This is a reference price as no car model has been selected.

Established for over 20 years, sold over 8,000 units per year, sold over 300 units per year, and achieved numerous sales and contest prizes! This is an online shopping site operated by Sound Evolution Onlog, which has a reliable and proven track record.

AUTHOR
DEALER
OF THE YEAR 2026

NATIONAL SALES RESULTS NO.1NATIONWIDE!!

In AUTHOR Alarm's fiscal year 2026 national sales rankings,

we are proud to have been named the No. 1 dealer nationwide.

We sincerely thank all of our valued customers for their continued support.

AUTHOR IGLA product package
AUTHOR SIREN BT product package
AUTHOR KLB product package

We are honored to have received the No. 1 nationwide sales award for AUTHOR Alarm's fiscal year 2026 results at "AUTHOR MEETING 2026."

Our journey into car security began about 32 years ago, when we heard a car siren while visiting the United States. Back then, we researched imported products with an English-Japanese dictionary in hand, building our skills and experience through trial and error on our own car.

It has been 26 years since we opened. Today, through both car audio and car security, we support our customers' car life from two sides: the joy of driving and the peace of mind of protection.

To keep providing smooth, high-quality service even with a small team, we are also developing and automating our own system that connects everything from website inquiries, quotes, and orders to payment, delivery, and after-sales support.

This No. 1 nationwide result was made possible by the many customers who have trusted us with their treasured cars, by AUTHOR JAPAN, and by the staff who support us every day. We offer our heartfelt thanks.

We will continue to face each and every customer's car with sincerity, striving to improve our technology and service so you can enjoy your car life with peace of mind.

Scene from the AUTHOR MEETING 2026 awards ceremony 1
Scene from the AUTHOR MEETING 2026 awards ceremony 2

For customers who wish to visit our store

Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Business days for reservations
Business days for reservations
Regular Holiday
Regular Holiday
Business days for reservations
Business days for reservations
Business days for reservations

New In-Store Reservation System—Now Live!

Online Consultations via Google Meet Also Start!

“Coming to the store right away is a bit of a challenge.”
“I’d like to ask first about what would suit my car.”
“Since I’m far away, I want to talk a bit before I head over.”

For customers like you, we’re launching a
new in-store reservation system and
online consultations using Google Meet.

In-store reservations are now smoother than ever.
And depending on your needs, you can also discuss online before your visit while we organize the direction together.

This is mainly for consultations such as
car security, car audio, battery replacement, and air-conditioner gas maintenance.

Of course, depending on the work required, a final on-site inspection of the actual vehicle may be necessary.
There may be parts that can’t be fully decided by email or online alone, but as a starting point for consultation, it’s become much easier to use.

Make Reservations and Consultations Even More Convenient.

So we can offer better proposals for your precious car in a way that’s not too demanding.
LOGON’s new reservation and consultation system is now live!

Inquiry Form

We’ve introduced a store-visit booking system that’s easy and allows you to reserve right away! In-person meetings are also possible via Google Meet! Notice of an upcoming temporary closure

Notice of Temporary Closure

Thank you for always choosing Sound Evolution Logon.

We will be temporarily closed during the following periods:

  • August 11, 2026 (Tue) to August 19, 2026 (Wed)
    We will respond sequentially starting from Thursday, August 20.

  • September 21, 2026 (Mon) to September 25, 2026 (Fri)
    We will respond sequentially starting from Saturday, September 26.

  • October 20, 2026 (Tue) to October 26, 2026 (Mon)
    October 27 (Tue) and 28 (Wed) are our regular closing days, so we will respond sequentially starting from Thursday, October 29.

Regarding inquiries received during the closure period, we will review and respond to them sequentially from the end of each closure period.

We apologize for any inconvenience this may cause customers who were planning to visit or consult with us. We will handle each vehicle carefully, so we appreciate your understanding.

CAR SECURITYSpecial PageAnti-theft solutions for Land Cruiser, Alphard & moreCar Security Specialist LOGON

We propose the best car security system to match your vehicle, parking environment, and usage.

Land CruiserAlphardVellfireLexusHiace
High-risk vehicles also welcome — please consult us
Learn more

LOGON Wins 1st Place Nationwide — AUTHOR "Dealer of the Year 2026"

LOGON Wins 1st Place Nationwide — AUTHOR "Dealer of the Year 2026"

On September 2, 2026, our shop was awarded 1st place nationwide in the "Dealer of the Year 2026" (2025-2026 annual sales ranking) hosted by AUTHOR JAPAN, the maker of AUTHOR ALARM car security systems.

This result belongs to every customer who trusted us with their car. Thank you from the bottom of our hearts.

We will continue to protect your car — and your ordinary, peaceful mornings — with vehicle-specific design and careful, one-by-one installation.

The ultimate audio plan is here—even without modifications!

The look is OEM. The sound goes to another dimension.

While preserving the OEM feel, upgrade your car audio to the next level.

