Rythmik F12se vs KEF KC62

[Ricardojoa]

If i can do over I would go for a pair of L12, small enough, budget friendly,does not consume many watts.

 

[Georgeadv]

If i can do over I would go for a pair of L12, small enough, budget friendly,does not consume many watts.

What l12?

 

[Blumlein 88]

What l12?

Rhythmik L12 sealed servo sub

 

[Georgeadv]

This guy from acoustic fields advises to use slightly larger sub driver from your main speakers in order to match the speed of your speakers
If you have 6 inch speaker driver, you should have 8inch sub not more, as it would be slower

does this have any merit?
Heres the vid

 

[Sancus]

This guy from acoustic fields advises to use slightly larger sub driver from your main speakers in order to match the speed of your speakers
If you have 6 inch speaker driver, you should have 8inch sub not more, as it would be slower

does this have any merit?

short answer is no. And any time people start talking about "speed" of a speaker you can immediately assume they don't actually understand the technical details at all.

 

[Georgeadv]

short answer is no. And any time people start talking about "speed" of a speaker you can immediately assume they don't actually understand the technical details at all.

Thanks!
Isnt more difficult for a larger driver to move? Thus making it less nimble than a smaller one?

 

[Hotwetrat]

short answer is no. And any time people start talking about "speed" of a speaker you can immediately assume they don't actually understand the technical details at all.

So this is basically me - I don't understand, but I try.

So when people talk about 'speed' this is the same as 'articulation' right? Which is basically, attack/decay? Like how fast the driver (amp?) can start and stop? - now, when talking about the ass end of attack/decay, as in, the decay part, is this not what we now know is actually 'damping factor' (room accoustics aside) and is actually to do with the AMP and not the actual speaker driver?

I really want to learn all this stuff so I can make more educated choices vs listening to subjective reviewers suck you in with utter bollards

 

[Sancus]

Thanks!
Isnt more difficult for a larger driver to move? Thus making it less nimble than a smaller one?

Not really, no. Keep in mind that a larger driver also means a bigger magnet and voice coil. F=ma. In theory you could probably build a large driver that was "slow" but it would have terrible frequency response and so it would be unusable. There have been some previous threads on this topic that you might find useful.

But what it boils down is that most of the important time domain characteristics of a speaker/subwoofer are in fact contained in a frequency response measurement. If there are significant impulse response issues then they will show up there as well. You can't simplify down to "driver size".

There are some edge cases where "speed"(typically measured as group delay for subs) can be an audible problem but this doesn't have anything to do with driver size, rather it's a result of the cabinet design, port tuning, and sometimes use of DSP. Smaller ported subs(eg 12" or less) with tuning in the audible range(>20hz) can have excessive group delay near their tuning frequency. But even then there's very little evidence that this is easy to hear or a big problem.

What causes "slow bass" is almost always overly excited room modes. There is a myth that smaller subwoofers are "faster" because they just don't play as low and thus don't excite those low frequency modes as much. The real way to fix this problem is with room correction EQ and multi-sub systems.

 

[Georgeadv]

Not really, no. Keep in mind that a larger driver also means a bigger magnet and voice coil. F=ma. In theory you could probably build a large driver that was "slow" but it would have terrible frequency response and so it would be unusable. There have been some previous threads on this topic that you might find useful.

But what it boils down is that most of the important time domain characteristics of a speaker/subwoofer are in fact contained in a frequency response measurement. If there are significant impulse response issues then they will show up there as well. You can't simplify down to "driver size".

There are some edge cases where "speed"(typically measured as group delay for subs) can be an audible problem but this doesn't have anything to do with driver size, rather it's a result of the cabinet design, port tuning, and sometimes use of DSP. Smaller ported subs(eg 12" or less) with tuning in the audible range(>20hz) can have excessive group delay near their tuning frequency. But even then there's very little evidence that this is easy to hear or a big problem.

What causes "slow bass" is almost always overly excited room modes. There is a myth that smaller subwoofers are "faster" because they just don't play as low and thus don't excite those low frequency modes as much. The real way to fix this problem is with room correction EQ and multi-sub systems.

Thanks! Its good to know. There is so much information out there that is really confusing and makes things even more difficult

 

[Hotwetrat]

Not really, no. Keep in mind that a larger driver also means a bigger magnet and voice coil. F=ma. In theory you could probably build a large driver that was "slow" but it would have terrible frequency response and so it would be unusable. There have been some previous threads on this topic that you might find useful.

But what it boils down is that most of the important time domain characteristics of a speaker/subwoofer are in fact contained in a frequency response measurement. If there are significant impulse response issues then they will show up there as well. You can't simplify down to "driver size".

There are some edge cases where "speed"(typically measured as group delay for subs) can be an audible problem but this doesn't have anything to do with driver size, rather it's a result of the cabinet design, port tuning, and sometimes use of DSP. Smaller ported subs(eg 12" or less) with tuning in the audible range(>20hz) can have excessive group delay near their tuning frequency. But even then there's very little evidence that this is easy to hear or a big problem.

What causes "slow bass" is almost always overly excited room modes. There is a myth that smaller subwoofers are "faster" because they just don't play as low and thus don't excite those low frequency modes as much. The real way to fix this problem is with room correction EQ and multi-sub systems.

