Kaj so visokotonci? Kaj počnejo visokotonci? Vodnik za visokotonske zvočnike

Odlično zveneči sistemi zvočnikov so sestavljeni iz več vrst zvočnikov, vključno z visokotonci. Toda kaj so tviteraši? In kaj počnejo tviteraši?

V tem obsežnem prispevku vam bom pokazal, kaj počnejo visokotonski zvočniki, različni materiali gonilnikov zvočnikov, kateri zvok je najboljši in še več!

Infografika – dejstva o visokotoncih

Kaj so visokotonski zvočniki?

Visokotonci so zvočniki, ki proizvajajo zgornji obseg zvoka, ki ga slišite v glasbi. Ker imajo višje zvočne frekvence manjše zvočne valove, je njihova velikost manjša od velikosti drugih zvočnikov, s katerimi delujejo skupaj.

Visokotonec je vrsta elektromehanskega zvočnika, ki proizvaja zvok in glasbo v zgornjem (višjem frekvenčnem) glasbenem območju. Dopolnjujejo nizkotonce in druge zvočnike, ki ne morejo proizvajati višjih zvokov, kot so tisti, ki se uporabljajo v dvosmernem paru zvočnikov za knjižne police.

Visokotonci so majhni, saj proizvajajo manjše zvočne valove in imajo majhen stožec. Na splošno jih je najbolje uporabiti, če so usmerjene proti poslušalcu.

Večina jih je omejena na določeno območje, na primer od 3 kilohercev do največ 20 kilohercev (kHz), čeprav je odvisno od omejitev posameznega zvočnika. Običajno območje človeškega sluha je okoli 20 Hz do 20 kHz.

Kiloherci so izraz, ki se uporablja za opis frekvence proizvedenega zvoka ali ciklov na sekundo valovne oblike zvočnega signala.

Osnovni deli visokotonca

Slika razstavljenega avtomobilskega visokotonca. Prikazan je sklop magneta (levo) in sklop kupole/rešetke/sponke za ožičenje (desno). Glasovna tuljava je pritrjena na zadnji strani kupole. Na tej sliki je kupola narejena iz srebrnega materiala – najverjetneje milarja ali kakšne druge vrste plastike ali drugega lahkega materiala.

Tipična zasnova visokotonca (čeprav obstajajo tudi drugi tipi) je sestavljena iz majhnega magneta s krožno režo znotraj njega. Zvočna tuljava iz navite bakrene žice, imenovana zvočna tuljava, je pritrjena na kupolo zvočnika, izdelano iz enega od številnih različnih materialov. Razlikujejo se po tem, da večina uporablja ukrivljeno obliko kupole, ukrivljeno navzven, za razliko od drugih zvočnikov, ki uporabljajo stožec, nagnjen navzdol.

Ta sklop je vstavljen in obešen znotraj reže magneta. Kupola je na straneh, tako kot drugi zvočniki, podprta s prožnim, a togim materialom.

Kaj počnejo tviteraši?

Uživate v dobri glasbi? Visokotonci omogočajo dobro glasbo v zvočnem sistemu, ki ga vidite povsod. Domači stereo zvočniki, kot so ti zvočniki za knjižne police Dayton B652, uporabljajo poceni, a učinkovit visokotonec, da zapolnijo zvočni razpon, ki ga srednjetonski zvočnik ali nizkotonec ne moreta proizvesti. Skupaj lahko proizvedejo celoten obseg zvoka in ustvarijo dobro zveneč avdio sistem.

Visokotonci se uporabljajo za ustvarjanje visokofrekvenčnega zvoka (visokotonci) in dopolnjujejo druge zvočnike, ki za to niso primerni. Ko so del celo zmerno cenovno ugodnega avdio sistema z nizkotoncem in dvosteznimi zvočniki, lahko zvenijo fantastično.

»Visoki toni« je beseda, ki se uporablja za opis delov glasbe v zgornjem območju, kot so činele, sintetični zvoki klaviature, učinki bobnov in »tssst tsst« (visok) zvok različnih glasbil.

