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Official Rythmik Audio Subwoofer thread - Page 234

post #6991 of 15100
Curious: If the two subs are not equidistant from the listener, I would think they would not be set at the same level? Otherwise one will be louder...

I suspect more top-end AVRs will have independent sub outputs in the future but at present it still seems rare.
post #6992 of 15100
I have the Denon 4311ci / XT32 in use with dual Rythmiks and it works wonders, my subs have never sounded better and this is coming from being fully calibrated with a BFD & REW.

Jason
post #6993 of 15100
Quote:
Originally Posted by DonH50 View Post

Curious: If the two subs are not equidistant from the listener, I would think they would not be set at the same level? Otherwise one will be louder...

First we want to formulate the problem. We need to have a set of constraints, and then we have the objective function that we try to minimize or maximize. For instance in room EQ with only one sub, the constraint is very simple, and most likely like this 1) don't do anything below 20hz no matter what happens, and 2) never boost any frequency band for more than 3db) and the objectiive functionton is minimal variance across the frequency bands (1/3, 1/6, 1/12, or 1/24) at each location. As an example, if we divide the frequency bands, and the volume setting for each band say is L1, L2, L3,...L10. Each frequency band gives different output in 5 locations and that gives output of 10x5 matrix as F1,1(L1), F1,2(L1), F1,3(L1), F1,4(L1), F1,5(L1), F2,1(L2), F2,2(L2),F2,3(L2) ... F10,5(L5) (or a more general form is F i, j(Li) for i=1 to 10, and j=1 to 5. Now the objective function is minimal variance of each sitting location and summed together. Now in the case of two subs, we can put in various form of constraint/objective function. For instance, if one constraint or objective function is max (flatten) output PER watt consumed by both subs combined, then the solution is very likely turn off the sub from the far end(because that sub is not gonna win under this new wattage efficiency constraint) . Now the complexity of problem is often expressed in term of a polymonial function of the size of the varibles you can control. For instance, the simplest problem can be solved within constant time. Then the next is linear time, and then quadratic,...etc. The worst type of problem is NP-complete with complexity expressed in an exponential function (which has a higher order than any polynominal you can think of). The time needed to solve the problem is crucial. That is why you see the progress of finer granularity of frequency bands these programs control. Now using two subs double the size of variables, using 3 subs tripple the size of variables. If the complexity is quadratic, then two subs take 4 times the run time and 3 subs take 9 times the run time. Most diffcult problems have complexity higher than quadtratic. Users cannot wait forever to get the answer. I used to write programs to help IC designers finish their jobs to RTL to GDS and almost all of the problems encountered are NP-complete. Then heuristic needs to be used to simplify the problem and be happy with sub-optimal problem (because it is proved that those problems are so difficult that it will take exponentialial amount of time to solve exactly). When I look at this multiple sub problem, I do so from software point of view. A lot of success in the IC design software field is not by brute-force, but by keen observation how the problem can be simplified without losing much of the solution quality. Let me play devil's advocate for a moment, what if the simplifying method we found is keep the most of the settings between sub1 and sub2 same?
Edited by Rythmik - 9/8/12 at 10:07am
post #6994 of 15100
Hmmm... My background is primarily high-speed (GHz and up) full-custom analog IC design so I am familiar with the design trades, and the lack of SW tools to do the job (which is actually OK with me since it allows me to express my ability to create artfully rather than punching a button on a computer and waiting until it says "done").

Multiple subs are used primarily to flatten the room response and provide more output. The former is more important though some may think otherwise. If you fix the volume you place one more constraint upon sub position since the flattest response requires both proper placement with respect to room modes and listener. I see your argument, I think, but in the general case it seems like tweaking the volume might allow a more pleasing (aesthetic) placement of the subs while still maintaining optimal flatness.

If all settings on the subs were the same, you would have to move them to optimize frequency response and live with where they end up in the room as well as the (likely sub-optimal) final FR. I realize there are likely multiple solutions and that the optimal solution might not be bad for aesthetics. As you add parameters like equalization, phase/delay (yes I know they are not exactly the same), and volume you provide more degrees of freedom to optimize placement and frequency response. Most certainly that is not always good; the more parameters you can adjust, the more knowledge of how they interact is required, and the harder it is to find the "best" solution. However, I tend to think that for most of us where we place the sub is limited to a few spots in the room due to other constraints (furniture, WAF, keeping it away from the kids, whatever) so to me the extra control is worthwhile. And, if I had the level control, I could always just set it the same for both and optimize away. With the trade in added noise etc. the level control might add, of course.

