Em cần 2 đĩa test tần số này để thử loa ạ, xem nó xuống đến được bao nhiêu Hz và lên cao được bao nhiêu KHz Theo em được biết thì 1 đĩa có 99 track còn 1 đĩa có 25 track Bác nào có cho em xin 1 bản copy Cám ơn nhiều
Hai đĩa trên thì em không có tuy nhiên cũng gợi ý với bác là google phần mềm miễn phí trên mạng chữ "Frequency generator", link: http://www.brothersoft.com/two-channels ... 48666.html Phần mềm này rất nhẹ và đơn giản. Bác có thể thay đổi tần số, phase, và âm lượng mỗi kêng riêng biệt tuy nhiên cần dây nhợ và dắc cắm để nối ngõ ra âm thanh của PC tới ngõ vào của bộ dàn.
Phần mềm này rất hay và đơn giản, thank bác nhiều . Dải nghe được của con người hình như là 0,3 - 3,4 Khz thì phải, em sẽ thử test theo cái đáp ứng tần của loa xem ko biết có phát hiện thêm được gì ko :lol:
Đĩa 99 track thì Em có Nhưng làm thế nào để gửi cho Bác đây ? Nếu Bác ở HN thì thử hỏi nick_Kool xem :lol: Vì lần trước lão ý có mượn CD của Em về không biết có chép lại không
Mời bác: - All that she wants is another Frequency http://www.audiocheck.net/audiotests_index.php - Bink Audio Test CD: http://binkster.net/extras.shtml Thân.
To: bác thichduthu và bác danthanhpho: cám ơn 2 bác nhiều, link các track thử tần số mà các bác cho thật đa dạng, em sẽ thử lần lượt từng cái, em chỉ sợ thử xong chán loa quá lại không nghe nhạc nữa thì khổ, nhưng cũng dũng cảm thử 1 lần cho biết ạ. To: bác kienaudio, em sẽ thử hỏi bác nick_kool xem sao, nếu bác ý không còn giữ lại thì hôm nào xuống HP em qua mượn bác vậy
Bink Audio Test CD Track List 1 Left-Right 2 Left, Right, Center, Surround (like Dolby Pro-Logic) 3 Dual Tone 700 L, 1k R 0dB 30s 4 700 0dB 30s 5 1k 0dB 60s 6 Log Sweep 20 to 20k, 0dB to -6dB, 32s 7 Linear Sweep 20 to 20k, 0dB to -6dB, 32s 8 80Hz warble +-40Hz -1dB 60s 9 100Hz warble +-40Hz -1dB 60s 10 120Hz warble +-40Hz -1dB 60s 11 16 -1dB 30s 12 20 -1dB 30s 13 25 -1dB 30s 14 31.5 -1dB 30s 15 40 -1dB 30s 16 50 -1dB 30s 17 60 -1dB 30s 18 63 -1dB 30s 19 70 -1dB 30s 20 80 -1dB 30s 21 90 -1dB 30s 22 100 -1dB 30s 23 125 -1dB 30s 24 160 -1dB 30s 25 200 -1dB 30s 26 250 -1dB 30s 27 315 -1dB 30s 28 400 -1dB 30s 29 500 -1dB 30s 30 630 -1dB 30s 31 800 -1dB 30s 32 1250 -1dB 30s 33 1600 -1dB 30s 34 2k -1dB 30s 35 2500 -1dB 30s 36 3150 -1dB 30s 37 4k -1dB 30s 38 5k -1dB 30s 39 6300 -1dB 30s 40 8k -1dB 30s 41 10k -1dB 30s 42 12500 -1dB 30s 43 16k -1dB 30s 44 20k -1dB 30s 45 Piano A4 440Hz 46 Piano solo, stereo 47 Drum solo, stereo 48 Digital Metronome 120bpm 4mins 49 Crest Wave 10s 50 DC Offset 10% Inverted Polarity 20s 51 DC Offset Full!! Inverted Polarity 20s 52 1k Inverted Polarity 0dB 30s 53 1k -60dB 10s 54 1k Square -2dB 30s 55 1k Square 0dB!! 30s 56 White Noise -9dB 60s 57 440 -1dB 20mins 58 Pink Noise -12dB 20mins 59 Digital Silence 2mins Using the Bink Audio Test CD Tracks 1-2: Track Identification. These tracks will help you confirm the correct Left and Right patching and routing through your system. Track 2 has (in order) Left only, then Right only, then both Left and Right together (Center), then Left and Right with inverted polarity (Surround.) If your system has a polarity problem somewhere between Left and Right then the "Center" sample will sound unlocalized or absent and the "Surround" sample will seem punchy and centered. In a mono PA "Surround" should disappear completely. Track 3: Dual Tone 700/1000. You can send these tones panned to extreme Left and Right to a broadcast or recording feed to set levels and to verify Left and Right channels. Left = Lower frequency = 700 Hz. Tracks 4-5: 700 & 1000. These are level-setting tones useful for channel gain pots, compressor and limiter levels, feeds to external mixers, etc. 1kHz is the de facto standard of broadcast audio level setting -- your satellite and mobile recording techs will expect to see 1kHz coming from your mixer. You still need to chat with them to define whether you are sending them A) the absolute ceiling level beyond which you'll never go or B) some idea of unity level or 0dB which includes a certain amount of headroom for peaks in the program. You should loop or repeat Track 5 if you need to send 1k tone for longer than one minute. You can also listen for crosstalk in your gear using these tones. For instance, check to see if your Aux sends leak some of this tone through when you assign the CD player to the main bus or the PFL bus. Track 6: Log Tone Sweep. This track is very useful for listening to your speaker systems in order to catch any peaks or valleys in the response. You will hear a brief dip or jump in SPL where the response isn’t ideal. Outdoors the response curve you hear will be mostly speaker- and array-related. Indoors you will