Do adjustments in subwoofer crossover frequency affect subwoofer out?
Answered
I have both a Powernode 2i and Node 2i and use the subwoofer out on both. I am happy the subwoofer crossover has been made adjustable. I know that the subwoofer output is always active. Is the subwoofer output now affected by adjustments to the crossover frequency? Or is the sub out still fixed at 80Hz? In other words, if I set the crossover for 60Hz, is the subwoofer output now rolled off @ 60Hz to match the mains?
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Official comment
The Crossover setting will set the cutoff for the audio going out of the SUBW OUT.
IF you have the Settings > Player > Audio > Subwoofer switch set to ON, this cutoff point is applied to the main outputs as well (the rolloff you described)
If this Subwoofer setting is OFF, the mains are unaffected by the Crossover setting.
Regards,
Sam R. -
Thanks for reply. Glad that the sub output is adjustable as well. What slope is the crossover?
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12dB
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This is interesting. I didn't know the BLUOS affected both the sub-out and mains-out. So am I right in thinking that it really is instituting a complete cross-over between the main speakers and sub. Am I also correct in thinking, that as long as the sub's own cut off frequency is a higher frequency than that of the BLUOS setting, that further fine tuning of the sub could just be limited to its overall volume? I am thinking of getting a REL T 7X for use with the new POWERNODE that I have on order.
Gord G.
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I too find that interesting. I am still not sure I have the outputs and filtering correctly understood. I was under the impression that you cannot do anything to the subwoofer output. It is always on and always full frequency range with volume tracking with the BluOS volume control. If that is so you need to make adjustments directly on the subwoofer (gain/volume and frequency cutoff point.
If that is true then I understand the subwoofer switch and frequency selection in BlueOS is only going to affect the mains output. It will adjust the low frequency point at which the mains will rolloff their output therfore releleaving the mains amplifier output from being used for the low frequencies being handled by the subwoofer.
In the end if that is true and you are driving your subwoofer from the mains output youshould never select subwoofer on in BluOS as you will restrict bass information getting to the subwoofer.
Looking for clarity.
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I'll try my best to clear it up.
Am I also correct in thinking, that as long as the sub's own cut off frequency is a higher frequency than that of the BLUOS setting, that further fine tuning of the sub could just be limited to its overall volume? I am thinking of getting a REL T 7X for use with the new POWERNODE that I have on order.
Shouldn't affect volume, just the frequency cutoff. Typically volume and crossover adjustments are exclusive to one another (depends on design, but volume would be amplifying the voltage and crossover would be filtering through an analog electronic filter)
Short answer: applying a crossover to an already crossover'd signal should not affect volume quality
I was under the impression that you cannot do anything to the subwoofer output. It is always on and always full frequency range with volume tracking with the BluOS volume control. If that is so you need to make adjustments directly on the subwoofer (gain/volume and frequency cutoff point.
Partly. The SUBW OUT of the BLS player is always fired up, but will not send full range - it is adjustable from 40Hz to 200Hz (at an early time it was hard set at 80Hz only, but now that is just the default).
[...]the subwoofer switch and frequency selection in BlueOS is only going to affect the mains output.
The Subwoofer switch will affect only the Mains out. The Frequency adjustment will affect the mains ONLY if the Subwoofer switch is on. The Frequency Adjustment will always affect the SUBW OUT.
In the end if that is true and you are driving your subwoofer from the mains output youshould never select subwoofer on in BluOS as you will restrict bass information getting to the subwoofer.
This just piqued my interest. I don't know if you could really run the sub on the mains of a BLS player. Perhaps NAD (but the SUBW OUT design on an NAD amp is usually different), but the POWERNODE isn't designed to run a sub via the speaker terminals and you'll likely get a ground loop if you try.
TL;DR:
Subwoofer (On/Off) only affects the Main RCA or Speaker out. Set to ON will apply a high pass filter to the RCA and Speaker Out based on the crossover freq set. Leaving this in the OFF position will send full range out of the RCA and Speaker Outs. The SUBW OUT output (nor digital outputs on the NODE/VAULT) will not be affected by this
Crossover adjusts the crossover point, between 40Hz and 200Hz. Anything below your set crossover will be sent out of the SUBW OUT of your player (active at all times). Only if the Subwoofer switch is set to ON, will the RCA/Speaker Out be affected (high-pass filter applied).
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That cleared up several points for me, but created one new one. So the subwoofer crossover “ON” setting does not affect the digital output? The crossover is applied only following DAC conversion and in the analogue domain and affects the RCA analogue main outs only? So digital out gets full range signal? I am using an external DAC/Active bookshelf and supplementing it with the subwoofer out to a separate active sub.
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Sam R. - you really cleared things up very nicely.
