How to choose

HP TouchSmart IQ820uk Desktop PC

2009-06-25T10:43:00.000-07:00

HP TouchSmart IQ820uk 25.5-inch Desktop PC with Intel Core 2 Duo Processor P7450, 4 GB RAM, 640 GB HDD, Ethernet, WLAN, NVIDIA GeForce

Product Features

Processor, operating system and memory

Operating system: Genuine Windows Vista Home Premium 64-bit Windows Vista® Home Premium 64-bit
Processor type: Intel® Core™ 2 Duo processor P7450
Chipset: Mobile Intel® GM45 Express Chipset
Standard memory: 4 GB
Memory type: DDR2-SDRAM
Memory slots: 2 SODIMM sockets

Internal drivers

Internal drives: 640 GB
Storage controller: SATA 3G Hard Disk Drive
Hard disk drive speed: 7200 rpm
Optical drive type: Slot-load Blu-ray player & SuperMulti DVD burner

System Features

Memory card device: 5 in 1 memory card reader
Network interface: Ethernet 10/100/1000BT integrated network interface
Video capture interface: IEEE 1394 FireWire® Interface
Wireless technologies: Wireless LAN 802.11 b/g/n, Bluetooth® wireless networking 2.0 EDR
Graphic subsystem name: NVIDIA® GeForce™ 9600M GS HD with PureVideo® HD technology
Video connectors: TV in, S-video in, stereo audio in, IR blaster out
Video RAM: 512 MB dedicated memory, up to 2303 MB total available graphics memory as allocated by Windows Vista®
TV tuner: TV (analog and DVB-T) tuner card, (DVB-T service not available in Ireland)
Internal audio: High Performance 2.0 speakers, High Definition Audio 5.1 (via digital output)
Audio connectors: front headphone port, front audio line in port, rear audio line out port, rear digital audio out port
Keyboard: Wireless keyboard with hide-away bay and numeric keypad, wireless optical mouse. Integrated VGA webcam with built-in microphone. Colored HP ambient light module with light control. Cleaning cloth
Remote control: HP Vista Media Center Remote Control
External drive bays: 1 Pocket Media Drive bay
External I/O ports: 5 USB 2.0 ports (2 in front); 1 FireWire®-IEEE-1394

Product Description

HP's 25.5-inch Touchsmart PC puts a world of digital entertainment at your fingertips with HP's innovative optical touch screen technology and tailor-made Touchsmart suite. A perfect addition to your living room, the latest HP Touchsmart PC features a sleek piano black design and a 25.5-inch full high definition touch screen. The HP Ambient Light enables you to select a colour lighting to suit your mood. Enjoy a whole new level of interactivity - at the touch of a finger, browse your music, videos and photos, or rediscover popular games through the power of touch. Breathe a new life into your favourite movies and TV shows with the integrated Blu-ray drive, built-in TV tuner, full HD widescreen and high performance speakers.

Box Contains

TouchSmart IQ820uk Desktop
Wireless keyboard with hide-away bay and numeric keypad
Wireless optical mouse
Integrated VGA webcam with built-in microphone
Coloured HP ambient light module with light control
Cleaning cloth
HP Vista Media Centre Remote Control
Power adapter
Product manual
Warranty

Best Price on HP TouchSmart IQ820uk Desktop PC

Compaq Presario CQ60-307SA

2009-06-25T10:10:00.000-07:00

Compaq Presario CQ60-307SA 15.6-inch Notebook with AMD Sempron Processor for Laptop PCs SI-42, 3 GB RAM, 160 GB HDD, Ethernet, WLAN, NVIDIA GeForce 8200M

Product Features

Processor, Operating System and Memory

Processor type: AMD Sempron™ Processor for Notebook PCs SI-42 2.10 GHz, Level 2 cache 512 KB
Operating system installed: Genuine Windows Vista® Home Basic with Service Pack 1 (32-bit)
Standard memory: 1024 MB
Memory layout: (1 x 1024 MB)
Maximum memory: Supports up to 4 GB DDR2 memory

Internal Drives

Internal drives: 160 GB
Storage controller: SATA Hard Disk Drive
Hard disk drive speed: 5400 rpm
Optical drive type: Lightscribe Super Multi DVD Writer (+/-R +/-RW) with Double Layer support
Lightscribe: Create silkscreen-quality disc labels direct from your PC with LightScribe: Just burn, flip, burn.

