I really could use some help here.....


This is a hopefully finely detailed question that gives the people who are seriously trying to help me all the info they need to answer this question which is about cables, routing and speaker connections. Hopefully I can explain it well enough that someone can tell me what I have done.

The connections are ONLY RCA jacks and banana clips. That's all. Let me describe how I have wired things.

Source signal is from an OPPO Digital BDP-105 running to the CD input on my preamp via RCA jacks. Simple.

The signal leaves my preamp via Preamp Out connectors, also RCA jacks, and runs to my Sunfire SDS-12 subwoofer which has two line level RCA jacks for input so you can make use of the hi pass filter built in. That is the easy part, here is where it gets tricky ( for my understanding anyway...this is where I need your help in understanding the circuit I created  and if it makes any difference at all ).

The signal leaves the Subwoofer via the RCA jacks using the Subwoofer Out connections and goes to my RCA jack inputs on my amplifier ( all this makes sense to me so far, here is where I need help understanding )...the amplifier has banana clips for the connections to the speakers. RIGHT THERE, I change things. I have Monitor Audio speakers that can be bi-wired or bi-amped and when I bought them, the fellow through in a pricey set of cables allowing me to do that ( this is BEFORE I added the subwoofer to the system  ) so the signal finally leaves my amp via 2 banana jacks and arrives and terminates at my speakers in with 4 banana jacks and plugged in using the bi-wire configuration. Am I clear in describing this, Christ I hope so.

If I am, can anyone tell me what that that circuit looks like sonically, what's going on with all the other connections, what the Hell am I hearing? 

In short, I originally had just normal preamp/amplifier connections then bi-wire straight to the speakers.

Now I have introduced that subwoofer pathway into the signal path between preamp and amplifier? I'd love serious explanation on what that did, if anything, to the signal. My hope was that it was going to make the subwoofer and amplifier more in sync than if I'd run a separate connection from my second Preamp Out to the subwoofer. This way it's all in one signal path. So, is this the optimum way to set this up? Or have I screwed this up somewhere and it should be connected a different way?

Thank you so much!

For others, please stop calling my gear "junk" and I should sell it all and by REL. You're not helping any and you're giving a bad reputation to Audiogon people who are seriously trying to help me.

Components
1993 B&K Sonota ST-202+ amplifier fully refurbished
1993 B&K Sonata Pro-10 MC preamp
2008 Monitor Audio Silver RS8 speakers
OPPO Digital BDP-105 Blu ray player
2018 Sunfire SDS-12 subwoofer

I hope I've given enough information for people smarter than me to tell me if I have things connected in the best fashion and I'm hoping someone will take a few moments to answer.

Thank you.

j


Please do not pop in to suggest I spend $6,000 on all new gear while insulting me. This is what I have to work with so that's how it will stay. Thank you.

stereoisomer
what the Hell am I hearing?

How does it sound to you now?  Better/worse/different to before you introduced the sub?

Adding the subwoofer made a HUGE difference. As I understand it ( correct me if I am wrong  ) adding  the subwoofer this way and using its controls to set the internal crossover at 60Hz stops the amplifier from trying to power the speakers below that entirely. Now, the subwoofer is the only thing powering lower frequencies leaving the amplifier to handle 60Hz and up.

I could tell immediately I'd done something very, very good. The sound from the RS8's now sounds like silk with no strain at all. To ME, anyway.

I guess my root question is...I didn't bother or forgot to change the speaker cable from amp to speakers back to a more normal connection or just leave it in that bi-wire setup? I don't think I'm hurting anything but I am no longer sure the system is still bi-wired.

But yes, I love the sound with the subwoofer added this way. Thank you for replying!

j
I'm not sure if this answers your question but here goes...
Your preamp sends the signal to the sub which has a low pass filter so that it's own driver plays only low bass frequencies. It also has a high pass filter to remove the low bass frequencies from the signal going into your main speakers. That might improve the performance of your main speakers as long as the crossover in the sub is not adding any distortion to the signal.
If it sounds good to you then no problem. If you want to try something else then a next step might be to put a DSP on the output of your preamp to give you control over the crossover and frequency response of the system.

