自作ASW(Acoustic Super Woofer)アコースティックスパーウーハーFostex FE103NVとFF85WK使用

[@kennewton9369]

Here is a small tip. The next time your build a dual-woofer sub, physically invert the mounting of one of the two woofers. So, one woofer facing inward, the other woofer facing outward. Then, reverse the wiring polarity to the inverted woofer. The two woofers now will still move in the same direction together, but from opposite sides of each cone. This pair configuration works to nullify the 2nd order harmonic distortion inherent to the woofers. Which primarily stems from the movement asymmetry exhibited by all woofer suspensions.

[@tasteapiana]

Ah, I get it now. At first this had me wondering. He's using the box like a cajón and the speakers are just there to kind of tap the front+side walls of the box so they radiate the lows by means of their surfaces vibrating. The port is large enough not to woof too much but the key to his thinking is the walnut slat exterior on the front+side walls. Interesting. I doubt that would perform the greatest above 110hz for rock or modern jazz but below about 60hz it should do quite well for everything. Most importantly, it should be very efficient as those two drivers use a lot less energy than, say, a singular long-throw sub-woofer with a 2" diameter coil which get expensive when you're needing low ohms. Yamanaka is a smart guy.

[@mpugne]

It's a series tuned 6th order bandpass.

[@thomasschafer7268]

The resonance frequency of the driver goes to 90hz. Subwoofer hahaha.

[@goodgoat3096]

The FFWK85 is a 5 watt full range speaker with an spl rating of 86.5 db at one watt and an fs of 115 hz. The FE103NV is also a 5 watt full range speaker with an spl rating of 88.5 db at one watt and an fs of 91.8 hz. The satellite speakers will play at a comfortably loud low 90's db from maybe 150 hz and up and assuming the two 4" "woofers" are wired in parallel, will play a little louder in a very narrow bass frequency range. there will be no deep bass but some decent "false" bass around 120-150 hz. Fostex recommends that these drivers be put into bass reflex cabinets.

[@tasteapiana]

@@goodgoat3096 As for resonance, any bass reflex open-air numbers are being soaked up by that pine cabinet. The walnut slats are much heavier than pine and are decoupled from the air being moved so will pump harder at a consistent 50% of whatever resonant frequency the drivers are comfortable at - hence, why I said 60hz. If you are still thinking strict ''open-air'' you don't get the concept and speaker manufacturers avoid any mention of structural losses or transmission because it gets real complicated real quick and they simply don't want the headache. Yes, there should be a considerable pump over 120hz in air and anything weighing less than around 6oz/bf but the waves passing through that pine are going to meet serious resistance once they hit the walnut which is at least twice the density. Q should be shifted down by 50% with a steeper overall curve, likely by 3:1, making any ''false bass'' less prominent. Transmission is real. It wouldn't surprise me if it creates standing waves around 90-110hz, anything extra in that range would need dealt with (EQ'd) before it hit the amp to avoid mud or phase issues. This same concept is in action on maple topped mahogany body guitars, without the maple slab top the mahogany guitar is rather poppy 220hz and above but flubby much below that. Once the much denser maple top is added the pop at 220hz is reduced and notes down around 110hz receive more focus - 110hz is the guitar's low E string. Guitar makers refer to it as fundamental tone. For a more open and airy mahogany guitar they use spruce (much lighter) tops on hollow bodies, some chambered bodies etc. The potential for muddiness on a guitar treated such is not so much in frequency broadband but in string length. The D note of the open 4th string is NOT doing the same thing to the overall instrument as the D note at the 10th fret of the 6th string on any guitar as the difference, due to the shortened string length, thicker 6th string and weaker harmonic peaks on the 6th string D, produces a much more resonant fundamental spread therefore making the 6th string D much more ''hollow'' sounding than its open D string counterpart - ie more of the top/body material difference is noticeable and the extra energy contained in the lower frequencies of the fundamental is produced, upper harmonics reduced. This phenomena drives piano manufacturers insane which is partly why Bösendorfer pianos cost insane amounts of money - the sound boards have to be shaved by hand over and over and over in very precise shapes and depths to tune and account for the extra low notes their pianos have while making sure that they don't adversely affect resonant harmonics octaves up the harp. Math from open-air scopes of loudspeakers is nice, very helpful, but once you go beyond open air and begin calculating for transmission it means next to nothing, practically speaking, other than a reference for what might happen in air or within a singular material enclosure.