System Features

Memory card device: 5-in-1 integrated Digital Media Reader for Secure Digital cards, MultiMedia cards, Memory Stick, Memory Stick Pro, or xD Picture cards
Modem: High speed 56K modem
Network interface: Ethernet 10/100BT integrated network interface
Wireless technologies: 802.11b/g WLAN
External I/O ports: 3 USB 2.0, 1 HDMI connector, 1 VGA port, 1 RJ45 ethernet connector, 1 RJ11 modem connector, 1 headphone-out, 1 mic-in
Display size: 15.6" Diagonal High Definition HP Brightview Display
Display resolution: 1366 x 768
Graphic subsystem name: NVIDIA GeForce 8200M
Video RAM: Up to 319 MB Total Available Graphics Memory
Webcam: Webcam with integrated microphone
Internal audio: 3D Sound Blaster Pro compatible sound 16 bit integrated
Speakers and microphone: Altec Lansing® speakers
Keyboard: 101 key compatible keyboard
Pointing device: Touch Pad with On/Off button and dedicated vertical Scroll Up/Down pad, volume control, mute button
Power supply type: 65 W AC Power Adapter
Battery type: 6-cell Lithium-Ion (Li-Ion) battery

Product Description

COMPAQ PRESARIO CQ60-307SA 2.10 GHz NOTEBOOK PC With Microsoft Windows Vista Home Premium or Microsoft Windows Vista Home Basic the Compaq Presario CQ60-300 combines essential features and attractive design to put the versatility and productivitynotebook computing within your reach

Box Contains

Laptop

Power adapter

Product manual

Warranty

Best Price on COMPAQ PRESARIO CQ60-307SA

Leica M8 10.3MP Digital RangeFinder Camera

2009-06-25T08:39:00.000-07:00

Leica M8 10.3MP Digital Rangefinder Camera

Product Features

The low-noise CCD sensor which is specifically matched to the extreme requirements of the high-resolution M lenses; and the future-guaranteed raw data format (DNG) and the raw data converter Capture One LE ensures maximum image quality.
All the main settings are made in clearly structured menus on the bright 2.5" display. For detailed quality control "on location", RGB histogram and clipping warning can be used on even the finest details of the subject.
The modern metal-blade slotted shutter enables extremely fast flash synchronization times down to 1/250 second. The new M-TTL flash technology ensures natural flash illumination through the activation of a metering pre-flash. The auto slow sync. function now allows available light exposures without camera shake in aperture priority mode combined with a natural fill-in flash.

Product Description

The Leica M system is now open for professional digital photography. Breaking completely new ground, the Leica M8 doesn t only look like an M - it utilizes all the benefits of the analog Leica M system for sophisticated and creative digital photography. It is the only digital camera for professionals to incorporate the rangefinder system with its advantages of discreet and quiet operation, speed and precision. And the no-compromise quality criteria of the M system continue to apply to the M8. Full compatibility with nearly all M lenses means that their unique imaging performance is now available for digital photography, too. The low-noise CCD image sensor with a resolution of 10.3 megapixels has been specifically matched to the compact lens design to guarantee superlative photographic quality. The controls and functions of the digital M still concentrate on the essentials. The proven M concept is complemented by the intelligent extra functions that digital technology has to offer.