Post removed 
Here is some info about bi-wire. You have everything hooked up correct. BTW, if you decide not to bi-wire you should put some tape on the spare wires to avoid shorting them!
https://www.lifewire.com/bi-wire-amp-stereo-speakers-3134901


yogiboy,

A better question for me might be...is my system still even bi-wired? It WAS, for a fact, before I added the subwoofer in the signal path. But now the Preamp Outs route to the Subwoofer In and the Subwoofer Outs route to the amplifier ( which means I've already altered the signal some ) and the signal out from the amplifier speaker posts is still in the bi-wire configuration. But, is it really still bi-wired since I put that subwoofer in the path between the preamp and amplifier? Or did doing that essentially remove the bi-wire effects even though the speaker posts and speakers are still configured like a bi-wire system?
Yes it is. The subwoofer you added has nothing to do with how you decide to run the main speakers!
You are GTG, your hookup is fine and you are using the lowpass crossover in the sub to eliminate low frequency going to the mains. You got it figured out and you say it sounds good. Job done.
But, is it really still bi-wired since I put that subwoofer in the path between the preamp and amplifier?

Bi-wire is running two sets of wires from one amp to one speaker. It really is still bi-wired.  
Or did doing that essentially remove the bi-wire effects even though the speaker posts and speakers are still configured like a bi-wire system?

These are different questions. What is the effect of bi-wire? The idea is supposed to be that some frequencies travel better through one wire than another. This by the way is supposed to happen even when the two wires are the same. (It does.) So no you have not "removed" the bi-wire "effect". 

Just as a matter of helping you think things through going forward, how would something done upstream ever possibly be able to remove the effect of something downstream that hasn't even been done yet? 

You guys are all awesome. Thank you ALL for your answers in this thread. I THOUGHT I knew what was going on, THOUGHT, but it's nice, really nice, to my thought confirmed by so many people who took the time to reply or message me.

This was really starting to bug me a bit...the not knowing for sure part...thanks again to everyone who helped me out!

j
I have always found the most musical way to hook up a sub is with speaker level connections that way when you dial in the sub level it will change with changes in the volume control i hope that helps.
I have always found the most musical way to hook up a sub is with speaker level connections that way when you dial in the sub level it will change with changes in the volume control i hope that helps.


^^ this ^^
In general bi-wiring means that you can run independent wires to the tweeter and woofers.  It is different from bi-amping in that no additional filters are added - the entire signal goes to both.  I fail to see the benefit frankly.
Anyhooo.  You have put the signal through a high pass filter int he subwoofer, and the entire HPF'd signal goes through both wires  - split to both the tweeters and woofers.  The signal below (about) 100Hz remains at the subwoofer.
So the only things that changes are:
1. one more filter in the path2. Added subwoofer performance3. Speaker's woofers or woof/mid are relieved of the below-100 Hz (or whatever) material - therefore less stressed and less modulation of midrange on very low, long waves of low bass.
Ought to be good.
A schematic would be some much easier to follow, but i'm not going to figure out how to scan and insert a scetch. :-)

G


If it sounds good to you, then it is right.  What you have is a LeaverRite.  LeaverRight there, you are done.
@stereoisomer ,

Congratulations, my Audio Brother!  Maybe it was in the way you laid out the parameters of your question, the clear and precise details given, or perhaps simply how you adamantly made it known up front that toxic members need not reply:
"For others, please stop calling my gear "junk" and I should sell it all and by REL. You're not helping any and you're giving a bad reputation to Audiogon people who are seriously trying to help me."
Whatever magic you posses, I hope that it spreads across the Audiogon Message Board faster than the COVID-19 Delta Variant!  Your question and reply thread is one of the first discussiona I've read on Audiogon since I became a member where every response was positive and helpful, and void of the usual Toxic Asswipes that enjoy spewing their "Holier Than Thou Pabulum" every chance they get. 

By the wording of your question, you know who and what behavior I'm talking about.  It's a real pitiful shame that Audio fans new to the hobby, or seasoned Audiophiles that just don't have the depth of knowledge others here posses, have to politely ask not to be trashed, mocked or ridiculed when asking a question.  Hopefully in the future, the thus far "Silent Majority" will start calling out the toxic keyboard warriors.  However, based on recent actions that are becoming more and more common, I expect that Admin will simply delete and censure any threads that "rock the boat" against certain members. 

I'm glad that you got some very solid advice on your wiring  conundrum!

Cheers.


....what interests me about bi-wiring, and the discussions it generates...

2 cables of a hopefully 'identical' type, gauge, et al....properly fused together @ both ends into a common connector type...