also get a lot of room response characteristics coloring the pure sound of the sweep. Knowing your own personal hearing curve will help you translate the sound of this track into beneficial system adjustments. A note: Listen for swishing and swirling sounds mixed in with the pure tone sweep to see if your CD player is poorly made or if something in your sound system generates harmonic distortion. Before critical listening please ask others in the venue to be quiet as this track more than any other makes people want to joke around by whistling or singing along -- it reminds many people of a cartoon where something is going to blow up..! But the high frequencies are rolled off at a gentle and constant rate to keep them from taking anyone's head off. This track is meant to be played at a constant fader level from start to finish. Track 7: Linear Tone Sweep. This track is like Track 6 but is for fine-tuning the HF response of your sound system. You can hear more clearly how your various higher bandpasses work individually and how they blend together. Due to its linear contour, this sweep goes quickly from 20 Hz to 2k and moves much more slowly from 2k to 20k. Using this track with people around will not make you any new friends… Tracks 8-10: LF Warbles. These up-and-down sweeps are for confirming your subwoofers’ smooth transition to your LF drivers. Pick the warble which is centered closest to your subwoofer crossover point. Playing this track will help you hear things like bandpasses out-of-polarity, SPL gaps between bandpasses, SPL peaks from overlapping bandpasses (very common) and room response quirks. Check to see if there is a sense of motion (a seeming change in location) from low to high and back as the sound shifts from sub to LF. You are looking for a solid wall of warble, not shifting localization. Tracks 11-44: Pure sine wave tones. These tracks include those centered on the ISO frequencies found on 1/3-octave graphic EQs. (1kHz is missing in this sequence since it is available at Track 5.) You might find these tones useful for ear training so that you can spot feedback frequencies more quickly during gigs. Have your tech friends quiz you as they play a track back. You can also use these tones to check driver polarity within a bandpass. Pick a frequency close to the middle of a bandpass (far from crossover points) and move your ear from a line through the center of one driver to the center of another driver in the same bandpass. If there is a level dip between them then you have a polarity problem. Several extra non-ISO frequencies are added in the lower ranges to help you understand the performance limits of your LF drivers and your subwoofers. The lowest few tones can help you determine the proper level of subwoofer HPF -- that is, whether you have enough 'low-cut' to keep your amps from overheating and to save your sub drivers from over-excursion. Very few live sound systems will yield any measurable SPL from the highest tone, 20kHz. Tracks 45-47: Piano, Drums. These soulless instrumental tracks (no Grammy in sight) are presented dry (no effects) and can serve as a reality check for system confirmation. Track 48: Metronome 120bpm. You can use this track after setting delay times to confirm that the main system meshes neatly with the delay system(s). Of course, if your delay is off by exactly 1/2 second, this track won't help you at all... Track 49: Crest Wave. This sound is a jarring mix of 100 Hz, 200, 300, 400 etc. tones continuing up the scale in 100 Hz steps to 1k, then in 500 Hz steps to 10k, then in 1kHz steps to 20k. Like white noise it can be used to set levels on gear not including speakers. Even though there is no DC offset, the energy of this complex wave touches the positive digital ceiling but only gets ~ 1/3rd of way down to the digital negative limit. Peak amplitude is 0dB. Average RMS power is -16.13 dB. This track can damage speakers if played too loudly. Tracks 50-51: DC Offset. These tracks look like flat lines on a graph; they are not sound waves at all. The Left channel is positive and the Right channel is negative. If added together and turned into mono they will cancel completely. If you pick just one channel these tracks are useful in discovering whether your amps can amplify DC or if they are sufficiently protected by high-pass filters. Track 51 is especially dangerous as it is full range -- the levels hit the digital ceiling and floor! The track ramps in from idle taking 2 seconds, lasts 20 seconds at full, then ramps back down to idle in 2 seconds. If you bypass all the HPF in your system and feed DC offset straight to your sub amps, you will