1999 Audi A4 Speaker Sizes and Audio System Guide
1999 Audi A4 Speaker Sizes and Audio System Guide
This page covers the factory speaker layout and upgrade considerations for the 1999 Audi A4, including where the speakers are located and how equipment can vary by trim, body style, or audio package. Some versions may include different audio hardware, so factory amplifier details should be verified by trim and audio package. Tweeters may be present if equipped, and selected audio systems may also include additional components.
Data verified by Nick Marchenko, PhD
Speaker Size Chart – 1999 Audi A4
Use this table as the main reference. Fitment depends on trim, factory audio package, mounting depth, and adapter availability.
| Location | Type | Factory Size | Note |
|---|---|---|---|
| Rear Deck Corner | Full-Range | 6.5 inch | |
| Front Door | Tweeter | 1 inch | if equipped |
| Front Door | Full-Range | 5.25 inch | |
| Rear Door | Tweeter | 1 inch | if equipped |
Generic speaker location diagram. The table above shows the specific factory sizes for this vehicle. Exact location details may vary by body style and trim.
Speaker Count by Trim – 1999 Audi A4
Speaker count and audio equipment vary by trim and factory audio package. This table lists known configurations from our database.
| Trim | Speakers | Amplifier | Radio | Navigation |
|---|---|---|---|---|
| 1.8 T 4dr Sedan | 8 | – | – | – |
| 1.8 T Avant Quattro 4dr Station Wagon | 8 | std | – | – |
| 2.8 4dr Sedan | 8 | – | – | – |
| 2.8 Avant Quattro 4dr Station Wagon | 8 | std | – | – |
Data sourced from manufacturer specifications. Verify with the window sticker or dealer before ordering audio components.
Vehicle and Audio System Specifications
This block helps identify the vehicle and its audio system configuration for fitment decisions.
Body Style Audio Differences
This 1999 Audi A4 can vary by body style, so rear speaker placement and factory audio packages may differ between versions. The shared speaker data shows 5.25-inch front door full-range speakers, optional 1-inch tweeters, and 6.5-inch rear deck corner speakers. Factory amplifier details should be verified by trim and audio package.
What Speakers Fit the 1999 Audi A4?
Aftermarket fitment should start with the factory speaker locations listed for this 1999 Audi A4, but diameter alone is not enough. Check mounting depth, bracket fit, connector type, and whether the vehicle has a factory-amplified audio system on the trim you are working with. The listed speaker sizes give you a reliable starting point, while the actual install can still vary by trim and audio package. If equipped, tweeters may also be part of the factory layout.
Usually Safe Upgrades
- If your vehicle uses the 5.25 inch front door full-range location, that size is the main starting point for replacement speakers.
- If your vehicle uses the 6.5 inch rear deck corner full-range location, that size is the main starting point for replacement speakers.
- If your vehicle uses the 1 inch front door tweeter location, replacement tweeters may be considered if equipped.
- If your vehicle uses the 1 inch rear door tweeter location, replacement tweeters may be considered if equipped.
Check Before Buying
- Confirm the exact speaker location before ordering, since front and rear positions use different sizes.
- Measure mounting depth and opening shape so the replacement will clear the factory location.
- Check the connector style and any factory adapter needs before choosing a speaker.
- Verify trim and audio package details because factory amplifier details should be verified by trim and audio package.
- If you are replacing tweeters, confirm they are actually equipped on the vehicle before buying.
Installation Notes
The 1999 Audi A4 uses an 8-speaker layout on the trims listed, with 5.25-inch front door full-range speakers and 6.5-inch rear deck corner full-range speakers. Tweeters are listed in the front and rear doors if equipped, so confirm the exact audio package before ordering parts. Panel removal is usually the first step, and trim pieces should be handled carefully to avoid cracking clips or scuffing the door panels. Wiring should be checked before disconnecting anything, since factory amplifier details should be verified by trim and audio package. Speaker depth is important in the doors, especially if you are upgrading to a larger magnet or aftermarket basket. Mounting adapters may be needed to match the factory openings, and harness adapters can help keep the factory wiring intact. If your vehicle has the factory subwoofer, plan the upgrade around that system as well. Test each speaker before reinstalling the panels so you can confirm polarity, balance, and fitment.
Moderate difficulty, since access, wiring checks, and fitment details can vary by trim and audio package.
Common Mistakes When Replacing Speakers
When shopping for speaker upgrades for the 1999 Audi A4, the biggest problems usually come from assuming every trim and audio package is the same.