Why would/should an electron with no known preference in a waveform created by untold quintillions of its' like end up in a particular cable?

Now, if half of the pair is of a different type, then one can state that claim...imho.

Now....extending this into cables in general, one can also claim that X 'sounds better/worse' than N, Q, CBGB.....

I concur that, Yes, there Is a difference.

I call it 'Inadvertent EQ'; changing an item that may have better in the first place but perceived as 'not so much'....and basically driven by prefered perception of perfection.

...but I'm just advocating the devil...;)
Don't let anyone tell you your B&K gear is "junk".  My EX-442 Sonata makes my Maggies sing. 

Literally.
OP, you’re good to go! I have a slightly different arrangement but my system also uses a woofer with a high-pass filter. In my system I’m using a vintage RH Labs sub which is powered by the amp. So my set up is like this:

Sources to Preamp
Pre to power amp
Power amp to woofer
Woofer to speakers (Electrostatic panels)

The filter and crossover are in the woofer. The removes the low frequency load from the electrostats which they aren’t the best at reproducing. The similarity between our two systems is that they both use a high-pass filter and your sub-woofer is powered.
Thank you for the tip on a powered sub with high-pass filter! I had asked about something like that on here a couple months ago but all I got were referrals to RHEL subs which don’t have a high pass filter. What I want to do is remove the low frequency load from my tube amp and let a powered woofer handle that duty. You’ve just given me a way to do that! The Sunfire SDS-12

Happy listening.


OP l also own the Oppo BD 105 and love all the features that it has, and praying it doesn't die on me as it's getting long in the tooth
In my system that consists of a pair of Maggie's and two SVS Ultra 13 Subs Because l have the two subs  I use an RCA Y splitter and then run RCA to the line level inputs on my subs  l use the built-in DSP in the Oppo to control the bass cross over You also have to set the main speakers to small  l'm just not sure if there is more sound degradation with my set up compared to your approach  FYI l have the Spectron musical MK ll amp and ARC LS15 tube pre amp 
You smartly improved your system, with the kind of sub I prefer: front firing.

I now encourage you to consider a second sub, locate them forward facing adjacent to the main speakers to achieve localization of bass instruments. It is the primary i.e. 30 hz, and the overtones: 60, 120, 240, ... that give localization of the bass notes.

as other's have said, you have used the sub's crossover to best advantage, letting the sub take the low bass job, sending only upper bass, mids, highs to your amp which continues to power your speakers in a bi-wire method.

just to clarify: the crossover (in the sub in this case) is not a specific frequency point, i.e. 60 below here, 61 above there. Using the dial, you choose the precipice of a SLOPE: beginning a gradual reduction of volume (strength of signal passed/sent) that will be sent back to the primary amp.

In your case your amp doesn't need a break, but the speakers do, they no longer try to make low bass, and your ears get the gift of extended bass from the sub and lack of distortion from the mains. Lower powered amps than your's benefit the most as they don't have to produce low bass. It's a great way to allow tube amps of moderate power to succeed. 
@stereoisomer 

I think you articulated yourself well in this thread. The way I conceptualize engineering and the audio reproduction hobby is that we are often making compromises rather than across the board improvements--getting one benefit by giving up another. You articulate two options here. But, I see a third option given your gear.

Now I have introduced that subwoofer pathway into the signal path between preamp and amplifier? I'd love serious explanation on what that did, if anything, to the signal. My hope was that it was going to make the subwoofer and amplifier more in sync than if I'd run a separate connection from my second Preamp Out to the subwoofer. This way it's all in one signal path. So, is this the optimum way to set this up?

You consider either (1) running the sub and mains power amp out of separate preamp outs, vs (2) adding the sub to the chain so that it the mains power amp receives only the higher frequencies. As you and others have stated, both are viable options. The third possibility (3) is that you keep the sub in the signal path but defeat its high-pass filter. 

Looking over your sub's manual, I see that you can defeat the high-pass filter by "by rotating the crossover frequency control fully clockwise." 
https://pdf.crutchfieldonline.com/ImageBank/v20150208141700/Manuals/877/877SDS12.PDF

You state that your goal was to "make the subwoofer and amplifier more in sync." Like you, I am also sensitive to the lag time of the bass frequencies. In my system, I use (1) because it's the only option with my sub, integrated, and room. It's better than no sub, but the sub frequencies arrive late. (One writer on the Darko forum states that latent subs are common, but certain brands make faster subs to remedy latency. See https://darko.audio/2021/06/kih-89-mind-the-gap/.)

