What is an exponential and a hyperbolic Horn?

An exponential horn is a type of acoustic horn that has an exponential flare rate. This means that the cross-sectional area of the horn increases exponentially from the throat to the mouth. A horn with a flare constant of 1.0 is a true exponential horn, while a flare constant less than 1.0 is a hyperbolic horn. The details as below.

The formula is as follows,

m and fc (cutoff frequency Hz), c (speed of sound 34400mm/s)

Correlation In the case of the hyperbolic horn, the formula is

So, the specific calculation is more complicated, so I won’t go into details. Interested friends can do their own research, and here are so many, the main purpose is to show that the horn is not simply stacked with several boards, make a radian, and then seal a board on the left and right. It will work.

Therefore, the size of the horn is also fixed, and it does not support changing it to be larger or smaller.

The exponential horn has an acoustic loading property that allows the speaker driver to remain evenly balanced in output level over its frequency range.

An exponential horn works by increasing the overall efficiency of the driving element. The shape of the horn allows for a controlled cross-section increase, resulting in an impedance match between the sound source and the surrounding air. This means that an acoustic horn can radiate sound efficiently in a large frequency range. Efficient radiation is obtained when the pressure is in phase with the particle velocity, which requires a large surface at lower frequencies . The exponential flare rate of the horn helps to maintain an even output level over its frequency range.

The benefits of using an exponential horn include increased efficiency and improved output level balance over its frequency range. The exponential flare rate of the horn helps to maintain an even output level over its frequency range, allowing the speaker driver to remain evenly balanced in output level. This can result in greater acoustic output power from a given driver. Additionally, the shape of the horn allows for an impedance match between the sound source and the surrounding air, which can result in more efficient radiation of sound in a large frequency range.

An exponential horn is different from other types of horns in the way its cross-sectional area increases from the throat to the mouth. The flare rate of an exponential horn is exponential, meaning that the cross-sectional area of the horn increases exponentially from the throat to the mouth. This is in contrast to other types of horns, such as hyperbolic-exponential horns, which have a flare constant less than 1.0 and flare more suddenly at their mouth . The exponential flare rate of an exponential horn helps to maintain an even output level over its frequency range, allowing the speaker driver to remain evenly balanced in output level.

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IWSITAO Customized 1 Pair TAD TH4001 Hyperbolic Stable Diffusion Empty Wooden Horn 2 Inches Throat Birch Plywood Wide 612MM with Adapter

IWSITAO Customized 1 Pair Hyperbolic Stable Diffusion Empty Wooden Horn 1 Inch Throat Birch Plywood Wide 400MM with Adapter

R Core Transformer for Vacuum Tube Amplifier

R core transformer is a type of transformer that uses a ring-shaped core made of cold-rolled grain-oriented silicon steel, and the cross section is round, like O core transformer It has many advantages over conventional transformers, such as low noise, low loss,  low flux leakage, low no-load current, high efficiency, and compact size.  R core transformer is a kind of copper saving transformer, needs less copper for each turn. Its explosive power in audio better than toroidal transformer. The bobbins of R core transformer are made of PBT plastic, which has a strong dielectric strength and fire resistance. 

R core transformer is widely used in industrial control, home appliances, hi-fi audio equipment, signal equipment, office device, communication apparatus, test instrument and medical instrument. In this blog post, I will introduce the basic structure and working principle of R core transformer, and explain some of its applications and benefits.

The R core transformer consists of two parts: the R core and the winding. The R core is a continuous ring-shaped core that has no air gap or cut. 

The winding is wrapped around the R core in a spiral manner, forming two coils: the primary coil and the secondary coil. The primary coil is connected to the input voltage source, and the secondary coil is connected to the output load. OFC(Oxygen Free Copper) copper wire applied in R core transformers, OFC has no hydrogen embrittlement, and has a high conductivity. It is commonly used in audio equipment, vacuum electronic components, wire and so on.

The working principle of R core transformer is based on the phenomenon of electromagnetic induction. When an alternating current flows through the primary coil, it generates a magnetic flux in the R core. The magnetic flux induces an electromotive force in the secondary coil, which produces an output voltage. The ratio of the output voltage to the input voltage depends on the number of turns of the coils. The more turns the secondary coil has, the higher the output voltage.

