I don't understand 2.1 monitoring systems

[Lights]

I’d like some education on 2.1 studio monitoring systems. I’m a little confused by the concept, but I think I might benefit from them. I read a book called “Mixing Secrets for the Small Studio” that strenuously recommended sealed-cabinet nearfield systems for small control rooms. The supplemental web information recommends the BlueSky 2.1 systems as good examples of a sealed-cabinet solution.

I currently use the original Mackie HR824 monitors (which aren’t ported, but use a passive resonator). I chose these monitors because I wanted to accurately represent the full frequency range. Also, I bought them when they first came out—I’ve had them forever. Back then, there weren’t many comparable monitors of similar quality as cheap as the HR824.

After tons of room treatment, I feel pretty good about how they work in my room and have a fairly smooth waterfall, but I do have one room mode that I have yet to squash (a null at 43Hz at the mix position only from the left channel). When I listen to bass, though, I hear even low bass tones that are supposedly omnidirectional in stereo and often do specific work to keep it tight and centered that I think pays off in the final product. I just can’t fathom hearing everything below 80 or 100Hz coming from under my desk.

On the other hand, I can see how having a single woofer that I can move around without affecting the stereo image could help the room response at the mix position, so I’m open to considering the solution.

Help me understand the tradeoff between a pair of monitors that deliver the full frequency range and a set of 2.1 nearfields.

Thanks!

P.S. - if there are any sealed cabinet monitors that don't require a subwoofer, I'd love to know about those too!

[Lights]

Nobody with a 2.1 system wants to advocate for it and explain to me how you can build an accurate mix with everything below 80Hz coming from under your desk?

[superwack]

Frequencies under 80 hz are not directional so it doesn't matter if the sub is under your desk (if your room acoustics allow it)

Also most if not all small near/midfield monitors are incapable of producing the level of LF you get from a sub

[theblue1]

I'm afraid I'm not from the 2.1 user camp, but rather those who are skeptical.

I've personally never heard a 2.1 system that sounded ideal to my way of thinking.

Obviously, phase issues are one source of concern -- and probably even more so if one were to try to compensate for room modes by 'creative' sub placement.

But, as you note, directionality is another.

While, without question, the lower the frequency, the greater dispersion, there is no threshold under which perception of source direction suddenly cuts off. To be sure, perception of directionality is greatly reduced as one enters double digit frequency territory, but the process is gradual. I will certainly stipulate that by 50-60 Hz in a typical environment that directionality is quite difficult to pin down

One might find it instructive to set up a sweep from 200 Hz or so down on one side and listen to the effect.

[Nick Laho]

I have a 2.1 setup. A pair of Ascend Acoustics CBM-170(first model) and a Emotiva Sub 12.

The CBMs are flat down to 100hz or so. I needed more information in the low end but did not want to get rid of the CBMs as I like them a lot. The Sub-12 is Sealed and I believe that leads to a nicer rolloff at the sub's lowest frequencies.

I have a modest amount of room treatment. (Lots of 2" Auralex on the 4 walls and 4 GIK Monster Traps closest to the corners as I could get.) The Room is 11'x14'.

I recently moved my subwoofer from between my speakers to my right side to see if the frequency response changed. I got a more even response but you do hear the sound shift kinda to that side in the low end. I'm going to move it to a few more places to find the best spot. Hopefully somewhere in front of me near the speakers if I can to avoid that shift of sound.

As for hearing the sound come from "under the desk" I agree that it is not ideal. I'd love to have a pair of sealed monitors that could go down to 30hz or so pretty flat.

[Lights]

Originally Posted by Nick Laho

I recently moved my subwoofer from between my speakers to my right side to see if the frequency response changed. I got a more even response but you do hear the sound shift kinda to that side in the low end. I'm going to move it to a few more places to find the best spot. Hopefully somewhere in front of me near the speakers if I can to avoid that shift of sound.

As for hearing the sound come from "under the desk" I agree that it is not ideal. I'd love to have a pair of sealed monitors that could go down to 30hz or so pretty flat.

Yea, that's what I was worried about. I'm concerned that I might be able to have more flexibility with bass mode issue management but lose way more in exchange for that flexibility.

As it is, my HR824s aren't sealed (bad) but my waterfall doesn't show much ringing/resonance at all (good) so perhaps the things I heard about HR824s' passive resonators being as problematic as ports (in Mixing Secrets for the Small Studio) were the newer Mk2 Chinese model.

Are there sealed monitors that don't require a sub? Who makes them?

[Enlightened Hand]

Originally Posted by Lights

I’d like some education on 2.1 studio monitoring systems. I’m a little confused by the concept, but I think I might benefit from them. I read a book called “Mixing Secrets for the Small Studio” that strenuously recommended sealed-cabinet nearfield systems for small control rooms. The supplemental web information recommends the BlueSky 2.1 systems as good examples of a sealed-cabinet solution.

I currently use the original Mackie HR824 monitors (which aren’t ported, but use a passive resonator)...

For the record a conventional port or a passive radiator is just a device that is designed to extend the low frequency bandwidth of a given speaker and cabinet. In conventional designs (not "every" design) they work very similarly and suffer from similar problems in that the frequencies that exit the port or passive radiator are always subtly lagging behind those that are leaving the driver that they are connected to. This lag causes a subtle blurring of low frequency transients. Low notes don't start or stop right on time as they are supposed to through the port or radiator. That combined with the filtering circuitry (that further increases the low frequency delay in conventional designs) that is designed to protect the low frequency driver in a ported or passive radiator model adds up to noticeably less accurate transient response. Things like kick drums overlapped with bass guitars are more difficult to place and balance in a mix when you have that blurred transient response in the low frequencies. One of the main reasons sealed cabinet designs are useful is because the low frequency transient response is more accurate and easier to work with over conventional ported designs.