Interesting discussion Brian, thank you for sharing your thoughts! I promise not to relate you to the Devil... biggrin.gif

All the best - Don
post #6995 of 15100
Just finished reading thought a LOT of pages. Phew! :-)

My next upgrade will be to a Rythmik sub. I'm deciding between the various 15" options.

I love the D15SE (little kids at home) but I read somewhere that Brian considers the front-firing ones more musical.

My room is ~1800 cubic feet with a half-wall opening to other areas.

I'm leaning towards the F15. Do I need to go HP?

Also, there is little to no mention of the E15 in the thread. Do any of you guys have one of these? Higher WAF is good, but I'm wondering if it's smaller enough to make a difference.
post #6996 of 15100
LF is pretty non-directional so either one is probably fine. I prefer front-firing if crossover is higher (my pair is crossed at 50 Hz).

Not a huge room; I would think the regular F15 would be fine.

No expereince with the E15.
post #6997 of 15100
I have answered previously to Skylinestar that if he wants to use FV15HP (same thing applies to FV15) he needs to set the extension filter to 14hz low damping. This is all because the excursion plot.

Here I will show an excursion plot for 2port mode when the extension filter is set to 14hz/ low damping.



This plot shows if one applies the signal of same voltage from 2.5hz to 125hz, how much excursion the woofer gets. The goal is to have a well balanced excursion plot. This is particularly important for vented subs because without any rumble filter, the woofer will get very very high excursion below the port tuning frequency.

Now for 1 port mode, if we put them in 14hz low damping, it will also have similar excursion plot except the port tuning frequency moved down to 12hz.



What is why I have answered to Sky to use 14hz low damping even though there is no rumble filter in 1 port mode. Let us next show the plot for 14hz mid damping in 1 port mode.



Now you can see low end exursion begins to creep up. Next the 14hz high damping in 1 port mode.



Now it creeps up even more. So why we offer this 14hz high damping in 1 port mode? It is becasue even though the excursion plot looks bad, it has much smaller group delay.

Can we predict the excursion plot based on just frequency response? The answer is no. Next I plot all three response curves in one plot.



There is absolutely nothing you can tell here even when you place all 3 together, let alone just look at one curve by itself. That is why I have emphasized over and over agan that one should not EQ below 20hz (as most ported sub should have a port tuning frequency of 20hz or so). Otherwise it will have catastrophic results. One can overload the sub without hearing much improvement in output. This is because all the excursion resourced are wasted in the subsonic band. It is the job of subwoofer manufacturers make sure the excursion plot is tuned just right and after that no one should touch it.

In our two port mode, we do have a 3rd order HPF, so even at 14hz/ high damping, the excursion plot still looks balanced.



But we should not push our luck by boosting below 20hz.
Edited by Rythmik - 9/8/12 at 2:33pm
post #6998 of 15100
I have an F15 in a listening area that's about 1400 cu ft., with a half wall, and then another 600 cu ft., for a total of 2000 cu ft. My F15 has no problem filling the listening area with fairly loud bass, even at 20 Hz (this is a second story living room with a concrete floor, and it shook the floor and sounded totally clean when I put a 20 Hz sine wave in and turned it up). I tend to usually listen at low to moderate volumes and I'm very happy with my F15. If you like to really get slammed by low frequencies, get the HP. Otherwise, I suspect the F15 will be enough for you.
post #6999 of 15100
Quote:
Originally Posted by nlpearman View Post

My room is ~1800 cubic feet with a half-wall opening to other areas.
I'm leaning towards the F15. Do I need to go HP?
Also, there is little to no mention of the E15 in the thread. Do any of you guys have one of these? Higher WAF is good, but I'm wondering if it's smaller enough to make a difference.

One reason to consider going HP would be to help future proof your system should you someday move to a bigger room. For me the E15 was ideal because I needed the HP output but didn't want a massive sub in my living room. The smaller size also helped when I decided to add a 2nd one.
post #7000 of 15100
Quote:
Originally Posted by nlpearman View Post

Just finished reading thought a LOT of pages. Phew! :-)
My next upgrade will be to a Rythmik sub. I'm deciding between the various 15" options.
I love the D15SE (little kids at home) but I read somewhere that Brian considers the front-firing ones more musical.
My room is ~1800 cubic feet with a half-wall opening to other areas.
I'm leaning towards the F15. Do I need to go HP?
Also, there is little to no mention of the E15 in the thread. Do any of you guys have one of these? Higher WAF is good, but I'm wondering if it's smaller enough to make a difference.

