against two other inventoried amplifiers: a Lab.gruppen fP 6400 and a QSC PL (PowerLight) 4.0. Granted, the QSC PL 4.0 is a little low in power rating comparison to the other two amplifiers, but it was the next closest that was in stock. All comparisons were made on two speakers — an EAW SB850 dual 18-inch subwoofer and a JBL SRX-712M stage monitor — with any necessary processor settings sent through an Ashly Protea crossover. To get an accurate difference between just the amplifiers themselves, the I-T12000HD's onboard processing was not used for this part of the evaluation.
Sonically, the fP 6400 and the I-T12000HD had a clearer low end than the PL 4.0, dismissing the power-rating difference, as this was the same at low, or higher, levels. The fP 6400 and the I-T12000 HD are very similar-sounding, too similar for me to name which brand/model I liked better. I would even have a hard time trying to describe what the sonic differences are between the two.
Next, I did a processor shootout, and two JBL SRX 712M speakers were used for this part of the testing. The output of a console went into channel one of the amplifier in which the onboard processing was used, and the other side went to various processors we had around the shop; so, the only variable were the processors themselves. The processing competitors for the I-T12000HD were a BSS 336 MiniDrive, a BSS 366 OmniDrive, and an Ashly Protea processor. JBL recommended settings were entered into the processors to keep the experiment as controlled as possible. Sonically, I would declare a tie between the BSS 366 and the I-T12000HD's processing. The Ashly sounded harsh, even a bit shrill and crunchy, especially when hit hard in comparison, even before limiters and clip meters were hit. Again, there was a difference between the 366 and the IT12000HD but exactly what that difference is was too close to call; it could come down to many variables in the experiment.
The Crown I-Tech HD is a great amplifier with a great onboard processor. It matched up with the best my own shop has to offer, and it has added benefits that our shop doesn't have to offer, including USB connectivity. If you get a new I-Tech HD into your own shop, updating it will takes minutes rather than hours via RS-232. Plus, the advantages of on-the-fly monitoring, sending signal from the amp, and superior sonic quality make this a nice addition to any inventory.
Karl Bader is currently a lead engineer for Washington, DC's Entertainment Sound Production.www.espsound.com