One of the main advantages of R core transformer is that it has low noise. Because the R core has no air gap or cut, it does not produce any mechanical vibration or humming sound when working. This makes it suitable for applications that require quiet operation, such as audio equipment, medical devices, and communication systems.

Another advantage of R core transformer is that it has low loss. The R core has high magnetic permeability and low hysteresis loss, which means it can efficiently transfer the magnetic flux from the primary coil to the secondary coil. The winding also has low resistance and low leakage inductance, which reduces the heat generation and power loss. As a result, R core transformer has high efficiency and low temperature rise.

A third advantage of R core transformer is that it has compact size. The R core has a simple and symmetrical shape that can fit into a small space. The winding also has a uniform distribution and a small diameter, which reduces the volume and weight of the transformer. This makes it easy to install and transport.

R core transformer is a versatile and reliable device that can be used for various purposes. Some of its applications include power supply, voltage regulation, isolation, impedance matching, signal transmission, and filtering. It can also be customized to meet different specifications and requirements.

There is a R core transformer, which is developed for vacuum tube preamplifier specially. Its primary voltage is AC 0-115V-230v, and its secondary voltage are dual 220V and dual 6.3V.

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IWISTAO R Type Transformer 35W Input 0-115V-230V Dual 220V 6.3V Tube Amp Preamp

How to Build a Center Speaker Cabinet with 2 Full Range Speaker Units

If you are looking for a DIY project to improve your home theater sound system, you might want to consider building your own center speaker cabinet. A center speaker is responsible for delivering most of the dialogue and sound effects in movies and TV shows, so it is important to have a good one that matches your left and right speakers. In this blog post, we will show you how to build an empty center speaker cabinet with 2 full range speaker units, which are speakers that can reproduce a wide range of frequencies without the need for tweeters or woofers.

The first step is to choose the speaker units that you want to use. There are many options available online or in local stores, but make sure they have the same impedance and power rating as your other speakers. You also need to check the dimensions and mounting holes of the speaker units, as they will determine the size and shape of your cabinet. For this example, we will use two 4-inch full range speaker units that have an impedance of 8 ohms and a power rating of 15 watts each.

The next step is to design and cut the cabinet. You can use any material that is sturdy and acoustically inert, such as MDF, plywood, or solid wood. You need to cut six pieces: a front panel, a back panel, two side panels, a top panel, and a bottom panel. The front panel should have two circular holes that match the diameter and position of the speaker units. The back panel should have a rectangular hole for the speaker wire terminal. The other panels should be plain. The dimensions of the panels depend on the size of your speaker units and your personal preference, but for this example, we will use these measurements:

- Front panel: 12 x 6 x 0.75 inches

- Back panel: 12 x 6 x 0.75 inches

- Side panels: 6 x 5 x 0.75 inches

- Top panel: 12 x 5 x 0.75 inches

- Bottom panel: 12 x 5 x 0.75 inches

The third step is to assemble and finish the cabinet. You can use wood glue, screws, or nails to join the panels together, making sure they are aligned and flush. You can also add some damping material inside the cabinet, such as acoustic foam or fiberglass, to reduce unwanted vibrations and improve the sound quality. You can then paint or stain the cabinet to match your decor or leave it natural if you prefer. You can also add some rubber feet or spikes to the bottom of the cabinet to isolate it from the floor.

The final step is to install the speaker units and wire them up. You can use any speaker wire that is compatible with your amplifier or receiver, but make sure it is long enough to reach your desired location. You need to connect the positive terminal of one speaker unit to the positive terminal of the other speaker unit, and then connect them to the positive terminal of the speaker wire terminal. Similarly, you need to connect the negative terminals of both speaker units to the negative terminal of the speaker wire terminal. You can then mount the speaker units on the front panel using screws or bolts, and attach the speaker wire terminal on the back panel using screws or nuts.

You have now completed your DIY center speaker cabinet with 2 full range speaker units! You can place it on a shelf or a stand below or above your TV screen, and connect it to your amplifier or receiver using a single speaker wire. You can then enjoy a more immersive and realistic sound experience in your home theater!

Now, we offer several models for empty center speaker cabinet, then you don't need to build it by yourself, you just buy one of them and fix it.

