Đấu dây single wire hay bi-wires?

Đấu dây single wire hay bi-wires?

Tôi xin mở chủ đề mới: "Đấu dây single wire hay bi-wires?"
Do cái chủ đề cục rề đã kết thúc bằng đề nghị của bác Triều Phương, tôi xin trích dẫn lại:
"Nhân tiện tớ muốn nhờ bạn mở đề tài mới mà ko mới về vụ dây loa đơn và Bi-wire - Tri Wire, tớ còn rất lờ mờ, khi dùng dây biwire có loa nghe thấy khác , có loa lại không. Thực ra tớ cũng có nghiên cứu về bộ phân tần nhiều rồi nhưng ko giải thích đc tại sao." - Hết trích dẫn.
Tôi đã bỏ một buổi chiều để đấu thử. Dụng cụ thử gồm: 1 cặp loa, 2 cái amply có công suất khác nhau.
Các trường hợp thử:
1. Loa 2 cầu đấu single
2. Loa 2 cầu đấu bi-wire (vào cầu A của amply)
3. Loa 2 cầu đấu bi-wire (low vào B của amply, hi vào A của amply)
4. Loa 2 cầu đấu bi-amps (Hi vào amply công suất nhỏ, Low vào amply công suất lớn).
Cảm nhận ban đầu như sau:
. Dường như rất khó phân biệt khác nhau giữa trường hợp 1 và 2, nếu có thì bé teo.
. Trường hợp 3 thì dễ nhận thấy nhất là tiếng có vẻ thoát (to) hơn. Âm thanh hình như có chi tiết hơn so với 1 và 2.
. Trường hợp 4 thì âm thanh rất lộn xộn chẳng ăn nhập gì với nhau cả. Sau khi cố gắng hiệu chỉnh âm thanh cho cân bằng thì qua bài hát kế tiếp lại bị lộn xộn, lại phải hiểu chỉnh.
Chán quá, em đi về đây, bồ em lại gọi nữa rồi. Chào các bác

Chào các bác, em vừa gặp mặt offline với bác Triều Phương. Xin phé bác Triều Phương cho em post lên đây những thông tin vừa trao đổi:
. Trường hợp 1& 2 chỉ khác nhau ở chỗ thay vì dòng điện được chia ở ngõ ra amply thì được chia ở cọc dây loa. Xét về mạch thì như nhau, chỉ khác là tiết diện dây đến loa trong trường hợp 2 to hơn nên có thể làm giảm thất thóat do trở kháng dây. Nhưng khả năng của tai giới hạn nên rất khó nhận biết. Ngòai ra, nhà sản xuất loa đã khuyến cáo đấu kiểu 2 chi tiết hơn, thì mình cứ cho là có chi tiết hơn đi?
. Trường hợp 3 và trường hợp 2, có người cho là như nhau vì trong amply cầu A và B chập làm một. Có người cho là khác vì khi chỉ bật A hoặc B trở kháng amply ví dụ là 4ohm, nhưng khi bật cả A và B trở kháng amply là 8 ohm họăc 12 Ohm hoặc 4 ohm tùy lọai amply.
. Trường hợp 4 âm thanh lộn xộn là đương nhiên vì 2 amply công suất khác nhau. Bác Triều Phương còn thử cả trường hợp 2 amply giống nhau nhưng tiếng ra vẫn hỗn lọan.
Em chán quá, chắc ngồi quán bar nhiều nên bị lãng tai rồi

Xin bác cho biết cấu hình test của bác? Loa, Amply, CD-player hay DVD, đĩa gì? dây tín hiệu? dây loa? Phòng nghe thế nào?
Còn đây là kết quả của bạn em:
Loa: China made mua ở chợ Giời 1200nghìn (2 way, tự chế 2 cọc cắm loa)
Amply: Karaoke California, 1 cái Nhật cũ
DVD: Tầu
Đĩa MP3 200 bài, đĩa VCD karaoke nhạc vàng.
Dây tín hiệu: mua ở chợ 5000đ
Dây loa: Trần Phú 1mm
Phòng nghe: nơi bán hàng ở chợ.
Kết luận: Lúc thì 1 hay hơn, lúc thì 2, lúc thì 3, lúc thì 4, nói chung mọi người thích nghe kiểu 1 hơn.
Còn ở nhà em thì chưa đủ đồ để thử.

