Onkyo AV receivers have created a big impression on the home theater market in recent years.
Their receivers have been winning awards and great reviews for a few years now, and they provide a strong line-up of products from entry-level models up to high performance machines.
There are currently three broad product categories to look for when researching an Onkyo AV receiver - the TX-SRxxx series, the TX-NRxxx series (which add networking capability) and the HT-RCxxx range (US only).
Most of these models are available in both the US and UK and share the same model numbers, however there are some regional differences which are highlighted below. You should also bear in mind that the exact specification may also vary slightly between different countries.
These Onkyo receivers are listed in approximate order of value (using the Manufacturer Suggested Retail Price as a guide) - starting with the entry-level models, and moving through the mid-range products and up to their flagship AV receivers.
The TX-SR308 is the entry-level receiver for the Onkyo range.
It features 5.1 channels and is rated at 65 watts per channel.
There are 3 HDMI inputs and 1 output. These connections are HDMI 1.4 meaning they support 3D video pass-through and also support the audio return channel.
This unit is able to decode Dolby TrueHD and DTS-HD Master Audio if sent direct from a Blu-ray player, and there are four DSP gaming modes - Rock, Sports, Action, and Role Playing.
Other highlights are a front-panel stereo mini jack port for connecting portable music devices, and there is a proprietary Onkyo U Port for an optional iPod dock.
Moving up the range we have the Onkyo TX-SR508 AV receiver.
It builds on the basic features of the TX-SR308 by providing 7.1 channels at a power rating of 80 watts per channel.
In addition to on-board decoding of HD audio, this unit features Dolby Pro Logic IIz processing which enables the system to incorporate height speakers in a surround sound setup.
With 4 HDMI 1.4 inputs and 1 output, there is full support for 3D video pass-through and the audio return channel.
This receiver also features bi-amping of the front left and right speakers, zone 2 support (either powered or line out), and also adds Audyssey 2EQ room correction with Dynamic EQ and Dynamic Volume.
The Onkyo TX-SR578 is a model that is only available in the UK product range, not in the US.
It has a very similar specification to the TX-SR508 receiver, however it adds advanced video processing features in order to improve picture quality and connectivity - especially if you are using analog video as a source.
This model adds Faroudja DCDi Cinema HDMI Video Processing in order to provide 1080p video upscaling of all video sources - with support for the upscaling of component video. The TX-SR508 also provides upconversion of video sources to HDMI.
The Onkyo HT-RC260 is the first of two 'HT' series receivers.
These models aren't available in the UK, and appear to be US-only models.
They are well-featured receivers with 7.2 channels at a rated power output of 100 watts per channel.
Full 3D video pass-through and audio return channel support is available through 6 HDMI 1.4 inputs and 1 output.
We are able to send audio to a second zone via either two powered channels or via a stereo RCA line out. This receiver also features 1080p upscaling of all video sources which can help to improve the picture quality on your TV.
The Onkyo TX-SR608 is a mid-range receiver with plenty of useful features.
Rated at 100 watts per channel, this 7.2 channel receiver will be suitable for many home theater systems.
There are 6 HDMI 1.4 inputs and 1 output, plus a whole host of audio decoding and processing modes - including HD Audio decoding, Dolby® Pro Logic® IIz and a THX Processing Mode.
The build quality of this unit is a step-up from previous models, and improvements are made to the audio quality by adding three-stage inverted Darlington circuitry and jitter cleaning technology.
The inclusion of Faroudja DCDi Cinema HDMI Video Processing also takes the video output to another level.
Other interesting features are the inclusion of a 15 pin D-sub PC input and an advanced on-screen GUI for easy setup of your system.
This receiver is also THX Select2 Plus certified.
Following on from the HT-RC260, this HT-RC270 AV receiver adds to the feature-set and offers some big improvements.
For example, THX Select2 Plus Certification signifies a step-up in overall specification of this model, and it is also certified by Onkyo to drive 4 ohm speakers.
Audyssey MultEQ room correction is added to the tools of this machine, which also features Dynamic EQ & Dynamic Volume. There is also the Audyssey DSX and THX processing modes.
Other improvements in the specification from the previous model are 7.1 analog multichannel inputs, and 7.2 pre-amp outputs for advanced connections to external amplifiers.
Like the HT-RC260, this model is only available in the US and not in the UK.
The TX-NR708 is the first model in the 'NR' series.
These 'NR' receivers are network-enabled machines which will connect to your home network for a range of media streaming and internet-based applications.
This model has an output of 110 watts from each of its 7 channels, and it also has two sub pre-amp outputs for the easy addition of two subwoofers.
There is a useful front-panel USB port for connecting memory devices and iPhone®/iPod® models, plus 7 HDMI 1.4 inputs and 1 output.
With support for 4 ohm speakers, and the inclusion of Audyssey MultEQ room correction, there are plenty of reasons to consider this machine for your system.
The next model up the ladder is the Onkyo TX-NR808.
For this 7.2 system, the power output is increased to 135 watts per channel.
For the first time there is support for a 3rd zone which could be useful for those with multi-room requirements.
Other highlights are network music streaming via DLNA or Windows 7, and support for internet radio and SIRIUS online radio system.
The TX-NR1008 AV receiver adds extra channels to previous Onkyo receivers we have looked at so far.
It has direct support for a 9.2 speaker system and is rated at 135 watts per channel.
HDMI 1.4 connections are 7-in and 2-out, which means this unit can be connected to two different screens at the same time - one TV and one projector for example.
This receiver offers decoding for Neural Surround, which means this receiver will play discrete surround sound audio from any 2-channel Neural-encoded soundtracks.
Other additions to this model are ISF video calibration for easy and accurate picture setup, a front panel optical input, and a learning remote control with on-screen remote programming.
Next in line is the TX-NR3008 AV receiver.
This unit has 9.2 channels and is rated at 140 watts per channel.
Full 3D video pass-through and audio return channel support is provided by 8-in/2-out HDMI 1.4 connections.
This unit has more advanced video processing with HVQ Reon VX technology, and also features an independent power supply with 4 separate transformers.
The TX-NR3008 is certified to THX Ultra2 Plus standard, and also adds Audyssey MultEQ XT32 room processing for more accurate setup of the audio in your room. Zone 2 also features the option to output video as well as audio.
The flagship model is the TX-NR5008 AV receiver.
It builds on the features of the TX-NR3008 but has a couple of extra additions.
Firstly, power output is increased to 145 watts per channel across the 9 output channels.
The independent power supply is improved by adding a toroidal transformer - which improves performance over other designs - and this model also features high-end Burr-Brown 192K/32 bit DACs for improving the audio quality.
Other additions include front and rear USB support for memory devices and the iPhone/iPod.
For more details: Onkyo Official Website