But all ported designs (or passive radiators) aren't the same. Some are unique in their approach and they find a way to allow the low frequency transient response to not be smeared or blurred or at least not noticeably so (Those Mackie HR824 for example aren't that bad for low frequency transient response, though they do have a resonate lag in the low frequencies that you won't get in a sealed design). The exceptional ported designs are usually quite expensive though compared to conventional designs.

...After tons of room treatment, I feel pretty good about how they work in my room and have a fairly smooth waterfall, but I do have one room mode that I have yet to squash (a null at 43Hz at the mix position only from the left channel). When I listen to bass, though, I hear even low bass tones that are supposedly omnidirectional in stereo and often do specific work to keep it tight and centered that I think pays off in the final product. I just can’t fathom hearing everything below 80 or 100Hz coming from under my desk.

On the other hand, I can see how having a single woofer that I can move around without affecting the stereo image could help the room response at the mix position, so I’m open to considering the solution.

Help me understand the tradeoff between a pair of monitors that deliver the full frequency range and a set of 2.1 nearfields.

It's not as simple as people make it out to be.

For starters those Mackies that you have don't come close to full low frequency bandwidth extension at audible levels from the mix position. They are listed as extending down to 37Hz. That's missing a lot of audible information down from 37 to 20Hz. Whether or not that information is important depends on your priorities. But for accuracy's sake you should know those speakers are not full audible bandwidth.

And that's the whole point of a subwoofer. The idea behind a 2.1 system is that you can have the sub take over where the mains start to roll off, so that you can hear that extra bit of low frequency extension. When this happens with a typical active sub in a 2.1 system the sub filters out the ultra low frequency content from the signal that is sent to the mains and that provides the benefit of letting the smaller drivers in the mains handle the midrange duties without needing to handle the low frequency duties simultaneously. This can increase mid range clarity and overall system headroom if everything is integrated well. And that's the problem, "if".

Integrating a sub (choosing the right sub, calibrating the system, finding proper placement to compensate for delay, making certain that the room can handle it) can be a hassle and is often not done right by most. So just tossing a sub into the system isn't an advantage. Only if it's integrated reasonably well will it be truly useful to you.

The issue of the directional nature of low frequency sounds is one that is often misrepresented. For starters the sounds come from where they come from. They don't magically "appear everywhere" at once when they get lower than 80Hz. Humans use arrival time differences, phase differences and level differences between the ears to determine direction. But as wavelengths get larger as they do with lower frequencies, bounce around the room and diffract around the head it becomes increasingly difficult to use interaural cues, which leads us to have a hard time determining direction. But 80Hz is not a magic cut off. You can tell pretty clearly down further than that. But the idea behind 2.1 is that the localization won't be so dramatic with the lowest frequencies, so having a single sub for the vast majority of music work will work just fine.

In practice I have found this to be the case. I've also found that when you have dual subs or mains that extend low enough it's even easier to work with the ultra low frequency content when in circumstances of placing bass instruments in a non-centralized location in the stereo field. So for me the ideal is stereo mains that extend down as low as I can hear. But in practice that requires very large mains, with multiple drivers or smaller mains with dual, integrated subs. All else being equal then 2.1 is IMO better for typical, stereo music mixing than 2-ch mains with limited bandwidth extension in the low frequencies. But it's not quite as good as having a 2-ch system with enough low frequency extension as to not need a sub, or using dual subs because you still can localize sounds below 80Hz (even if it's not very much more below, it's enough to notice that the sound is coming from your sub wherever you place it, if you're only using one sub).

[Lights]

Phenomenal writeup, Enlightened Hand. Thanks for that!

[Lights]

Oh, one more thing. Here is the waterfall from one of my "mk1" mackies as taken by room eq wizard with a simple sine sweep:



As you can see, I'm still fighting a small issue in the 40-50Hz range, although I don't think it's anything major.

Perhaps it's the MK2 version that goes to 37Hz? As these seem to have pretty smooth response almost down to the bottom of the audible range.

[mixerguy]

I have never heard a 2.1 system sound 'right'

they tend to sound inarticulate in the low end,

and the low bass seems disconnected (as it is)

i can also localize the sub, even if the sound does go in all directions.

i would suggest a better, larger 2 speakers, then using a sub.

just my 2c

[flatfinger]

Every speaker designer knows that when he releases his creation into the wild that it's going to be put in rooms good to grotesque ........ I've read a good many of them never design in the full measure of baffle step compensation because if they do every user who puts them right back on the wall is going to think they are bass heavy.

80hz is the x-over specified by the Dolby spec and has become the "de-facto standard ,... Who amungst us is ready to believe that that is is the magic frequency in which no room ever built has modes or standing waves


Sub integration ( which has to start w/ a sub built with music and tightness in mind ; not thunderous theatrical room shaking effects at all compromise !!) has to begin with room treatments ( BASS TRAPS ) measurements , then satellites and subs that have adjustable Xover frequency and filter slopes . Then nulls and and/or hot spots can be compensated for with the proper over lap or underlap around the right frequency ( even asymmetrical slopes can come in handy )



Of the shelf 2.1 systems W/ fixed xover frequency ( and usually an anemic 12 db slope ) are a hit and miss proposition . Half of the users end up thrilled , the other half ; not so much .....