Best Price on Leica M8 10.3MP Digital RangeFinder Camera

Ghostbusters: The Video Game

2009-06-25T08:09:00.000-07:00

GHOSTBUSTERS

Product Features

An all-new storyline - same blend of humor and fright that made the movies a pop culture phenomenon. A continuation of the movie series, set 2 years after the events of Ghostbusters II.
Blast and wrangle ghosts with an arsenal of unique and upgradeable equipment. Throw out a trap, hook a struggling ghost, and slam it into submission for final capture.
Switch between 4 weapon sets to access 8 unique proton pack weapons ¿ different weapons are optimized for each enemy class.
Use gadgets like the PKE Meter and Ghost Light to scan and analyze targets. Spend the money you¿ve earned to upgrade the power and duration of each weapon.
Equipped with a variety of unique weapons and gadget

Product Description

When Manhattan is once again overrun by ghosts and other supernatural creatures, players will take on the role of a new recruit joining the famous Ghostbusters team.

Best Price on GHOSTBUSTERS

Punch Out

2009-06-25T07:41:00.000-07:00

Punch Out

Product Features

Players have the option to play using the classic layout from the original NES controller. Use the 1 and 2 buttons along with the cross pad to throw hooks and jabs or to dodge.
The ultimate boxing underdog Little Mac returns as the hero in this re-imagining of a gaming classic.
Large character roster including: Little Mac, Glass Joe, King Hippo, Doc Louis, Von Kaiser and others.
Players can obtain special 'Star Punches,' which allow Little Mac to take more Health from his rival in a single punch.
The Wii Remote/Nunchuk controller configuration allows players to simulate punching and ducking for a realistic boxing feel.

Product Description

One of the biggest names in boxing returns after a 15-year hiatus. Grab a Wii Remote controller in one hand and a Nunchuk controller in the other and step back into the ring with a modern update of the classic Punch-Out!! Little Mac is back! Everyone’s favorite underdog from the 1980s joins the best of the original Punch-Out!! cast in a modern re-imagination of the series. Players will find familiar names like Glass Joe, King Hippo and trainer Doc Louis. These boxers come to life again in cel-shaded 3-D, complete with hilarious fighting animations and back stories that capture all the fun and flair of the original Punch-Out!! games. The motion-sensitive controls of the Wii console mean that when players throw punches, Little Mac throws punches as well. Additionally, you can control hooks and jabs by combining motion control with control-stick movement. The motion-sensing Wii Remote and Nunchuk controllers turn real-life swings into on-screen punches, so anyone can play. The game can also be played with classic NES-style controls by turning the Wii Remote sideways.

Best Price on Punch Out

EA Sports Active

2009-06-25T07:13:00.000-07:00

EA SPORTS ACTIVE

Product Features

Game includes a deep co-operative multiplayer game mode.
Engage in fitness made easy through 20 minute circuits feature a variety of familiar activities that target upper body, lower body as well as cardio.
Follow the guidance, motivation and training tip of your very own virtual personal trainer.
30 day challenge' of tailor made 20 minute workouts, that change as you progress each day, and track calories, intensity and progress throughout your journey.
Gameplay/workout options are extended with the included Nunchuck strap and resistance band accessories, and compatibility with the Wii Balance Board (not included).

Product Description

Revolutionize your workout regimen with EA SPORTS Active, the ultimate interactive fitness program that's designed for you. Get fit with a holistic approach to fitness that combines nutrition and lifestyle factors, with a variety of activities, all from the convenience of your living room. From customized routines that target upper body, lower body, and cardio to a guided 30-day challenge that tests muscle endurance, coordination and agility, stay in shape with fitness made fun and easy

Best Price on EA SPORTS ACTIVE

Onkyo HT-S5200 7.1-Channel

2009-06-24T09:41:00.000-07:00

Onkyo HT-S5200 7.1-Channel Home Entertainment Receiver/Speaker Package (with Dock for the iPod®) Black

