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"Bass management" in a stereo system. My take.

Jmudrick

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Interesting issues. No real arguments against your points but I've chosen to go the high pass route in my three AVR-less systems...not that it is as necessary but I see it as desirable. So powered JBL subs in the listening room have a built-in high pass, and in the less critical tv room and bedroom I use Crown amps which have adjustable low and high pass filters. As for DSP I again take the view it's better using than not so I have PW-Link Anthem RC in all three systems. Bedroom and den I'm typically in the same listening position. Listening room is trickier but still believe that employing room correction for bass for one listening position is better than none at all and the PW-Link streamers are cheap. Summed mono with two subs in the listening room and den. Stereo sub cabling would be less messy for sure.
 

Holdt

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Just use the pre-outs from your amp to subwoofer's plate amp and adjust low-pass filter on the sub. Easy peasy.. BUT your main speakers still get the full-range signal and may or may not interfere with the sub. If one of your reasons for using a sub is to play louder or make some headroom for your amp, this solution is not it. Then you need to x-over (bass management) from the amp to divide the signal in two (sub // speakers). (Which it can't)
 

waynel

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So your port isn’t putting out any output above 80hz?
Not much and it doesn’t matter anyway because the subs are also crossed over so no overlapping regions with different phases
 

Head_Unit

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Also my main speakers are designed to be run full range from whatever amplifier they are connected to. I know of no speakers on the market that the manufacturer recommends they be high pass filtered to play properly.
Um, not really. But having worked as a marketing whore I can say of course the manufacturer wants you to think every speaker of theirs can play every note with perfection. No brand is going to commit sales suicide and say they must have a highpass.* Having worked as a loudspeaker engineer with a lot of friends doing that, I have to say many speakers of course cannot really handle the full spectrum at full blast. That's called "physics" ha ha. So unless the mains are pretty large (like our Focal 936, yeah no highpass really needed unless for some crazy EDM or movie special effects, at very high volume) there's more distortion.
If this distortion was a big problem, why are so many people enthralled with the sound of two way monitors?
- For one as I believe you alluded in passing, it sharply depends how loud you're playing. Us crazed metalheads aren't going to be happy, and if we need smaller mains due to space will definitely want a highpass. Someone who listens to The Kingston Trio and chamber music, eh, no problem. In which case the highpass won't matter really as you say.**
- I've never read of anyone enamored with a two-way monitor because of the bass sound. It's always about "transparency" "imaging" "depth" and so on. Many people seem to believe that a big tower can't have these qualities as well as a tinier speaker. (That hasn't been my experience, and while there is some engineering justification for that it's not something that can't be designed around IF the engineers have enough freedom. Some engineers are stuck designing to a spec thrown over the wall from sales/marketing I can testify firsthand. Heck I've sometimes been the one doing the throwing! Though I took pains to meet with the engineers and explain why certain lacks of design freedom were necessary to increase sales).

My advice about all this has become to take the most bass heavy selections you listen to and crank them as loud as you ever wood and listen especially to the bass. If it sounds fine, eh, no highpass needed. If you're not happy, try a highpass. It's unfortunate a lot of stereo equipment stupidly does not allow that option.

*excepting a few specialists-JTR, PSA/Power Sound Audio-that build models with bass purposely sacrificed for high sensitivity, in the stated assumption the system will have subwoofers.
**unless as someone alluded there is an infelicitous phase mismatch which can't be cured by the subs polarity and crossover settings.
 
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rwortman

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I've never read of anyone enamored with a two-way monitor because of the bass sound. It's always about "transparency" "imaging" "depth" and so on.
I have also never heard of a person that is enamored of the small monitor sound and doesn’t use a subwoofer who found the need to insert a high pass filter to make them sound better. If they sound good full range without the sub, they will sound fine with one.
 

Jmudrick

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Um, not really. But having worked as a marketing whore I can say of course the manufacturer wants you to think every speaker of theirs can play every note with perfection. No brand is going to commit sales suicide and say they must have a highpass.* Having worked as a loudspeaker engineer with a lot of friends doing that, I have to say many speakers of course cannot really handle the full spectrum at full blast. That's called "physics" ha ha. So unless the mains are pretty large (like our Focal 936, yeah no highpass really needed unless for some crazy EDM or movie special effects, at very high volume) there's more distortion.

