Welsh steveee boyo 😳🤔😂🤣

W, Yes, We recently measured low-frequency energy from a single 18" sub at 300' from source. We were testing the amplitude drop over time and distance.

P, Yes, just like bass is exaggerated in small rooms.

LOL

I hope this comment is reel

I have two bass in the double digits. 👍

Yeah..in my previous apartment most of the bass was in the bathroom..🙈😂

D, Placing a subwoofer in the corner of a room will produce an additional 3 - 6 dB of room gain. Its quantity, not quality. It will also excite all other modal issues that end in the corners of rooms. If you treat your room correctly with the required surface area coverage and technology you have many more positioning options that produce quality, not quantity. For a critical listening environment minimizing room, distortion must be your goal.

@@AcousticFields room gain is a fundamental function of any room. A sealed subwoofer designed well has a tendacy to naturally roll off at low frequencies approximately equal to the gain profile associated with those frequencies. The end result is often getting you closer to a flat overall frequency response which is absolutely desirable. Coupled with minimising/reducing the first reflextion point distance from source and the fact unwanted additional gain is easy to correct for these days, and I personally will take that corner load positioning without much worry. For reference, I've tried all sorts of positioning options, including in floor or ceiling IBs, in baffle wall subs, floor to ceiling stacks and dual stacks (could claim line array if you like) , and upto 4 subs in a room spread out. I've spent hundreds of ours in lots of rooms doing this as well, so I am drawing from experience. Don't get me wrong, I'm not arguing again treatment of a room, I think this is one of the most important things that's needs to be addressed and often overlooked, but to blanket discredit corner placement of a subwoofer is, in my view, incorrect.

@@moonfly1 We have tried corner loading with low-frequency drivers, no low-frequency room treatment and non-corner loading with treated rooms and find three distinct differences. We have found that the attack and decay rates with the treated rooms/no corners to produce tighter attack and decay rates, along with better separation and definition.

@@AcousticFields that's an entirely possible result, but isn't given context. If you simply plonk any old sub in the corner of a room, and go measure the response in the opposing corner, with no room treatment or room correction in place, that's the obvious result. Boundary reinforcement boosts frequencies according to room modes. That means you get lower decay rates at those particular frequencies, whatever thay may be for any given installation, because you have more energy in the room. This is the easiest acoustical problem to correct for because you simply remove the excess energy from the original signal. In doing this you flatten the response to what it should be at the listening position, returning the audible result to what the director intended you to hear. The other benefits are an overall reduction in room modes you need to correct for, a greater probability of only needing to correct peaks in response (nulls can't be corrected very well if at all electronically), a reduction in distortion produced at the amplifier, and a reduction in distortion produced at the driver. In the old days, before powerful processors and good eq was readily available, corner loading could be problematic, especially when back then subwoofer performance was inferior and you couldnt tame the boosted output, but that's simply not the case anymore. You should always measure a room and optimise the subs location to get the best natural response, and that location may very well not be in the corner, but blindly dismissing corner loading and ignoring any potential benefits you could might gain is an outdated idea in my honest opinion and experience.

Daniel Chatburn wow, thanks for putting this out there, I’ve been struggling with this corner dogma and the fact that in my very small square room, using an offset studio layout, the sub seems to work so much better in the corner, centered between the mid range monitors, behind the desk, but to my chagrin very precisely in a corner. I should add that the room is treated with a primacoustic london 12 kit, an additional full bass trap, and a couple of ceiling clouds. I use Sonarworks Reference 4 to calibrate room correction profiles, and I believe I’ve seen the exact phenomena moving the sub around the room, where in the corner I have a couple of expected peaks, which as you said are easiy compensated for by the software EQ profile.

I prefer Audioholics as they present more Practical examples and refer to research papers. As much as i would like to levitate my sub off the floor, practically ot not possible for various reason. There must be compromise here. Sometimes I prefer quantity, nothing wrong with that, why cant we have both

RB, Go ahead and try raising your sub with those material types. Report back to us your findings.

J, Everyone's perceptions, belief systems, and usages are different. Thank you for sharing yours with our audience.