Ko se ojačen glasbeni signal uporabi za visokotonec prek pozitivnih (+) in negativnih (-) žičnih povezav, glasovna tuljava ustvari magnetno polje znotraj območja trajne magnetne reže magneta.

To spremenljivo polje povzroči, da se tuljava in kupola visokotonca premikata naprej in nazaj, pri čemer se zrak zelo hitro premika po signalu. Ko se to zgodi, se proizvaja zvok.

Tweeterji pri reprodukciji glasbe – zakaj so pomembni

Glasba je sestavljena iz veliko več kot le omejenega obsega zvokov. Je zelo kompleksna kombinacija različnih tonov, frekvenc in drugih značilnosti. Te tvorijo različni inštrumenti, glasovi pevcev in elementi, dodani ob snemanju glasbe.

Visokotonci so ključnega pomena v zvočnem sistemu za ustvarjanje celotnega obsega zvokov, ki jih lahko slišite. Glasba je zaradi tega veliko bolj prijetna in zveni veliko bolj naravno.

Stereo slikanje

Stereo slikanje je izraz, ki opisuje, kako je glasba posneta in predvajana, da daje prostorske znake, ki vašim možganom povedo, od kod prihajajo zvoki. Na primer, glasba, ki so jo posneli glasbeniki, ima lahko nekaj instrumentov v levem kanalu, sredini in desnem kanalu. Visokotonci pomagajo reproducirati zvočne signale višjega obsega in ustvarjajo stereo »sliko«.

Glasba ima različne zvoke v skoraj vseh razponih, ki jih lahko slišijo naša ušesa. Poleg tega je običajno posnet v stereo načinu, ki omogoča reprodukcijo originalnega studijskega instrumenta in postavitve zvoka (levo, desno, sredina itd.).

To ustvari tako imenovano stereo sliko, ko poslušate kakovostno glasbo z vašim zvočnim sistemom.

Avtomobilski visokotonci

Slika, ki prikazuje 3 najbolj značilne tovarniško nameščene nosilce za visokotonce. Levo:armaturna plošča. Sredina:nameščen na steber. Desno:nameščena zgornja vrata. Tako kot domači stereo zvočniki se uporabljajo skupaj z drugimi zvočniki, kot so nizkotonci. V avtomobilih so pogosto nameščeni višje, ker so visokotonci usmerjeni in to zmanjša izgubo glasnosti.

Ker visokotonci proizvajajo visokofrekvenčne zvoke, se v avtomobilih uporabljajo kot del zvočniškega sistema v avtomobilih, vendar ne sami. Uporabljajo se skupaj z drugimi, kot so komponentni zvočniki ali za dopolnjevanje in izboljšanje tega, kar že obstaja.

Avtomobilski avdio sistem z boljšim zvokom bo uporabljal nizkotonec, eno ali več pasivnih kretnic in ločen visokotonec. (Upoštevajte, da imajo avtomobilski visokotonci pogosto trajno pritrjeno rešetko za zaščito).

Srednjetonski gonilnik proizvaja srednje do nižje frekvence, ki imajo večje zvočne valove in niso tako zahtevne glede lokacije. Visokotonci pa so usmerjeni, saj se zvok, ki ga proizvajajo, najbolje sliši, ko so usmerjeni proti ušesom.

Tovarniški visokotonci so pogosto nameščeni na manj kot idealni lokaciji. To je zato, ker je to kompromis med prostorom v vozilu in proizvodnimi stroški tekočega traku.

Lokacija visokotonca se proizvajalcem avtomobilov ne zdi zelo pomembna, razen pri luksuznih vozilih in drugih vrhunskih zvočnih sistemih.

Avtomobilski stereo sistemi po meri pogosto dosežejo najboljši zvok z uporabo namestitve po meri, da premagajo omejitve prostora in lokacij namestitve. Poleg tega so poprodajni (netovarniški) visokotonci na voljo v široki paleti kakovostnih ravni, o katerih bom podrobneje razpravljal.

