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Subwoofers "for music" vs "for movies"?

polmuaddib

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I believe there is a difference, but it’s not about the sound.
It’s all about connectivity. Subs for music usually have some High level connection or stereo line level with input and output along an LFE input so that you can connect it to a stereo AMP without having an AVR or dedicated sub out.
HT subs usually have some LFE input and need AVR or some sub out with crossover setting.
Some have both. It’s not a real distinction, mind you. Mostly marketing.
 

ta240

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The whole "musical sub" myth comes from people using improperly setup subs with no EQ. Subs that go lower and play louder are more likely to trigger unpleasant room modes, and instead of resolving the issue they just say the sub "sounds slow" and buy a smaller one.

A good sub is a good sub, it will work well for both. How much sub you want/need is a different question than quality.

A good sub is a good sub, but some are better for some people. For people that don't have the ability to EQ the sub (or even don't want to mess with it) and lack the interest and time to spend trying to properly incorporating a sub without EQ then a sub that doesn't go as low or loud can be much easier to incorporate. It is much more fun to call them 'musical' rather than 'lower output'. Nobody wants to say "I bought this sub because it has less output and is easier to blend with my speakers".

A poorly blended sub can really make the music sound bad, beyond just overly bassy. That gets interpreted as the sub not being good for music. So, musical just means easy to integrate.

Now, whether them calling them musical and non-musical annoys you or not, is all up to the individual.
 

Walter

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I think you're more getting into bass extension rather than linearity there
Actually, I'm saying that for music, it is generally preferable to trade some extension (and max SPL) for increased linearity.
 

Ultrasonic

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Actually, I'm saying that for music, it is generally preferable to trade some extension (and max SPL) for increased linearity.

OK - I refer you to my original comment then :). I don't agree.
 

Ultrasonic

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@Walter perhaps an example would help. Here's an in-room measurement of the output of my current subwoofer at the MLP, with no EQ or low-pass filter applied. I don't think it's obvious how linear or not the raw sub output may be, and it would have to be seriously bad to start to compete with the variations seen here. This response is also pretty good compared to many in-room examples you'll see - it took effort to get it this good!

S1510 response from 3 Hz.jpg
 
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squeedle

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I owned two SVS ported subs (one cylinder and one box) that would easily shake the house with movies. However, I had difficulty getting get them to sound good with music. I have since sold both. What I have now are all sealed subs (two 10", 12", 15", and twin 15"). YMMV.
This is fascinating to me and I think is most relevant to my original post. Theoretically, the sub should only be reproducing the signal that was there in your music. So do you think it's a matter of personal preference, of simply not wanting to hear all of that signal? If so, would some kind of high-pass filter on the sub make it sound more like a sealed sub and therefore more to your liking for music?
 

Pdxwayne

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This is fascinating to me and I think is most relevant to my original post. Theoretically, the sub should only be reproducing the signal that was there in your music. So do you think it's a matter of personal preference, of simply not wanting to hear all of that signal? If so, would some kind of high-pass filter on the sub make it sound more like a sealed sub and therefore more to your liking for music?
The first one (cylinder) I sold before I understood more about room modes. So, that one hard to say.

The second one (box shape ported SVS sub), I would say it is more about how clean it sounded. I could sense muddiness when using it. Maybe the 2nd, 3rd, etc. order distortions were higher than I like, thus making the higher bass notes sounded a bit muddy.

The sensitivity of distortions varies person to person. I believe I am a bit more sensitive to distortions than average populations based on my recent tests.

You can take the distortion tests as mentioned in my thread here:

If you are not that sensitive to distortions, I guess the kind of subs won't matter too much to you for music nor movie.
 

Ultrasonic

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This is fascinating to me and I think is most relevant to my original post. Theoretically, the sub should only be reproducing the signal that was there in your music. So do you think it's a matter of personal preference, of simply not wanting to hear all of that signal? If so, would some kind of high-pass filter on the sub make it sound more like a sealed sub and therefore more to your liking for music?