I have an E15 in a room just a little smaller than yours. The room is rectangular with three large openings (two on one wall, one on the opposing wall). The E15 has no problem pressurizing this room. In fact, when you turn the master volume up on the receiver and the bass heavy scenes in a movie start playing, you find out all the loose items in the room. tongue.gif

And even though the sub is isolated as much as possible from the floor (homemade subdude type pad) on those scenes you will feel the vibrations on your feet through the floor. (Of course we all know how musical these subs are - this E15 blends so well with the front L/R speakers I sometimes have to put my hand on the sub to make sure it is actually on and working - it makes bookshelf speakers sound like full range floor standers.)

But if you can fit the larger F15HP, why not? It is 2 inches wider and 1 inch deeper than the E15. (Both use the more powerful 600w amp whereas the F15 uses the 370w amp, so the E15 is just a smaller F15HP.) Of course, if you look at the specs on the Rythmik site (which you probably have), the E15 is down only .5db from the F15HP. So you really aren't giving up much.

If WAF is a big concern (not my issue) or space is at a premium (this was my issue) have no regrets with the E15. And I would recommend that HP version (even without knowing what you will be listening to/watching or at what volume - it will give you more headroom).
post #7001 of 15100
Big thanks for the responses, guys!

Quote:
Originally Posted by DonH50 View Post

LF is pretty non-directional so either one is probably fine. I prefer front-firing if crossover is higher (my pair is crossed at 50 Hz).
Not a huge room; I would think the regular F15 would be fine. ...

I plan on crossing at 80 Hz. Would you then recommend front firing? Thanks for your thoughts on the F15.

Quote:
Originally Posted by Eldave View Post

... If you like to really get slammed by low frequencies, get the HP. Otherwise, I suspect the F15 will be enough for you.

I know the posted relative output stats are at 20hz but, the F15HP has 2db greater output than the F15. Is that noticeable? I'm wondering what the upgrade would really get me in real-world performance.

@ holt and realjetavenger: Thanks for your E15 impressions, guys! The E15 (at 20hz) has only 1.5 db of extra output over the F15 which, again, makes me wonder about the increased performance.

On the size front, the D15 has the smallest footprint, the biggest internal volume and a good price considering the gloss. This decision is getting tough....
post #7002 of 15100
Power is exponentially related to SPL in dB. A 1 dB change is barely noticeable to most people and takes 1.26x the power. Unless I am paying close attention I could not tell if the volume was nudged by 1 dB. 3 dB is about where it sounds a "little" louder or softer and that takes 2x the power. If I am on a mixing board and somebody says nudge it a hair, I generally move the slider 3 dB. 10 dB sounds twice as loud and takes 10x the power. A 2 dB change will be barely noticeable (and adds only a little headroom at the very maximum output).

80 Hz is the recommended crossover frequency for most people as at that point the bass cannot be "localized" -- you cannot tell where it comes from. The down- or front-firing does not really matter. Based on testing I helped run many years ago, as well as articles in the AES etc., people vary from ~50 to 100 Hz but 80 Hz is good for the majority. I fell in at about 60 Hz, but could not tell you if I would notice if it was 50 or 80 Hz today. (I should run an experiment, but have my subs nicely integrated with my mains at 50 Hz and am tired of fooling with the system; I just want to listen/watch!) I would not worry about it.

My guess is you will not notice a significant difference among any of your choices. All would sound great in your room...

HTH - Don
post #7003 of 15100
Before I have my FV15HP, I was worried about how powerful the sub should be. Today, I have dual FV15HP's...and I'm still worried if they are under-powered at reference level (having large area for subs to fill). Maybe it's just me worrying about bottoming out my subs.

Lesson: get the most powerful sub you can afford...and as many as you can biggrin.gif
post #7004 of 15100
Hi,

based on the damping settings, what will be the best setting for damping and rumblefilter if only movie will be played in HT when using two FV15HP in a 1400cft room? I planned to use 1-Port mode.

