JP3921831B2

JP3921831B2 - Speaker device

Info

Publication number: JP3921831B2
Application number: JP23081598A
Authority: JP
Inventors: 亮山岸; 正男藤平
Original assignee: Sony Corp
Current assignee: Sony Corp
Priority date: 1998-08-17
Filing date: 1998-08-17
Publication date: 2007-05-30
Anticipated expiration: 2018-08-17
Also published as: JP2000069581A

Description

【０００１】
【発明の属する技術分野】
本発明はスピーカ装置に係わり、特に定在波の立たない小型軽量な薄型のスピーカ装置に関する。
【０００２】
【従来の技術】
従来からスピーカ装置の低域再生限界を伸ばすための有効な手段として例えば、スピーカを設けたバッフル板に開口及びダクトを設け、スピーカの振動板の背面から出た音の位相を反転して、ダクトを介して開口から外部に放射させて、スピーカの振動板から前面に出る音波を強め、低音域を歪まない様にしたバスレフレックス型（位相反転型）のスピーカ装置は良く知られている。
【０００３】
この様な位相反転型スピーカ装置は図５に示す様にスピーカボックス１の前面に設けたバッフル板２に穿ったスピーカ放音孔２ａに対向してスピーカ３を固定する。
【０００４】
このスピーカ３は例えば、図５に示す如く、リング状マグネット４と、このリング状マグネット４を挟むように取付けられたプレート５及びヨーク６とを設け、プレート５の内周側とヨーク６のセンターポール６ａとの間に磁気空隙７を形成する。またプレート５にはスピーカ３のフレーム８が取付けられ、フレーム８の外周部にはエッジ９が設けられ、このエッジ９によってコーン型の振動板１０の外周部が保持されている。
【０００５】
一方、振動板１０の内周部にボイスコイルボビン１１が取付けられており、このボイスコイルボビン１１にはボイスコイル１２が巻装され、ボイスコイル１２はプレート５及びヨーク６のセンターポール６ａによって形成された磁気空隙７内に挿入する様になされている。１７はこのボイスコイル１２をこの磁気空隙７内に保持するためのダンパである。
【０００６】
またスピーカボックス１の外部の所定位置に設けられた入力端子１３ａよりの音響信号を接続線１４ａを介してスピーカ３の端子１５に供給し、端子１５よりの音響信号を錦糸線１６を介してボイスコイル１２に供給している。
【０００７】
また、バッフル板２のスピーカ放音孔２ａと同一面に開口１８ａを有するダクト１８を設け、スピーカ３の振動板１０の背面から出た音の位相を反転して、このダクト１８からスピーカボックス１の外に放射し、この振動板１０の前面からでる音の低音域を広げている。
【０００８】
上述の様に位相反転型のスピーカ装置とすることで、密閉型に比べて低音再生限界を低くすることが出来て、スピーカ３の低音共振周波数ｆ₀の約８０％程度まで低域再生範囲を拡げることが出来るとされている。
【０００９】
【発明が解決しようとする課題】
上述の様なスピーカ３をスピーカボックス１内に収納して位相反転型のスピーカ装置を得る場合に、スピーカボックス１を図５の様に薄型化を図る場合にはスピーカ３も薄型にしなければならないのは当然で、この様に小型薄型化したスピーカで低域を再生しようとすればパワーを上げて低音拡大を図ることになるが、振動板１０の振幅が増大し、ダンパ１７がフレーム８等に当たって、パワーを上げることが出来ず、更にスピーカボックス１が薄型で容積が小さいために、低域の拡大は更に困難に成ると云う問題があった。
【００１０】
更に、スピーカボックス１を薄型化すると、小さな容積であるため定在波が立ち易く、これら定在波の腹や節等の影響も大きく、スピーカ３の振動板１０に大きな負荷が掛かり利得−周波数特性は図６の様に中域の１０００〜５０００Ｈｚの周波数範囲での山谷のあばれが生じて音質を悪化させる問題があった。尚、図６で縦軸は利得（ｄＢ）及びインピーダンス（Ω）、横軸は周波数（Ｈｚ）で１９はインピーダンス−周波数特性曲線、２０は正面での利得−周波数特性曲線であり、スピーカボックス１の容積６３０ｃｃ内に口径６５ｍｍφのスピーカ３を配設した場合の特性曲線である。
【００１１】
【課題を解決するための手段】