Way to be man! the particulars of perfection can damper allot of fun in experimentation. Glad to see you trying stuff out, and going yr own way. I'm building a 7 channel surround sound set with big 35hz towers in all channels, against popular advice of crossing over into dedicated subs. It's more quadraphonic in philosophy. We'll see how it goes :) There will be many chapters of experimentation for sure.

Glad you like them!

A, Yes, I completely agree. I can get one sub to sound better than 4 subs. Its all about energy management through room size and treatment. Using multiple subs to achieve a small gain in frequency response is neither cost effective nor quality producing. The process and reasoning is similar to the loudness wars a few years back.

I also find smaller subs tend to be more musical. In my home setup I have best experience with smaller diameter subs. I have a much more expensive 12 in sub that can't match the speed and musicality of my 8 inch.

G, They want to bring more room sound into their product's presentation value. They want quantity versus quality.

@@AcousticFields cheers for reply

That is one part. Now, focus on absorption close to the source and vibration management in your new design.

IG, Experiment with different positions within the room and different heights.

@@AcousticFields ok

N, Set up is only the starting point. Set up alone will not ensure anything without low-frequency management and Rt-60 times must be designed for.

@@AcousticFields True. The fortunate/unfortunate fact is im about to realize my dream of a home theater, but it has to be in my basement. The room is not ideal and ill just have to manage as best i can because my options are very limited. Again, i appreciate the knowledge cause im learning a lot. At the very least my next home theater will be purpose built with knowledge gained and not with whats available. We all gotta start somewhere. Take care.

E, Start with your sub woofer in the room center. Move left 1' then right 1' . Start in the center and move 1' forward and 1' backwards. With this method you will get a handle on your room sound.

Acoustic Fields Thanks for the tip! This is very useful.

Take all the guessing out of the equation. Get a room analysing tool, there are even good free ones like REW you can get from Home Theater Shack. Measure the subwoofers response in the available locations around the room so you can visualze the in room response. From there you will be able to place the subwoofer optimally with confidence.

Isolation, elevation, and attenuation are our goals with low frequency sources.

M, Low-frequency energy is pressure based and radiates in 360 degrees from source. Middle and high frequency energy is "reflection" based.

We are all about resolution. Vibrations that transfer energy are not part of our paradigms.

B, The reason other companies tell you to place your subs in the corners is because they lack the technology to treat unwanted modal issues throughout the room. We guarantee our rooms to be flat at + - 1 dB from 30 - 6,300 Hz. In order to provide that guarantee you must have powerful low-frequency technology that is predictable and consistent in performance. Our carbon technology does all of that. Once you have all the low-frequency room modal issues addressed in your room and it measures flat like it should, you can then place the subs in the room where they sound the best based upon room usage requirements..

Placing subs in the corners is not cost/benefit effective. We have tried this technique and the cost of the multiple subs for a small 1.5 dB benefit / sub was not justifiable to us considering the poor sound quality that resulted. Remember that most room modes end in the corners of a room. Why would you want to add more energy in an area of the room that is already plagued with multiple modal issues? Its all about quantity not quality with this methodology. If you can make it to my new studio in Burbank, I can show you what a properly treated room with no subs in the corners sounds like. Your low-frequency reference will be changed forever.

@@AcousticFields I see what you're saying and I would absolutely love to get out to a listening session one day. Right now I have a monsterous LFE setup. Some of my subwoofers are indeed corner loaded. Currently my LFE channel consists of 6 15" drivers and 3 18" drivers and I'm tuning to be flat down to around 15Hz or so. I've been using my MiniDSP for timing, phase, XO and PEQ. Are you saying your philosophy is something along the lines of placement, treatment, tuning? I still have a LOT to learn about all of this, HAHAHA but it seems like quite a few professionals like yourself are teaching a different methodology. Placement, tuning, some more tuning, then at the end, as the pièce de résistance, treat the room. At least that's my understanding (and trust me, I'm a US Marine, I've been wrong A LOT, LOL!) on what they're trying to convey.