Kind regards

Harry
post #7005 of 15100
Quote:
Originally Posted by Harry_THX View Post

Hi,
based on the damping settings, what will be the best setting for damping and rumblefilter if only movie will be played in HT when using two FV15HP in a 1400cft room? I planned to use 1-Port mode.
Kind regards
Harry
Brian's advice to me was:
14Hz, low damping, 1 port mode, rumble filter off, limiter on.
post #7006 of 15100
2 FV15HPs in a mid size living area is already generating enough headroom. Adding more subs might be fun but WAF starts to kick in at this point unless yours is a bachelor pad. cool.gif

I knew a guy who had 2 FV15HPs in front with a F15HP at the back of the couch in his 3,300 cu ft living area. Talking about multiple subs eek.gif
post #7007 of 15100
Quote:
Originally Posted by Rythmik View Post

That is why I have emphasized over and over agan that one should not EQ below 20hz (as most ported sub should have a port tuning frequency of 20hz or so). Otherwise it will have catastrophic results. .

Hi Brian,

I presume you mean to say "we should not EQ FLAT or boosting" below 20Hz ? I say this as I have EQed in a very sharp roll off below ~14Hz (48db/octave Butterworth using the crossover on my MiniDSP). This effectively cuts off the lower end where I have (by listening) determined the cone is just moving for no audible effect (nor any useful physical effect due to my room diemsions/shape). It also seems to have the effect of not wasting power on "useless" areas and making the remaining sound more punchy. In other words, we can use EQ but only if it's helping to reduce the unwanted excursion rather than making it worse? smile.gif

Is it OK to EQ with from e.g. 14Hz to 20Hz with the sealed models?

Cheers,

Andy
Edited by Nemesis.ie - 9/10/12 at 1:37am
post #7008 of 15100
Quote:
Originally Posted by DonH50 View Post

My guess is you will not notice a significant difference among any of your choices. All would sound great in your room...
HTH - Don
Quote:
Originally Posted by Skylinestar View Post

Lesson: get the most powerful sub you can afford...and as many as you can biggrin.gif

Thanks again fellas. I appreciate the feedback.

I'm overseas and I have to contemplate both international shipping and a 25% import duty (yikes!). D15SE it is :-)
post #7009 of 15100
Quote:
Originally Posted by Nemesis.ie View Post

Hi Brian,
I presume you mean to say "we should not EQ FLAT or boosting" below 20Hz ? I say this as I have EQed in a very sharp roll off below ~14Hz (48db/octave Butterworth using the crossover on my MiniDSP). This effectively cuts off the lower end where I have (by listening) determined the cone is just moving for no audible effect (nor any useful physical effect due to my roodimensionsns/shape). It also seems to have the effect of not wasting power on "useless" areas and making the remaining sound more punchy. In other words, we can use EQ but only if it's helping to reduce the unwanted excursion rather than making it worse? smile.gif
Is it OK to EQ with from e.g. 14Hz to 20Hz with the sealed models?
Cheers,
Andy

Andy,

You are correct that I meant EQ FLAT or boost. It is ok to cut, like what you have done.

For sealed sub, the consideration is different. In ported subs, the excursion is the resource that we want to make best use of and power consumption below port tuning frequency is relatively low. On the other hand, in sealed sub, not only the excursion quadruples as frequency goes from 20hz to 10hz, the power consumption also rises (also may quadruple, the actual amount of increase varies with models). It is still a good practice not to boost below 20hz in sealed subs. One advantage that our subs have is we also have a well defined bass extension response right out of box. We don't want to alter that too much. It is very different from a complete unequalized sub goes through roomEQ (to correct the lack of out of box extension) and when roomEQ software sees that it will take 10db to boost the low end, it will most likely not do it. On the other hand, same roomEQ may see that our sub only need 3db boost and 3db may sound ok and roomEQ goes ahead with the boost. But the starting point of these two subs are different so they should not apply the same criteria.
Edited by Rythmik - 9/10/12 at 6:47am
post #7010 of 15100
Quote:
Originally Posted by Rythmik View Post

Andy,
You are correct that I meant EQ FLAT or boost. It is ok to cut, like what you have done.
For sealed sub, the consideration is different. In ported subs, the excursion is the resource that we want to make best use of and power consumption below port tuning frequency is relatively low. On the other hand, in sealed sub, not only the excursion quadruples as frequency goes from 20hz to 10hz, the power consumption will also rises (also maybe quadruple). The actual amount of increase varies with models, but it is still a good practice not to boost below 20hz in sealed subs. One advantage that our subs have is we also have a well defined bass extension response right out of box. We don't want to alter that too much. It is very different from a complete unequalized sub goes through roomEQ and when roomEQ software sees that it will take 10db to boost the low end, it will most likely not do it. On the other hand, same roomEQ may see that our sub only need 3db boost and 3db may sound ok. But the starting point of these two subs are different so they should not apply the same criteria.

