Rythmik L12 Subwoofer Review

[Kal Rubinson]

Sealed subs are popular because they are much less obtrusive, can be designed to be "good enough" for music in smaller spaces, and will be less likely to exhibit response errors that can cause localization (chuffing).

For sealed subs, "good enough" shrinks in significance with the use of multiples and the smaller size allows for that more easily.

 

[ShadyJ]

Hii guys, I’m new to subwoofers and considering adding one to my two channel system, I have a smaller size room at 13’x15’ with 9’ ceilings and am currently using a pair of the smaller magnepan mg12 speakers. The L12 sounds intriguing given the price point, but I’m trying to understand what benefits there would be moving up to the F12? Thanks

 

[blueone]

Hii guys, I’m new to subwoofers and considering adding one to my two channel system, I have a smaller size room at 13’x15’ with 9’ ceilings and am currently using a pair of the smaller magnepan mg12 speakers. The L12 sounds intriguing given the price point, but I’m trying to understand what benefits there would be moving up to the F12? Thanks

Hi James. Why are you here trying to fool people with this BS about you being new to subwoofers, when many of us know you test them for Audioholics?

 

[blueone]

I doubt that's James Larsen from Audioholics, despite using the same forum handle he's used in the past. "ShadyJ" isn't that uncommon of a nickname and had he been trying to fool people into thinking he's somebody else, he wouldn't have used the same name.

Perhaps I'm mistaken... I've never heard that nickname used otherwise. If so, my apologies.

 

[ShadyJ]

Perhaps I'm mistaken... I've never heard that nickname used otherwise. If so, my apologies.

No worries, I’m not James, actually John with no connection to audioholics. Looks like I picked a bad nickname.

 

[blueone]

No worries, I’m not James, actually John with no connection to audioholics. Looks like I picked a bad nickname.

Not at all, just an overloaded one.

 

[KaiserSoze]

Small sealed subs like the ones Revel sells usually have the worst distortion.

It took me a while, but I eventually decided that the correct way to interpret this is most likely that (1) small sealed subs usually have worse distortion than other types, and that (2) Revel is the name most readily associated with bad-sounding small sealed subs.

Sealed enclosures are generally smaller, so I suppose it is reasonable to combine small subs and sealed subs into a single type. But is it really reasonable to say that this type of sub typically has worse distortion than other types? The number of variables that will influence this is fairly large. Suppose we compare a sealed sub with a ported sub where both have the same size driver and where the linear excursion of the driver (Xmax) is the same for both. In this comparison you would expect similar distortion levels at a given SPL, except for the way that the port influences excursion. At the port tuning frequency, the driver will be nearly motionless, thus distortion from the driver itself will be very small at and near the port tuning frequency. However, the impedance to air flow in the port increases as the square of the velocity, and therefore as the square of SPL. This effect produces compression and thereby distortion, although it typically is not as great as what the driver distortion will be in a sealed enclosure for the same SPL and at that same frequency, the port tuning frequency. But then you have to also consider what happens at frequencies below the port tuning frequency. As frequency decreases, below the port tuning frequency, the excursion of the driver skyrockets, which does not occur with a sealed enclosure. In spite of the very large driver excursion, the SPL output from the speaker is low because the wave emitted from the port is out of phase with the wave from the driver (below the port tuning frequency; this is the reason that the rolloff of ported speakers is steeper than the rolloff of a sealed speaker). If the port is tuned adequately low it won't matter, however depending on the port tuning and on how low in frequency the music or sound effects are, the audible distortion from a ported speaker can be substantially worse than the distortion from a sealed speaker using a similar driver. This will typically only happen with a so-so ported sub and with movie sound effects (explosions), but in this scenario, with movie sound effects and a middle-of-the-road ported sub, the sound from the ported sub can be overwhelmed by the distortion.