On the subject of flat to ULF (because that's what makes my beard hair stand up happy) I feel my theater is relatively tame in the low end. I have a roughly 1000 square feet of room that I've got pressurized to around 125dB when the bass REALLY hits hard and I'm getting 10Hz at around 100dB of those. You flip over to one of my friends, Scott, who is running 9 18" subwoofers and he's FLAT down to around 8Hz or so. My subwoofers, according to your videos, are no where NEAR ideally placed. They're decoupled, but they're still "on the floor" (though my floor is cement and earth) and 2 of my 9 subwoofers are corner loaded. Reaching down to and well below 15Hz is nice to me and it makes me super happy as my tuning capacity evolves and I get richer and fuller bass lower and lower down the spectrum. What are your thoughts on ultra low frequencies (I think calling them cycles sounds way cooler, btw) I mean those frequencies that quite literally cause your house's structure to fail. I'm only pushing about 7000 watts to my LFE channel, I feel like if I were to do like my friend Scott, convert things over to 240v with dedicated circuitry and start pushing into the 20 to 25 kilowatt range, I'd be able to dig that much deeper, flatter.

B, The issue they have is that they lack the proper rates and levels of low-frequency absorption in their "technologies". Once you hear a room where the low end is as clearly defined as the mids and highs are with separation, definition, and the proper attack and decay rates below 100 Hz. you realize that treatment is the answer and its analog which make sit even better. Everyone's belief system is based upon their sonic references which are based upon poorly designed and implemented treatment types. Come to LA. I will change your life. What is your room size?

You need a new reference for quality. What you are hearing is not low frequency sound quality. It is sound quantity. They are not related at all.

Thank you for your support and following.

V, You are confusing sound pressure which is wave energy with ray energy. Low-frequency energy is all about pressure waves which are omni - directional.

Acoustic Fields Yes and low frequencies are pressure waves, and they are Omni directional provided the effective diameter of the transducer is less than a quarter wavelength in size. Exactly why placing them on the floor creates a perfect half sphere radiator. Placing them any significant distance from a boundary (like a floor) will create a reflection that will cause a dip in the response as a function of the distance which will vary with different positions in the room depending on the relative distances between your position and the sub and the floor. Also the response will be affected by any transition from half sphere and whole space which will be function of the distance from the floor and the operating band of the subwoofer. There is an inherent step function in response as the transducer transitions form half sphere radiation to whole space. This is very basic stuff and the fact that you are denying it makes all your useful information on room treatment questionable.

I understand that you are looking at the situation form the point of view of room interaction but you can not forget about the basic physics of boundary effects on directionally and reflections. In a small room placing the subwoofer on the floor can in effect create a pressure zone resulting in idealized low frequency performance. Suggest you Rea the work done by Don Davis and Crown on this as it applies to PZM microphones. It is exactly the same only with regard to output rather than input transducers. I also suggest you read up on modern directional subwoofer arrays the concept that subwoofers are always Omni directional has been significantly changed since we are now starting to effectively measure their directional characteristics and can now model subwoofers in both free field and recently in real rooms.

The worst thing you can do is place subwoofers at different locations relative to the major room boundaries and hope that the resulting response irregularities randomly correct each other. Your points about mechanically decoupling the sub from the floor or room is good but it can be done at these frequencies while keeping the sub close enough to the floor to be a half sphere radiator over it’s operating band.

@@VueAudiotechnikSound Modern Subwoofer arrays?

Thank you for your support.

Z, The room only sees energy. It does not care how it is produced. We do not use down firing subs. Their quality of sound production depends on the floor surface area construction, materials used and density. This is too many variables to manage.

Spending money to buy 4 sub woofers to treat just low-frequency energy is not cost effective. Why not treat the full range of room issues with the same dollars.

Audio playback and sound behaviour in small room acoustics is well understood. There's way too much bad information and bass mythology advice that is put forth as absolutes. This particular video included. Granted, I'm guessing other content from AF is likely solid advice. The physics; 1.) Room modes (resonances) are determined by the room's dimensions. 2.) Which resonances are excited are determined by speaker placement. 3.) Which resonances are heard are determined by listener placement. Utilizing this information, if the desired response is achieved with the LF source placed on/against a boundary, that's great. Enjoy the benefits that accompany spatial loading (ie Room Gain, Boundary Reinforcement, SBIR Mitigation, etc.).