Ý bác nói là em nghèo không có tiền mà bày đặt hi-end chứ gì? Hà hà, nếu bác giàu hơn em thì em cũng không dám mượn đồ của bác, dù em chuyên trị sài đồ mượn. Dụng cụ mượn về thử gồm:
- Một đầu CD Aiwa (không nhớ moden)
- Amply Sansui alpha 607, Accuphase E-405
- Loa Kef Q65
- Một cục giắc chia tín hiệu Nhật Tảo
- Dây loa: cái lọai gì đó lõi 800 sợi không có thương hiệu, dây amply: cái lọai gì đó của Đài Loan
- Dĩa: tùm lum thứ, em chỉ nghe thử những bài em thích cho dễ phân biệt.
Lãng tai rồi, chán wá

Được thanhtruc03 sửa chữa / chuyển vào 13:07 ngày 17/07/2004
Được thanhtruc03 sửa chữa / chuyển vào 13:30 ngày 17/07/2004
Được thanhtruc03 sửa chữa / chuyển vào 13:34 ngày 17/07/2004

Dây tốt hay dây xấu quan trọng hơn nhiều, nếy dây vớ vẩn thì đấu thế nào cũng vậy thôi.
Có một quy tắc nhỏ đấu dây cho system highend : cùng một loại dây cho tất cả các loa và nhất là dây phải có độ dài bằng nhau