This is a seriously informative post

 

[YSC]

I think room size is the determining factor as the only reason you want a kc62 and not even their own larger models are space limitation, e.g. in my own listening room measuring like 2m*3.5m I put a genelec 7040A under the desk and it already need some attenuation and have some bass rumble, if put in your room it likely just sound ok at moderate listening level. In my understanding as long as the brands produce okish even frequency response then you would like to put a larger sub to have the extra headroom

 

[richard12511]

Thanks!
Isnt more difficult for a larger driver to move? Thus making it less nimble than a smaller one?

Yes, but a larger driver also has to move less distance.

 

[yodog]

So would a Rythmik F18 be superior or would it be obsolete?

 

[Chromatischism]

So this is basically me - I don't understand, but I try.

So when people talk about 'speed' this is the same as 'articulation' right? Which is basically, attack/decay? Like how fast the driver (amp?) can start and stop? - now, when talking about the ass end of attack/decay, as in, the decay part, is this not what we now know is actually 'damping factor' (room accoustics aside) and is actually to do with the AMP and not the actual speaker driver?

I really want to learn all this stuff so I can make more educated choices vs listening to subjective reviewers suck you in with utter bollards

In my experience, "speed" is generally our perception of sound, but it's not what you intuitively think. Factors at play:

1. Room bass decay. Long decay times can give a perception of bass that hangs around longer. Below about 100 Hz, equalization is the most effective tool here. Since long decay times in a room can increase the perception of bass and show up as a peak, reducing output in a resonant range to flat can nullify most of that perception.
2. Frequency response. This is king. First, a speaker or sub with a flat response, that is, one that does not have big ups and downs in its output at various frequencies, whether they would be caused by design or by a room, is going to sound more articulate. A lot of this has to do with a lack of masking. Peaks can mask adjacent sounds, especially if the adjacent sounds live in a response dip. Linear bass = articulate bass. Secondly, if a speaker has more low-bass, it may sound fuller, but "slower". Think of a ported speaker vs sealed. A sealed speaker may sound like it has "faster" or "cleaner" bass. It doesn't – it just has less bass! The same is true for subwoofers. Equalized to the same exact response, no one would be able to tell apart a low-tuned vented and sealed sub, for example a Rythmik FV15 vs F15.

 

[Chromatischism]

So would a Rythmik F18 be superior or would it be obsolete?

Compared to what? It's way better than the small ones discussed up to this point.

 

[Chromatischism]

The F12SE is $1150, which honestly seems a bit steep when dual SVS PB-1000 Pro is $1150. If you have the space for dual subs I don't see much reason not to go that route.

You don't have to buy the piano gloss SE version if you can live with black oak or black matte.

L12 is half that.

F12-400 is currently $849.

If compactness is a priority, stick with sealed. But if you can give up a little more space, the vented subs are better and especially in terms if performance per dollar.

 

[Chromatischism]

I wont do hpf as my amp does not support that. I will be driving the ls50 full range.

I recommend re-thinking this plan. Your LS50's will sound more clear if you relieve them of the stress of low-bass which they do not do well. They will also be easier to integrate smoothly, and you'll be getting a lot more bass by not limiting the sub so much.

My ls50 in room, roll of at 35db! So i plan to lpf the sub at that frequency or maybe little higher..

This, I really doubt. I run Buchardt S400's, and they crush the LS50 in bass output. THEY go down to 35 Hz in-room. I believe the KEF R3 should be close to that as well. The LS50 does not do bass nearly as well as the R3. I would be surprised if you were getting anything below 60 Hz. Generally people need to cross the LS50 at 100 Hz.

 

[thewas]

Mind you bass response is highly room and placement dependent, my normal Hifi listening pair of LS50 really doesn't go much below 50 Hz

but my desktop pair (both in the same room!) goes linearly down to almost 35 Hz without any boosting filters (I use only few negative ones for room modes):

 

[Georgeadv]

I recommend re-thinking this plan. Your LS50's will sound more clear if you relieve them of the stress of low-bass which they do not do well. They will also be easier to integrate smoothly, and you'll be getting a lot more bass by not limiting the sub so much.

This, I really doubt. I run Buchardt S400's, and they crush the LS50 in bass output. THEY go down to 35 Hz in-room. I believe the KEF R3 should be close to that as well. The LS50 does not do bass nearly as well as the R3. I would be surprised if you were getting anything below 60 Hz. Generally people need to cross the LS50 at 100 Hz.

I have a hegel h190 which does not have a crossover

and here is my in room response

 

[alex-z]

I have a hegel h190 which does not have a crossover

and here is my in room response

So get an amp with a crossover or use external DSP to add it. It doesn't matter how good the amp is, without the ability to high-pass the speakers you are severely limiting the overall quality of your system.

This is a basic physics problem. The speaker cone has inertia, so when asked to play 2 frequencies at once, it cannot play both perfectly, and the further apart the 2 frequencies are, the worse it becomes. This is known as intermodulation distortion, and is more significant than simple harmonic distortion.

So by not high-passing your speakers, you compromise the entire mid-bass/mid-range spectrum.