Sunday, May 18, 2008

Crawling for Bass - Subwoofer Placement

Since i used to be a PC enthusiastic I've used Sub Woofer PC sound Systems. I tried every bit of me to get the maximum bass output from the sound systems,too bad. I'm not an audiophile(Well..mm.. I'm a lame audiophile :P). My room and the furniture didn't allow me to do as i wanted :(.

I came across several reviews on the net and thought that would be useful for you(Who are passionate about music!). So here it goes..

Perhaps one of the most difficult tasks in placing your speaker system whether it is a 2 channel or multichannel surround system is finding the best location for your subwoofer. It is not only a matter of choosing which location will sound best, but it is also a matter of ergonomics and dealing with space constraints of the listening room.

My advice in this matter is simple yet useful. I recommend doing the following procedure listed below when nobody is home or at least able to witness what you are doing as it may potentially result in having you committed or at the very least it will lead to a psychiatric evaluation.
Subwoofer Placement Procedure
onnect the "Sub Out" of your Receiver / Preamp Processor using an RCA cable into a Y-cable into the "L" and "R" inputs of your subwoofer. Note: Unless otherwise stated by the manufacturer, be sure to utilize both inputs of the sub as many subs sum the "L" + "R" inputs to yield a 6 dB gain from the input voltage of the processor.
lace the Subwoofer in the most common location of your listening area. (Usually your couch, chair, or bean bag).
lay a bass heavy CD or other format (not 8 track!) that you are familiar with and turn the volume up so that the sub is really working.

ote: The reason why you should crawl is that standing will put you about 5 feet off axis (depending on how tall you are) with the sub and thus will change the characteristics of the sound enough to potentially cause you to place the sub in a non optimal position.
Now get on your hands and knees and pay homage to the subwoofer (just kidding). Seriously, for the next part of this set-up, prepare to do some crawling (this is the part that could get you committed, but its all worth it!)
rawl around the listening room and listen for when the sub seems to sound the best. (IE. Listen for depth, loudness, tightness and definition)
f possible, place the sub as close to this position as you can. This will ensure you have chosen the best location in the room.
ow get off your knees and calibrate your system.

or Example:

Adjust crossover point on the sub for optimal blend with main speakers.
djust gain control of sub to tonally balance your system.
epeat A + B until satisfied.

This is a starter for those integrating a Subwoofer into their system for the first time. A more detailed placement guideline will be presented shortly for the more advanced users.

Sunday, May 11, 2008

GDDR5 in Production

Qimonda, a leading manufacturer of advanced dynamic random access memory (DRAM), said that it could deliver next-generation GDDR5 memory for graphics cards and other applications that require high memory bandwidth in volume. At this point Qimonda can supply makers of graphics boards GDDR5 memory with up to 4.50GHz clock-speed.


“Qimonda was the first to announce samples of GDDR5 back in November 2007. We have proven the technology and we can deliver in volume production to the market today,” said Glen Haley, communications director of Qimonda in North America, in an interview with X-bit labs web-site.

Presently Qimonda has 512Mb (16Mx32) GDDR5 chips at 3.60GHz, 4.0GHz and 4.50GHz clock-speeds in PG-TFBGA-170 packages in production. It is interesting to note that current-generation GDDR3 chips from Qimonda use PG-TFBGA-136 packing, which means that GDDR5 has more pins and requires more complex print-circuit boards of graphics cards.

It is projected that GDDR5 will play a substantial role in the next round of war between the leading designers of graphics processing units (GPUs) because it can double bandwidth available for graphics chips. Unfortunately, the price of GDDR5 memory from Qimonda is unclear. But while Qimonda does not unveil the exact pricing, it is likely that GDDR5 will be more expensive than GDDR3 and GDDR4, at least initially.

“If you look at the best performing GDDR3 parts today, they are running at about 2Gbit/s. With our GDDR5 we are able to at least double this data rate. We believe that Qimonda offers the highest performing graphics memory. There is a price/performance curve, and we are well-positioned to accommodate market demand as adoption increases,” Mr. Haley said.

Existing GDDR3 memory chips may run at 2.0GHz – 2.2GHz, which provides up to 140.8GB/s memory bandwidth in case of 512-bit bus, though, such chips are pretty expensive, just like print-circuit boards with 512-bit memory bus. For ATI, graphics product group of Advanced Micro Devices, the use of high-speed GDDR4 is an option, but Nvidia’s GeForce 8 and 9 GPUs do not support GDDR4. Therefore, the company either needs expensive GDDR3 in conjunction with wide memory bus, or GDDR5 with its extreme clock-speed potential.

In addition to Qimonda, Hynix Semiconductor and Samsung Electronics also plan to make GDDR5 memory.

Xbox 360 "Jasper" 65nm GPU in Production

Microsoft preps 65nm GPU for cooler Xbox 360s

VR-Zone: Technology Beats

Chip process evolution is a usual thing in a console’s lifecycle, but rarely has it been as important as in the case of the Xbox 360.

Known for its relatively hardware fragility, the original design of the Xbox 360 would frequently fall to the “Red Ring of Death” failure, which Microsoft terms as the three flashing red lights. While improvements in cooling and a CPU die shrink to 65nm in the Falcon revision have surely improved the situation, the problematic GPU still sits with its 90nm process.

The 65nm drop for the GPU in the Xbox 360 revision codenamed Jasper isn’t expected until August, a time frame backed up by a report from CENS. Microsoft has contracted Taiwan Semiconductor Manufacturing Co. (TSMC), Advanced Semiconductor Engineering Inc. (ASE) and Nanya PCB Corp. to build the chips that will ship with the Jasper consoles later this summer.

TSMC will produce the 65nm chips, ASE will package and test them, and Nanya will supply the flip-chip packaging substrates. Microsoft has supposedly booked a production capacity at TSMC estimated to be at around 10,000 300mm wafers.

Inventory of the existing Falcon chips are reportedly depleted, paving the way for the transition to Jasper. The next step for the Xbox 360 console is dubbed “Valhalla,” which will integrate both the GPU and CPU in a single package as a cost-cutting measure, isn’t expected until a year after Jasper.