Frequency range of 5.1 sound band

Hi all.
I have a small object about 5.1. It require me design a convert circuit with INPUT is STEREO 2.0 and OUTPUT is 5.1 surround (use OP-AMP). Please give me some information about frequency range of 5.1 sound band and circuit.
Thanks.

There is no frequency difference in 5.1 ,There is each track for each output ?
Why did you ask about the frequency range .What you mean ?

Sorry because I speak English is not good. That mean I need frequency range of Front-L, Surround-L, Front-R, Surround-R, Sub Woofer, Center (5.1). I tried but not found them on Internet.

Hi ,
There is no such frequencies the Front-l,Front-r,S-l,S-R,Center has the frequency range almost same because this is used to hear the nature sound . only the Sub woofer amplifier produce low frequency .
you must understand the technique of 5.1 then you will get the details
each tracks has its own amplifier

---------- Post added at 02:14 ---------- Previous post was at 02:13 ----------

just read details about 5.1 from google

**broken link removed**

---------- Post added at 02:17 ---------- Previous post was at 02:14 ----------

just read details about 5.1 from google

**broken link removed**

you can open and see what controller use,and then find a pdf file to have more information :wink:

yo2ldk said:

you can open and see what controller use,and then find a pdf file to have more information :wink:

Click to expand...

My teacher require me use op-amp

Titalas said:

My teacher require me use op-amp

Click to expand...

audio is located from ~ 200Hz to 14oooHz (if you need to calculate band pass filter
for five band with op-amp you can use LF356 (MOSFET input) or TL072 and one for bass (TL071) with band pass filter between 200 -400Hz
hope this help you..

What are you doing your projects ?
are you making a Equalizer circuits for an audio system ?
Or
Are you creating a stereo to 5.1 sound system ?

please tell me
i can help you ?

In 5.1, all speakers other than the subwoofer should be approximately 120Hz-20kHz (Dolby standard) or 80Hz-20kHz (THX standard). The subwoofer should be around 20hz-120hz (Dolby standard) or 20Hz-80Hz (THX standard).

As for converting stereo to 5.1, that's going to be more like creating a pseudo-5.1 signal, since stereo will not have the necessary multiplexing to encode true 5.1 audio. What you'll most likely be doing is to use the ProLogic technique of making the rear signals a combined mono of left and phase-inverted right signals. The center channel is slightly more complex, but if I remember it correctly, it is a slight phase shift of both left and right channels combined, with a high-pass filter.

My project is design a conversion system: Input is Stereo (left + right) - Output is 5.1 (center + subwoofer + left front + left rear + right front + right rear). My teacher require me use op-amp (not use IC).

Example below the system. But I need output is 5.1.


Thank for helps :grin:

Hi all.
I found the subwoofer. Please help me to complete the system.

Below: IN: Left (L) + Right (R)
OUT: Subwoofer

tinkerer73 said:

In 5.1, all speakers other than the subwoofer should be approximately 120Hz-20kHz (Dolby standard) or 80Hz-20kHz (THX standard). The subwoofer should be around 20hz-120hz (Dolby standard) or 20Hz-80Hz (THX standard).

As for converting stereo to 5.1, that's going to be more like creating a pseudo-5.1 signal, since stereo will not have the necessary multiplexing to encode true 5.1 audio. What you'll most likely be doing is to use the ProLogic technique of making the rear signals a combined mono of left and phase-inverted right signals. The center channel is slightly more complex, but if I remember it correctly, it is a slight phase shift of both left and right channels combined, with a high-pass filter.

Click to expand...

Do you know frequency range of CENTER band? Please tell me

I'm pretty sure the center is the same frequency as the left, right, and surround (80Hz-20kHz for THX, or 120Hz-20kHz for Dolby)

You just need to pick which standard you want to design your circuit by, and use that crossover frequency for everything.

Original question was about.........................

design a convert circuit with INPUT is STEREO 2.0 and OUTPUT is 5.1 surround (use OP-AMP).

Click to expand...

I think we should talk about decoding 5.1 channels out from stereo 2.0.

i.e. for example secrets in Dolby Pro Logic and Dolby Pro Logic II encoding and how to decode it. ( other systems can we find too )

for soft start
Dolby Pro Logic - Wikipedia, the free encyclopedia

next steps
**broken link removed**
**broken link removed**

The Schematic added here is an Enhanced Hafler Matrix Decoder

This surround-sound decoder is based on the "Hafler" principle, first discovered by David Hafler sometime in the early 1970s.

i.e. Dolby Surround 3.0 or 4.0 not Surround 5.1

there is no signals -j(0.707* rtot) = rear right or +j(0.707* ltot) = rear left
i.e. 90 degrees shifted signals

look tables Dolby encoding matrices in above wiki site

But after all this .............

You have signals Main R , Main L , Rear R = L-R , Rear L = L-R , Middle = R+L
and sub = R+L

Mathematical there is 5+1 signals "can we say 5.1 surround , i dont know"

This is the Original "Hafler" Surround-Sound Matrix configuration
**broken link removed**



Regards KAK

What about subwoofer?

Read these general info parts...................

Surround sound - Wikipedia, the free encyclopedia

Subwoofer - Wikipedia, the free encyclopedia

**broken link removed**

Any receiver with a .1 setup will have a discrete subwoofer channel that handles all the LFE
and sums whatever bass you're not sending to your other speakers.

Subwoofers are an important part to any surround sound system. They produce extremely low
frequencies which can be enjoyable when watching an action movie with lots of explosion or
listening to music with lots of percussion.
Subwoofers deliver deep bass. They are omni directional and can be placed anywhere in the room.

The signal sent to the subwoofer line-out of an AVR consists of two components:
1. The low frequency content in each channel.
2. Content below the crossover frequency set for each speaker is redirected to the subwoofer.
3. The content found in the separate LFE track in 5.1 content

Unfortunately there is a great deal of confusion in the terminology
and many refer to the subwoofer signal as "the LFE signal".

Your system has only sum of L and R not LFE signal
Use lowpass filter 200Hz and external amplifier for subbass channel
By listening find out best settings for other channels bass levels
Test by listening best place for sub (not in room corner or close the wall ) and
woofer phasing ( by changing speaker elements + and - wires )

Regards KAK

Someone please help me to design this circuit and tell me how does it operate, plz !!!