本発明のスピーカ装置は、先ず、方形の底面板と、底面板の一辺に接触し、垂直方向より傾斜して設けられるバッフル板と、底面板の最後端部から前記バッフル板の上部に向かって所定の曲率を有するカーブを形成する後面板とを含むスピーカボックスを設ける。
バッフル板には低音用スピーカを第１の開口部に設ける。
また、バッフル板には第１の開口部より小さい第２の開口部を設け、これに設けられる第１のダクト部、後面板に沿って設けられる第２のダクト部、第１のダクト部に平行に配設され、低音用スピーカの背面に開口端が設けられる第３のダクト部よりなるダクトを設ける。
そして、スピーカボックスの頂上に、バッフル板に垂直な方向に設けられる高音用スピーカを設ける。
【００１２】
この様なスピーカ装置によればスピーカボックスを薄型化出来て、低域の拡大が可能で定在波を減少出来るので、音質の改善を図ることの出来る。
【００１３】
【発明の実施の形態】
以下、本発明の１形態例を図１乃至図４によって説明する。尚、図５との対応部分には同一符号を付して示している。
【００１４】
図１及び図２（Ａ）〜（Ｆ）は本発明の１形態例のスピーカ装置の側断面図及び正面と側面の略線図を示すもので、スピーカボックス１Ａは底面板１Ｄが略方形で底面積、特に奥行方向は図５で示したスピーカボックス１の底面積より大きくとる様にして、載置部２１に小型軽量なスピーカ装置をより安定に載置可能な様に選択する。
【００１５】
スピーカボックス１Ａを構成するバッフル板２及び後面板１Ｂは図２（Ａ）及び図２（Ｅ）の様にバッフル板２を正面から視た正面図に示す様に長方形状或は図２（Ｃ）の正面図に示されている様に三角形状に成されている。
【００１６】
更に、スピーカボックス１Ａを構成する左右側板１Ｌ及び１Ｒは図２（Ｂ）及び図２（Ｆ）に示す様に三角形状に選択するか、図２（Ｄ）の様に長方形状に選択し、全体として、頂部（先端）に行くにしたがって前後或は左右の側板間の間隔が狭くなる様に成され、ＡＢＳ樹脂等でバッフル板２或は後面板１Ｂを除いて１体に屋根型に形成されている。
【００１７】
図１の例ではバッフル板２の下側に穿ったスピーカ放音孔２ａに対向して、スピーカ３を配設する。
【００１８】
本例の場合はバッフル板２のスピーカ放音孔２ａの下側に更に、バッフル板２の成型時に一体にダクト１８及びダクト用の開口１８ａを形成する様に成す。
【００１９】
又、スピーカ３の構造は図５で説明したと同様の動電型スピーカであってもよいが、本例ではスピーカボックス１Ａの底面１Ｄの面積を図５の様に薄型で小さくとる必要がないのでスピーカ３の奥行方向も充分に大きなものを用いることが出来る。
【００２０】
従って、図１例ではスピーカ３のヨーク６の後方に厚み方向にＮ．Ｓと着磁したマグネット４と反対方向にＳ．Ｎと着磁したキャンセル用マグネット２２を接着剤で接合し、カップ状の金属から成るシールドケース２３の内径をプレート５の外周に接合させた防磁型と成している。
【００２１】
従って、スピーカ３全体を図５のスピーカ３に比べて大きくすることで、従来例と比べて略同一の容積のスピーカボックス１及び１Ａであっても本例では低域を増強可能なスピーカ装置とすることが出来る。
【００２２】
又、本例のスピーカ装置ではバッフル板２の下側にダクト１８の開口１８ａを上側に向く様に傾けて配設されているので、ダクト１８の空気の放射力Ｆ_Dの反作用力−Ｆ_Dの垂直分力Ｆ_DVはスピーカ装置の自重Ｍに加算されるため小型軽量なスピーカボックス１Ａを載置部２１により安定に固定させる様になる。
【００２３】
更に、スピーカボックス１Ａの外部の頂部に高音用のツイータ２５を後面開放状態で配設する。図２（Ａ）（Ｂ）の場合は、バッフル板２の頂部に正方形状突部から成るツイータ取付板２７を延設し、図２（Ｃ）及び図２（Ｄ）では円盤状のツイータ取付板２７ａを、図２（Ｅ）及び図２（Ｆ）ではバッフル板２の頂部を全幅に亘って延設したツイータ取付板２７ｂにツイータ２５を取り付けたものである。
【００２４】
これらツイータ２５は指向性が鋭いのでツイータ取付板２７，２７ａ，２７ｂ等には放射孔を穿たずにツイータ２５のフレーム等に穿った開口部２６を介して高音を放音させる様に成すことでスピーカボックス１Ａ内にツイータ２５を配置した場合に比べて、バッフル板に与える振動の影響を大幅に低減出来る。
【００２５】
図１及び図２（Ａ）〜（Ｆ）に示したスピーカ装置では図１、図２（Ａ），（Ｂ）、図２（Ｅ），（Ｆ）ではバッフル板２と後面板２Ｄ間で、図２（Ｃ），（Ｄ）では左右側板１Ｌ及び１Ｒ間でバッフル板と後面板並びに左右板間が傾斜しているためスピーカ３駆動時の特に低域での定在波が立ち難く、これら定在波による影響を回避出来るものが得られる。
