Rythmik L12 Subwoofer Review

[Chromatischism]

I disagree, subwoofer should always be crossed over at 80Hz or above, and if you have bass capable speakers than you can certainly cross them lower. Having 4 sources of bass is better than 2 in the scheme of fighting nulls.

I disagree with the first part, "always", due to the potential for subwoofer localizability and a degradation in sound quality. 60-80 Hz is often the sweet spot but it depends on a lot of factors that are different in each system.

I get what you're trying to do with the second part - even if it's not part of any standard system I've seen and not even in the more advanced EQ systems I have seen, such as Dirac Bass Control. In theory more bass sources could be better, however these bass sources in this case are not equal in capability. Unless you are trying to address a specific issue and understand well the limitations of each piece of equipment, I would stick with the standard of low passing and high passing at the same frequency.

 

[Chromatischism]

Yeah I have a really bad null, likely because of my 3 foot wide cloth ottoman

I really doubt this is the case, generally it's not possible to remove that much energy at those frequencies from absorptive treatments. Otherwise, we would all use them. That is easy to test by moving it out of the room and measuring again.

 

[CumSum]

Yeah I have a really bad null, likely because of my 3 foot wide cloth ottoman

No way is a small ottoman doing that in those frequencies. Remove it from the room and remeasure if you think it is!

You might have to change your listening position. That's a lot of suck out in the mid-bass. Instead of rolling off towards the low frequencies you are sky rocketing up. Is your room rectangular? If so then you can run a room mode simulation program that could help you find the best place for your subs and your ears.

You can try and make do with what you currently have. For time saving, you can experiment with DIRAC using one or three measurements and see what DIRAC can make of it. You always have to be careful with the curve and the headroom of your subs, but since you aren't in need of boosting sub bass, but rather cutting it, you may be just fine.

 

[CumSum]

I disagree with the first part, "always", due to the potential for subwoofer localizability and a degradation in sound quality. 60-80 Hz is often the sweet spot but it depends on a lot of factors that are different in each system.

I get what you're trying to do with the second part - even if it's not part of any standard system I've seen and not even in the more advanced EQ systems I have seen, such as Dirac Bass Control. In theory more bass sources could be better, however these bass sources in this case are not equal in capability. Unless you are trying to address a specific issue and understand well the limitations of each piece of equipment, I would stick with the standard of low passing and high passing at the same frequency.

Localizability is a potential issue, but that typically occurs past 80Hz. And with two subs you should have a bit less localizability.

You aren't wrong, the subs should be responsible for the bass produced in a speaker system. I just don't think this restriction of the crossovers having to be identical is necessary. I've seen too many misguided audiophiles (which is almost all of them) feel that the crossovers have to be identical and they will follow the stupid rule of picking the crossover point 10Hz above their speakers -3dB point.

So you get people with very large speakers, that can play down to 30Hz, spending tons of money on subs, only to be crossed over at 40Hz. With the nulls you will experience in most rooms you want that sub contributing to the fight as much as you can. I wouldn't ask a speaker to fill a 20Hz null the sub experiences, but if it can help out on a 60Hz null just a little bit, I'll take the help (if the speaker is capable). Ideally you would have 4-8 subs so you can have it all but not everyone is willing to go that far.

 

[carewser]

I would love to see picture of a room with all those subs.

I actually just added another sub today so now i'm up to 11. The latest one is the big one on the far left although i'm sure with my wonky room acoustics and their placements they're all out of phase and sync. For one thing my ceiling is all of 6" so it's a good thing i'm not tall. My speakers are by Logitech (X3), Audioengine (X2), Klipsch, Edifier, M-Audio, Paradigm, Corsair, and Kanto

 

[Chromatischism]

For one thing my ceiling is all of 6" so it's a good thing i'm not tall.

Indeed!

 

[pozz]

I actually just added another sub today so now i'm up to 11. The latest one is the big one on the far left although i'm sure with my wonky room acoustics and their placements they're all out of phase and sync. For one thing my ceiling is all of 6" so it's a good thing i'm not tall. My speakers are by Logitech (X3), Audioengine (X2), Klipsch, Edifier, M-Audio, Paradigm, Corsair, and Kanto

You've set up an audiophile symphony orchestra. Horn duet in the center

 

[3dbinCanada]

I disagree, subwoofer should always be crossed over at 80Hz or above, and if you have bass capable speakers than you can certainly cross them lower. Having 4 sources of bass is better than 2 in the scheme of fighting nulls.

The math will add up when you get acoustic timing results close to zero when testing the right speaker, and both subs against the left speaker with the delays you've come up with. Your channel matrix looks good.

Your REW charts have too much span in terms of SPL (-20dB to 160dB), which makes your results look flatter than what they really are. Change the span so you only have a 50dB spread, example from 55-105dB. Even with your "flat" looking graph, I can see it isn't flat and I see suck out from 35Hz to 65Hz that looks substantial. Resize the graph to get a better idea of how many dB you are down in that region.

