The latter - you run speaker cable from the tube amp to the sub (speaker in) then from the sub (speaker out) to the speakers.
The in's & out's are generally connected. So if you have nice cable already, that reaches from valve amp to speakers, you could run a second cheaper wire from amp to sub. Or even speaker to sub. The sub just needs to see what it needs to play. It doesn't need to actually pass through it. Making your idea of parallel or series, a case of whatever.
@friendly1uk
Doesn't my suggested method of connection permit use of the subwoofer's crossover to prevent the low bass frequencies from being reproduced by the L/R speakers, whereas your method means the L/R speakers will run full range, which may not be desirable?
Here's a typical subwoofer manual entry which compares the two methods:
"If you wish to run your main speakers full range with no low frequency roll-off, hook them directly to the main speaker output terminals of your receiver or amplifier as in any normal hi-fi system. This is recommended ONLY if your main Left/Right speakers are true full-range systems. If not, you may find that you are over-driving your main speakers. You will be able to play your system louder without over-driving your main speakers by using the built-in high-level high pass crossover."
Doesn't my suggested method of connection permit use of the subwoofer's crossover to prevent the low bass frequencies from being reproduced by the L/R speakers, whereas your method means the L/R speakers will run full range, which may not be desirable?
Here's a typical subwoofer manual entry which compares the two methods:
"If you wish to run your main speakers full range with no low frequency roll-off, hook them directly to the main speaker output terminals of your receiver or amplifier as in any normal hi-fi system. This is recommended ONLY if your main Left/Right speakers are true full-range systems. If not, you may find that you are over-driving your main speakers. You will be able to play your system louder without over-driving your main speakers by using the built-in high-level high pass crossover."
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IIRC, the only difference is the speaker level input is run through a resistive network in parallel with the line level, without any separation so my guess is that the answer is no, unless you add a switching network as suggested.
That suggests there is a passive high level pass. The sub amp plate pictured, has a low pass filter. It doesn't speak of crossover point, as it might, with it's in&out phono connectors.
I have the mission cube thing here. Satellites that only came down to 500Hz, and all 4 run through the sub, as they are a set. Yet, the speaker terminals are just linked. No capacitor. Though I bet the satellites have one inside. This could be easily metered out on the sub in question, and it would be wise to do so. Along with speaker ground to phono ground. It that were to 'beep' then the positive would want testing. If it is just resistive, I'm not so happy about the two amps idea.
The high level pass is on the speaker outs. It is usually a simple cap of 100 to 200 mfd.
The high level ins do not have that. It is simply an option for those without a line level out, in order to feed the external woof.
The high level ins do not have that. It is simply an option for those without a line level out, in order to feed the external woof.
I don't know why you call it "serial", it could be a my fault.
However, AFAIK the speakers input/output are simple a different type of input that the amp inside your subwoofer needs to work, in addition to the low level ones with the RCAs.
The amp inside the subwoofer will lower the signal level coming from your speakers and cut the high part at a crossover frequency suited to the woofer needs and you will modulate the volume from your external amplifier.
I don't see why call it "serial", but it could be a my fault as said.
Obviously, if I interpret your statement correctly, you mean you have two pairs (L/R) of speaker cables because you're talking about a pair of cables (L/R) runs from each of the two amplifiers (so two pair of L/R cables), right?
Edit to add: I don't realize the double set of cables, frankly I don't realize why you don't just use the "SW" output from your HT amp (that you said you had, if I remember correctly) and the speakers cable from you tube amp.
Instead you use (also?) the speaker cables from your HT amp that indeed has the "SW" output (RCA, low level).
I don't realize this.
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First, the sub is a Polk PSW111. The diagram in a previous post is what the manual calls option 2. There is no comment in the option 2 notes to indicate whether the signal is passed through to the speakers without filtering, or whether the output to speakers is high pass filtered. However, the manual also states that this connection would be effected by the subs frequency adjustment. This in common vernacular would mean the speakers were hooked up in series (serial) with the sub,
amp-sub-speaker.
If I hook up the sub to the tube amp speakers' output, along with the speakers, two sets of wires off of the tube amp one set to the sub, another set to the speakers. This would commonly be said to be a parallel connection,
Sub
/
Amp
\
Speaker
This connection would mean that the speakers would get the full frequency output instead of the high pass (potentially).
It also states that the two types of connections line and speakers should not both be connected, but I am assuming this means from the same amp. Anyway, I am going to get some speaker wire and hook it up both ways.
amp-sub-speaker.