【００２６】
図４は図６と同一条件でのインピーダンス−周波数特性曲線１９Ａ及び利得−周波数特性曲線２０Ａを示すもので、これら特性を比較した場合利得−周波数特性曲線２０Ａの１０００Ｈｚ〜５０００Ｈｚの周波数特性のピーク及びディップは大幅に減少し、定在波の腹や節の影響を受けないスピーカ装置が得られたことが解る。
【００２７】
尚、図１で頂部の前後、或は左右側板の狭くなった部分に、中高音部を吸音させる吸音材２４等を装着させて、ツイータ２５の振動の影響や定在波等を吸音させる様にしてもよい。
【００２８】
図２（Ａ）及び図２（Ｂ）に示す構成では図１とは異なってダクト１８を後面板１Ｂの下側に底面板１Ｄに向けて傾斜する様に配設した場合の略線図を示している。
【００２９】
又、図２（Ｃ）及び図２（Ｄ）の場合はダクト１８を同じく底面板１Ｄに傾斜する様に向けて、右（左）側板１Ｒ（１Ｌ）に開口１８ａと共に配設した場合である。
【００３０】
図２（Ｅ）及び図２（Ｆ）は図３で後述するダクト１８の構成を模式的に示したものである。
【００３１】
以下、図３によって、ダクト１８部分を詳記する。図３でスピーカ３の構成は図１と同一であり、スピーカボックス１Ａ′の後面板１Ｂ′は図１の様に直線状に変化することなくエキスポネンシャル状、或は指数函数的に底面板１Ｄの最後端部からバッフル板２の上部に向かって所定の曲率を有するカーブを形成する構成とされ、各部位で定在波が立たない様に選択されている。
【００３２】
又、スピーカ３のスピーカ放音孔２ａはバッフル板２の最も下側に配され、ダクト１８の開口１８ａはスピーカ３の上側に穿たれている。
【００３３】
更に、このダクトの開口１８ａはバッフル板２から後面板１Ｂ′に連通する第１のダクト部１８ｂと、後面板１Ｂ′の一部を用いてこの後面板１Ｂ′の曲率に沿って設けられた第２のダクト部１８ｃ並びに第１のダクト部１８ｂと平行に配設され、スピーカ３のセンタラインと同一センタラインにある様に一端を開口１８ｅとなすを可とした第３のダクト部１８ｄで構成されている。
【００３４】
図２（Ｅ）と図２（Ｆ）及び図３で示したスピーカボックス１Ａ′ではスピーカ３の駆動時の音放射力Ｆ₁に対する反作用力−Ｆ₁で生ずる第３のダクト部１８ｄ内の開口１８ｅからの空気の流入力−Ｆ_Dと、第１のダクト部１８ｂ内の開口１８ａからの空気の放射力Ｆ_Dとは互に釣合っているのでスピーカ３の音放射力Ｆ₁の反作用力−Ｆ₁をスピーカ装置の自重Ｍで支える様にすればよい。
この時、第２のダクト部１８ｃを開口１８ｅから斜めに上方に向かう空気の放射力Ｆ_D1の反作用力−Ｆ_D1の垂直方向分力Ｆ_D1Vは下方に向かうのでこの垂直方向分力Ｆ_D1Vが自重Ｍに加算されて、軽量なスピーカ装置をより安定に載置部２１に載置可能と成る。
【００３５】
【発明の効果】
本発明のスピーカ装置によるとスピーカボックスを薄型にしても安定に載置部に載置出来て、従来の薄型スピーカの様にスピーカ装置を立設させる為の脚台を必要とせず、比較的大きいスピーカを底面板側の広い部分に配設することで低域の拡大が容易となり、定在波の立たないスピーカボックス構造であるために中域での音質が大幅に改善され、スピーカボックスの底面板方向に重量が掛かる様にスピーカを配した為に軽量なスピーカ装置をダクトの配置と相俟って安定化させることが出来るものが得られる。
【図面の簡単な説明】
【図１】本発明のスピーカ装置の側断面図である。
【図２】本発明の他のスピーカ装置の正面及び側断面を示す略線図である。
【図３】本発明の更に他のスピーカ装置の側断面図である。
【図４】本発明のスピーカ装置の周波数特性曲線図である。
【図５】従来のスピーカ装置の側断面図である。
【図６】従来のスピーカ装置の周波数特性曲線図である。
【符号の説明】
１，１Ａ，１Ａ′‥‥スピーカボックス、２‥‥バッフル板、３‥‥スピーカ、１８‥‥ダクト、２５‥‥ツイータ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a speaker device, and more particularly to a small, lightweight and thin speaker device which does not have standing waves.
[0002]
[Prior art]