Product Features

- 130 Watts per Channel at 6 Ohms, 1 kHz, 1%
- DTS-ES™ Discrete/Matrix, DTS Neo:6®, DTS 96/24™, Dolby® Digital EX™, Dolby® Pro Logic® IIx Decoding
- 4 HDMI™ Inputs and 1 Output for Video, HDMI Pass-Thru*1 (Version 1.3 Compatible with 1080p, Deep Color™, and x.v.Color™)
- Dedicated Port for Single-Cable Connection of the Dock for the iPod
- SIRIUS™ Satellite Radio Ready

Product Description

If you want an idea of where Onkyo's home theater packages are heading, the HT-S5200 is well worth checking out. Like previous Onkyo 7.1-channel receiver/speaker packages, the HT-S5200 delivers reassuringly hefty amounts of power and all-round performance. And in line with other recent offerings, it's also perfectly suited for high-definition entertainment in the home.

The 1080p video takes center stage from sources such as Blu-ray Disc, DVD, HD broadcasting, and gaming. The emphasis is still on Onkyo's audio prowess, so the HT-S5200 is equipped with three groundbreaking Audyssey technologies that will give you the edge in terms of surround sound. It also features some exciting innovations from Onkyo: a dedicated port that connects the iPod via the Dock for the iPod and DSP modes specifically designed for gaming.

A Suite of Audyssey Technologies for the Ideal Listening Environment

The HT-5200 has three Audyssey technologies to help create the most suitable listening environment for your home. The first is Audyssey 2EQ™ for Room Acoustic Correction. The HT-5200 uses Audyssey 2EQ to counter distortion created by walls, furniture, and other objects. This technology detects speaker distance, and then sets levels, delays, and crossovers, while also measuring room acoustics. Compared to one-position room correction systems, Audyssey 2EQ covers a much wider listening area. Moreover, it corrects problems in both frequency response and time domain (where most of the problems lie) across the entire listening area. The results are immediately obvious--a clear, well-balanced, and natural sound.

The second is Audyssey Dynamic Volume™ control. This technology allows you to set the volume level that you want and keep it there, without having to constantly adjust it. By anticipating sudden spikes and dips in the audio soundtrack and compensating for them in real time, Audyssey Dynamic Volume ensures consistent volume levels, regardless of the content you're enjoying. Thanks to Audyssey Dynamic Volume, quiet dialogue is easier to pick up, loud passages retain their impact, and commercials are less intrusive.

The third is Audyssey Dynamic EQ™ for Loudness Correction. In professional sound studios, music and movies are recorded at reference levels far louder than what is typical for home listening. As a result, when you play audio content at a low volume on a standard home theater receiver, the bass disappears, voices change in timbre, and the surround soundstage loses definition. To counteract this audio deterioration, Audyssey Dynamic EQ continuously adjusts frequency response and the surround soundstage loses definition. To counteract this audio deterioration, Audyssey Dynamic EQ continuously adjusts frequency response and surround levels to produce the ideal balance for a given volume level

HDMI™ Pass-Thru* for Connecting up to Four Video Sources for Output to a High-Definition Display

The HT-S5200 takes up to four HDMI video inputs from sources such as Blu-ray Disc players, DVD players, gaming consoles, and set-top boxes, and delivers the output to a compatible high-definition display. Video is passed in its native resolution--right up to 1080p--from Blu-ray Disc, PlayStation® games, or HD broadcasts.

Dedicated Port for Single-Cable Connection of the Dock for the iPod

The HT-S5200 features a proprietary port, located on the rear side of the unit, to which you can connect Onkyo's Dock for the iPod. The dock sends both video and audio signals through a single cable. Earlier versions of Onkyo's Dock for the iPod can be connected via our Remote Interactive (RI) system. Now you can experience your music in your surround sound system and listen to it like never before.

Music Optimizer™ and Convenient Front-Panel Audio Input for Portable Devices

An audio input on the front panel of the HT-S5200 enables you to connect your iPod or other MP3 player directly to the system. The HT-S5200's onboard Music Optimizer technology then works to enhance the quality of your compressed digital music files by compensating for bit information lost at higher frequencies.