If I hook up the sub to the tube amp speakers' output, along with the speakers, two sets of wires off of the tube amp one set to the sub, another set to the speakers. This would commonly be said to be a parallel connection,
Sub
/
Amp
\
Speaker
This connection would mean that the speakers would get the full frequency output instead of the high pass (potentially).
It also states that the two types of connections line and speakers should not both be connected, but I am assuming this means from the same amp. Anyway, I am going to get some speaker wire and hook it up both ways.
Roger means "series" where the amp, sub and speakers are arranged in a single line.
Roger is using the SW out on his HT receiver, but wants to simultaneously use the speaker outs on his tube amplifier.
EDIT: I have just seen Roger's post above.
The consensus remains that it would be unwise to connect two amplifiers unless possible interaction is prevented by an input switching arrangement.
First, you're saying the model number just right now and my guesses were an obvious result of not knowing which model it was.
Second, with the manual in hand, everyone is good at pontificating while we didn't even know the model.
Yet it wasn't enough for you to read the very clear instructions, but you wanted to ask the same.
The above "in common vernacular" means you don't have to do it.
The following is the simplified image for easier reading of option 2 which corresponds exactly to what I had already guessed and shows no need for double set of cables in parallel.
Galu, were you really explaining this to me?
Thanks, but as you can see below I had already realized that. 😉
It's just the double set of cable for the speakers in parallel that continues to make no sense for me.
Edit for clarity:
That's the Hookup Option 1
That's the Hookup Option 2
As we already knew, the manufacturer does not recommend using them at the same time.
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A double set of cables can be used to connect the tube amp to the subwoofer and speakers as shown below.
This is in accord with Roger's statement, "If I hook up the sub to the tube amp speakers' output, along with the speakers, two sets of wires off of the tube amp one set to the sub, another set to the speakers. This would commonly be said to be a parallel connection."
In a parallel connection all components share just two nodes. If we look at the left hand channel in the above diagram, both the subwoofer and the speaker share two nodes - the black and red amplifier speaker terminals.
Does that help or are we having translation trouble?
EDIT: Looking back, I think it is translation and that is my problem.
"It's just the double set of cable for the speakers in parallel that continues to make no sense for me" makes sense to me when I insert the word "using" between the words "just" and "the".
So you understand the wiring but do not understand why Roger would choose that option? In that case please ignore my "tutorial" above!
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@Galu
Friendly, sometimes I don't understand you.
It seems like you want to square a circle even if it's not yours.
Mind you, it's not a criticism, but it's a strong feeling.
Which however "forces" me (but I do it voluntarily, of course) in some way to explain things that would otherwise go without saying...
However, and said another way, the drawing you showed is not the drawing from the Polk PSW-111 manual as indeed I posted.
Also, it is a completely nonsensical drawing related to this subwoofer Polk.
Your drawing in fact shows a hypothetical subwoofer that has only 4 input binding posts and not 8 like the Polk 4 input and 4 output, and it is not the same thing at all!
If you compare the two diagrams, the one I don't know where you got it from and the original one of the Polk PSW-111 Hookup Option 2, they represent two completely different things.
The Polk simply cannot be connected in the way you have shown, which makes no sense.
If it made any sense, Polk would have put it in the manual as Option #4 (in which instead just does not exist), don't you?
As matter of a fact, from Polk PSW-111 user's manual you can read a completely different thing compared to the diagram you posted (which mistakenly connects both front speakers and subwoofer together on the same connectors):
"OPTION #2—
Note: Do not use the LINE IN inputs in this configuration.
• Connect the left and right front speaker outputs of your receiver to
the speaker level inputs of the powered subwoofer using speaker wire.
• Then, connect the left and right front speakers using speaker wire from
the speaker level outputs from the powered subwoofer.
• Connect the Center Channel Speaker directly to the center channel
output from your receiver.
• Connect the Rear Surround Satellites directly to the rear or surround
channel outputs from your receiver".
However, the purpose of having 4 inputs (Red-Black/Red-Black) and 4 outputs (Red-Black/Red-Black) on the rear panel of the Polk is to pass only a portion of the signal to the front speakers through a high-pass filter inside the amplifier inside the subwoofer.
Otherwise the front speakers would receive the full passband and would not cross optimally due to a overlap.
In fact, there is also a potentiometer on the rear panel of the Polk to modulate the cutoff frequency of the front speakers to modulate the transition from subwwofer to front speakers in an optimal way.