Rhythmik,

I am considering your F15HP vs. the pre-order for the SVS SB13-Ultra (with the pre-order pricing vs the F15HP with shipping the price is not that dissimilar).

I am having trouble understanding the frequency graph provided on the F15HP.... what is the zero level on the graph? Reference? 100dB? Also, I notice that the sub drops off very sharply at around 70dB and am trying to understand this, is this a function of the curve set on the EQ for better gain at lower frequencies? I have a very large room (over 3000 cubic feet) but have extremely limited floor space for a subwoofer, so I'm going to be limited to the smallest single sub I can get that will provide me with better home theater immersion.

Thanks.
post #7011 of 15100
Quote:
Originally Posted by jmpage2 View Post

Rhythmik,
I am considering your F15HP vs. the pre-order for the SVS SB13-Ultra (with the pre-order pricing vs the F15HP with shipping the price is not that dissimilar).
I am having trouble understanding the frequency graph provided on the F15HP.... what is the zero level on the graph? Reference? 100dB? Also, I notice that the sub drops off very sharply at around 70dB and am trying to understand this, is this a function of the curve set on the EQ for better gain at lower frequencies? I have a very large room (over 3000 cubic feet) but have extremely limited floor space for a subwoofer, so I'm going to be limited to the smallest single sub I can get that will provide me with better home theater immersion.
Thanks.

The graph is a FR in the linear range. It is different from the max output curve. The max output curve for almost all sealed subs start roll-off at 30-40hz range. Our subs are very efficient. The max output is a lot of times is higher than those with slightly higher power amplifiers.

The plot of the F15HP is very similar to F15. Both have two modes: line-in and LFE in. I guess you are looking for LFE in frequency response. It will be similar to the LFE response of F15. I will update the FR plots as soon as I can.
post #7012 of 15100
Quote:
Originally Posted by Rythmik View Post

The graph is a FR in the linear range. It is different from the max output curve. The max output curve for almost all sealed subs start roll-off at 30-40hz range. Our subs are very efficient. The max output is a lot of times is higher than those with slightly higher power amplifiers.
The plot of the F15HP is very similar to F15. Both have two modes: line-in and LFE in. I guess you are looking for LFE in frequency response. It will be similar to the LFE response of F15. I will update the FR plots as soon as I can.

That would be great and help me make a decision. I suspect that your F15HP would work better in my open area and with my atypical room placement. The pull to SVS though is strong,l I have had SVS subs for about 10 years.
post #7013 of 15100
The graphs confuse me a bit, too.

For instance, I can't tell where zero is on the left-hand Y-axis (it may not be important). I also can't figure out what increments the horizontal lines represent, especially since 5.0 seems to be placed in the middle of -20 and 20, where zero would normally be. Then there's the units for the 5 - db/D. What's that mean?

Could you help me out?
post #7014 of 15100
jmpage2---I too had been looking at and was planning the purchase of a SB13Plus. It really appears to be an excellent sub, and I completely understand it's appeal to you. But I am SO happy that by the time I was ready to pull the trigger on one, SVS had discontinued it for updating. It's inavailability gave me the time and opportunity to discover Rythmik, and to fully investigate the SVS and Rythmik engineering and design philosophies. Brian's highest priority is sound quality---SVS's is sound quantity. Rythmik offers ported subs for those whose rooms and/or needs are best served by that design, and sealed for those who place sound quality above all other considerations. SVS dismisses the notion of the sealed sub having an intrinsic sound quality advantage (low group delay/ringing), and offer a couple of sealed subs for he or she whose room can't accomodate one of their "real" subs---ported. The choice was obvious---Two F15's, please! And a pair of Rythmik/GR OB subs while I'm at it---but that's another story.
Edited by BDP24 - 9/10/12 at 7:52pm
post #7015 of 15100
Quote:
Originally Posted by nlpearman View Post

The graphs confuse me a bit, too.
For instance, I can't tell where zero is on the left-hand Y-axis (it may not be important). I also can't figure out what increments the horizontal lines represent, especially since 5.0 seems to be placed in the middle of -20 and 20, where zero would normally be. Then there's the units for the 5 - db/D. What's that mean?
Could you help me out?