Another good way to tell if the time alignment is having a positive effect is to compare it to having no delays at all. The one with correctly set delays will have more output across most of the spectrum. Here is an example of such a difference I measured, green is with a time alignment, red without. It makes a huge difference in my case since the delay's go up to 10+ms. Your delays are pretty small so the difference probably won't be as dramatic, but there should be an improvement.

View attachment 159072

Comparison of the group delay

View attachment 159074

I want to create a guide, and have already to some degree, but I'll eventually get around to finishing it so I can just drop it every time someone has a question about integrating subs.

I disagree with your assessment about 4 speakers covering all the nulls in bass and here's why. The main speakers could be in a position within the room that could be out of phase with the subs and actually lower the bass output. Unless one measures their cumalitive effect, there is no way knowing whether or not the speakers are enhancing or detracting from the bass response. Maybe thats what you meant but the message didnt come across like that.

 

[3dbinCanada]

Some more graphs:

All tests, crossed over 50hz /24dB for speakers, 100hz/24dB for subwoofers (time aligned):
View attachment 159087

Subwoofers without speakers:
View attachment 159088


Speakers without subwoofers (something crazy is going on with the left speaker at 65hz):

View attachment 159089
Left and Right Channels:

View attachment 159092


All firing together:

View attachment 159090


Not entirely sure what I'm looking at here though? That dip on my left speaker is absurd though, wondering where I should move it

I apologize for the barrage of questions but I would like to get a clearer picture of what you are working with. What mic are you using for measuring? Are you using an AVR or a HT pre-amp that allows you to set distances? Please run your measurements again from 20Hz to 20KHz with subs employed and smooth the graph out to 1/12 . There's enough detail to see what is going on. Also, please post several pics of the room that shows the system and listener position, especially near room openings if any.

The thing is you now have subs dialed in BUT you have not integrated them yet with the speakers. Cross your speakers over at 80 Hz and measure full frequency. Leave the settings alone on the miniDSP and start experimenting with the distance of the virtual sub (the combined subs and filter corrected via the miniDSP) through the AVR. Everytime you change a distance setting, measure to see if the changes are getting better or worse.

 

[DonH56]

@AdamG247 would it be possible to split out the discussion of optimization and placement? Great stuff, but not L12-specific, and like so many discussions will be lost later when somebody asks and we cannot find it because it is buried in an unrelated (relatively) thread.

 

[xovaan]

@AdamG247 would it be possible to split out the discussion of optimization and placement? Great stuff, but not L12-specific, and like so many discussions will be lost later when somebody asks and we cannot find it because it is buried in an unrelated (relatively) thread.

Oh yeah, I'm happy to start a new thread-- I'll organize what I've done thus far with everyone's help and use it to help make the post referenceable as well.

Gonna put together a post and will put it into the acoustics subform

I apologize for the barrage of questions but I would like to get a clearer picture of what you are working with. What mic are you using for measuring? Are you using an AVR or a HT pre-amp that allows you to set distances? Please run your measurements again from 20Hz to 20KHz with subs employed and smooth the graph out to 1/12 . There's enough detail to see what is going on. Also, please post several pics of the room that shows the system and listener position, especially near room openings if any.

The thing is you now have subs dialed in BUT you have not integrated them yet with the speakers. Cross your speakers over at 80 Hz and measure full frequency. Leave the settings alone on the miniDSP and start experimenting with the distance of the virtual sub (the combined subs and filter corrected via the miniDSP) through the AVR. Everytime you change a distance setting, measure to see if the changes are getting better or worse.

Never apologize! I'm really having a blast with this-- the more questions you ask, the more I learn and the better this all ends up

 

[CumSum]

I disagree with your assessment about 4 speakers covering all the nulls in bass and here's why. The main speakers could be in a position within the room that could be out of phase with the subs and actually lower the bass output. Unless one measures their cumalitive effect, there is no way knowing whether or not the speakers are enhancing or detracting from the bass response. Maybe thats what you meant but the message didnt come across like that.

2 speakers and 2 subs will not cover all nulls in all cases (below 100Hz). And if it doesn't then more subs is the solution.

I'm all about the cumulative effect which is why I measure everything individually and then measure things combined. If the speakers were to cause issues that could not be corrected by either a polarity inversion or by time delays, then I certainly wouldn't advocate to run it at lower frequencies.

In practice, the subs should be running 6-10dB louder than your speakers to achieve a desired target curve. So in reality the speakers, even when run full range, do very little regarding bass as measured and for the bass you hear. But if you experience a 60Hz null that goes 20dB deep, maybe the speaker can turn that into a 6dB null. Ideally you add more subwoofers to fix the issue.

