Great video! Both should indeed perform about the same, as they're based on the same principle (the helmholz resonator). In a 2-way, a passive radiator has a big advantage. In such speakers, a bass reflex port will most likely generate significant amounts of port resonance in the passband of the midbass driver. This can be avoided by using a passive radiator.
Passives actually dig deeper, they're less peaky (what most people call punchy) and more linear. You should upgrade your system to account for the deeper lows the passive loaded sub has.
@@TheUniversalid care to explain, because I don't think it holds any merit. It all depends on how you design the subwoofer. Huge woofers coupled with a big port tuned to the right frequencies and coupled with a heavy amp should be able to dig deeper and move a lot of air but can also sound slow and boomy. In theory a sub with passives should sound more precise and fast even more so with servo woofers.
@@TheUniversalid if you model passive versus ported, passive always rolls off faster than the ported equivalent even when set to the same tuning frequency. There is a scientific reason for it, but I can't remember it at the moment. What you often see in ported designs is very compromised ports that don't allow the driver to get near the tuning frequency and achieve x-max which may give the impression that a well set out PR can out perform it. Even in this video you can hear that the ported is playing slightly lower than the passive, but you have to be careful not to be tricked by your ears. The ported woofer in this demonstration has a much longer decay time than the passive radiator and this can fool your ears into thinking there is more bass there than there actually is. You need to look the frequency it is reaching not the duration of the note.
@@SoundBlab the passive radiator has two additional spiders to help return the driver to its neutral position and the volume of air is captive (has some stored energy). While the port has to move its column of air mass backwards and forwards within the port / port openings. Any movement of air through a port is subject to friction and therefore drag (why a single big port is preferable). This directly affect the drivers ability to return the cone back to its starting position. This condition is often referred to as sounding muddy, because it is often trying to play the next note while it is still trying to play the current one due to the slow returning driver cone. Resulting in a smeared sound. This is not punch, as that is the domain of Force Factor, the Bl (motor strength) of the driver which determines the drivers ability to punch the cone forward. Definition is the ability to hear the subtle nuances of instruments, not the clarity in which it is played. Even though they are often linked. What is extremely noticeable even through your RU-vid video is that the passive radiator has far more control over the driver than the ported one. This is what gives the woofer a much crisper sound to the notes, it is not being smeared like the ported woofer. For the ported woofer I would redesign that with a larger diameter single port and much longer. Don't be afraid to take the port out of the box and bring it back in to get the length you need.
Despite what most people think, bass is the hardest part of the frequency to get right. The modeling software can tell you that they look the same on the screen, but your ears will know the difference. Ported by it very nature will have more SPL than PRs, some of what you heard may be attributed to that, but in general a badly designed ported will sound boomy.
Nice comparison. The PR sub sounded cleaner and punchier. I use to only have ported subs but the last one I built, I used PRs. Much cleaner sounding. One thing to note is, even though they are the same concept, the PRs usually roll off faster than a ported box.
@@ashyouknow7420 welcome to the audio world where everything is a compromise. I gave up about a decade ago trying to make the perfect speaker because it is impossible. The laws of physics are working against us every chance they get. The best you can hope for is to determine what sounds good to you, and optimise best you can to achieve that result, but perfection is an unobtainable dream. Guess that is why we spend so much money trying to get close to it.
The whole Concept of using a passive radiator (to me) is Genius! I have noticed that most of the time, Passive Radiators are used in small to very small enclosures. Being able to tune (somewhat) with the weight added or deducted to the Passive Radiator is very cool! I thought up a way to do this with a water bladder years ago but never did it. Life gets busy, so someone play with that and don’t forget me when you get wealthy! 😉
The purpose of the passive radiator is to save space. However, these enclosures are nearly the same size. In my opinion, not the best way to demonstrate the full potential of radiators, but entertaining and educational nonetheless. Thumbs up.
Good build but very hard to hear the sub properly over the other speakers. You need to disconnect the other speakers to get a real sense of clarity of the sub.
