User:NetsrohT

From DRC

Home Theatre Setup

The following home-theatre setup runs in the loft of my house for some years now. Though the following text is not completed yet, though my english might appear an impertinence, and though there might always be something to do about optimising, there is still a lot of fun and joy about brutefir and DRC are doing their magic.

Loft room:

A=6mX6m

Preamplifier:

selfmade: 'DSPreamp'

1 analog stereo input (XLR)

2 AES/EBU inputs (XLR)

2 SP/DIF inputs (RG58 non-bal.)

2 SP/DIF inputs (optical)

2 AES/EBU outputs (XLR)

Microcontroler AT 90S8515

IR (remote-control), RS-232c (BruteFir-CLI for digital volume-control and filterbank-switching,)

DSP TMS 32xxx for simple Surround-Channels

I guess, there might be some lawyer awaking, when I start writing "DOLBY-Surround"??

But, my dear, it is something like that. Back-engineered.

Convolver:

64-Bit AMD on ASUS-MB, low speed fan heatsink

RME DIGI9636

openSuSE 10.3, sleeping HDD

BruteFIR 1.0g

BruteFIR runs (thank you, thank you, thank you, Anders!!!)

- the two four-channel crossover (Thiele-Small, thanks to Uli Brueggemann)

which are supplied by DRC-Filters computed by DRC (thanks to Denis Sbragion)

- the two active sound absorbers in the back of the room

convolve-delay is 800 ms

D/A-Converters:

2 X RME ADI-8 DS

2 X NTP ????

Power-Amps:

selfmade: 'IntelligAmp'

for main-speakers

8 X 100 W @ 0,01% THD

Microcontroler AT 90S8515 (temperature-, voltage-supervision)

AC-Softstart

RS-232c

passive thermal sinks

2 X Urei ?????

2 X 80 W

passive thermal sinks

for surround-speakers

for active sound absorbing (subs in the back)

Main speakers:

selfmade, direct driven by 'IntelligAmp'

1 X VISATON DSM 25 FFL

1 X VISATON DSM 50 FFL

1 X VISATON W 200 S (into closed cabinet)

1 X VISATON W 300 S (into 300 liters reflex-cabinet, fres = 22 Hz)

Active sound absorbers:

selfmade, direct driven by one UREI

1 X VISATON W 200 S (into 2 X 60 liters BP)

I did some experimenting about low-frequency absorbers (mass-absorbers) because I had some HEAVY negativ superimpositions at my listing position at 47Hz and 78 Hz with about -20dB or more. I labored the whole summer long. Without measureable success. So I came to the active absorbers. Two Bandpass-Cabinets in the back corners of my room, driven by small power UREIs (you will never need no more than 50 Watts...), convolved LP and - that's the point - delayed for 17 ms (that's the 6 meters) and signal-inverted (remember, I try to absorb!). Success: no standing waves any more. -3dB-point at 18 Hz, full signal at 25 Hz. Disadvantage: My poor dog tends to leave the house as long as the system is in use.

Other stuff:

8 X passive absorbers:

selfmade, 0,5 m X 1 m semi-rigid foam, aluminium-framed (thanks to Jens)

Audio/Video-Player:

xine-vdpau (selfpached for default A/V-Delay)

to be continued