Re - I don't know if you could really run the sub on the mains of a BLS player. Perhaps NAD (but the SUBW OUT design on an NAD amp is usually different), but the POWERNODE isn't designed to run a sub via the speaker terminals and you'll likely get a ground loop if you try.
I should have specified this meant driving a powered subwoofer like a Bowers & Wilkins that can be driven with speaker level inputs. You hook it up to speaker output on the Powernode and continue from the speaker output on the subwoofer to the main speakers. In this case the subwoofer switch would be off on the Powernode and the subwoofer would be adjusted with the crossover and gain control directly on the subwoofer.
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Scott - that's correct, digital outputs are unaffected by subwoofer switch, full range all the time (and unaffected by Tone Controls as well - we try not to make any changes to the digital outputs to the goal of providing digital content out as original as possible)
Craig - ah. Now that you mention it I have come across that before, once.
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Wow, This is crazy. I love my Bluesound products but the lack of clarity in the documentation about how to use the sub out is difficult to understand. I assume Bluesound like to have a very minimal approach to the product to make it user friendly but I think there needs to be a dedicated FAQ or something from Bluesound about this. Is there any additional documentation other than "its a 12 DB crossover? Also, I assume the filter is DSP?
But to sum up, let's be as clear as possible....
1) The sub-out has a continually operating low pass filter that is set at the frequency indicated on the crossover setting and sub output is always on.
2) The mains-out has a high pass filter applied to it when the sub setting is toggled "on" and its frequency is indicated by the crossover setting.
3) Digital out is always pure signal regardless of crossover or sub setting.
Can someone from Bluesound confirm?
Cheers,
Gord
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So this doesn’t seem to be the case with the NAD M10 and I wonder if it is true about the C658 (on the way). With the M10 there is most definitely zero signal to the sub from the sub out RCAs when “No Subwoofer” is selected in the BluOS audio menu, and selecting 1 or 2 subs in the same menu does indeed low pass the sub and high pass the mains. I wish there was an option to Augment the sub bass, low pass the sub out but send full frequencies to the mains.
Additionally, with other DSP crossovers there’s usually a low pass selectable frequency and a high pass selectable frequency so that you don’t cross both at the same freq. Doing that sums the levels at that frequency causing a bump. I assume BluOS’s crossover is taking this into account however?
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I'm confused too. Why is it so hard to get a straight and clear answer from Product Support? Maybe it's just me....but it really shouldn't be this difficult.
I own both Node 2i and Powernode 2i, and use powered subs with each.
Based on all I've read, my understanding is in line with Gglendon above. Just to say it another (perhaps clearer?) way, I think it boils down to this:
SUBWOOFER TOGGLED TO OFF:
(1) the signal at analog outputs is full range.
(2) the signal at SUBW output is low-passed, as determined by the x-over setting.
(EDIT 2/27/22: this is incorrect, I've since learned that the low-pass defaults to 80Hz)SUBWOOFER TOGGLED TO ON:
(3) the signal at analog outputs is high-passed, as determined by x-over setting.
(4) the signal at SUBW output is low-passed, as determined by x-over setting.
In summary:
(5) the SUBW output is always low-passed (as determined by x-over setting), regardless of position of subwoofer toggle switch.
(EDIT 2/27/22: this is incorrect, I have since learned that XOVER setting only applies when toggled ON. When OFF, XOVER at SUBW OUTPUT defaults to 80Hz)
(6) the analog output is only high-passed (as determined by x-over setting) when subwoofer is toggled to on. With subwoofer toggled to off, the full range signal is delivered to analog outputs.
Is my understanding correct? If not, please use the numbers above to provide correction(s) where necessary.
Thanks -- John
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OK, I just ran an experiment so I need to amend what I said above.
I set the PowerNode x-over to 200Hz. With my hand on the SW cone (my sub is front firing) I used the SUBWOOFER control to toggle between ON and OFF. When in the ON position the driver was outputting much more than in the OFF position. So clearly the low-pass returns to some lower default setting when the SW control is toggled to OFF.
So numbers (2) and (5) above are obviously incorrect. Now the question is: what is the default low-pass setting when SW control is in the OFF position?
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When sub woofer is off, the cross-over point and below are sent to the sub-woofer AND the speakers. When SUB-WOOFER is enabled, the cross-over point and below are sent ONLY to the sub-woofer and above the cross-over point is only sent to the speakers.
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I'm sorry Tony, no offense intended, but your first sentence provides no clarity and must be wrong. Please re-read it.
You say with SW OFF, both the sub and speakers receive only low frequencies. Makes no sense for the mains. Can't happen. Impossible. You probably meant to say that the speakers are getting full signal.