You should turn mids and highs off so we can hear better the bass. Also u should use songs with more low notes, i feel like i cant decide which one is better because there is no graphics too
There are more mechanical losses with PRs, especially multiple PRs but they sometimes make up for it by taking up less air volume inside the box compared to port tubes. They also allow for smaller enclosures to be tuned lower since PRs can be tuned lower by increasing the moving mass instead of making ridiculously long ports that don't fit inside the box. PRs also don't suffer from port turbulence and chuffing. I do agree that there are more advantages to PRs than ports, even if slightly less efficient, however, cost is definitely a big disadvantage since PRs can cost as much as active drivers.
The guys from parts express told me to never add more than 160% of weight of the normal Mms of the speaker itself Data sheet says it has about 40g x 1,6 -> 64g, you´ve added 125g ?! that´s like about the double amount of that. Can you explain why you´ve added that much ? Did you do measurements, what the tuning frequency finally was ?
In a remote listening it seems to me that the PR has a better decay on transients and a higher damping than the Reflex. It must be said that for a good reflex tuning you should NOT use a tube longer than three times its diameter to avoid the “organ pipe” effect that is clearly heard in the reflex design. In the project with PR it seems to me that there is some imbalance between the dimensions and parameters of the woofer and the passive radiators. Normally the passive radiator is a "size" higher than the diameter of the woofer and must have a useful excursion about double compared to the woofer that drives it. Increasing the mass and diameter of passive radiators a lot is not always an advantage, I would have tried with the woofer and only one passive radiator on the opposite side. Not knowing the parameters of the components you used I could also be wrong. Congratulations on a very well done job.
Thanks. The PRs were modelled in WinsISD, so they check out in theory. One was not able to cope with the excursion of the subwoofer on its own unfortunately.
Luca that was my observation also. The PR had much better decay rates to the point it was very noticeable. I have not heard the theory that the port length shouldn't be any longer than 3 times the diameter before. That sounds like a very generic rule of thumb. To achieve a short port length you must reduce the port diameter which in most cases means that you are never going to achieve x-max, and when driven at high power you are going to exceed desired port air speed which is going to cause chuffing. Since the column of air mainly moves backwards and forwards in a Helmholtz resonator the length of the port is unimportant to some degree. I would be much more concerned with friction / turbulence in a smaller diameter pipe than I would with excessive length. The larger the diameter the less pressure / air speed the pipe is going to experience, and less time in changing the direction of the air. Not sure why you would have tried a single PR over two PRs when all sizing formulas suggest at least double the air volume of the driven driver. To my way of thinking the PR is not electrically controlled like the driver, and it only has the spider and compressible air to control it's movement, so I would be looking for the least amount of cone excursion I could get. Ideally I think I would go with more PRs to reduce the cone movement further still if it was both practically and economically affordable. The TC Sounds 18" VMPs I bought for my sub cost me like $1,000 each delivered, so I have bough only two, otherwise I would have bought more.
The problem with ports is in small boxes they have to be long and/or skinny to play low because air is so light. If you listened in an Argon atmosphere perhaps you could have sensible port dimensions, but seeing as you want to breathe, passive radiators are good being heavy enough to resonate down low.
@@SoundBlab as strange as this may sound, female vocalist can have some of the strongest bass tracks. For example Celine Dion - The Power Of Love. The good thing about female voices is they are not competing in the lower frequencies you are trying to listen to, so there is a clear line between the bass track and the vocals.
@@SoundBlab of course if you are looking for something a little more mainstream bass then it is pretty hard to go past something like ChoirBoys. Boys Will Be Boys is a decent bass track. The whole Big Bad Noise album is pretty decent.
I just found out that I could build something called Isobaric Subwoofer @@SoundBlab I think my question was if I can use 2 Subs that have a magnet in the same enclosure with just the one amplifier. Similar to adding the passive Radiator
Is there a video where you go in mroe detail about the circle cutting jig? Do you use one bit to route the lip, and then adjust the jig and change bits to cut through all the way?
I do not have a video like that, but perhaps something I should do for the future. I use the same straight cut bit for both actions. I just adjust the cutting circle for each cut. To cur the lip, I will make one cut to establish the outer diameter, then adjust inwards incrementally until the width of the lip is cut, then I cut all the way through.