And even if the generalization were a good generalization, it probably would not be fair to equate Revel with bad-sounding small sealed subs, in the way that you implicitly did. Revel makes one subwoofer with a single 8" driver, and it is sealed. They make an in-wall sub that uses a sealed enclosure, but it uses two 8" drivers, which is equivalent to a single 14" driver. They make a 10" sealed subwoofer, a 10" ported subwoofer, a 12" sealed subwoofer, and a 12" ported subwoofer. Six different subwoofers all in all, an only one of them would conform to the description of a "small sealed sub", unless you want to include the 10" sealed sub. I have not heard the B110v2, but in all reasonable likelihood and based on reading some of what went into its design and construction, I fully expect that it is a phenomenally good subwoofer. As for the B8, the most I would hope for is that it holds its own again other 8" subs similarly priced, which is to say that I would not expect it to sound especially good, however if it were ported and a little bigger this would not likely make it sound any better.

 

[jhaider]

You're right – sealed are recommended for very small rooms because space is at a premium and you get a unique room gain effect that brings up the low end a lot anyway. However, they won't produce the same rumble, which is why I'm switching to low-tuned (12.5 Hz) vented, even if they are larger. Plus the efficiency advantage is impossible to ignore.

The problem with large vents is large pipe resonances.

 

[q3cpma]

It took me a while, but I eventually decided that the correct way to interpret this is most likely that (1) small sealed subs usually have worse distortion than other types, and that (2) Revel is the name most readily associated with bad-sounding small sealed subs.

Sealed enclosures are generally smaller, so I suppose it is reasonable to combine small subs and sealed subs into a single type. But is it really reasonable to say that this type of sub typically has worse distortion than other types? The number of variables that will influence this is fairly large. Suppose we compare a sealed sub with a ported sub where both have the same size driver and where the linear excursion of the driver (Xmax) is the same for both. In this comparison you would expect similar distortion levels at a given SPL, except for the way that the port influences excursion. At the port tuning frequency, the driver will be nearly motionless, thus distortion from the driver itself will be very small at and near the port tuning frequency. However, the impedance to air flow in the port increases as the square of the velocity, and therefore as the square of SPL. This effect produces compression and thereby distortion, although it typically is not as great as what the driver distortion will be in a sealed enclosure for the same SPL and at that same frequency, the port tuning frequency. But then you have to also consider what happens at frequencies below the port tuning frequency. As frequency decreases, below the port tuning frequency, the excursion of the driver skyrockets, which does not occur with a sealed enclosure. In spite of the very large driver excursion, the SPL output from the speaker is low because the wave emitted from the port is out of phase with the wave from the driver (below the port tuning frequency; this is the reason that the rolloff of ported speakers is steeper than the rolloff of a sealed speaker). If the port is tuned adequately low it won't matter, however depending on the port tuning and on how low in frequency the music or sound effects are, the audible distortion from a ported speaker can be substantially worse than the distortion from a sealed speaker using a similar driver. This will typically only happen with a so-so ported sub and with movie sound effects (explosions), but in this scenario, with movie sound effects and a middle-of-the-road ported sub, the sound from the ported sub can be overwhelmed by the distortion.

And even if the generalization were a good generalization, it probably would not be fair to equate Revel with bad-sounding small sealed subs, in the way that you implicitly did. Revel makes one subwoofer with a single 8" driver, and it is sealed. They make an in-wall sub that uses a sealed enclosure, but it uses two 8" drivers, which is equivalent to a single 14" driver. They make a 10" sealed subwoofer, a 10" ported subwoofer, a 12" sealed subwoofer, and a 12" ported subwoofer. Six different subwoofers all in all, an only one of them would conform to the description of a "small sealed sub", unless you want to include the 10" sealed sub. I have not heard the B110v2, but in all reasonable likelihood and based on reading some of what went into its design and construction, I fully expect that it is a phenomenally good subwoofer. As for the B8, the most I would hope for is that it holds its own again other 8" subs similarly priced, which is to say that I would not expect it to sound especially good, however if it were ported and a little bigger this would not likely make it sound any better.

I think we can agree that bass porting implementation quality can vary a lot. I said it in another thread, I think that this is one of the things that can still separate manufacturers between those using FEA to model the perfect port for a specific model and the others.

 

[q3cpma]

The problem with large vents is large pipe resonances.

Isn't bending and dampening by affixing the other end the usual way to deal with those?

 

[jhaider]

Isn't bending the usual way to deal with those?

Passive radiators are the effective way to get the efficiency boost without pipe resonances.