- Buying based only on the body-style label instead of checking actual speaker locations on the vehicle.
- Skipping trim and audio package checks, even though speaker count and amplifier details can vary by trim.
- Assuming the front or rear tweeters are always present instead of confirming whether they are equipped on the specific vehicle.
- Ignoring mounting depth and connector style, which can cause fitment problems even when the speaker size matches.
- Overlooking the rear deck and door speaker sizes and replacing them by size alone without confirming the exact location and type.
- Reassembling the panels before testing the new speakers, which can hide wiring or polarity problems until everything is already back together.
Generation & Model Family
The 1999 Audi A4 belongs to the First generation (B5) - Facelift (1999–2001) family. Nearby model years often share similar speaker locations and audio layouts, but exact fitment can vary by trim and audio package – verify before ordering.
Recommended Upgrade Path
The 1999 Audi A4 B5 facelift uses an 8-speaker layout on the trims listed here, and equipment can vary by trim and audio package. Front-stage upgrades usually give the biggest improvement first, especially when tweeters are included. Factory amplifier details should be verified by trim and audio package before planning any larger system changes.
| Goal | Best Upgrade Path | Why |
|---|---|---|
| Better clarity | Start with the front door speakers and front tweeters if equipped, since the front stage has the biggest impact on vocals and detail. A quality speaker upgrade up front can clean up mids and highs without changing the rest of the system right away. | Clarity comes mainly from the front of the cabin, and this model may include tweeters in the front doors. Improving the front stage first usually gives the most noticeable gain in detail and imaging. |
| More bass | Add an aftermarket subwoofer to complement the factory speakers and fill in the low end. If the car has a factory bass solution on a specific audio package, verify how it is integrated before replacing or adding to it. | The listed speaker layout focuses on full-range door and rear speakers, so a dedicated subwoofer is the most effective way to add low-frequency output. |
| Louder sound | Use properly matched speakers and amplifier integration to improve volume and reduce distortion. Before adding aftermarket amplifiers, verify factory amp and premium system integration by trim and audio package so the new gear works correctly with the existing setup. | Higher volume without harshness depends on matching the speakers and amplifier correctly, especially on trims where factory amplification may be present. |
| Budget improvement | Replace the front door speakers first with same-size replacement speakers with correct mounting brackets. If the budget allows, add the front tweeters if equipped after the main front speakers are done. | The front doors handle the most important part of the sound, so upgrading them first gives the best value for the money. |
| Factory look | Use same-size replacement speakers with the correct mounting brackets and harness adapters for a clean install that preserves the factory wiring and appearance. | This approach keeps the interior looking original while still improving sound quality, and it helps avoid unnecessary changes to the factory wiring. |
Mounting Adapters and Wiring
The same nominal diameter does not guarantee a direct mount. Before ordering, confirm:
- Speaker depth: Aftermarket speakers often have larger magnets – measure available depth at each location.
- Mounting brackets: Door locations typically need a bracket or spacer to clear the window regulator and achieve correct mounting depth.
- Wiring harness adapters: Use a plug-and-play harness adapter to preserve factory wiring.
- Tweeter mounting cups: Replacing OEM tweeters may require surface-mount cups or brackets depending on the location.
- Factory or premium amplified systems: If the vehicle has a premium or factory-amplified audio system, confirm how the factory radio, amplifier, and speakers are connected before adding aftermarket amplifiers. Depending on the setup, a line output converter, DSP, integration harness, or professional installation may be needed.
- Connector type: Factory connectors vary by trim and model year – confirm compatibility before splicing or using an adapter.
Frequently Asked Questions
What size are the front door speakers in the 1999 Audi A4?
The front door full-range speakers are 5.25 inches. Tweeters are listed as 1 inch if equipped.
What size are the rear speakers in the 1999 Audi A4?
Rear deck corner speakers are listed at 6.5 inches. Rear door tweeters are 1 inch if equipped.
Does the 1999 Audi A4 have a factory subwoofer?
A factory subwoofer is not listed in the available data. If your vehicle has one, it should be verified by trim and audio package.
Can I replace the speakers without replacing the radio?
Yes, speaker replacement can be done without changing the radio. The vehicle uses 8 speakers on the listed trims, so match the new speakers to the existing locations and sizes.
Do I need mounting adapters for speaker replacement?
Mounting adapters may be needed depending on the speaker you choose and the vehicle location. Check the speaker size and mounting depth before ordering.
Does the 1999 Audi A4 have a factory amplifier?
Factory amplifier details should be verified by trim and audio package. The data shows it is present on some trims, but it is not universal.