I made an effort to compare the sealed vs ported difference in the post below, where I carefully applied EQ to match their responses. For me it was more a question of being different rather than one being better than the other. What I'm unclear on though is whether the difference I heard may be more widely applicable than the two subs I was using. I suspect the difference could be measured in terms of different Q / impulse response.

 

Chrispy

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I believe there is a difference, but it’s not about the sound.
It’s all about connectivity. Subs for music usually have some High level connection or stereo line level with input and output along an LFE input so that you can connect it to a stereo AMP without having an AVR or dedicated sub out.
HT subs usually have some LFE input and need AVR or some sub out with crossover setting.
Some have both. It’s not a real distinction, mind you. Mostly marketing.

You can get all this in a sub if you need to. Most subs only have a low pass filter, not an actual crossover.
 

Chrispy

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I agree that a good sub is good whether it is for music or movies. However, if you know the sub will be used only for music, then your priorities may change a bit to favor a flatter response over subsonic output.
Don't think it's flatter response particularly, but perhaps you can give up some lower extension depending on some types of music.
 

trl

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I guess it all comes down to sealed vs. ported subs and general idea is that sealed are somehow better for music due to a lower group delay. Also, ported subs might have port noise (rattle), so I guess it's all about finding a good measurement for the sub you wanna buy and take your pick based on the measurements.

I'll also add here few links for those that want to read more about the above and draw their own conclusion:

 

Walter

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@Walter perhaps an example would help. Here's an in-room measurement of the output of my current subwoofer at the MLP, with no EQ or low-pass filter applied. I don't think it's obvious how linear or not the raw sub output may be, and it would have to be seriously bad to start to compete with the variations seen here. This response is also pretty good compared to many in-room examples you'll see - it took effort to get it this good!

View attachment 164167
No, I certainly understand that the room has a major effect on bass. I'm simply saying that for music only, given a fixed budget, if one must choose between higher SPL and greater extension vs. flatter response, I recommend the latter as long as the deficiencies are proportional. Based on his recent budget 12 inch sub shhotout, it appears Erin (@hardisj) agrees, as well. Of course, if you already know that in your particular room and position there will be a significant boost right at the frequencies where the sub is falling off, there may be no need to make any tradeoff.
 

polmuaddib

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You can get all this in a sub if you need to. Most subs only have a low pass filter, not an actual crossover.
I am aware. REL, SVS and a few more offer many connectivity options and you can use them hooked up to an AVR and speakers at the same time with independent low pass control.
But there are some subs that can be connected to an AVR only.
Because there are no real SQ differences between subs to be called to musical or HT, these are the only factors that come to mind.

I will say that I reject the whole notion of separating Movie sound and music! If you care about sound and make a good surround setup, both movies and music will sound great.
 

MZKM

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Here is what SVS says:

A properly designed sealed subwoofer will typically exhibit less phase rotation, lower group delay, and reduced ringing in the time domain. Sealed cabinet subwoofers are generally more accurate in frequency response and better at rendering instrumentals in a convincing way. These characteristics make the sealed subwoofer a natural choice for critical music applications and are typically described by enthusiasts as sounding tighter and more articulate or musical, with less perceived overhang.

One of the most persistent myths in the audio industry is that ported subwoofers perform poorly on music. This reputation was largely earned by the public suffering through decades of small, ported boom boxes so common in 5.1 home-theater-in-a-box systems and brick/mortar retail outlets. At SVS, we call these imposter subs. These subwoofers don’t sound bad on music because they are ported; they sound bad on music (and movies too) simply because they are bad subwoofers.

SVS ported subwoofers have a flat frequency response, low distortion, excellent bandwidth linearity and a very deep tuning frequency (typically 20 Hz or deeper). The deep system tuning frequency shifts port-induced phase rotation and associated group delay below the typical music bandwidth, where we are relatively insensitive to it. By doing this, SVS subwoofers remain accurate in frequency response and maintain crisp speed in transients so you don’t experience the “bloat” or “boominess” found in lesser ported subwoofers.