Conventionally, as an effective means for extending the low-frequency reproduction limit of a speaker device, for example, an opening and a duct are provided in a baffle plate provided with a speaker, and the phase of the sound emitted from the back surface of the speaker diaphragm is reversed to form a duct. A bass reflex type (phase inversion type) loudspeaker apparatus is well known in which a sound wave emitted from the opening to the outside through the horn is strengthened and sound waves emitted from the loudspeaker diaphragm to the front are strengthened so that the low frequency range is not distorted.
[0003]
In such a phase inversion type speaker device, as shown in FIG. 5, the speaker 3 is fixed so as to face the speaker sound emission hole 2 a formed in the baffle plate 2 provided in front of the speaker box 1.
[0004]
For example, as shown in FIG. 5, the speaker 3 includes a ring-shaped magnet 4 and a plate 5 and a yoke 6 attached so as to sandwich the ring-shaped magnet 4, and the inner peripheral side of the plate 5 and the center of the yoke 6. A magnetic gap 7 is formed between the pole 6a. A frame 8 of the speaker 3 is attached to the plate 5, and an edge 9 is provided on the outer periphery of the frame 8, and the outer periphery of the cone-shaped diaphragm 10 is held by the edge 9.
[0005]
On the other hand, a voice coil bobbin 11 is attached to the inner periphery of the diaphragm 10. A voice coil 12 is wound around the voice coil bobbin 11, and the voice coil 12 is formed by the plate 5 and the center pole 6 a of the yoke 6. It is designed to be inserted into the magnetic gap 7. Reference numeral 17 denotes a damper for holding the voice coil 12 in the magnetic gap 7.
[0006]
Further, an acoustic signal from an input terminal 13a provided at a predetermined position outside the speaker box 1 is supplied to a terminal 15 of the speaker 3 through a connection line 14a, and the acoustic signal from the terminal 15 is voiced through a tinsel line 16. The coil 12 is supplied.