Em chán wá, hôm nay chắc các bác đi nghỉ mát hết rồi?
Em độc thọai vậy:
Biwiring and biamping your speakers
Judging from our postbag, readers seem to be in a right old tangle about the pros and cons of biwiring, not to mention how it''s actually done. And when it comes to biamping, the confusion just gets worse.
For example, reader Ming Chong Yap wants ''a step by step way of biwiring and biamping - despite the definition at the back of What Hi-Fi? I don''t seem to understand them''. And Stuart Manners has a question about his Aiwa NSX-A90 system: it has three way speakers, and he wants to know if it''s worth opening up the speakers to triwire them. Here come all the answers...
The simplest hook-up between an amplifier and a pair of speakers uses a two-core cable per speaker - one conductor is designated positive, and marked with a ''+'' symbol and/or red plugs and terminals. The signal goes into a crossover in the speaker: an electrical circuit that splits it between the drive units.
So in a two-way speaker, the bass and midrange signals go to the woofer, while signals above a certain frequency (often around 3kHz) go to the smaller tweeter. In a three-way speaker, the signal is split into bass, midband and treble. Bear in mind (ghi nhúá), however that a speaker with three drivers may not be a three-way speaker - the term purely refers to the way the signal''s split. Mission''s 753 Freedoms, for example, use five drivers, but are in fact only two-way speakers.
But we digress - back to the crossover. One of the problems with a standard crossover is that since one pair of cables carries the signal to and from the amp, bass signals can tend to swamp (di chuyïín thaânh àaân) the more delicate (mong manh) treble stuff (chêët liïåu), especially in the return (or negative) connection back to the amp.
By separating the signal all the way back to amplifier''s output stage, using two runs of cable or a purpose-made four conductor biwire cable, these effects can be greatly reduced. To do this, you need speakers designed for biwiring. That means the crossover needs to be completely split, without the common negative found in standard design.
To all intents, a biwirable crossover is two separate circuits - one to filter the treble out of the signal for the bass driver, the other to prevent the bass from reaching the treble driver. The dead giveaway is four terminals - two positive, two negative - on the back of a biwirable speaker. No multiple terminals, no biwiring - sorry, Stuart, that means it''s not worth ripping your Aiwa speakers open!
To allow them to be used with a single two-core cable, the terminals on biwirable speakers are usually connected by some kind of jumper bar or link - the speaker instructions will tell you how to remove these to prepare the speaker for biwiring. That done, you need two positive and two negative connections between the speaker and the amp.
Whether you use two separate two-core cables or a four-core biwire run is a matter of taste, but most users will find the latter tidier. At the speaker end, the four conductors - two positive, two negative - are connected to the terminals, but what happens at the other end depends on the outlets the amplifier provides.
With the possible exception of amps with springclip terminals, which have trouble accommodating even single cables, any amp can be used for biwiring. Some provide twin sets of speaker terminals specifically designed for biwiring, while others have A and B speaker outlets you can use to the same effect. If the latter''s the case, you need both sets of terminals turned on all the time.
An amp with a single set of terminals (ie just left +/- and right +/-) can also be used: the two positive conductors from the left speaker are connected into the left ''+/red'' terminal, and the two negatives into the ''-/black''. Repeat this for the right speaker, and that''s it. If you have an amp with 4mm banana socket terminals, most cable manufacturers and dealers will supply biwire cables ''commoned'' into a single set of plugs to make this even easier.
If, however, you have to use bare wire connections or are soldering up your own cables, check and double check the polarity of each amp-to-speaker connection - it''s all to easy to get, say, the left tweeter out of phase with both the left bass and the right speaker. You won''t do any damage to either amp or speakers, but it''ll sound pretty odd. Get it all right, and what you should hear is better focus and clarity in the treble and (particularly), plus better soundstaging. But you can go further...
If a speaker can be biwired, it can also be biamped, which involves using one amplifier channel for each drive unit to give further improvements. A stereo pair of two-way speakers will thus need four channels of amplification, and there''s a variety of ways of doing this. The currently fashionable way is the use of an integrated amplifier along with a power amp.
There are two provisos, and the first is that the integrated in question must be fitted with a pair of preout sockets for this purpose. Some models are designed in this way, having preouts that work in tandem with their own power sections. Amps such as some NAD models, in which the pre and power sections are linked with jumper bars, are generally not suitable for biamping. If in doubt, check with your amp''s manufacturer.
The other point is that the power amp you use should have the same gain (though not necessarily the same power output) as the integrated amp you have. That means that for a given input voltage, both the integrated''s onboard power section and the external power amp you use will give the same output. If they didn''t, you''d have a sound with much louder bass than treble, or vice versa. In general terms, the requirement for this gain-matching means using combinations from the same manufacturer, designed to be used together.
To biamp, your four-conductor runs to the speaker will need four connectors at the amp end, be these plugs or bare wires. The integrated amp and the power amp are connected together with a stereo pair of interconnect cables, pre-out on the integrated to pre-in on the power amp. You then use one amplifier to drive the left and right treble (or high frequencies), and the other to power the left and right bass. In general terms, the integrated drives the treble, and the power amp the bass, but it''s worth experimenting to get the sound you want.
Let''s recap: the four conductors from your left speaker will split between the two amplifiers, the two conductors hooked to the speaker''s ''high frequency +/-'' terminals going to the integrated amp''s ''left +/-'' outputs, and those from the ''low frequency +/-'' to the power amp''s ''left +/-''. Repeat for the right channel. Make all these connections with both amps turned off, and double-check all connections before switching on.
Then, as your finger hovers over the power buttons, go back and check it again - it''s all too easy to get your wires crossed, and the result could be that you trip one or both amps'' protection circuits, blow an internal fuse requiring service attention to fix, or even wreck the amp''s output device. No, you can''t fry yourself, but mistakes could prove costly.
Finally, it''s also possible to biamp using a preamplifier and two stereo power amps or, as in our Audiolab reference system, a pre and four monoblocs. The hookup is the same as the integrated/power amp configuration, and the best thing is that each of these steps up is worth every penny!
Biwiring questions answered
We''ve been here before, but while the benefits of biwiring are understood, the practicalities still baffle many readers?
Yes, we know we''ve already covered biwiring your speakers, but the volume of traffic on the chat page of our website suggests many readers are still confused. So we''ve decided to revisit the subject, and answer some of the questions that have arisen.
Biwiring involves the use of two runs of cable between an amp and a suitable pair of speakers, and works because the return feeds between the speakers and amplifier aren''t carrying full-range signal, but only that relevant to the appropriate part of the speaker.
So the treble and mid/bass are kept apart right from the speaker outputs of the amp to the speakers, the result usually being a sound with greater bass control and punch, and a crisper, cleaner treble. All this is heard as a greater focus of the sound, and better presence and detail.
OK, so down to the practicalities. If your amp has two sets of speaker outputs, biwiring becomes simpler - no need to cram two sets of thick wire into a single set of terminals. Don''t worry about sections in the manual about limitations when both sets of terminals are used - these only apply when you are actually using two pairs of speakers. Connecting one pair of speakers using both sets of terminals means the amp''s output devices are only ''seeing'' the same impedance as when you connect with a single pair of cables, so it''s no problem.
If your amp can drive your speakers, it can drive them biwired. But the speakers need to be designed to be biwired. In a biwirable speaker, the two halves of the crossover - the circuitboard that takes bass frequencies out of the feed to the treble drive unit, and vice versa - is physically split into two sections. One filters out low frequencies from the feed to the tweeter, the other loses the squeaky stuff from the terminals connected to the mid/bass woofer unit.
Only when the link bars are in place for single-wired operation is there any electrical connection between the two halves of the crossover. (As an aside, if you''re single-wiring a biwirable speaker with the link bars in place, experiment with using the upper or lower terminals - there''s often a subtle change in the sound.)
So what about cables? There used to be a belief that a thin wire was best for the treble leg of a biwire set-up, with a thicker cable used for the mid/bass feed. There''s some logic in that, and you could tune your speakers'' sound by using a treble-happy, or even softer-sounding cable on the bass, and something fat and lush, or bright and lean, on the treble.
It can be done, but in general terms we''d say the best starting-point is the use of the same cable on both legs, or even a dedicated four-conductor biwire cable. The latter is the neatest solution, especially when it''s an ultra-flat cable, but you might prefer the macho hawser-style wire - our TechEd is rather attached to the hefty Monster M2.4s elephant trunks.
Finally, should you biwire? In almost every case where biwiring is possible we''ve found it beneficial, but it''s something worth investigating during the demonstrations before you buy. If you really can''t hear the difference you''ve just saved yourself the cost of two runs of cable.
WhatHiFiSound+Vision
Hi audio experts! Please help me with the following questions about biwiring. Millions of thanks.
1> Can I connect the low-frequency (LF) posts on the speakers to speaker A on amp, high-frequency (HF) posts to speakers B on the amp and run speaker A and B simultaneously? If yes, do I need to care about impedence? FYI, my speaker''s impedence is 8ohms and minimum requirement for impendence when running both A and B channels is 12 ohms on the amp.
2> Is bi-wire similar to connecting speakers in parallel? If yes, how can I match that with amp?
3> Though it''s advisable to run the same kind of cables on both LF and HF, I can''t do so at the moment. Temporary, if I have one silver cable (QED Silver) and one copper cable (B-Flat), how should I connect?
Hieu
Reply: (by Anonymous)
Assuming your system has A and B speaker terminals, connect LF to speaker A and HF to B. Don''t worry about the limit of impedance required by the amp as in this case the amp recognize this as only one speaker, not two.
If your system doesn''t A and B, or you want to make it neat behind the amp, just cram two positive cables of LF and HF to the positive (red) post and negative to the negative (black post). Sometimes it not that easy as the speakers are too big to fit two into one banana plug.
You''d better use cables of the same brand and model and even same thickness even though some tend to believe that cables for treble should be thinner. I personally don''t see the difference. - COCO