Your second sentence I agree 100%
But you basically say the user-set low-pass is always in effect, regardless of ON / OFF position. But I strongly suspect that in OFF position, the low-pass applied is not user-set, but rather defaults to some value.
I tried to prove this earlier with logic supported by what I observe in reality. That is:
* x-over set to 200Hz (with app)
* place hand on SW driver.
* toggle SW ON and OFF (with app)
* feel the driver: ON = very strong vibration; OFF = much weaker vibration. This is quite obvious, not subtle.
The ONLY way this can happen is if the LOW-PASS automatically drops when the SW is toggled to OFF, and the SW driver then receives less information. If (as you say) the low-pass stayed constant regardless of ON / OFF position, the cone vibration would not vary when toggling. The SW low-pass is clearly changing as a function of the ON/OFF switch. Either that or my unit is defective.
Please explain. If my logic is faulty, howso?
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I would agree with your statement on the first sentence.
He are some observations I have made with my NODE 2i and a Pulse+ Sub. Your mileage may vary.
Wireless sub connection & BlueOS sub switch on = output to the sub
Wireless sub connection & BlueOS sub switch off - no output at sub
Wired RCA sub connection & BlueOS sub switch on - output to the sub same as wireless
Wired RCA sub connection & BlueOS sub switch off - output to the sub as if EQ slider was set to the lowest frequency setting and only very low bass (like 40Hz or less) continues from the RCA output.
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I heard back from tech support and they confirm exactly my suspicions as I stated above. That is, when using the SUB OUT the low-pass defaults to 80Hz when the toggle is switched to OFF. So your last sentence is correct. When ON, low-pass to sub (and high-pass to analog outputs) is as per the X-OVER set by the user.
With Powernode and Node there is always signal delivered to SUB OUT regardless of ON/OFF position. What changes with the ON/OFF toggle is the actual low-pass frequency used.
No experience with wireless sub connection, so I can't comment on it.
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Thanks for the followup clarification work @spellyny. I am the OP. Myself, I have never understood the rationale of the “always active sub output”. Why keep the processing and output active when Sub is Off? I love that it remains active when Digital Out is chosen (the way I use it), but I would like to be able to switch on and off the subwoofer output to aid in setup - crossover/phase/location/etc. Since it defaults to 80Hz when switched off, it seems to be a software item and could be made to turn off completely.
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@nstzya.......When I use DIGITAL OUTPUT (coax) to run my Node 2i into a separate DAC, neither the TONE CONTROLS nor the CROSSOVER (high pass) to main speakers works. This is because that processing occurs inside the Node's internal DAC and is delivered only to the Node's analog (and SUBW) outputs, but not the DIGITAL OUTPUTS. I know this because it is what I experienced in my system, and I confirmed it with tech support.
As stated previously, SUBW OUT is always active, and the low-pass level applied is either the CROSSOVER selected when ON, or 80 Hz when toggled to OFF.
In order to switch subwoofer on and off to aid in setup, you would need to use power switch on sub itself. That's what I do.
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@spellyny
I concur with your findings and it matches my experience and experimentation as well. I’d just like to be able to turn sub on and off completely from my listening chair. I don’t understand why the sub out defaults to 80Hz crossover rather than silent when Sub is OFF.
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It's obviously just a naming thing. Apparently, given how things actually work, the ON / OFF refers to high-passing the mains or not, and at what frequency the sub is low-passed, ie: chosen by user or default setting. It does not refer to turning sub ON or OFF, since the output is always active. Just a matter of which low-pass frequency is employed.
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There does seem to be a difference between a wired sub (RCA connector) operation and wireless sub operation. I have observed as others with the RCA output when sub selected to off. There remains output from 80Hz and below on the RCA connector. With the Bluesound wireless sub it is off, no output, nothing when the control is selected to off.
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@spellyny thanks for clearing things out. Could you help me with an advice?
I have the node2i connected to a tube amp through main outs and to a T+A active sub through sub out.
The settings I use are SUBWOOFER toggled to ON and crossover set to 60hz (my Canton Ergo 302's are rated to go down to 27hz, so I roughly doubled that value).
From what I undestand, the signal that goes to the sub is low passed. I have a 'crossover' knob on the sub that can be adjusted from 40hz to 180hz. What setting should I use? There is audible difference if I leave it on full vs set at 60hz. My hearing tells me that leaving it on full is the right way, but I'm just asking to be sure. Thanks!
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@Dan Sandulescu: Some subs have a "x-over bypass" switch on the rear panel. This takes the sub's xover out of the circuit and allows you to control it further upstream at the processor. Use it if you have it. If not, just set your sub's x-over higher than the x-over you have setup on the Node 2i. This insures that the sub receives all the frequencies as per your setting on the Node 2i low-pass filter.