[0007]
Further, a duct 18 having an opening 18a is provided on the same surface as the speaker sound emission hole 2a of the baffle plate 2, and the phase of the sound emitted from the rear surface of the diaphragm 10 of the speaker 3 is reversed, and the speaker box 1 The low frequency range of the sound emitted from the front surface of the diaphragm 10 is expanded.
[0008]
By using the phase inversion type speaker device as described above, the bass reproduction limit can be lowered as compared with the sealed type, and the low range reproduction range can be reduced to about 80% of the bass resonance frequency f ₀ of the speaker 3. It can be expanded.
[0009]
[Problems to be solved by the invention]
When the above-described speaker 3 is housed in the speaker box 1 to obtain a phase inversion type speaker device, when the speaker box 1 is made thin as shown in FIG. 5, the speaker 3 must also be thin. Naturally, if the low-frequency range is reproduced by such a small and thin speaker, the power is increased and the bass is expanded. However, the amplitude of the diaphragm 10 is increased, and the damper 17 is connected to the frame 8 or the like. In this case, there is a problem that the power cannot be increased, and furthermore, since the speaker box 1 is thin and has a small volume, it is more difficult to expand the low range.
[0010]
Further, when the speaker box 1 is thinned, a standing wave is likely to be generated due to a small volume, and the influence of the antinodes and nodes of the standing wave is large, so that a large load is applied to the diaphragm 10 of the speaker 3 and gain-frequency. As shown in FIG. 6, there is a problem in that the sound quality is deteriorated due to the occurrence of irregularities in the valley in the middle frequency range of 1000 to 5000 Hz. In FIG. 6, the vertical axis represents gain (dB) and impedance (Ω), the horizontal axis represents frequency (Hz), 19 represents an impedance-frequency characteristic curve, and 20 represents a front gain-frequency characteristic curve. It is a characteristic curve at the time of arrange | positioning the speaker 3 of 65 mm diameter in the volume of 630cc.
[0011]
[Means for Solving the Problems]
The speaker device of the present invention first has a rectangular bottom plate, a baffle plate that contacts one side of the bottom plate and is inclined from the vertical direction, and a rear end of the bottom plate toward the top of the baffle plate. A speaker box including a rear plate that forms a curve having a predetermined curvature is provided.
The baffle plate is provided with a bass speaker in the first opening.
Further, the baffle plate is provided with a second opening smaller than the first opening, and the first duct portion provided on the baffle plate, the second duct portion provided along the rear plate, and the first duct portion are provided. A duct composed of a third duct portion that is arranged in parallel and has an open end on the back surface of the bass speaker is provided.
And the speaker for high sounds provided in the direction perpendicular | vertical to a baffle board is provided in the top of a speaker box.
[0012]
According to such a speaker device, the speaker box can be thinned, the low frequency can be expanded and the standing wave can be reduced, so that the sound quality can be improved.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS. Note that portions corresponding to those in FIG. 5 are denoted by the same reference numerals.
[0014]
1 and 2A to 2F show a side sectional view and a schematic diagram of the front and side of a speaker device according to an embodiment of the present invention. The speaker box 1A has a bottom plate 1D having a substantially square shape. The bottom area, particularly the depth direction, is set to be larger than the bottom area of the speaker box 1 shown in FIG. 5 so that a small and lightweight speaker device can be placed on the placement portion 21 more stably.
[0015]
The baffle plate 2 and the rear plate 1B constituting the speaker box 1A are rectangular or as shown in the front view of the baffle plate 2 viewed from the front as shown in FIGS. 2 (A) and 2 (E). It is made in a triangular shape as shown in the front view.
[0016]
Further, the left and right side plates 1L and 1R constituting the speaker box 1A are selected in a triangular shape as shown in FIGS. 2B and 2F, or in a rectangular shape as shown in FIG. 2D, As a whole, the distance between the front and rear or left and right side plates becomes narrower as going to the top (tip), and is formed into a roof with ABS resin etc. except for the baffle plate 2 or the rear plate 1B. Has been.
[0017]
In the example of FIG. 1, the speaker 3 is disposed opposite to the speaker sound emission hole 2 a formed on the lower side of the baffle plate 2.
