309 Custom Audio

309 Custom Audio Saturday and Sunday by appointment.
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Veteran-Owned

We specialize in:
🔊 Motorcycle Audio & Customization
🚗 Car Audio Systems
❄️ Remote Start Installations

From roaring bikes to clean car installs, we bring loud, clean sound and professional craftsmanship to every ride.

🔊 Victory Magnum Transformation Complete! 🔥From new amplifiers to sealed & ported bag upgrades and Limitless Lithium bat...
06/20/2026

🔊 Victory Magnum Transformation Complete! 🔥

From new amplifiers to sealed & ported bag upgrades and Limitless Lithium batteries from front to back, this Magnum is built to play loud and play all day. 💪

Ready to take your bike to the next level? 309 Custom Audio – Live Life at Full Volume. 🎶🏍️

Ground Zero Audio - USA

06/17/2026

🔥 12 Speakers. Endless Hours. Unreal Sound. 🔥

John's 2019 Street Glide Special is finally coming together!

This 12-speaker audio build is making serious noise, and while there's still some fine tuning left to squeeze every ounce of performance out of it, it's already proving why custom builds are on another level.

From the custom metallic purple finish to the massive audio system, this bike was built to stand out and be heard.

Turn it up and let us know what you think! 🎶🤘

📍Built by 309 Custom Audio
🎯 Professional DSP tuning
🔊 Harley-Davidson motorcycle audio specialists
🇺🇸 Veteran-owned

Follow for more insane Harley audio builds, custom fabrication, and behind-the-scenes content!

This past weekend we had the CVMA IL 24-7 annual ride and no way was John missing it. Late nights after hours, minimal s...
06/17/2026

This past weekend we had the CVMA IL 24-7 annual ride and no way was John missing it. Late nights after hours, minimal sleep, and alot of stress, but she was worth it. Plenty more to do but she is in one piece and riding. Now it is time to get tuning dialed in.

A big thank you to everyone that helped out along the way!

🔥 SAVE 25% on Soundigital EVO XP 400.4, 800.4 & 1200.4 amplifiers! 🔥Upgrade your ride with incredible power, crystal-cle...
06/09/2026

🔥 SAVE 25% on Soundigital EVO XP 400.4, 800.4 & 1200.4 amplifiers! 🔥

Upgrade your ride with incredible power, crystal-clear sound, and unbeatable value.

⏳ Sale ends June 15 or while supplies last.
Stop by 309 Custom Audio or message us today to lock yours in before they're gone!

Today we remember and honor the men and women who made the ultimate sacrifice for our country.As a veteran-owned busines...
05/26/2026

Today we remember and honor the men and women who made the ultimate sacrifice for our country.

As a veteran-owned business, Memorial Day means a little more around here. Thank you to those who gave everything so we can enjoy the freedom to do what we love every day. 🇺🇸

We hope everyone has a safe weekend with family, friends, and plenty of miles on the road.

— 309 Custom Audio

A few people have asked lately why we’re booking a couple weeks out… and honestly, we couldn’t be more thankful. 🙌The an...
05/20/2026

A few people have asked lately why we’re booking a couple weeks out… and honestly, we couldn’t be more thankful. 🙌

The answer is simple… you guys keep us BUSY. Between Harley audio builds, custom installs, lighting upgrades, DSP tuning, powder coating, and fixing some “questionable” wiring from other shops… the schedule fills up quick. 😅

We’re beyond grateful that so many riders and customers trust 309 Custom Audio with their builds. It’s been incredible watching this shop continue to grow year after year. Veteran-owned, small town, and still chasing bigger goals every single day. 🇺🇸

If you’re thinking about getting on the schedule before riding season gets completely crazy, now’s the time to reach out. We promise the wait is worth it. 🔊🏍️

This 25 CVO ST is about to give a whole new meaning to lighting up the night. 😈🔥We knocked out a full lighting upgrade w...
05/14/2026

This 25 CVO ST is about to give a whole new meaning to lighting up the night. 😈🔥

We knocked out a full lighting upgrade with Shark Demon headlights and matching LED turn signals.

Pictures honestly don’t do this setup justice.

A lot of people think we only do audio around here…
but we’re doing lighting upgrades, suspension, maintance work, air ride, bars, gauges, and all kinds of custom work every week in the shop.

If it bolts onto a bike and makes it better, there’s a good chance we’re into it. 😂

Remember when upgrading your stereo meant a detachable faceplate and a trunk full of CDs? 😅Now this 1985 Dodge Diplomat ...
05/07/2026

Remember when upgrading your stereo meant a detachable faceplate and a trunk full of CDs? 😅

Now this 1985 Dodge Diplomat is sitting here with an Elite 9” touchscreen loaded with wireless Apple CarPlay & Android Auto.

Probably the only Diplomat around here mixing old-school class with this kind of modern tech.

There’s just something cool about keeping the classic body lines and vintage feel… while sneaking in the kind of technology we could only dream about back in the day.

No FM transmitter.
No cassette adapter.
No tangled aux cords.

Just hop in, fire it up, and cruise. 🇺🇸

Rethink.Elite

We’re gonna be closed Thursday & Friday this week.Back open after that and ready to get loud again 🔊If you need anything...
04/29/2026

We’re gonna be closed Thursday & Friday this week.

Back open after that and ready to get loud again 🔊

If you need anything, hit us up before or we’ll catch you when we’re back.

Appreciate all of you 🤝

Address

609 210th Avenue
Monmouth, IL
61462

Opening Hours

Monday 10am - 5pm
Tuesday 10am - 5pm
Wednesday 10am - 5pm
Thursday 10am - 5pm
Friday 10am - 5pm

Telephone

+13093687609

Website

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