F, Room gain which is the result of unwanted modal pressures, SBIE which is the result of room boundary surfaces, and a whole host of other room distortions impact sonic presentation value. If the room was not there, there would be no room distortions.

@@AcousticFields not all boosts in response are unwanted though. Room gain and boundary gain (they are different) can actually aid at times in a beneficial manner. Sealed subwoofers in particular are designed around this where their natural response is targeted to roll off with the average room gain profile that increases with lowering of frequency. We don't want exaggerated peaks, but boosts in the response that bring it up level can actually be beneficial, and to write all gains off as negative isn't telling the whole story.

D, Once again quantity is not quality. If you can get to my new studio in Burbank, I will demonstrate this for you. You need a new reference to draw upon. Once you hear the difference you will have a new reference in sound quality. A reference where the low-frequency energy has the same attack and decay, definition, and separation as middle range frequencies. Once you have heard the difference, your sonic perceptions will be changed forever.

The room only sees energy. The source or method of delivery into the room is not a concern. However, a downfiring sub brings into play the surface it is firing into.

M, The room only sees energy. The displacement of that energy into the room speaks more to definition of each low frequency than the room issues.

R, Do not put a low-frequency energy producing device in the room corners.

B, People that use our carbon technology tell us that their low end is no as defined and separated as the mid ranges in their presentation. This is quality sound.

451, Yes room response will improve with a 12" - 24" height in 8'-10' rooms

F, You place the sub on a platform that elevates, isolates, and attenuates.

You could use something like the SVS isolation feet.

R, The goal with any low-frequency producing device within a room is threefold. First, elevate the sub off the floor to improve room response. Second, isolate the vibration producing device from the floor and three attenuate. The best place to place low-frequency absorption is close to the source. Once the energy enters the room it becomes room distortion if it doesn't fit into room size. Choose the proper technology that accomplishes all three. You will be much happier with the sound quality doing all three objectives. Review the comments by those who have done this.

Don't use a wooden box unless it's a specially built custom dampening box. Use a foot high slab of acoustic open cell foam. Pyrosorb-S is probably the best option as it is open cell but very high density, very good at stopping vibrations as well as sound obsorbing. Easily available to buy in custom sizes online. I use 50mm custom size Pyrosorb-S foam on my stands for my bookshelf speakers. With platinum silicone anti vibration decoupling pads on top of the Pyrosorb-S. £54 total cost but well worth it. Gives the best performance out of my 30hz-20khz bookshelf speakers that produce a lot of bass from the rear firing bass ports.

@@C--A thank you

Chinda Ajoku Nice input... thanks for sharing.

D, Set up is critical. Make sure your side wall distances are equal.

D, With L shaped rooms, you must position your rig so that you have a front wall and two sidewalls connected. Put the L behind you.

Foam is not a low frequency absorption technology. You must elevate, isolate, and attenuate with the proper SW absorption technology.

@@AcousticFields SW??

F, What are your room dimensions? Yes, especially in your case with multiple sources.

@@AcousticFields my room is 13 x 25 x 7 gear situated along a long wall, with an acoustic tile drop ceiling, an open entry doorway in the back wall corner that I will use a room divider to close off during sessions. My subs are all matching JBL PB10. I was thinking about using four tapered 4x4 wooden legs as uprights joined with rails between and with divots in the end to accept the rubber feet of the sub. Overall I'd like to keep the top of the subs to 30" to be as aesthetically pleasing as possible and perhaps also used as a pedestal for the surround speakers. That configuration would create approx 18" of free space from driver to slab. Thanks for the information. And how do you feel about incorporating a mini DSP and room eq software? My processor is Sony's current flag, the STR ZA5000ES. -✌🏼

T, Low-frequency energy is sound pressure. It is wave energy. It is multi - directional. Ray energy is directional. Ray energy is middle and high frequency energy.