[0018]
In the case of this example, a duct 18 and a duct opening 18a are integrally formed at the bottom of the speaker sound emission hole 2a of the baffle plate 2 when the baffle plate 2 is molded.
[0019]
The structure of the speaker 3 may be an electrodynamic speaker similar to that described with reference to FIG. 5, but in this example, the area of the bottom surface 1D of the speaker box 1A need not be as thin and small as in FIG. Therefore, a speaker with a sufficiently large depth direction can be used.
[0020]
Therefore, in the example of FIG. In the opposite direction to the magnet 4 magnetized with S. A canceling magnet 22 magnetized with N is joined with an adhesive, and the shield case 23 made of a cup-shaped metal is joined to the outer periphery of the plate 5 to form a magnetic-shield type.
[0021]
Therefore, by making the entire speaker 3 larger than the speaker 3 in FIG. 5, a speaker device capable of enhancing the low frequency in this example even if the speaker boxes 1 and 1A have substantially the same volume as the conventional example. I can do it.
[0022]
Further, in the speaker device of this example, the opening 18a of the duct 18 is inclined below the baffle plate 2 so as to face upward, so that the reaction force -F _D of the air radiation force F _D of the duct 18 is arranged. Since the vertical component force F _DV is added to the weight M of the speaker device, the small and lightweight speaker box 1A is stably fixed by the mounting portion 21.
[0023]
Further, a high-frequency tweeter 25 is disposed on the top of the outside of the speaker box 1A with the rear surface open. In the case of FIGS. 2 (A) and 2 (B), a tweeter mounting plate 27 consisting of a square-shaped protrusion is extended on the top of the baffle plate 2, and in FIGS. 2 (C) and 2 (D), a disk-shaped tweeter is mounted. In FIG. 2E and FIG. 2F, the tweeter 25 is attached to the tweeter attachment plate 27b in which the top of the baffle plate 2 is extended over the entire width.
[0024]
Since these tweeters 25 have sharp directivity, the tweeter mounting plates 27, 27 a, 27 b, etc. are made not to radiate holes but to emit high sounds through the openings 26 formed in the frame of the tweeter 25. As compared with the case where the tweeter 25 is arranged in the speaker box 1A, the influence of vibration on the baffle plate can be greatly reduced.
[0025]
In the speaker device shown in FIGS. 1 and 2A to 2F, the baffle plate 2 and the rear plate 2D are shown in FIGS. 1, 2A, 2B, 2E, and 2F. 2 (C) and 2 (D), since the baffle plate, the rear surface plate, and the left and right plates are inclined between the left and right side plates 1L and 1R, standing waves at the low frequency are difficult to stand particularly when the speaker 3 is driven. What can avoid the influence by these standing waves is obtained.
[0026]
4 shows an impedance-frequency characteristic curve 19A and a gain-frequency characteristic curve 20A under the same conditions as in FIG. 6. When these characteristics are compared, the peak of the frequency characteristic from 1000 Hz to 5000 Hz of the gain-frequency characteristic curve 20A and It can be seen that the dip is greatly reduced, and a speaker device that is not affected by the standing wave belly or node is obtained.
[0027]
In FIG. 1, a sound absorbing material 24 or the like that absorbs the mid-high sound part is attached to the front and rear of the top part or the narrowed part of the left and right side plates so as to absorb the influence of vibration of the tweeter 25 and standing waves. It may be.
[0028]
In the configuration shown in FIGS. 2A and 2B, unlike FIG. 1, a schematic diagram in the case where the duct 18 is disposed below the rear plate 1B so as to be inclined toward the bottom plate 1D. Show.
[0029]
2 (C) and 2 (D) are cases in which the duct 18 is disposed on the right (left) side plate 1R (1L) together with the opening 18a so that the duct 18 is similarly inclined to the bottom plate 1D. .
[0030]
2E and 2F schematically show the configuration of the duct 18 described later with reference to FIG.