[@tasteapiana]

@@goodgoat3096 Also, note that on the frequency response chart www.fostex.jp/wp/wp-content/uploads/FE103NV_specification_sheet_web.pdf everything above 1k begins to drop off sharply at 30 degree increments. The lower it goes the more consistently omni the power curve becomes due, obviously, to the physical width of frequencies being produced. At 1w this phenomena is apparent, at 5w it is all there is as power begins to flatten any 1w curves into a ruler flat slope, meaning power has to be transferred increasingly toward bass reproduction. Pure physics of mass, no more mechanical offsets due to balanced power to frequency ratios. Just look at that chart and picture what a 90 degree offset would be - everything above 3k would be between 5db to 25db down (at just 1w, at 5w likely 10db to 50db down) Toward the end of this clip, you can hear the sub attempting to produce transients of plucked bass notes (poppy-ness) which are well below 91.8hz. The fundamentals of sub 60hz frequencies are there as are the less prominent harmonics between 400hz-1k+ but those harmonics are out of phase with the satellites which informs us that no EQing is involved, only a random power crossover that exists due to the satellites running out of power around 90hz-110hz. If that sub were crossed over at 100hz-120hz with a 24db or even 16db slope the bass guitar would be much clearer and those loudspeakers would be much more efficient. As is, that amp is working too hard so everything it produces is more compressed than it needs to be and that is causing phase issues within the transmission through all available mass. He is spending twice the energy he needs to in producing everything from, my guess is, 110hz to 1k. That's fine if you like a sound stage resembling that of being down the hall and around a corner from your monitors (ie in a house where transmission is just mud and reflections are stacking in odd phases), but it's not my preference lol

[@Helectronics]

Great build and video!

[@上村勝己-h3c]

おじさんは、FE103を、久しぶりに見ました。長岡鉄男氏設計のスピーカー、造ったなぁ~!鳴らし込むと、もっといい音になりますよね。

[@猫砂撒き太郎]

穴あけ工具何をお使いなのですか、 自在錐と回すやつ？教えて下さい 安いのでお願いします😂

[@simonwinter9123]

Amazing job love every step god bless you yamanaka

[@ВладимирСтадухин-й4ж]

Профессионал !!!

[@faverodefavero]

Do you sell those speaker kits in flatpacks maybe, please? Thanks for the great vídeos.

[@SatriaSpeaker]

👍

[@HIACE_4311]

オイルは何を使用していますでしょうか?

[@djordjejon4849]

Exellent 🎓👍 frend gretings from serbia

[@JefersonCesconetto]

parabéns, ficou linda

[@МихаилВотяков-н2л]

Отлично 👍

[@wellingtonguides]

Show de bola . Que som limpo

[@knulcess1]

I didn´t like the finish coating on the two small speakers, neither the unfinished part on the outlet cajón.

[@mihusiyo4503]

めちゃ切れそうな丸鋸。見てて気持ちいい。w

[@АлексейФедоров-х9б]

Очень круто!👏🏻👏🏻👏🏻

[@АндрейПироговский-е2и]

Why do you use wood? Is it better for sound then MDF?

[@chickenpotpie4045]

MDF is better for sound as it's more stable and has a standard resonance, wood is a little more unpredictable, but way prettier. He's a master woodworker, I'm sure he dislikes MDF as many others do. Wood is natural, MDF is man made, I feel like they think it's sacrilege to call yourself a woodworker and use MDF as it isn't wood. MDF is also much easier to work with than wood, where's the challenge in that? I've seen many people fail at just cutting out the speaker hole in hardwood without ruining the piece, MDF is super easy to work with and that just doesn't show off his incredible skill.

[@samuelsalins8309]

🔉🎶👌

[@chanelserabutan423]

nex making 2.1 speaker subwoofer..

[@creativeYouTube1]

12:31 Listen！

[@edtechph5444]

Watching ED TECH PH

[@MrMad-lp7in]

Рукастый плотник.

[@HS-rv1fl]

フルレンジ、スピーカー 2個で、スーパーウーファーを、自作おした見たいですが、バスレフホート、からの音が、出ていますが、バスレフ型を、ダクト型に、すると、スーパーウーファーの音が、もつと、低音の、音が、出ます！ 箱の半文を、スピーカーの、空気ひつにして、あとの、半文わ､ウーファーの、空気ひつに、すると音が、低音がブースト押します！