Four Game Modes for More Thrilling Action

A new addition to the Onkyo home theater, these four gaming modes create an experience with more realism and impact. You can select from Rock, Sports, Action, or Role Playing Game (RPG) modes to match your gaming content. Don't just play your games--live them, breathe them, feel them.

SIRIUS™ Satellite Radio Ready*

By using the SIRIUS input on the A/V receiver's rear, it's possible to enjoy SIRIUS Satellite Radio. SIRIUS brings access to over 130 digital-quality channels, including 69 channels of 100% commercial free music, plus exclusive channels of sports, news, talk, entertainment, traffic, weather, and data.
*SIRIUS requires separate purchase of subscription, compatible tuner, and antenna.

Best Prices On Onkyo HT-S5200 7.1-Channel

HP Pavilion G60-230US 16.0-Inch Laptop

2009-06-24T08:21:00.000-07:00

HP Pavilion G60-230US 16.0-Inch Laptop

Features

- 2.0 GHz Intel Pentium T4200 Dual-Core Processor
- 3 GB RAM (4 GB max)
- 320 GB Hard Drive, LightScribe dual-layer DVD Drive
- Windows Vista Home Premium (32-bit, SP1)
- 16-inch screen, Intel GMA 4500M graphics (up to 1319 MB total)

Product Description

Pared down to the essentials, the new G60-230US is defined by minimalist lines. High-gloss reflective top cover and palm rest area surfaces contrast cleanly with matte everywhere else. HP Imprint finish in piano black on the top cover with silver across the palm rest and touchpad provides greater durability than traditional painted surfaces. The streamlined look is enhanced with a color-matched keyboard and touchpad. The HP G60-230US delivers easy-to-use entertainment. Enjoy full-screen DVD playback on the crystal-clear 16:9 16.0-inch diagonal HP Brightview display. Burn audio CDs and DVDs to share your favorite songs and video clips with friends and family. Built-in Altec Lansing speakers bring your entertainment to life. And the 5:1 digital media reader enables photo transfer in seconds. For those who want technology to connect and manage everyday computing tasks in a stunning design that balances performance and mobility, the HP G60-230US Notebook PC delivers. Its elegant piano black and silver Imprint finish helps protect your system. The G60-230US ships with Genuine Windows Vista Home Premium with Service Pack 1, Intel Pentium Dual-Core Processor T4200, Intel Graphics Media Accelerator 4500M (shared) with up to 1309MB total available graphics memory, 3072MB DDR2 System Memory (2 Dimm), 320GB (5400RPM) Hard Drive (SATA), LightScribe SuperMulti 8X DVD±R/RW with Double Layer Support, Wireless LAN 802.11a/b/g/n WLAN. Dimensions: 14.88 (L) x 9.90 (D) x 13.80 (min H) approx., weight: 6.57 lbs. approx

Best Price On HP Pavilion G60-230US 16.0-Inch Laptop

Sapphire Radeon HD 4890 Graphics Card

2009-06-23T06:17:00.000-07:00

Sapphire Radeon HD 4890 1GB DDR5 PCI-Express Graphics Card

Product Features

- 1 GB of GDDR5 memory
- DirectX® 10.1 support
- 800 stream processing units
- 24x custom filter anti-aliasing (CFAA) and high performance anisotropic filtering
- Quad mode ATI CrossFireX™ multi-GPU support for highly scalable performance
- PCI Express® 2.0 support
- Dynamic geometry acceleration
- Game physics processing capability
- ATI Avivo™ HD video and display technology & ATI Stream technology
- Dynamic power management with ATI PowerPlay™ technology