Kako se uporabljajo visokotonci?

Pogoste uporabe v sistemih zvočnikov

Za visokokakovosten zvok lahko uporabite komplet, kot je ta sistem avtomobilskih komponent CT Sounds Strato. Komponentni zvočniški sistemi običajno uporabljajo nizkotonce in visokotonce, povezane s kretnicami zvočnikov prek zvočniške žice.

Zasnovani so tako, da se ujemajo z zvočniki in ločujejo proizvodnjo zvoka ter jo pošljejo tistemu, ki je za to najprimernejši.

Visokotonci se v sistemih zvočnikov uporabljajo iz omejenega števila razlogov (nikoli se ne uporabljajo sami):

V 2- ali 3-steznem sistemu zvočnikov drugi zvočniki ne morejo proizvajati zvoka
Za dodajanje več visokofrekvenčnega zvoka (visokih tonov) za dodaten učinek

Večina sistemov zvočnikov, ki so danes v uporabi, se imenuje "2-stezni", saj uporabljajo kombinacijo dveh zvočnikov, ki proizvajajo omejen obseg zvoka. To je zato, ker skoraj noben zvočnik, ki se danes prodaja z eno membrano, ne more proizvesti celotnega obsega zvoka, ki ga lahko slišite.

Glavni razlog za to je, da veliki zvočniki ne morejo dobro proizvesti višjih (visokih) frekvenc, majhni zvočniki pa ne morejo proizvesti višjih (nizkih) frekvenc.

Zvočniki so na splošno specializirani in najbolj primerni za razpon zvoka.

Zvočnik srednjega tona, kot so nizkotonci (včasih imenovani tudi zvočniki »srednji nizki toni« ali »srednjetonski zvočniki«), imajo običajno grozno zmogljivost v višjem obsegu zvoka.

Zato so visokotonci ključni za zagotavljanje tega manjkajočega obsega zvoka.

Zakaj visokotonci potrebujejo kretnice?

Crossoverji za avtomobilske zvočnike (levo) in crossoverji za domače stereo zvočnike (desno) so odgovorni za usmerjanje nizkih tonov v pravilne zvočnike. Ščitijo visokotonec in blokirajo popačenje ter morebitno škodljivo moč nizkih tonov pred preglasitvijo.

Kot sem že omenil, visokotonci potrebujejo kretnice, kot so tiste na zgornji sliki, iz več razlogov:

Visokotonci ne morejo predvajati nizkofrekvenčnih zvokov – močno popačijo
Lahko se poškodujejo, če jih poganja dovolj močan nizkofrekvenčni signal ali signali
Zmanjša uporabljeno moč in ga pomaga zaščititi

Razumevanje kretnic zvočnikov

Dvosistemske (pasivne) kretnice zvočnikov so zelo pogoste. Visokotonec sprejema zvoke, ki lahko preidejo nad točko križanja. Prikazana dvosmerna kretnica je narejena s prečesavanjem visokoprepustnega in nizkoprepustnega odseka. V tem diagramu je induktor (žična tuljava) prikazan kot »L«, kondenzator pa kot »C«.

V mnogih primerih so visokotonci opremljeni s preprostim kondenzatorjem, zaporedno povezanim z enim od sponk za ožičenje. To je običajno pozitivni (+) terminal po dogovoru.

Kondenzatorji delujejo kot avdio križanec enega reda (enostopenjski). To pomeni, da imajo naklon kretnice, ki deluje s hitrostjo -6 decibelov na oktavo (dB). Oktava je izraz, ki se uporablja za zvok in predstavlja podvojitev ali razpolovitev frekvence. Na primer, 400 Hz je ena oktava nad 200 Hz.

Crossoverji višjega reda filtrirajo še več nizkih tonov, ki bi dosegli visokotonce, in so še učinkovitejši. -12 dB/oktavo (2. red) je eden najpogostejših in je učinkovit, ne da bi bil predrag.