Since you have the Node's x-over set to 60Hz, I'm not sure why your sub would deliver more info when it's x-over is set to "full" vs 60Hz. In both cases the sub should be playing the full 60Hz and below delivered at the Node's subw output. I can only guess that your sub has some sort of steep roll-off slope at around 60Hz.
In summary, assuming you sub doesn't have a bypass / defeat switch, just set its x-over higher than the Node's x-over setting if you wanna control it with the Node.
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@spellyny Thanks for the reply! Yeah I know it's pretty weird with the difference between 180hz and 60hz setting, from what I can hear it's mostly a slight volume change, not a freq. shift. The sub doesn't have a x-over bypass switch. I'll just leave it at 180hz and lower the volume a bit.
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I'm a little bit confused. I own a powernode and the sub. I just connected the sub to the only exit that I have. The sub ou is in off position. and I regulated the external sub at 130 to use it also with the soundbar. I understand that switch the sub control in all is a pure crossover. So I'm limiting the frequency to the mains speaker.
Please someone could confirm my understanding?
My aim is only to reinforce the bass for my B&W 804.0 -
Stefano your understanding is good. If you read back through this long thread you will gain further understanding. In your current set up the wired sub out defaults to 80hz when selected off in the BluOS app. The mains are unaffected and receiving full audio spectrum. The sub is not actually ‘off’ unless you turn the sub off on the sub itself. When the sub is selected on in the BluOS app you now control the crossover point between your sub and mains. The BlueOS app will allow you to control the frequency and level going to the sub so have the volume and frequency turned up on the sub so you can maximize the control through the BlueOS app.
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If you have the sub low passed and and mains high passed via the RCA....does the RCA need to have variable out to keep consistent volume between the mains and sub?
I am thinking that if the RCA to the mains is fixed level, then the volume is controlled by your amplifier, whereas the Sub output is controlled by the Bluesound, and therefore you could get a mismatch in volume between the sub and main speakers?
To this point, is there any loss in quality in using variable output? Some devices are designed to run at fixed output and the there is data loss limiting the volume in this way.
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Short answer, yes. If you use the Bluesound to do your bass management (crossover, relative volume control of bass) you will need to use the variable output to keep the subwoofer matched to your main speakers. The variable analogue output does not compromise quality. Keep in mind that you will still need to match the relative output of the subwoofer to the main speakers by initially adjusting volume on the sub to match the mains - just like always. Once that is matched, however, varying the volume with the Bluesound app will raise and lower sub output along with the mains output. Otherwise, with fixed output, the sub output will stay fixed (and full volume!).
If you use your preamp/integrated amp/receiver to do the bass management, you of course will turn subwoofer and variable output off on the Bluesound.
The way that I use the Bluesound is a bit unconventional. I use the digital coax SPDIF output to the digital input of my DSP active main speakers whilst still using the analogue subwoofer out to a conventional analogue input subwoofer. Essentially, I use the Bluesound as a streamer/preamp with bass management and sub out. I still need to match the volume set on the digital active speakers to that of the subwoofer, but once matched, I can use the variable digital output of the Bluesound to change volume. The analogue subwoofer output varies along with the digital output. There is no audible degradation with the variable digital volume control. Today’s digital volume controls are much better. Regardless, I minimize the amount that I digitally attenuate by setting the volume of the DSP speakers close to where I listen most of the time.
Edit: I should also note/clarify that with my setup the digital output is always full range and unaffected by the sub ON or OFF. I still turn Sub ON so that I can use the sub crossover to play with the sub output crossover point and match it to the DSP mains natural roll off at about 50-60Hz.
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For your first question, this is the configuration I am running. Although I am driving the sub wirelessly, the volume tracking you describe is the same. This allows for a single volume control for your system via the BluSound app once you set the sub gain level.
If you were to select fixed output I would be guessing that it becomes fixed for both mains and sub. If so, it would be as you said requiring two volume adjustments when adjusting your listening level. One on the amplifier and the other on the sub. If so, very annoying and inconvenient. If you were siding toward this arrangement to not have any volume adjustment in the Node that might possibly change the audio quality in some way by not being at full gain with no attenuation, you would be best served to hook the sub up to the amp if it has a variable output for a sub. Or if your sub supports speaker level input, chose that and once you set the gain on the sub for the desired mix you can make all of your volume adjustments on the amp with a single control.
In my current arraignment on the Node using the internal volume function I do not notice any loss of fidelity. Note that this is not my high resolving system. On my high resolving system I am using fixed volume and speakers with an integrated powered sub. All volume is adjusted at the receiver with a single volume control. My thought is go simple and achieve a single volume control set up and enjoy the music.0
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