Bass Management - Need Advice
May 16, 2008 at 2:04 PM Thread Starter Post #1 of 4

Mozhoven

100+ Head-Fier
Joined
Jan 10, 2006
Posts
268
Likes
12
Location
Midland, MI
Alright,

So I bit the bullet and bought a 2nd DefTech PS100tl sub (because I love the one I have so much, I didn't want it to be lonely)

Anyway, I did this before I realized that my pre-amp doesn't have 2 sub-outs.

So, I assume that if I want "stereo" bass, I must use the speaker level inputs, correct? My ultimate goal is to keep my mains full-range if possible, but keep my subs sounding their best.

Now, for my real questions:

1) Will my speakers sound as good coming from the sub as they do coming straight from the amp? In other words, are their any appreciable differences? (other than the bass now being diverted to the sub?

2) Will my speakers (coming from the sub) still receive their full power? (as if connected straight to the sub) *I know they won't receive full-range, just asking about amped power by itself. I seem to remember that it's best to keep as many electronics out of the loop as possible for the "purist" sound.

----------------

Now, my receiver has the ability to use separate amps at the same time using the speaker-outs on the back. How would it benefit me to use the receivers speaker-outs to run the dual subs (left/right), and to continue to run the speakers straight from the amps?

Keep in mind that I would prefer a full-range signal to my mains if possible.

My main concern with the later option is sound quality. Will the bass sound as good coming from the speaker outs on the receiver as it would coming from the speaker outs on the amp?

P.S. I seem to remember someone saying in an earlier post on a similar subject that it is possible to run the speakers full range straight from the amp while also having the sub's speaker-wire coming from the same terminals. Would this be the best variation?
 
May 16, 2008 at 5:00 PM Post #2 of 4
If your preamp has an LFE out, and the sub has an LFE input, that would be equal to an L/R connection. Regarding your questions about which method sounds better, why not try it out for yourself since you already have everything? No one but yourself should be able to tell you what sounds good.
 
May 16, 2008 at 6:28 PM Post #3 of 4
Unfortunaetly, my preamp only has a Sub-Out, no LFE (although the sub has one).

As for trying all methods, that would be fine but would require me building a new FFRC cable set. The first set took me several days, and although this set would be shorter by far, would still take longer than I would like.

Just thought I would glean any advice from those who have gone before me before I invest more of my time (and my wife's patience).

I should also mention that all of this will be installed in-wall for the studio I am currently building. This is why I am asking so many questions lately - I don't want to have to redo any construction just because I made a poor decision early on!
 
May 16, 2008 at 11:16 PM Post #4 of 4
Hans over at TNT suggested that I run a cable from the woofer terminals on the back of my speakers directly to the high-level inputs on the subwoofer for each corresponding speaker.

I'll reproduce the corospondance here:

Hans:

You can use any simple cable from the main speakers (keeping extra
cable capacitance at minimum) to the subwoofers like a single run of
cat 5.
Using the main amp speaker output gives good integration of the woofer
because the amps dynamic behaviour is part the subwoofers signal path.
If the subwoofer out is used subwoofer and mains speakers depend on
their own amps which can be quite different.

I prefer 2 separate woofers over 1 for many reasons.

------------
Me:

Thanks for the quick reply. Just to make sure I understand correctly,
I'll lay it step-by-step for myself below: (please correct me if I am
wrong)

In order of connection:

1)Preamp
2)Amp
3)Speakers (main)
4)Subwoofer

--------------------
Method:

1) Normal run of FFRC from Amp to Speaker

2) Single cable (cat5 or 6) from speaker teriminals (back of speaker)
to subwoofer speaker-level in.

3)Note: Do not use LFE or Sub Pre-Out on preamp/receiver as this would
be mixing amps possibly leading to a poor match audio-wise.

That way, the mains receive their full signal and the subwoofer gets
the appropreiate low-frequency signals from the same amp that powers
the mains. The other benefit is having the subwoofers in stereo.

One more question:
If my speakers are bi-wired, from which terminals
do I run the single cable to the subwoofer: tweeters, woofers, or both
(meaning 4 single cables going to 4 single terminals on each sub)
-----------------------

Hans:
Connect the woofer cable /terminal to the subwoofer.
The interaction of speaker and amp becomes part of the subwoofer
signal so these merge better.
This is available from either terminal, woofer or tweeter.
The high impedance of the subwoofer input will not make any difference.
If you use only one subwoofer, the two channels will connect to the
same signal ground of the subwoofer.
Some subwoofers are safety earthed. Any unwanted signals on the neg
wire can affect the delicate tweeter signal, so using this can have
some unforeseen side effects.
The woofer cable will be less sensitive to noise or any side effects,
its signal is stronger and bandwidth limited. So you better use the
woofer cable to connect the subwoofers.
I admit, I never tried the alternative because I was convinced that if
there were any difference it would be like described above.


----

I have tried this with only one subwoofer (as the other has not arrived yet) with promising results. The output is higher through the speaker inputs (as opposed to the LFE or pre-out jacks) and it seems to be more "musical" - but that might me projecting a bit.

I would love to hear what you all think about this method.
 

Users who are viewing this thread

Back
Top