Personally I prefer the Passive Radiator version because I think it allows more flexibility in room placement. The ported version is probably less expensive to make if you can find the 40mm PVC pipe with a 36mm internal diameter.
love it. from the way im hearing it (ive been making music for a long time, and have a good set up)... i prefer the ported by far. impossible to tell give the sircumstances. have you done one of these vids of a larger driver?
It really is a close call between the two. I went back and forth in my mind when listening to these as to which one I thought is tops. Have not done a larger sub comparison this way, but hopefully in the future!
Tough to tell with this setup (via recording on RU-vid), but I think he's right on the clarity. In the first clip especially the ported enclosure seems to have a peak that makes the bass somewhat more prominent. Ultimately it's subjective.
Ported enclosures have both port chuffing as well as box noise funnelling out of said port. Passive is far tighter and cleaner, but benefits from the same energy as a port and is far easier to tune.
I would of liked to have seen you do a calibrated microphone test on both of these so we can compare the graph. It may of helped show where the distortion was coming from.
We use the weight to tune the resonance frequency of the PR, in turn this determines the bass output of the speaker system. By making the weight more or less, we can make how low the subwoofer goes more or less, within the limits of the PR of course. A very basic explanation, but I hope it helps to understand how it works.
It is a Triton, an Australian make. Try toolcraft.co.za or topdogtools.co.za . These come in 3 different size models. I have the smaller and medium sized ones.
How do you properly calculate the passive radiator displacement volume (V_d) which is the surface area (S_d) times maximum excursion (X_max)? Obviously it would be based on the specs of the speaker driver you are complementing but I feel things get messy when you add in weights a such. How is that you can define these parameters and then find the right passive radiator online (not many options for smaller setups). Also, when calculating net volume of enclosure with the passive radiator, does the volume depend on the size of radiator you choose or vice versa?
@@SoundBlab Thank you for the heads up. I'm curious though, I just downloaded the program and have been playing around with it. As for the passive radiators I'd be using for my enclosure size (very small bluetooth speaker setup), none have any parameters listed by the manufacturers (ebay) that I can input except "Sd." How can I get around this; is it ideal to match the free resonant frequency of the driver to the passive radiator or the passive radiator to the box?
I honestly couldn't tell the difference with my earbuds. However, I'm sure they both sound great in person. I have only owned ported subs for my setup. Nice to see something different.
That's because ear buds can't play anywhere near low enough to hear sub notes. Forget what the marketing speel tells you, you need diameter to reach low notes.
@@DodgyBrothersEngineering a lot of IEMs can produce bass frequencies loud enough to hear. A 9mm driver won't be as loud as a 12in driver, but the 9mm of the in ear monitor actually goes inside of the ear, unlike a 12in loaded sub box, you'll have problems if you try to put that inside your ear hole, don't recommend..
and that is the point you should stop spending money Fernando. I can hear a massive difference, but if they sound the same to you buy the cheaper one, no point in spending money on what you can't hear.
@@Fernando.Canal2 I have been in this hobby for 40 years, so I have done a lot of critical listening in that time. Sometimes all you need is a lot of exposure to it to be able to start hearing it, but until you can hear the difference you may as well spend that money on beer or wine to drink while you enjoy what you have. Have a good one...
Olá amigo,você pode ajudar com um projeto,tenho um woffer de 6.5 polegadas de 180w com o fs de 44 hetz,um par de Tweeter domo de seda e um radiador passivo de 6.5 polegadas também, qual litragem você me indica pra esse projeto?
why use two ports .you will need to extent the tube length on both port making it able to flex ..you are better off using a slotted port .A single port would do the same job with shorter tube ..i can't stand passive radiators especially if they are mounted on the same baffle ..as a studio sound engineer i can clearly hear phasing on certain frequency .Ported sub are far superior and practical
There was no optimal space for the slotted port without obstructing the back panel where the amp goes. A single port would've been too big and potential port noise. Designs are a combination of compromises, and there is often no perfect solution.