- For one as I believe you alluded in passing, it sharply depends how loud you're playing. Us crazed metalheads aren't going to be happy, and if we need smaller mains due to space will definitely want a highpass. Someone who listens to The Kingston Trio and chamber music, eh, no problem. In which case the highpass won't matter really as you say.**

Um, not really. But having worked as a marketing whore I can say of course the manufacturer wants you to think every speaker of theirs can play every note with perfection. No brand is going to commit sales suicide and say they must have a highpass.* Having worked as a loudspeaker engineer with a lot of friends doing that, I have to say many speakers of course cannot really handle the full spectrum at full blast. That's called "physics" ha ha. So unless the mains are pretty large (like our Focal 936, yeah no highpass really needed unless for some crazy EDM or movie special effects, at very high volume) there's more distortion.

- For one as I believe you alluded in passing, it sharply depends how loud you're playing. Us crazed metalheads aren't going to be happy, and if we need smaller mains due to space will definitely want a highpass. Someone who listens to The Kingston Trio and chamber music, eh, no problem. In which case the highpass won't matter really as you say.**
.

Ah but for the subsonic subway rumble on The Weavers at Carnegie Hall...
 

Chromatischism

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I think well-designed 2-way stand mounts with subs sound sublime. I'd go to towers if I wanted to increase output and reduce distortion beyond 96 dB. I see that happening in a large room but I don't listen that loud here. I top out at 85-90 dB on average and it's enjoyable there. If I run it up to 100 dB, it's just for fun and momentary.
 

anotherhobby

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If they sound good full range without the sub, they will sound fine with one.
Yes, but they will also sound better with properly set up crossover if using a sub. If fine is good enough for you, then roll without a high pass, but don't pretend it's as good as a proper crossover between subs/mains.
 

waynel

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This whole thread is a rationalization for sub-optimal subwoofer integration. As pointed out several times, it is very difficult to match for a flat amplitude response when the sub and the main speaker are not in phase with each other over the frequency range of overlap, A crossover solves this problem.
 

dshreter

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Once again, these distortions don’t occur because you bought a subwoofer. They are cooked into the design of the speakers. If this distortion was a big problem, why are so many people enthralled with the sound of two way monitors? Yes, high passing your main speakers will probably effect the distortion profile. But if you already like the way they sound it can’t be that big of an audible problem, If you are adding the sub to a system with three way mains, even less of s problem.
I think your method of arguing your point is very strange. Listening with cheap earbuds isn't a problem. Listening to speakers without a subwoofer isn't a problem. So along those lines adding a subwoofer without a high-pass isn't a problem either. But if you want to assert the claim that bass management isn't very useful in stereo you should back that up with some measurements or other evidence or it's just some musings.

Subwoofers vary significantly in their features and functionality, and I would concede that some subwoofers offer almost complete bass management capabilities of their own including Low Pass, High Pass, parametric EQ, phase correction...
  • but then again most systems these days don't have separate pre-amps and amps to make this easy to setup with a loopback from the sub
  • and many subwoofers don't have all of these capabilities
Every room I've ever measured has shown that bass EQ / room EQ is necessary for a high fidelity response. I consider that part of bass management. It is also more practical to do that in "electronics" than in the subwoofer and active speakers.
 

Andysu

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I guess it all depends on your opinion. I'm not convinced that the woofers in the mains won't start outputting some audible distortion. I also am a big fan of DSP and IMHO for optimal stereo sound in basically any room one will need access to DSP so that means an AVR or something like a miniDSP SHD.
rel isn't a fan of dsp .
 