[0031]
Hereinafter, the duct 18 portion will be described in detail with reference to FIG. In FIG. 3, the configuration of the speaker 3 is the same as that in FIG. 1, and the rear plate 1B 'of the speaker box 1A' is not changed linearly as shown in FIG. It is configured to form a curve having a predetermined curvature from the rearmost end portion of 1D toward the upper portion of the baffle plate 2 and is selected so that no standing wave is generated at each portion.
[0032]
The speaker sound emitting hole 2 a of the speaker 3 is disposed on the lowermost side of the baffle plate 2, and the opening 18 a of the duct 18 is formed on the upper side of the speaker 3.
[0033]
Furthermore, the opening 18a of the duct is provided along the curvature of the rear plate 1B 'using the first duct portion 18b communicating from the baffle plate 2 to the rear plate 1B' and a part of the rear plate 1B '. A third duct portion 18d that is arranged in parallel with the second duct portion 18c and the first duct portion 18b, and whose one end can be an opening 18e so as to be in the same center line as the center line of the speaker 3. It is configured.
[0034]
In the speaker box 1A 'shown in FIGS. 2 (E), 2 (F) and 3, the opening in the third duct portion 18d generated by the reaction force -F ₁ with respect to the sound radiation force F ₁ when the speaker 3 is driven. Since the air flow input -F _D from the air 18e and the radiation force F _D of the air from the opening 18a in the first duct portion 18b are balanced with each other, the reaction force of the sound radiation force F ₁ of the speaker 3 is balanced. a -F ₁ may be set as support under its own weight M of the speaker device.
In this case, the vertical component force F _D1v the reaction force -F _D1 of radiation force F _D1 of the air toward the second duct portion 18c upward from the opening 18e obliquely this vertical component force F _D1v since downward By adding to the own weight M, a lightweight speaker device can be placed on the placement unit 21 more stably.
[0035]
【The invention's effect】
According to the speaker device of the present invention, even if the speaker box is thin, it can be stably placed on the placement portion, and does not require a footrest for standing the speaker device like a conventional thin speaker, and is relatively large. By arranging the speaker in a wide part on the bottom plate side, it is easy to expand the low range, and the speaker box structure with no standing wave improves the sound quality in the middle range significantly. Since the speaker is arranged so as to be heavier in the direction of the face plate, a lightweight speaker device can be stabilized in combination with the arrangement of the duct.
[Brief description of the drawings]
FIG. 1 is a side sectional view of a speaker device of the present invention.
FIG. 2 is a schematic diagram showing the front and side cross sections of another speaker device of the present invention.
FIG. 3 is a side sectional view of still another speaker device of the present invention.
FIG. 4 is a frequency characteristic curve diagram of the speaker device of the present invention.
FIG. 5 is a side sectional view of a conventional speaker device.
FIG. 6 is a frequency characteristic curve diagram of a conventional speaker device.
[Explanation of symbols]
1, 1A, 1A '... Speaker box, 2 ... Baffle plate, 3 ... Speaker, 18 ... Duct, 25 ... Tweeter

Claims

A square bottom plate,
A baffle plate that is in contact with one side of the bottom plate and is inclined from the vertical direction;
A first opening provided in the baffle plate;
A second opening smaller than the first opening provided in the baffle plate;
A rear plate that forms a curve having a predetermined curvature from the rearmost end of the bottom plate toward the top of the baffle plate;
A bass speaker provided in the first opening in a direction perpendicular to the baffle plate;
A first duct provided in the second opening in a direction perpendicular to the baffle plate;
A second duct part connected to the first duct part and provided along the rear plate;
A third duct portion connected to the second duct portion, disposed in parallel with the first duct portion, and provided with an open end on a back surface of the bass speaker;
A duct consisting of
A speaker box including the baffle plate, the back plate, and the bottom plate;
A treble speaker provided on the top of the speaker box in a direction perpendicular to the baffle plate;
A speaker device comprising:

The speaker device according to claim 1, wherein the rear plate has a curvature that changes exponentially or exponentially from the rearmost end of the bottom plate toward the top of the baffle plate.

The speaker device according to claim 1, wherein the second duct portion is provided along a curvature of the rear plate by using a part of the rear plate.