As you can see in the image above a 2nd order (-12dB) crossover requires an additional component called an inductor. These are coils of wire which react to music and reduce the output to the speaker at certain frequencies.

Shown:A typical 2-way home stereo speaker with a tweeter. In this low-cost design, a single capacitor is used in series as a high-pass crossover to filter out bass. This prevents distortion and potential damage to it as well.

What does a tweeter impedance rating mean?

Impedance, rated in Ohms, is a term used to describe the total electrical resistance to current for a speaker. A tweeter’s voice coil is made of a long amount of wire wound into a coil. This wire has electrical resistance.

Impedance is important as crossovers are designed for the rating of your tweeters. Additionally, tweeters should be matched with woofers and other speakers with a similar rating.

If you mismatch speaker impedance one will play at a higher volume than the other as more power drives them. This is because the power developed by a speaker is directly rated to its Ohms rating.

Traditionally, home stereo speakers are rated at 8 ohms while car speakers are typically 4 ohms. What’s interesting is that, for example, 8 ohm speakers aren’t exactly 8 ohms. That’s an approximation as they’re usually somewhat below that (say 6 to 7Ω for example).

Tweeter power ratings

The average tweeter can’t handle large amounts of power as larger speakers can. Woofers and other larger speakers can dissipate larger amounts of heat and have a larger voice coil wiring gauge.

With some exceptions, power ratings like 15W (watts) RMS and above are realistic. 25W-50W is fairly common for mid-priced models sold today.

Tweeters must match the rated impedance expected from an amplifier. Amplifiers can overheat if used with speakers that are too low for their design. (For example:using 4 ohm tweeters with a stereo rated at 8 ohms minimum is not acceptable).

Tweeter efficiency (SPL rating)

Just like other types of speakers, tweeters have an efficiency rating. This tells you how much volume, in decibels (dB) a tweeter produces for a specific amount of power. This is normally listed as the “SPL” parameter.

In the case of speakers, higher efficiency is better. For average tweeters, you might expect to find this at between 89dB to 91dB at 1W.

Note:dB @ 1W/1m is a standard way of measured speaker efficiency with test equipment with a microphone positioned 1 meter away. However, there are 2 types of tests for this and can be confusing.

It’s important when comparing tweeters to be sure that the measurements are based on similar measurements types. Whenever possible, compare 2 tweeters with measurements based on the same efficiency standard (1W/1M or 2.83V/1M).

The reason for this is that 8 ohm tweeters need a higher voltage applied to create 1W of power as opposed to a 4 ohm model. Similarly, matching tweeters to woofers requires similar care when shopping.

Common tweeter types and materials

Materials

Examples of some of the most common types of tweeters today. A soft dome tweeter (left) is often made with textiles or silk materials as shown. A metal dome tweeter (right) is typically made from aluminum, titanium, or some hybrid design. Some listeners prefer one over the other, although a well-designed tweeter of one type may be able to outperform the other. It’s important to check all the specifications and the frequency response if provided.

There are simply far too many materials used to list here, but I’ll cover some of the most common. Don’t forget that some sold today are made of a variety of less common materials.

Also, it’s important to always check closely as sometimes the specifications aren’t clear and are misleading.

Some of the most common materials used for tweeters include:

Silk, textile, or other cloth
Mylar or other plastics
Metal-coated plastics &PEI materials
Metals:aluminum, titanium, and alloys
Ceramics and ceramic-coated domes
Kapton (in ribbon tweeters)

Silk and textile are some of the most common materials used. Titanium and other types of metals like aluminum are also fairly common for mid-to-upper price range tweeters as well.

Silk tweeters

A silk dome tweeter is one of the most popular types and often a good compromise between cost, performance, and sound quality. A great example is this pair of Polk Audio DB1001 car tweeters.

These types tend to perform well and because of their extra stiffness are often associated with a certain “color” of sound. Other special materials like ceramic and even diamond are used in others too.

However, it’s very important to understand that the type of material used for the tweeter dome alone doesn’t determine its quality . You need to always check the specifications such as the frequency response chart if provided.