The graph is in a relative scale. 5db/D is 5db per division. All graphs (except the one for FV12) are plotted in such a way that the plateu of the graph is about at 3db and that makes the -3db crossing easy to read.
post #7016 of 15100
Brian I have a question for you or anybody else that can answer it. I can understand why you would not want to boost a signal below 20Hz. I have read from you and other places not to boost the signal more than 3db but never an explanation as to why not. I have a dip in my FR starting at around 50Hz and running thru about 65Hz, I can correct this with one filter of about +7db using a Behringer 1124 or I could use three narrow filters placed fairly close together of +3db each. I have also read to use as few filters as posible, so do I use 5 filters or eight filters total (the other four are all cutting slightly to smooth the curve). The end result is the same a very smooth house curve that sounds great. I can post graphs if it would help.
Larry
post #7017 of 15100
Quote:
Originally Posted by LarryU View Post

Brian I have a question for you or anybody else that can answer it. I can understand why you would not want to boost a signal below 20Hz. I have read from you and other places not to boost the signal more than 3db but never an explanation as to why not. I have a dip in my FR starting at around 50Hz and running thru about 65Hz, I can correct this with one filter of about +7db using a Behringer 1124 or I could use three narrow filters placed fairly close together of +3db each. I have also read to use as few filters as posible, so do I use 5 filters or eight filters total (the other four are all cutting slightly to smooth the curve). The end result is the same a very smooth house curve that sounds great. I can post graphs if it would help.
Larry

I suppose it depends somewhat on the situation but in general because a 3 dB boost is already doubling the power used at that frequency, there's a risk of overdriving the system with greater boosts. Also, often the Fr valleys result from room effects -- sound bouncing off walls and recombining out of phase or partly out of phase with the original sound to mutually cancel to some extent. when you turn up the source, you also unavoidably turn up the bounce so the two still cancel each other out. If you had a perfedt null you could turn it up 100 dB and you'd still get zero at the point of the null. 1-1=0 and 100-100 = 0.
post #7018 of 15100
Quote:
Originally Posted by Rythmik View Post

The graph is in a relative scale. 5db/D is 5db per division. All graphs (except the one for FV12) are plotted in such a way that the plateu of the graph is about at 3db and that makes the -3db crossing easy to read.

Thanks! It's all clear now. smile.gif
post #7019 of 15100
Quote:
Originally Posted by JHAz View Post

Quote:
Originally Posted by LarryU View Post

Brian I have a question for you or anybody else that can answer it. I can understand why you would not want to boost a signal below 20Hz. I have read from you and other places not to boost the signal more than 3db but never an explanation as to why not. I have a dip in my FR starting at around 50Hz and running thru about 65Hz, I can correct this with one filter of about +7db using a Behringer 1124 or I could use three narrow filters placed fairly close together of +3db each. I have also read to use as few filters as posible, so do I use 5 filters or eight filters total (the other four are all cutting slightly to smooth the curve). The end result is the same a very smooth house curve that sounds great. I can post graphs if it would help.
Larry

I suppose it depends somewhat on the situation but in general because a 3 dB boost is already doubling the power used at that frequency, there's a risk of overdriving the system with greater boosts. Also, often the Fr valleys result from room effects -- sound bouncing off walls and recombining out of phase or partly out of phase with the original sound to mutually cancel to some extent. when you turn up the source, you also unavoidably turn up the bounce so the two still cancel each other out. If you had a perfedt null you could turn it up 100 dB and you'd still get zero at the point of the null. 1-1=0 and 100-100 = 0.

+1. Nulls caused by cancellation can be quite deep and by cranking the EQ to (try to) bring them up at the listening position you may be heavily overdriving the speaker (and it will be very loud at that frequency everyplace else). A 3 dB boost is doubling the power into the driver; 10 dB is ten times the power. The only reasonable solutions are to move the listening position or add another sub to cancel the cancellation. Room treatment can also work, but you need a lot of absorption/diffusion at LF or a specialized panel (resonator-type) that targets the null frequency.
post #7020 of 15100
At one point a while ago, there was talk of Rythmik making a downward-firing 12" that was similar to the D15SE. Does anyone know if that's still potentially on the way?
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