IWISTAO HIFI Full Range Speaker Empty Cabinet CenterLabyrinth Speaker 3~4 Inch MDF 

IWISTAO 4-inch Double Bass Treble Center Speaker Empty Enclosure Birch 5.1 Home theater 12L

IWISTAO 2 Way 6.5 Inches Center Speaker Empty Cabinet Speaker Enclosure 15mm High Density Board

Why should a toroidal transformer be shielded?

A toroidal transformer is a type of transformer that has a doughnut-shaped core made of ferromagnetic material. Toroidal transformers have several advantages over conventional transformers, such as higher efficiency, lower weight, and smaller size. However, they also have some drawbacks, such as higher cost and higher leakage flux.

Leakage flux is the magnetic flux that escapes from the core of the transformer and induces currents in nearby conductors. This can cause interference, noise, and heating in the surrounding circuits and devices. To prevent this, a toroidal transformer should be shielded with a metal enclosure that blocks the leakage flux and reduces its effects.

Shielding a toroidal transformer can also improve its performance and safety. By reducing the leakage flux, the shielding can increase the coupling between the primary and secondary windings, which improves the voltage regulation and reduces the losses. Moreover, the shielding can protect the transformer from external magnetic fields that could saturate the core and cause overheating or damage.

Enclose the transformer in an magnetic shield enclosure to make sure it has much lower flux leakage. this kind of transformer has not only a good appearance but also high performance. It effectively reduced the magnetic flux interference to other components. And it is suitable for hi-end audio system.

There is a toroidal transformer shielded, which is developed for vacuum tube preamplifier or headphone amplifier specially. Its primary voltage is AC220v, and its secondary voltage are 170V and dual 3.15V.

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IWISTAO 60W Toroidal Transformer Dedicated Filling Glue Tube Preamp Headphone Amp AC170V 3.15V

The song Angel from 6F3 drive 300B Vacuum Tube Amplifier

Vacuum tube 300B is a mysterious vacuum tube with a long history, and don’t know how many music fans are fascinated. I still don’t know how many people are struggling to find its real voice. The audiophiles think that 300B is a female voice representative. But our 300B kit circuit is the embodiment of the sound of rigidity and softness. It is not only an attentive and charming woman, but also an iron and tender prince charming.

There are also rumors that the low frequency of 300B is not good. From an electrical point of view, the internal resistance of 300B is only about 800 ohms, which shows its damping coefficient is very good. Why is the rumors so? This is depended on the quality of the power supply, time constant of the circuit design and other reasons.

 

In fact, 300B tube is the best way to reflect the original atmosphere of music, because the tube’s characteristic curve distribution is excellent, coupled with second-harmonic sense of hearing, the mouth shape of the singer, the low-frequency tension of the chest resonance, its dynamics can be said to reach the perfect state, if regardless of the power, hundreds of thousands of transistor world-famous machines are difficult to surpass in the same power range as the 300B. From the acoustic point of view, the sound of the 300B tube amplifier is more expressive and richer, musical sense.

 

Our vacuum tube 300B kit has a unique acoustic and electrical regulatory concepts from the design to the selection of the output transformer.

The vacuum tube 6F3 is a relatively unpopular composite tube, which is quite a 12ax7+6p14 inside. Because of the large inventory, the price is related low, but its performance is extremely excellent, especially when it is connected as triode tube, which output internal resistance is particularly low, and linearity is good, driving 300B is absolutely no problem. In addition, many senior enthusiasts will inevitably ask, why use large loop feedback? This is our consideration of sound and stability. The large loop will sacrifice the transparency of mid and high frequencies. However, in order to improve the weakness of the low frequency of the tube, adopt the large loop can will make the internal resistance of the 300B tube amplifier lower, so that its overall sound balanced.

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Finished Vacuum Tube Amplifier:

IWISTAO Single-ended Tube Amplifier Tube Amplifier Mono-block Integrated West Electric Master 2x8W Vacuum Tube 6F3 Drive 300B 5Z2P Rectifier

DIY Vacuum Tube Amplifier Kits:

Vacuum Tube Amplifier 300B Kit Single-ended Class A No soldering 6F3 Preamplifier DIY Kits HIFI