Hanging a sub won't cause any perceptible movement because the cone movement is symmetrical canceling out any potential movement. Plus if there was any asymmetrical cone movement, the inertia of the mass of the sub prevents any significant motion. I actually did this myself hanging my sub in the corner of my basement forming a very efficient bass horn. Merely adjusting the volume of the sub kept the base from being overwhelming.

B, Don't do the thinking for the manufacturer, do your own based upon what your room requires.

you can build a bunch of absorbers and diffusers on stands and place them near the walls during listening sessions and then stack them out of sight for family time

Yes but you will still have a smoother response if you raise it 12 - 18"

V, Yes, room size and volume must be matched to energy usage.

@@AcousticFields what size of a subwoofer (subwoofers) would you recomend for a 1450 Cubic feet concreat seald 21ft long and 6.7ft high and 11ft wide. It is accustic treated on walls and big rugg on the flor and a fabric couch. 7.2.4 movie only room. I have 2 svs pb4000 today probloby "BIG" overkill but i realy like bas in my movies and whant that chest slam to realy hit me..😂 Were would you recomend to put thes big subbs in this room, hard to say probloby "sub crawl" but what would you Think..?

M, Raising a low-frequency generating device up and away from a surface area will improve overall room response especially below 100 Hz. The composition of the boundary surface is not an issue.

sure ok, you did say especially if it's not a solid floor

@@powerinnumbers6159 Consider that there are four states of matter: solid, liquid, gas and plasma. If a floor is not solid, then it must be one of the other three. A liquid "floor" would not be a floor at all, but a pool or a bath. Gas and plasma are even more ridiculous. This guy really doesn't know what he's talking about, and is using imprecise language out of ignorance. Of course you are going to have a solid floor. Whether or not a floor conducts sound to an extent to be bothered with is not a matter of it being solid or not! Another thing that he doesn't understand is that, because levitation isn't a thing, suspending a speaker from a wall or ceiling will enable the speaker to transfer energy to that solid thing, so nothing has been cured. And because walls and ceilings are not necessarily designed to hold the weight of heavy objects like that, it's a dandy way to maim or kill someone. Don't even think about flying your own speakers at home! Rigging is not for amateurs.

@@StringerNews1 I don't dare say he doesn't know what he's talking about. I know he knows more than I do. What I am trying to find out is how much is typical snake oil BS and how much he's really "helping " out his subscribers. It seems to me, every single video they put out has a way to highlight the need for one of their products. That's why I wanna know why he generalized so much. It seems by generalizing he opens his products up to more customers that may not really need them, the case in point is a person with a concrete floor. He says and I quote " so here's what happens, if your floor IS NOT SOLID" that is what he said, however he said this AFTER telling EVERYBODY to not put subs on the floor. So he first generalized and secondly put a case forward that only explained why for people without solid floors.

@@powerinnumbers6159 I think I explained adequately why anything but a solid floor is beyond the realm of possibility for humans. If I failed to adequately explain why you can't hang a speaker from anything but a solid, I'd be happy to elaborate. You may live in a climate that permits you to live outdoors, so you don't have walls or a roof, but since we're talking on the Internet I'm sure that you know that most people live inside solid buildings. And if you've picked up and let go of pretty much anything, you know that everything falls to the ground unless a solid structure that's ultimately connected to the ground holds it up. That fact invalidates his claim that "you can't put a sub on the floor _because it's solid"_ conclusively. I _can_ say that he doesn't know what he's talking about because I've been a working professional doing audio and video production and engineering (my college major was electrical engineering) for more than 40 years. In that time I have learned which is industry jargon and which is nonsense. He's talking nonsense. I've heard all the hi-fi salesman doubletalk many times before.

H, Yes, we do commercial applications. Fill out the information in this link: www.acousticfields.com/free-room-analysis/

S, We have tried this technique. We used 4 subs and even raised or lowered them in the corners for some tests and did the same for various room positions. We could achieve around 1.5 dB improvement per sub depending on sub height and room position. Our subs at that time cost 3,500 each. A 6 dB improvement for 14,000.00. Another thing we did not like was the attack and decay rates with any sub woofer count and position using this methodology. There is simply no substitute for matching sub woofer count and driver diameter with room size and volume. If you couple this tactic with the proper rates and levels of low-frequency absorption to match amplitudes, you have a quality sound instead of quantity sound. Remember you must use tactics to create a sonic strategy.