System Requires

- PCI Express® based PC is required with one X16 lane graphics slot available on the motherboard
- 500 Watt or greater power supply with two 75W 6-pin PCI Express® power connectors -recommended (600 Watt and four 6-pin connectors for ATI CrossFireX™ technology in dual mode)
- Certified power supplies are recommended. Refer to http://ati.amd.com/certifiedPSU for a list of Certified products
- 1GB of system memory
- Installation software requires CD-ROM drive
- DVD playback requires DVD drive
- Blu-ray™ / HD DVD playback requires Blu-ray / HD DVD drive
- For a complete ATI CrossFireX™ system, a second ATI Radeon™ HD 4890 graphics card, an ATI CrossFireX Ready motherboard and one ATI CrossFireX Bridge Interconnect cable per board are required

Product Description

The latest addition to ATI's Radeon HD 4800 series of graphics cards falls short of the performance benchmark set by NVIDIA's GTX285. Nevertheless, if you are after decent performance without the credit card debt, the Sapphire Radeon HD 4890 will provide a modest boost in performance over the Radeon HD 4870.
In most respects, the Radeon HD 4890 isn't all that different from its predecessors, though ATI has made some tweaks under the hood. The card runs an altered 55nm RV770 GPU dubbed the RV790 which, thanks to tweaks and an increase in transistors, features a standard clock speed of 850MHz. Along with the GPU alterations, ATI has made 1GB of GDDR5 memory a mainstay of the Radeon HD 4890, with a clock speed of 975MHz for 124.8GB per second total memory bandwidth.
These changes also decrease the power consumption, going from the 90W required for the Radeon HD 4870 to a comparatively green 60W, though the Radeon HD 4890 graphics card will still require two 6-pin power connections. Temperatures also see a drop, going from hellish 90 degrees Celsius to more reasonable temperatures of 34 degrees at idle and a peak of 51 degrees during intensive operation. There is a cost to pay for this cool operation, however, as the video card's fan reaches sound levels that rival a construction site and, without an automatic fan monitoring utility, the fan's continuing attempts to deafen you will surely become a nuisance if installed in the wrong enclosure. The Radeon HD 4890 graphics card measures 241mm in length for an easy fit in most ATX cases, though it will still take up two PCI slots. ATI provides a single S-Video and two DVI outputs, with the latter enabled for HDCP and audio throughput, making connection to a conventional television or HDMI-equipped monitor easy to accomplish.
Despite the noise, the Radeon HD 4890 performed quite well in our tests, which we ran on Windows Vista 64-bit PC with an Intel Core i7 965, 6GB of DDR3 RAM and a Western Digital VelociRaptor (WD3000GLFS) hard drive, in an Antec Skeleton case.
In Futuremark's 3DMark06, the Radeon HD 4890 graphics card scored a total of 10509 points, a significant advantage over the 9708 points that the NVIDIA GTX285 managed. However, in the 3DMark Vantage benchmark tests, the Radeon HD 4890's score of X4718 was inferior to the GTX285's X6191.
In real world gaming benchmarks, ATI's single GPU graphics card managed 131.42fps in Half Life 2: Episode Two and 60.3fps in Call of Juarez. These results are commendable, though the Radeon HD 4890's 48fps fell behind the GTX285's 60.17fps in Far Cry 2. In the DirectX 10 version of Lost Planet, the Radeon HD 4890 performed at 34.45fps to the GTX285's 50.1fps. Surprisingly, the two graphics cards were on par in Crysis: Warhead, showing a negligible 0.2fps between the ATI graphics card's 35.1fps to the GTX285's 35.3fps. Though the GTX285 remains a clear winner overall when comparing the two graphics cards, the Radeon HD 4890 still performs well.
While overclocking potential is generally not an area we pay too much attention to, it is definitely worth mentioning with the Radeon HD 4890 as overclocking the GPU and memory modules beyond their standard clocks is an easy and — in this case — a rewarding task. Using only the standard cooler and ATI's own Overdrive utility (available in the Catalyst Control Centre), we managed to overclock the Radeon HD 4890 reference design to a GPU clock of 1GHz and memory clock of 1200MHz without losing system stability. At these increased speeds we managed to squeeze an extra 3.1fps out of our Crysis: Warhead benchmark, a decent result for little effort.
The small improvements made to the Radeon HD 4890's GPU core and increased memory make for a decent boost in performance over other single GPU Radeon HD 4800 series cards, without inflating the price significantly. Though the noise is worrying, the performance and overclocking potential are well worth it.