Vậy bác đấu kiểu nào là nghe hay nhất? 1, 2, 3, 4? Bác thấy âm thanh nó khác nhau thế nào kể cho em nghe với?
[/quote] Dây tốt hay dây xấu quan trọng hơn nhiều, nếy dây vớ vẩn thì đấu thế nào cũng vậy thôi.
Có một quy tắc nhỏ đấu dây cho system highend : cùng một loại dây cho tất cả các loa và nhất là dây phải có độ dài bằng nhau
[/quote]

Bác Tican còn đó không? Bác có phải là anh Ty 3/2 không?

Mình đã thử đấu single lẫn Bi-wiring thấy chẳng khác nhau tý nào. Mình dùng dây Hardstone , system gồm SACD Marantz DV 6400 , AV receiver Marantz SR 7400, đôi thùng loa Phonar Credo .

<BLOCKQUOTE id=quote><font size=1 face="Arial" id=quote>Trích từ:
Ý bác nói là em nghèo không có tiền mà bày đặt hi-end chứ gì? Hà hà, nếu bác giàu hơn em thì em cũng không dám mượn đồ của bác, dù em chuyên trị sài đồ mượn. Dụng cụ mượn về thử gồm:
[/QUOTE]
Bác Minh cho bác thanhtruc03 leo cây thì phải.,
Bác Minh ơi, hôm trước offline, có cái ảnh bác có đôi NAMMON, Ampli Tiến đạt nữa mà không đem ra thử luôn thể nhỉ.
Được coleo sửa chữa / chuyển vào 18:14 ngày 18/07/2004