Sunday, June 29, 2008

Swapping out the HK 635

I picked up a second hand Yamaha RX-V2600 and swapped out my HK 635. I couldn't pass up the sale price. My Hk635 doesn't have HDMI inputs, so in order to use the new sound formats (True HD, DTS-HD, etc. ) I was using the 5.1 analog outputs. The Yammy does have HDMI 1.1, so I can now send the multichannel PCM straight to the receiver when using the HD DVD player. This should hold me over for a few more months until I replace it with a receiver that has HDMI 1.3.

One advantage to the Yammy is that it is THX 2 certified and has the surround options for THX cinema. I have only had a chance to play a couple of movies, and so far I can not tell that much of a difference in the two receivers.

Another difference is that the Yammy has the ability to be configured as a bi-amp for the front speakers. My Def Tech towers could be wired for bi-amping if I decided to go that route. It is something to consider when I am bored one afternoon.

Wednesday, June 04, 2008

The New Toys for Calibration

I ordered an MFW-15 Sub from AV123 on May 7. Not sure when it will be delivered, as they are backorder because of their popularity right now. This will allow me to have a dedicated LFE channel instead of using the SuperCubes built into the DefTech 7001's. The DT's will then be free to handle the main fronts on their own.

In preparation for the arrival of the MFW-15 sub, I started reading and learning more about tools for sub calibration. After doing some research at a couple of the forums, I downloaded Room Equalization Wizard software and purchased an external CreativeLabs Live24 USB soundcard for my old laptop. I tinkered around with the software long enough to know I really liked it and decided to take the next step and purchase a Behringer SSP 1124P Equalizer (BFD) and M-Audio USB to Midi dongle last night.

I got everything set up last night and started taking measurements and downloading filters to the BFD through the Midi device. Amazing what you learn from looking at the graphs and playing with the filter combinations.

I think I have it figured out well enough that when the MFW-15 arrives I will be able to tune it in. Right now I am just playing around with the front tower subs to get a feel for how everything works. This is going to be a very valuable tool in positioning the sub and knocking down some of the room modes.

From what I have gathered so far, there are 3 room frequencies that will be problematic. The first occurs down around 28 Hz. This is a huge bump in the graph of almost 15 dB. The next two occurs further up and are more on the magnitude of 6-7 dB. Definitely need to get the corner bass traps in place to tame things down and smooth out the response.