[kukku]

Hi,

I am going to build a beta22 4 boards balanced configuration. I also intend to drive a pair of bookshelf speaker by this amp.

From my research, most of the bookshelf can't produce good bass or doesn't have good low-frequency respond. Thus, it is better to have a separate subwoofer for the low frequency.

So My question is: there is any good DIY filter/preamp that I can build it in the Beta22 like a add-on board for the sub out ?
I know some sub can have a passive mode that accept the input form speaker output of the amp but I want a general solution for most sub.

thanks

 

[nattonrice]

I belive the best solution as rec'd by Ti is to include a loop out on your case and use a powered sub.

 

[El_Doug]

at the same time, many active subs have a crossover built-in, and have a high-power output to speakers. thus, you can simply attach B22 speaker-outs to the sub as normal, and then connect the speakers to the sub

 

[amb]

Be careful with running balanced speaker outputs through a subwoofer, many of them will have common grounds and are not compatible (it would short circuit the cold outputs of the two channels).

The best solution is to use a special loop out connection (wired after the volume control) to feed a powered subwoofer, and run the bookshelf speakers full range directly from the amp. Adjust the subwoofer's crossover frequency to match the natural rolloff characteristics of the speakers.

 

[tonsosnot]

I have a line-out in the B22 that I am having built with output to a sub as its intended use. Many of the subs that I have been looking at have line-level inputs. Is there a difference with having a line-out instead of a loop-out on the B22? Is one preferable for use with a sub?

 

[kukku]

Quote:

Originally Posted by tonsosnot /img/forum/go_quote.gif I have a line-out in the B22 that I am having built with output to a sub as its intended use. Many of the subs that I have been looking at have line-level inputs. Is there a difference with having a line-out instead of a loop-out on the B22? Is one preferable for use with a sub?

Most of the Home Cinema Receivers have dedicated sub output, 1 RCA channel only.

I have a Sub that have only 1 RCA input accepting that pre-filter output from the receiver. That's why I ask for a add-on board for the dedicated sub output.

thanks for all the replies, seem to be time to upgrade Sub which accepts more inputs

 

[amb]

Quote:

Originally Posted by tonsosnot /img/forum/go_quote.gif I have a line-out in the B22 that I am having built with output to a sub as its intended use. Many of the subs that I have been looking at have line-level inputs. Is there a difference with having a line-out instead of a loop-out on the B22? Is one preferable for use with a sub?

I am not sure what you mean by "line out" in this case. Normally, line out refers to the outputs of source components, such as CD players, DACs, sound cards, etc. Since the loop out on an amp is simply its line input connected to an extra pair of jacks (to allow you to daisy-chain more amps to the source, without the need for using Y-cables), it is therefore also "line out".

Unless you have a pre-amp before the amp, and use the pre-amp's volume control (or use a source that has a volume control), connecting a subwoofer to the loop out means that the subwoofer's input is being tapped before the amp's volume control. Hence the subwoofer will be at a fixed (very loud) level which doesn't vary with the amp's volume knob.