Andysu

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More informative? I guess. Ultimately I am going to be sitting in one spot. What it sounds like somewhere else doesn’t change what I hear. If I am not using those other measurements to make EQ decisions, what are they good for? If I am using them, then I must be deviating from whatever my ideal curve is at the listening position. Look, I have done this both ways. For live sound reinforcement in a large room, I take multiple measurements to get an EQ compromise. Then I play music I am familiar with and walk all around the room. The goal is as good as possible sound for everyone. In my home room, the goal is to get it as close to perfect as possible for just me. What’s going on a few feet away doesn’t matter. If my head has moved two feet, I fell out of my chair. Wavelength at 100hz is nearly 12 feet. Bass nulls are not going to be inches apart, or even two feet apart.
sit in one seat more less be same at . well firstly . what cinema you like going to ? what was first Dolby Stereo movie you saw ? what was first CDS , Dolby digital you saw ? what was first 70mm Dolby Stereo you saw ? what was first THX cinema you been to and the film and where was you sat ? how many times have you been to a THX cinema ? what was first movie in sensurround that you saw and where was you sat ?
 

dshreter

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rel isn't a fan of dsp .

Their article on this. I think talking about "speed" is a bit of pseudoscience, but time alignment is definitely an issue. This is another argument for why bass management or more generally any features that introduce latency, should be managed by a single box rather than in multiple latencies introduced in multiple parts of the chain.
 

Andysu

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Their article on this. I think talking about "speed" is a bit of pseudoscience, but time alignment is definitely an issue. This is another argument for why bass management or more generally any features that introduce latency, should be managed by a single box rather than in multiple latencies introduced in multiple parts of the chain.
i'm neutral on this at present
Yeah that's their schtick, but I ain't buyin' it.
i knew you say that . :p
 

Andysu

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Their article on this. I think talking about "speed" is a bit of pseudoscience, but time alignment is definitely an issue. This is another argument for why bass management or more generally any features that introduce latency, should be managed by a single box rather than in multiple latencies introduced in multiple parts of the chain.
then again . "nature is not flat" john hunter , rel . true its all random sound levels frequency .
 

Andysu

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heart's war 2002 , i put the dvd on for 2nd time not played this movie for 12 , 15 years ? wow the disc still looked clean as it been on the shelf . i tried the scene mentioned by , john hunter . wow that , gery summers mix is intense . the screen bass and surround bass and LFE discrete , whew .
 

levimax

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For what it's worth I recently added 2- SB3000 sub woofers to an almost full range stereo system. I tried it without a crossover and then with a 80 Hz LR 4 crossover. The measured performance was better with the crossover and so was my subjective preference. Didn't really hear any bass difference but mid range seemed better with crossover
 

ernestcarl

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While sub+mains integration is entirely possible either way with or without a HPF...

Some things to look out for are distortion and esp. higher order harmonics with increasing SPL levels. If you don't listen to audio content with peaks above 95 to +100 dB all that much -- and distance to speakers is short -- then skipping the HPF for smaller speakers may be okay.

I live in a townhouse, and I really shouldn't be playing all that loud when the neighbors are around... At lower SPL volumes the main front LR bookshelf speakers when sitting at my listening sofa perform fine.

50 Hz seem a bit low, but the ff. is a sweep of my bass managed front left speaker with/out a HPF:

HP L 1.png 1661922197766.png 1661922203171.png

Notice distortion is reduced around the high-passed region. Although, there's still a bit more distortion peaking around 100Hz from the mains. In the past, I also tried higher xo points -- which did seem to make the mid-range sound a little clearer/better in my two-way studio monitors (EQ adjusted to be approximately level). But again, I do not listen very loud that much anymore, and 95 dB shown above is only the ~maximum per channel peak transient SPL.
 
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Dlomb11

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As for me, Audiolense XO with its automatic management of multi-way systems, does exactly what needs to be done for correct integration:
Crossover, frequency linearization, time alignment, phase linearization.
Clearly the perfect integration is obtained for a single point, on a larger volume there is no perfection. But this is a problem with all (non-coaxial) multiway systems, not with the digital correction.
However, to me a system corrected for a single point corresponding approximately to the listening point, always sounds better in the rest of the room than a system not corrected, especially in low freq and in case of subwoofer(s).
Clearly there may be random sweet spots in incorrect systems, but they remain rare and limited in space.
 
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