If none is provided, it’s best to consider seeking out more information and buy a model that provides that information.

Otherwise, you’re taking a gamble with buying a tweeter that’s too “bright” or “harsh” in that it may have certain ranges of sound it emphasizes too much or not enough.

Mylar, PEI, and others

Mylar and PEI types use plastics for the dome. They’re often found in budget component sets or coaxial speakers. While they’re lower cost, they usually aren’t very good for accurate, crisp sound. You can often hear the difference when comparing them directly against a silk dome tweeter pair.

Some models are hybrid and use a type of metal coating that may or may not offer better performance. All of the types listed are usually cone tweeters in how they’re shaped.

Horn and compression horn tweeters

A horn tweeter (left) can driven by a magnet assembly or piezo driver. Piezo tweeters are very loud and efficient but aren’t very good in terms of music quality. A “super tweeter” is usually magnet driven and produces more volume and has a higher power rating than average products. Both are often used for outdoor music events and gatherings.

Horn tweeters are a special class of speakers. Entry-level models like piezo tweeters are inexpensive and not great at producing good musical tones, but they’re cheap and very efficient. Their volume is often much higher than standard tweeters (96dB vs. 91dB produced at 1 watt, for example).

Unlike models that use a magnet, a piezo tweeter uses a piezoelectric crystal coupled to a mechanical diaphragm like a digital watch or electronic clock uses for sound. They usually have a very high impedance and may not even need a crossover. A piezo tweeter is low-cost, efficient (good dB output per watt) but not good for sound quality.

Other horn tweeters used in extremely high-quality home stereos systems have a very good frequency response as well as sound. These are most often “compression horn” type speakers with a magnet and dome that attach to a horn body that expands outward.

This helps to direct the sound more effectively and can radiate sound more evenly than others.

Super tweeter and bullet tweeter models

These are similar to others but may have a “bullet” shape attached to the dome to help produce high sound levels. They’re great for volume and more power handling.

You can use tweeters like these for situations where high power handling and loud volume are the main requirements. For critical listening and enjoyment indoors, they’re normally not very practical.

Ribbon tweeters

A ribbon tweeter is a bit different from the others. They use a unique design with a very thin “ribbon” diaphragm which moves back and forth in a linear fashion to produce sound.

Tweeters of this type are some of the best and most musical available today, but it depends greatly on the design &quality. Prices range from in about $25 to $600 or so.

One reason they’re so unique is that unlike tweeters based on a voice coil and a magnet, their impedance is much more flat over the frequency response range.

This means there’s less interaction with your crossover due to fluctuations that occur when the audio signal frequency changes.

Ring radiator (concentric) tweeters

Dual-ring radiator (sometimes called “concentric” ring) tweeters are a unique type of tweeter with a moving surface consisting of several rings and a center plug. These types are more sonically accurate and musically detailed tweeters.

Tweeters of this kind are less common, however.

A downside is that unlike other types they produce far less sound at angles (called the off-axis response ). This means that they’re best suited for speaker systems where they’re aimed directly at the listener.

Tweeter frequency response basics

Tweeters have unique characteristics just like any other speaker. In this image, you can see the level of sound produced over different frequencies (called the “response”). These graphics show the sound response at different angles.

In the graphs above we can see that Tweeter A has dips and peaks that will cause the sound to be lacking in some ranges and is too “harsh” (too high) in others. Tweeter B has a much more flat and ideal response, as it’s almost consistently the same over the range of sound produced.

Tweeters, just like any other type of speaker, have limitations. For a given range, they have frequencies at which their response (volume level for a given power applied) is higher or lower than an average decibel (dB) volume produced.

These peaks and valleys (areas where the sound production is higher or falls lower) cannot be overcome without an equalizer or other compensation. Frequencies at the bottom end of the response range are best left to midrange speakers

There’s no such thing as a “perfect” tweeter speaker – they all have good and bad characteristics along with price, mounting, and performance factors to consider.