So, I think (2) may help you to achieve your goal better than (1) by placing the sub prior to the mains power amp in the signal path and getting those sub activating earlier vs the mains. However, I believe that (3) is also worth a try because, in theory, you may retain the sub's priority in the signal path, but you can have the added benefit of allowing the mains to produce sub frequencies too. That is, you have a multi-sub system of sorts with better timed bass. The downside to (3) may be that, with your specific sub, defeating the high-pass also requires your sub to play the entire range from 30-150hz. So, you might find that when overlapping frequencies with your mains, you may get too much sound from 60-150hz, say, and not enough from 30-60hz. 

Tying back into the initial thought about engineering often being a game of compromises, I see the two prevailing sub setups as compromises. Connecting subs via speaker cable allows for better integration with the mains, and allows for a focus on sub latency. And connecting subs via RCA gives up that integration with the mains for smoother bass response in each seating position and across more seating positions, and can free up power on the mains amp.
I don't think anyone addressed this part of your question explicitly yet. Regarding the bi-wiring, you are still getting that benefit if the frequency of the speaker crossover is higher than your subwoofer crossover. So if you are only sending above 60HZ to the main amp (taking into account the slope issue of the previous comments) and your main speakers cross over around 2K, then everything from 60-2K are going through one wire and the higher frequencies go through the other.

You're lucky that you got a great improvement right off the bat. Subwoofer placement, crossover point, and volume should provide you loads of tweaking opportunities, too!

Enjoy, and I second the complement about encouraging civility.
@asvjerry FYI, I only recently bought a pair of speakers that are made to be biwired, so I researched why something so odd could work. My Totems sounded different to me biwired, and this research provides an explanation beyond "listen to the difference." https://www.qacoustics.co.uk/blog/2016/06/08/bi-wiring-speakers-exploration-benefits/

Biwire done correctly is about two things:
the larger field from bass signal can be moved to a different set of wire and physically spaced ( 4” is a good place to start ) so that field does not modulate the HF signal. The second thing is the crossover in the speaker extends back to the amp from an electrical perspective. Many listeners and competent speaker designers provide biwire provisions for a reason.
you have more options to explore in hooking up your system. ( and learning to discern Sonic differences ) For example just doubling up the biwire and using jumpers and listening…. You should also experiment w that second set of preamp outs - you are betting all your sonics on the quality of filters iMO  implemented in your sub.
have fun
enjoy
jim
You can download any Vandersteen manual ( model 2 and up ) for a quick phd on biwire, and a math based approach to initial location for your mains. Free.
You can also download Vandertones which are bass test tones ( not aligned to octave ) but to typical modes found in many American listening rooms ) that and the right inexpensive SPL meter will tell you what’s going on in your room below 120 HZ. ….  Tones are free, SPL meter Nearly free…
Frankly and Totally Honestly, this is the best damned thread I've read on Audiogon in a long, long time. I had little to do with it, I just tried my best to post the question as thoroughly and intelligently as possible.

YOU, EVERYONE WHO REPLIED, were courteous, interested, polite, brought up aspects I hadn't even thought of....this was just a great thread to read no matter who started it. I have tons of information to think over ( including relocating the subwoofer next to the speaker....BTW, yes, I DID find another SDS-12 for a steep discount so I decided to throw a bit more money into it by adding it ), every reply helpful, no one hateful, dismissive or contemptible. Thank you ALL for replying with such care and detail. When that second subwoofer arrives, I'll come back and let you all know how it sounds....and probably ask some new questions as well.

Thanks again to everyone.

j
"...well, Our work here....is Done."

Tune in tomorrow for the next episode of....
                              The Audvengers
One final question. I noticed that I goofed originally  ( this will sound really  bad  ) but O was checking things over today and noticed that I'd never removed the jumpers from either speaker.

It ran just find, sounded great, there wasn't a smell of burning electronics ever but leaving the jumpers on like that possibly altered the whole bi-wire concept. So, while apparently not inherently dangerous to the components, I should probably ditch those jumpers, correct?
@tomic601 

Thank you. It was clear there wasn't a danger of a short or miswiring danger but when I saw the jumpers in place, I thought "Hmm. I bet that defeats something." Thank you, again.

j