@@AcousticFields Ooh I like that allot man! Sonic strategy, quality over quantity, volumetric pairing, nice stuff!

@@AcousticFields a lot of this advice seems to really ignore some acoustic principles of subwoofer design. Multiple sub deployments can be problematic if you don't know how to set them up, but multiple subwoofers set up correctly with proper room correction on top are a very well documented way to tackle in room response problems. More drivers and amplifiers reduce the stress on each amplifier lowering distortion. Decay rates from each subwoofer can be reduced quite a lot due to the lowered output required from each unit. These things seem to be being completely ignored. You can cause problems with mutli subs as well, so I agree on the caution being advised. Without proper alignment of the subs you will absolutely create issues, a flat response alone isn't the whole story and as you say, decay rates are a critical component of accuracy and quality. Quantity in and of itself though isn't simply the worst thing ever, it's like saying a car is bad because it has a high top speed. You want headroom in a system for it to remain composed and your end result to have the required dynamics, but get these things right and the end results can be stunning. These things can also be especially useful in rooms where aesthetics are limiting the actual acoustic treatments you can deploy. I would like to reiterate that addressing the acoustics of the room is very important and I'm all for that, it's as important as the proper system set up in my view, but we seem to be ignoring everything else to promote it as the only silver bullet solution here. Maybe I'm reading things a little wrong, but I think addressing these points is important. One thing I will absolutely agree on is the importance of reducing decay times, RT60 should never be ignored.

A, I do not understand your question. Please be specific.

@@AcousticFields instead of raising off the floor using chains, stand ,etc. Cannot simply put it on a thick foam wedge?

@@alexm4515 you can and it stops the resonance but if you do it on a foam you will hear the bass but not feel it as if it was on the floor if you want to even out the bass just have 2 subwoofers

And also 2 smaller subs has a punchy sound and bigger subs has low bass it all depends on your taste

C, Good for you. What is your ceiling height?

Acoustic Fields the ceiling is 13 ft it’s not huge but the sound is more equal as I walk around the space and no boom sounds i don’t mind where the box is as this is becoming a listening room in the house.thanks for your helpful video.im just beginning to build up an audio system so still learning as I go along.

R, One of the issues film engineers have is getting the low-frequencies that they need for car crashes and explosions to translate from a small room in which most are produced to a larger theater room which the public hears the end result. We are currently building a new facility in Burbank next to Warner Bros. to address this very issue.

what the hell is "drastic park"?

A, Go to the shop tab on center top of home page.

Z, If its down firing then you can raise the whole unit from the floor. Put 12" wood legs under it and move it around the room.

If it's down firing it has been specifically designed to pressure the floor.

seraph or designed to avoid ventilation noise

S, Lets don't miss the forest for the trees. Stay focused on topic and message.

😄 ... Seb, a cycle is a wave form with a measured distance. Wave size is relevant to contructing spaces. The associated unit of time is not A sound wave is a form of moving energy You're 0 for 2

I get a feeling that this is not a clip for us people with 100$ pc speakers.

R, Yes we did the same in our first studio. We had three subs on winches that we could raise or lower at different heights. This is how we realized the importance on room response.

Thank you.

P, Quantity is not quality. We are about resolution, fidelity, separation, and listening to all of the music without hearing the room.

Its all about surface area coverage with the proper rate and level of absorption. The cost is directly related to both of those two variables.

@@AcousticFields its marked way up. Good for you. Your business is dedicated sound rooms. I get it. A little book shelf speaker sitting on a giant absorber column, looks ridiculous. Just saying.

B, Its amazing to me that people think a sub woofer sitting on the floor does not produce distortion. How about SBIE which is unwanted pressure between source and boundary surface for any speaker type. They even have a name for the distortion it is so prominent.