usually see the drivers move outward if they are fed the Left channel and inward if they are fed the Right channel. Some systems are wired differently due to crossover characteristics... Certainly check to see if all the drivers are moving the same direction. Track 52: 1000 Hz Reversed Polarity. This track is helpful in determining whether your panning is perfectly centered. A centered pan pot combined with identical channel trims and fader levels will result in complete cancellation of this tone. Normal low-level distortion and hiss will let a wee bit of 1000 Hz through but in any case you can center your pan knob by noting the lowest level of audible 1k tone as you turn it. Track 53: 1000 Hz Very Low Level. This tone is buried 60 dB down from the digital ceiling and is usually heard amid system hiss. You can use it to check system linearity before your quieter gigs and on the feeds to recorders. Tracks 54-55: Square Waves. Watch out for these tracks! Turn your amps off first! Square waves are sometimes used in destructive testing at audio R&D labs... Don't run them at high volumes if at all. The most vulnerable part of your system are the HF drivers which can fry with square waves! These tracks are useful in setting CD input trims. If your channel input doesn't distort from Track 55 (which slams in at 3 dB above digital ceiling!), it won't distort from nearly any commercially available CD out there. You can also listen for crosstalk on other channels -- it comes through most severely with square waves in neighboring channels. It is not ever necessary to send square waves out to amps and speakers in a normal live sound setup situation. Track 56: White noise: This track has equal energy at every Hz. It can be used to calibrate levels of various pieces of gear not including speakers. It sounds much too bright for use as a main EQ setting tool and can damage HF drivers. This track has an average RMS power of -9.03 dB and a peak amplitude of -2.57 dB. Track 57: 440 Hz sine 20 minutes. You can use this tone and a cheap piezo tweeter to adjust the gain stages of all the pieces of gear up to but not including the crossover. Run the 440 into a mixer and out of a line level output into the piezo tweeter. Turn up the input trim and the faders until you hear distortion artifacts (mainly 1320 Hz and higher) start to become audible in the piezo. Back the trim down a bit: you've just determined the ceiling beyond which this piece of gear goes into distortion (despite what the red overload LEDs are reading.) Continue through your various devices, hooking the piezo up to each output under test, and listen for high-frequency artifacts coming out of the piezo, ignoring the red LEDs. Align all your gear to distort simultaneously and you will benefit from lower system hiss and greater total dynamic range. Warning: some CD players add a little too much harmonic distortion to their output. First thing to do is listen to your CD player's output straight into the piezo... Track 58: Pink noise 20 minutes. Double Mono - same signal on both Left and Right. This track allows you to set system EQ controls while using a high-quality omnidirectional test microphone and a software audio analyzer tool like SmaartLive, SIMM or SpectraFoo. Some experienced techs can EQ by ear with pink noise. You can also use pink with audio analysis programs to set delay times. And pink noise is helpful in setting bandpass levels on crossovers. This track has these power characteristics: Average RMS Power= -12.2dB. Max RMS Power= -8.77. Min RMS Power= -14.9dB. Peak Amplitude= -1.65dB Track 59: Silence. You can use this track (along with the commands Stop and Pause) to discover whether your CD player is adding small amounts of noise to your test tracks. Some cheaper CD players add a low-level, chirpy digital whine while playing which will make your test results less precise. Others have excessive harmonic distortion -- you might need to play a tone into a computer analysis tool or 440 Hz into a piezo tweeter to discover this fault. Em đang đau tới trắc thứ 47/59 chuẩn bị bơn! :lol:
Hôm trước em có xem bác Phúc test loa, bác ấy dùng phần mềm trên máy tính phát ra tần số từ cao xuống thấp đồng thời dùng micro đặc trước loa test khoãng 1m để thu lại âm thanh từ loa và đưa vào máy tính để vẽ lại đáp tuyến tần số của loa, từ biểu đồ đó mới phân tích được điểm hay dở của loa đó.
Mong bác chia sẻ thêm chi tiết đi bác, tìm ra được điểm dở (yếu) thì bác ấy trị ra sao ạ, và chỗ ưu điểm (chỗ đáp tuyến lồi) ?
Về cấu trúc của thùng loa thì không thể sửa được rồi, chỉ có cách là làm lại bộ phân tần để làm sao đáp tuyến tần số tương đối phẳng là OK.