It all depends on the level of your speakers. Running a floor standing speaker with dual 15" drivers only down to 80Hz is a waste. Now I will be the first one to argue that a speaker with dual 15" drivers is a waste in the first place. But when I go out to help other audiophiles calibrate their systems, that's exactly what they will have. And good luck convincing them to crossover their monster speakers at 80Hz.

 

[Chromatischism]

I'll say that I'm getting better overall sound quality with a 60 Hz crossover vs 80, but it is very system and room dependent, and it is very hard to see why when looking at measurements unless you've done extensive testing and start to correlate the graphs with what you're hearing. You'll never see it on a full-range sweep. You have to break out each speaker and sub and look at where each extends to and correlate that with what musical content is doing.

Then you have effects the room adds. My room just doesn't like a lot of bass energy above 80 Hz. Not at all.

 

[xovaan]

@CumSum @Chromatischism @3dbinCanada I've started a new thread here:

Speaker placement and subwoofer integration for a small living room using MiniDSP SHD + REW

Hey everyone! First, I want to give a big thanks to everyone for helping me get this far-- there's an overwhelming amount of info online for integrating subs into a 2.2 system, both in general knowledge and program interface navigation for testing. The below is what I've learned through the...

www.audiosciencereview.com

 

[3dbinCanada]

2 speakers and 2 subs will not cover all nulls in all cases (below 100Hz). And if it doesn't then more subs is the solution.

I'm all about the cumulative effect which is why I measure everything individually and then measure things combined. If the speakers were to cause issues that could not be corrected by either a polarity inversion or by time delays, then I certainly wouldn't advocate to run it at lower frequencies.

In practice, the subs should be running 6-10dB louder than your speakers to achieve a desired target curve. So in reality the speakers, even when run full range, do very little regarding bass as measured and for the bass you hear. But if you experience a 60Hz null that goes 20dB deep, maybe the speaker can turn that into a 6dB null. Ideally you add more subwoofers to fix the issue.

It all depends on the level of your speakers. Running a floor standing speaker with dual 15" drivers only down to 80Hz is a waste. Now I will be the first one to argue that a speaker with dual 15" drivers is a waste in the first place. But when I go out to help other audiophiles calibrate their systems, that's exactly what they will have. And good luck convincing them to crossover their monster speakers at 80Hz.

What Im trying to say is that the speaker placement for 2 channel's sweet spot in the room may cause an interference and therefore cause the suckout in the bass. For that reason alone, Im not a proponent of speakers with built in subs as speaker placement for minimizing room interaction is seldom conducive to producing good bass. One is better to eliminate the speakers from the equation and add more subs.

I also have a house curve setup for my bass based on Fletcher & Munson curves for the two rooms containing multiple subs.

 

[Everett T]

What Im trying to say is that the speaker placement for 2 channel's sweet spot in the room may cause an interference and therefore cause the suckout in the bass. For that reason alone, Im not a proponent of speakers with built in subs as speaker placement for minimizing room interaction is seldom conducive to producing good bass. One is better to eliminate the speakers from the equation and add more subs.

I also have a house curve setup for my bass based on Fletcher & Munson curves for the two rooms containing multiple subs.

I use subs in my Salk 2ch system, and they play down into the low 20hz range. Originally I needed more spl for the lower end, however the smoothing of the response around the room was the biggest benefit.

 

[BoredErica]

There are 34 pages in this thread and not one result when I search this thread for 'noise' or 'hiss'?
I'm assuming the L12 and F12 are actually that silent? (I am very easily annoyed by noise.) I just wish L12 had XLR to get rid of ground loops without an isolator, but I can pony up the cash for the F12.

 

[CumSum]

There are 34 pages in this thread and not one result when I search this thread for 'noise' or 'hiss'?
I'm assuming the L12 and F12 are actually that silent? (I am very easily annoyed by noise.) I just wish L12 had XLR to get rid of ground loops without an isolator, but I can pony up the cash for the F12.

Have both L12 and F12, both silent using unbalanced sources. More silent than all of my studio monitors.

 

[JayGilb]

I actually just added another sub today so now i'm up to 11. The latest one is the big one on the far left although i'm sure with my wonky room acoustics and their placements they're all out of phase and sync. For one thing my ceiling is all of 6" so it's a good thing i'm not tall. My speakers are by Logitech (X3), Audioengine (X2), Klipsch, Edifier, M-Audio, Paradigm, Corsair, and Kanto

View attachment 159129

Must be a full time job just keeping those picture frames sitting square.

 

[Presently42]

There are 34 pages in this thread and not one result when I search this thread for 'noise' or 'hiss'?
I'm assuming the L12 and F12 are actually that silent? (I am very easily annoyed by noise.) I just wish L12 had XLR to get rid of ground loops without an isolator, but I can pony up the cash for the F12.

I've the older LV12R: there's zero noise from it - even when I put my ear against it. Just a superb product