 

[q3cpma]

Passive radiators are the effective way to get the efficiency boost without pipe resonances.

Price and space are a concern here. I also vaguely remember passive radiators having their own problems, though I don't remember said problems (something about midrange leakage through the membrane, maybe?).

 

[jhaider]

Price and space are a concern here.

Then IMO sealed multiples

 

[sigbergaudio]

For passive radiators you typically need two for each driver to avoid bottoming out, so it's a more expensive and more complicated approach, and you might be better off just adding a second active driver instead.

Vented is fine for larger cabinets (if designed correctly), but finding the space for a port that is long enough to avoid port noise borders on the impossible in compact enclosures, and/or takes up so much internal space you have to increase the volume, and suddenly it's not so compact anymore. Which is why sealed is a good choice for smaller subs. Powerful drivers and powerful amps also means it's less of a compromise than it used to be.

 

[q3cpma]

Then IMO sealed multiples

I guess, but what's the problem with properly ported speakers?

 

[sigbergaudio]

I guess, but what's the problem with properly ported speakers?

size.

EDIT: Oh, and phase issues.

 

[q3cpma]

For passive radiators you typically need two for each driver to avoid bottoming out, so it's a more expensive and more complicated approach, and you might be better off just adding a second active driver instead.

Vented is fine for larger cabinets (if designed correctly), but finding the space for a port that is long enough to avoid port noise borders on the impossible in compact enclosures, and/or takes up so much internal space you have to increase the volume, and suddenly it's not so compact anymore. Which is why sealed is a good choice for smaller subs. Powerful drivers and powerful amps also means it's less of a compromise than it used to be.

The "fanboy" (jokingly, I can find some faults with Genelec too) in me will continue to post this

 

[KaiserSoze]

I agree. Do I need a ported beometh for that effect? My opinion has changed. Rhythmic, SVS and Revel produce and sell sealed subs for a reason. I suspect not just for saving space and unobtrusive. Maybe I am wrong.

Everyone is going to give a recommendation based on what works for them. In general ported subs (and subs with passive radiators) have a lower -3 dB point compared to sealed subs of similar size and cost. As such, if you think you really need for a sub to be flat down to 20 Hz, a ported sub or one with a passive radiator might be better, but not necessarily, because there are complicating factors that need to be considered. Most better subs nowadays include built-in EQ of one sort or another, which potentially will give a sealed sub the same deep bass extension as a ported sub or sub with PR. Furthermore, the bass rolloff of a sealed sub is not as steep as it is with a ported sub or sub with PR, and because of this the quoted -3 dB values can be misleading. Whether it or isn't misleading depends on what you're listening to and on how loud you're playing it, and on the port tuning of the ported sub.

For low-cost subs that barely avoid being a waste of money my personal preference is for a sealed sub because typically it will not sound boomy like a typical low-cost ported sub. Once you get high enough in price (maybe above $500), there isn't likely to be a noticeable difference, because the port in the ported sub is going to be tuned very low and the sealed sub is going to include EQ. (If you get a sealed sub without EQ, you can add EQ via a separate DSP device but of course this will add to the total cost.)

Given that you've had bad experiences with ported subs, I don't think there is any question that your next foray into subwoofer should be a sealed sub of reasonably good quality. The L12 is apparently one such sub. SVS also makes a couple of sealed subs that have earned solid reputations. For people with money that is burning holes in their pockets, Revel makes two similar sealed subs, one 10" and the other 12". I haven't heard either of them but I have no doubt that they are both amazingly good, amazingly musical subwoofers. But whether either of them is sufficiently better than the L12 or the SVS sealed subwoofers, to justify the significantly greater cost, is a difficult question.

 

[q3cpma]

size.

EDIT: Oh, and phase issues.

Hmmm, audibility of such "issue" is debatable, but low port tuning should move it in the sure-it-won't-matter group delay by frequency zone.

 

[sigbergaudio]

The "fanboy" (jokingly, I can find some faults with Genelec too) in me will continue to post this

Those have a fun looking port, but they're actually not all that small. The 7360a has a 10" driver and is more than twice the size (in box volume) than the sealed 10" subwoofers we are building.