Best Price on Sapphire Radeon HD 4890 1GB DDR5 PCI-Express Graphics Card

3-way to choose a good Speaker for Amplifier

2009-02-24T03:05:00.000-08:00

3-way to choose a good Speaker for your Amplifier
The thing that’s changed the least over the past 20 years is the speaker. After all, there’s only so many ways you can move air to produce sound. With that in mind, matching speakers to an amplifier should be easy, right? Here the explains.
Impedance:Measured in ohms (Ω), typically 4, 6 or 8. The lower the impedance, the more demand the speakers place on the amplifier, which is why matching the impedance of your speakers to your amplifier is important. Most home theatre speakers will be 6 or 8Ω, as are most home theatre amplifiers.
Power handling:An often misunderstood specification. Measured in watts, it is best represented by RMS (root means square.) This figure tells us how much power the speaker can comfortably handle for a sustained period of time. Also referred to as continuous, or nominal power. The other way to measure speaker power handling is PMPO (peak music power output) is essentially the measure of the speaker operating at or near its absolute limits on the verge of serious damage. It is not a useful rating, and easy for manufacturers to inflate - so avoid it completely. So Avoid to buy speaker with PMPO label.
Sensitivity:Sensitivity is a rating often listed for speakers but not terribly well understood. Measured in decibels (dB), it refers to the speakers ability to turn the power from the amplifier into sound. The higher the rating, the more efficient the speakers are. Anywhere from 87-93 dB is typical of most speakers, but anything 90 dB or above is a good rating.

The thing that’s changed the least over the past 20 years is the speaker. After all, there’s only so many ways you can move air to produce sound. With that in mind, matching speakers to an amplifier should be easy, right? Here the explains.
Impedance:Measured in ohms (Ω), typically 4, 6 or 8. The lower the impedance, the more demand the speakers place on the amplifier, which is why matching the impedance of your speakers to your amplifier is important. Most home theatre speakers will be 6 or 8Ω, as are most home theatre amplifiers.
Power handling:An often misunderstood specification. Measured in watts, it is best represented by RMS (root means square.) This figure tells us how much power the speaker can comfortably handle for a sustained period of time. Also referred to as continuous, or nominal power. The other way to measure speaker power handling is PMPO (peak music power output) is essentially the measure of the speaker operating at or near its absolute limits on the verge of serious damage. It is not a useful rating, and easy for manufacturers to inflate - so avoid it completely. So Avoid to buy speaker with PMPO label.
Sensitivity:Sensitivity is a rating often listed for speakers but not terribly well understood. Measured in decibels (dB), it refers to the speakers ability to turn the power from the amplifier into sound. The higher the rating, the more efficient the speakers are. Anywhere from 87-93 dB is typical of most speakers, but anything 90 dB or above is a good rating.

How to choose amplifier

2009-02-23T00:48:00.001-08:00

how to choose an amplifier, with all sorts of "Is this good...?" types of questions. Here is what I look at when choosing an amplifier, and in their order of preference:

1. Power
I know, this is where MOST people look first, but it's the very reason you are buying an amp, right? Also knowing Ohm's Law, and knowing that I will almost always load an amplifier with the maximum specified impedance (impedance - 4 ohms or higher, NOT load - 4 ohms or lower), I need to know exactly how much power I am looking at to start with. When loading an amp with a higher impedance, the amp will make less power, so I have to keep this spec in mind the whole time. My speakers are almost always chosen before I decide to start looking for an amplifier, I know the impedance and efficiency numbers when I start. This will help me decide how much power I need or want for that particular driver compliment. I will NEVER look at "Max Ratings". They are often worthless, generally overinflated, selling tools, designed by old-school, low-end amplifier companies, originally made to sell product. (You remember how it went (and still goes today)... This 800 watt amplifier is only 200 dollars, but the Nakamichi 160 watt monoblock is 1300 bux for the pair. Which were (are) YOU going to buy?) Ahhhh, the power of advertising... Classic Nakamichi, Alpine, Linear Power, Orion, Eclipse, etc., THEY never posted "Maximum Power" numbers, did they? Unfortunately, even the good products of today will state maximum power output, I just disregard the numbers posted.