As matter of a fact, from Polk PSW-111 user's manual you can read:
"Low Pass—This control adjusts the subwoofer’s frequency range as well as selects
LFE (Low Frequency Effects), which bypasses the subwoofer’s internal filter and uses
the filter built into your receiver. When using smaller main speakers, the upper range
of the control will probably yield the best results. With larger speakers, the lower
end of the control range will probably sound best, but always let your ear be the
final judge. If male vocals sound “thin,” turn this control up until the voice sounds
rich but not “boomy.” If male vocals sound too “thick” or “chesty,” turn this control
down until the voice sounds natural".
Please note that LFE function is used in Hookup Option 1 only:
"OPTION #1—
Receivers that include a “Sub Out” feature—the most common hookup
method with Dolby ® Digital receivers.
• Set the low-pass filter knob to “LFE"".
Friendly, sometimes I don't understand you.
It seems like you want to square a circle even if it's not yours.
Mind you, it's not a criticism, but it's a strong feeling.
Which however "forces" me (but I do it voluntarily, of course) in some way to explain things that would otherwise go without saying...
However, and said another way, the drawing you showed is not the drawing from the Polk PSW-111 manual as indeed I posted.
Also, it is a completely nonsensical drawing related to this subwoofer Polk.
Your drawing in fact shows a hypothetical subwoofer that has only 4 input binding posts and not 8 like the Polk 4 input and 4 output, and it is not the same thing at all!
If you compare the two diagrams, the one I don't know where you got it from and the original one of the Polk PSW-111 Hookup Option 2, they represent two completely different things.
The Polk simply cannot be connected in the way you have shown, which makes no sense.
If it made any sense, Polk would have put it in the manual as Option #4 (in which instead just does not exist), don't you?
As matter of a fact, from Polk PSW-111 user's manual you can read a completely different thing compared to the diagram you posted (which mistakenly connects both front speakers and subwoofer together on the same connectors):
"OPTION #2—
Note: Do not use the LINE IN inputs in this configuration.
• Connect the left and right front speaker outputs of your receiver to
the speaker level inputs of the powered subwoofer using speaker wire.
• Then, connect the left and right front speakers using speaker wire from
the speaker level outputs from the powered subwoofer.
• Connect the Center Channel Speaker directly to the center channel
output from your receiver.
• Connect the Rear Surround Satellites directly to the rear or surround
channel outputs from your receiver".
However, the purpose of having 4 inputs (Red-Black/Red-Black) and 4 outputs (Red-Black/Red-Black) on the rear panel of the Polk is to pass only a portion of the signal to the front speakers through a high-pass filter inside the amplifier inside the subwoofer.
Otherwise the front speakers would receive the full passband and would not cross optimally due to a overlap.
In fact, there is also a potentiometer on the rear panel of the Polk to modulate the cutoff frequency of the front speakers to modulate the transition from subwwofer to front speakers in an optimal way.
As matter of a fact, from Polk PSW-111 user's manual you can read:
"Low Pass—This control adjusts the subwoofer’s frequency range as well as selects
LFE (Low Frequency Effects), which bypasses the subwoofer’s internal filter and uses
the filter built into your receiver. When using smaller main speakers, the upper range
of the control will probably yield the best results. With larger speakers, the lower
end of the control range will probably sound best, but always let your ear be the
final judge. If male vocals sound “thin,” turn this control up until the voice sounds
rich but not “boomy.” If male vocals sound too “thick” or “chesty,” turn this control
down until the voice sounds natural".
Please note that LFE function is used in Hookup Option 1 only:
"OPTION #1—
Receivers that include a “Sub Out” feature—the most common hookup
method with Dolby ® Digital receivers.
• Set the low-pass filter knob to “LFE"".
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Did not mean to raise such extensive discussion. I understand the manual stating not to use both line and speaker connections. I think for now I will unplug the HT sub out and see if adding the sub to my tube amp system makes a satisfying addition.
Thanks for the attention, and help.
Roger
Thanks for the attention, and help.
Roger
If I may, I would like to point out one more related thing.
Beyond our generic assumptions about a possible harmful interaction in using the two options #1 and #2 together, I believe that at least in this case about Polk PSW-111 the real reason seems yet another one.
The above does not seem like a generic warning from the manufacturer, but a technical necessity related to how the amplifier inside the subwoofer was designed.
The low-pass filter knob must be positioned in two different positions depending on which Option is chosen.
This fact will probably prevent you from even trying to see how and if the two options together work.