The graph shows group delay curves for a variable tune ported subwoofer in 20 Hz ported, 16 Hz ported and Sealed operating modes. Note the group delay curves for all three modes are coincident from 120 Hz-30 Hz (which covers the typical music bandwidth), only diverging at the very deepest frequencies. While Sealed mode unquestionably has the lowest overall group delay, the two ported modes also have exemplary time domain behavior >30 Hz and can deliver excellent sound on music, as well as stellar movie performance.

For maximum dynamic impact and deep bass extension, ported subwoofers have the edge over sealed, which is why they are generally considered better for home theater. That said, it’s a myth to say that sealed can’t be great for home theater.

For musicality, accuracy and transient speed, sealed subwoofers have the edge, though for certain kinds of music and listening preferences, ported works better.
 

Ultrasonic

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No, I certainly understand that the room has a major effect on bass. I'm simply saying that for music only, given a fixed budget, if one must choose between higher SPL and greater extension vs. flatter response, I recommend the latter as long as the deficiencies are proportional. Based on his recent budget 12 inch sub shhotout, it appears Erin (@hardisj) agrees, as well. Of course, if you already know that in your particular room and position there will be a significant boost right at the frequencies where the sub is falling off, there may be no need to make any tradeoff.

Firstly, if you're still referring to where the response is falling off then we are talking about bass extension not linearity.

My key point was the following.

If someone isn't using EQ then how flat the response is above the low-frequency roll-off will make some difference and can absolutely then be of some relevance. Although in this context we'd also most likely be talking about a situation where no high-pass filter is applied to the main speakers and so the sub will be just be trying to fill-in a relatively small frequency range. The combination of low-pass filter and low-frequency roll-off there is probably very little 'flat' response region to speak of.

Anyone truly interested in bass sound quality should though be using EQ though, at which point the linearity becomes irrelevant and distortion/peak output are principally what matters instead. This is why I believe it is rare for anyone to mention linearity when choosing subwoofers*, and why I'll be honest I gave it zero thought when I've bought my last two, for a system where music reproduction is the priority. My concern here is that if someone prioritised linearity over output they may ultimately be worse off as distortion could be higher.


*Erin's video that you mentioned was actually the first occasion I can think of where I'd come across anyone doing so. I had watched this video before replying to this thread for what it's worth.
 

Walter

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OK. We've both stated our opinions.
 
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squeedle

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I recently bought two SVS PB-3000's, and after a couple weeks of getting used to them, I'm finding I think there is some ultra-low bass that I prefer NOT to hear when listening to music. Even just setting a HPF around 25Hz with 6db/octave slope seems to improve the sound for my tastes. People say music doesn't have content that low, but there sure seems to be something happening down there from time to time...
 

richard12511

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if you know the sub will be used only for music, then your priorities may change a bit to favor a flatter response over subsonic output.

I'm not so sure that's really a concern. For one, it's not difficult to design a sub with a flat response, and all well made subs should be flat. Second, the subs actual response is almost irrelevant in actual use; it's primarily the room that determines the response.

For me, it's all about max distortion limited output and extension. Once the room is involved, the more powerful sub can almost always be EQed to be just as flat as the "anechoically flatter" sub, and most often it will be even better(flatter).

I will admit there are seemingly sound arguments from people much more knowledgeable than me on both sides of the sealed vs ported for music debate. Subjectively, post EQ, I don't think I can really tell my sealed subs(JTR) apart from my ported subs(Rythmik). I tend to reside more on the "pro ported" side of the debate, since the power differences are very real.
 

Walter

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I'm not so sure that's really a concern. For one, it's not difficult to design a sub with a flat response, and all well made subs should be flat.
I am not aware of a single sub that even approaches a flat response over most of its useful range. Maybe some of the really expensive ones with DSP and servo control and a powerful enough amp to enable boosting as well as cutting frequencues. Can you give an example? Preferably one well under $1000. It would certainly move very high on my sub wishlist.

Also, people who disagree seem to have missed the fact that I said "may" and "a bit." Of course the room will be a major factor, as will the ability, or lack thereof, to apply EQ. If you already know your room's transfer function in the location where the sub can be placed, then it would be better to try to find a sub that will be as flat as possible with little or no boost required IN THAT LOCATION, as opposed to anechoically.
 
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