2. Signal to noise ratio
This one I place a bit more weight on, especially when the amplifier is going to be used in a mid-bass (important), mid-range (more important) or highs (MOST important) application. The higher the better, and there is no exception to this rule for me. Amps with tube stages are typically less capable than their solid state stablemates in this area, but I do make exceptions for tube amps. It is NOT a terribly important spec for a bass amp, so when shopping for a bass amp, don't bother with this number. Dedicated bass amps, BTW, usually offer awful SNR numbers.

3. Efficiency
Here's where you will be able to tell a decent manufacturer from the crap. Let's say you are looking at an 250 watt (RMS) amplifier. The first physical thing I look at, is how big a fuse do they recommend (or what size fuse is in the end of the amp)? I know right now that 250 watts OUT will demand (and I use 50% efficiency to keep it simple) 500 watts in. 500 watts in, divided by the (car running) battery voltage (14.4v) is about 35A. If I look at the end of the amp, and see a 20A fuse, I'm walking away, as there is no way that amp can make 250 REAL watts, continuously. 14.4v times 20A, equals 280 watts in. 250 watts out, divided by 280 watts in, translates to an 89% efficiency. In a class A/B amp, this is an impossible number, and it even stretches the imagination for digital amps, as well. The theoretical MAXIMUM efficiency for class A/B is 66%, (95% for digital) so someone is lying. I don't care WHO the manufacturer is, if these numbers don't add up, I will start looking elsewhere... Now, if all the other specification look good, AND I can get in the vicinity of the RMS power I am looking for, I will buy an amp that's efficiency number might be stretching the truth a bit. My old Nak 160 watt monoblocks had 40A (that's 480 watts in - a 33% efficiency, people!) fuses in each one, and they ran hotter than a firecracker, even loaded at over 8 ohms. I liked that.

4. Terminals
A frequently overlooked part of an amp, this is a very important part of an amp to me. A car is a place frought with vibrations. A cheap or cheezy feeling connector in power or speaker terminals and most ESPECIALLY in the RCA inputs, will often cause problems in the future. Setscrews for power, quality terminal blocks for speaker outputs, and Tiffany style RCA connections (the type attached to the chassis, rather than a block of plastic soldered to the PC board.) The quality of the I/Os can be a direct indicator of the attention to detail paid to the rest of the piece. Translation? Overall Quality.

5. Heat sink
This one is simple. How does it look? I eventually chose Eclipse gear, because it looked like jewelry. Fine finish and appearance. Also, heatsink size and quality can be another indicator of quality of the amplifier as whole. A heavy heatsink will also provide better thermal stability, a nice thing in an amp.

6. Damping Factor
I used to place more emphasis on this spec, but my research recently (over the last few years, really) has, while not proven to me it is a useless spec, has not proven to me it is an extremely important spec. This is why this particular spec is a little further down the list. While I place a bit more emphasis on it for a bass or mid-bass amp, I, admittedly, place less weight here than I used to...

7. Price
Money rarely means much to me in an amp, (much like my computers - "Life's too short to build slow computers." - David Draper) it's something I am going to be keeping for a long time usually, so I will save if necessary to get EXACTLY (or close to) what I am looking for. These are the things I look for when trying to decide on an amp. OBVIOUSLY, there are going to be VERY few amps on the market that will make me happy across the board, but then some of the physical characteristics listed above can be made to fit me and my desires with a little time, a couple extra bux, and some careful use of a soldering iron. All of the above things will cost more, but it will ADD more to the finished product as well...