Recently, we’ve been getting more inquiries from customers who want to improve only the sound—while keeping the usability of the factory navigation or display and making full use of the interior design as-is.

Not an audio system that’s heavily modified to stand out, but an
audio installation that finishes naturally and with quality, while keeping the OEM appearance as intact as possible.

At LOGON, we move forward with proposals to enhance sound quality in a “factory-like” style—confirming not only the OEM parts from higher grades, but also the structure specific to each vehicle model.

The look stays OEM.
But once you play music, you can clearly feel the difference.

With that kind of finish in mind, we’ll build the sound in an achievable way—taking into account your vehicle’s OEM system, speaker placement, interior structure, and even how you plan to use it going forward.

“For this car, since it has an OEM system, I can’t touch the sound.”
“I don’t want to do major modifications.”
“Considering resale, I’d prefer a setup that’s easy to return to stock.”

This is the style we want you to know—especially if you’ve given up on upgrading your audio for reasons like these.

At LOGON, we’ll check your vehicle’s condition and the factory system one by one, and work with you to find methods that can raise your current sound by one step, then another.

Modern cars have wiring structures and vehicle control systems that are becoming more complex year by year.
There are also more cases where you can’t judge based on simple installation alone—such as errors when removing OEM parts, impacts to the vehicle, and serviceability.

That’s why our shop aims to install while carefully considering potential effects on the vehicle, including checks before and after installation and verification using diagnostic equipment.

We also try to avoid leaving any concerns for the future—like resale, vehicle replacement, and even during inspections (shaken). Where possible, we avoid large modifications, and we place importance on how easily the system can be returned to OEM.

Keep the OEM feel, and evolve the sound properly.
As a way to enjoy car audio in the future, LOGON will continue to nurture this style.

We’ll also roll out proposals by vehicle model in stages, so if you want to enjoy music even more comfortably while preserving the OEM atmosphere, please feel free to consult us once.

Regarding efforts to revise on-board failure diagnosis equipment

When installing electrical equipment, we always use a vehicle diagnostic device to check for errors. If an error occurs, we will report it to the owner in advance and strive to return the car in the same condition as before the work. From October 2024 onwards, vehicles with errors at the time of vehicle inspection may not pass the inspection, so future installation work will require sufficient knowledge and equipment. At our shop, we not only check for errors when the car is brought in, but we can also print out and hand over the OBD diagnosis results after the work. Prefectures with the most car thefts: 1st place Chiba 3rd place Saitama Why? Click here

Sound Evolution Logon is Chiba Prefecture's largest car audio and car security specialty store.

Many customers visit us from distant areas. Why? It's because of our demo board boasting the best speaker variety in Japan! You can compare different speakers and discover “What kind of sound do I personally like?” together with us.
From upgrading factory audio systems to making smartphone and Bluetooth connections more seamless, using digital audio players (DAPs) in your car, or replacing stock speakers with everything from trade-in types to true high-end ones, we support a wide range of both domestic and imported vehicles!
Our work environment is fully equipped. With climate-controlled pits to protect your car, precision woodworking equipment, and diagnostic tools compatible with all manufacturers, we ensure perfect checks. We also handle the latest HFC-1234yf refrigerant gas and use trusted Snap-on tools for high-quality finishing.
Vehicles left in our care are protected around the clock by ALSOK and 10 security cameras, offering 24/7/365 monitoring. You can leave your car with complete peace of mind.
If you're thinking “I'd like to tweak the sound a bit” or “I want to take my time choosing the right one”, please feel free to consult with us. An exciting experience is waiting for you!
サウンドエボリューションログオン

demo board
A special page has been opened that allows for Japan's only types and listening patterns! !
Special page opened! !

Work on your car at the optimal temperature
air conditioner pit

latest woodworking equipment
Shorter work time and accuracy

computer diagnostic machine
Diagnostic equipment compatible with all manufacturers

Scratch prevention
thorough body masking

security
24/7 monitoring system with ALSOK and 10 cameras

Car Security is the shortest normal installation date!

IGLA 2026-09-12 (Sat)
Grgo 2026-10-05 (Mon)
Panthera 2026-10-05 (Mon)
AUTHOR's new product has arrived!! It's called Siren BT, an unprecedentedly powerful and groundbreaking product that will dramatically upgrade the experience for customers who already have AUTHOR products installed.

Latest car audio construction examples

DAIHATSU
2026/08/22 (Sat) NEW

TAFTLA9#0S

Today we'll be showcasing a car audio installation in a DAIHATSU TAFT LA9#0S.
Chiba customers
No manufacturer setting Insurance repair
No manufacturer setting deadening

TOYOTA
2026/08/18 (Tue)

HARRIER6BA-MXUA80

MITSUBISHI
2026/08/18 (Tue)

OUTLANDER PHEVFJA/VJA300W

Today we'll be showcasing a car audio installation in a Mitsubishi Outlander PHEV FJA/VJA300W.
Saitama customers