28mm Mylar Speaker: Choosing a Voice Announcement Driver for Doorbells and Intercoms
Doorbells and intercom systems need something quite different from hi-fi. Wide frequency response and large dynamic range are irrelevant here. What matters is clear midrange, small footprint, low cost, and five years of trouble-free operation. A 28mm mylar speaker lands in a practical spot for exactly that set of requirements.
Specifications
| Model | XDEC-28M04T14NF25-D100 |
| Type | Mylar speaker (M series) |
| Dimensions | 28×5.3mm |
| Impedance | 4Ω |
| Rated Power | 2W |
| Max Power | 2.5W |
| Resonance F0 | 600Hz |
| Sensitivity | 87±3dB |
| Frequency Range | F0~20kHz |
| Distortion | 5% Max |
| Polarity | Positive |
| Load Test | White noise 48 hours |
Dimension Drawing
Dimension Drawing / 尺寸图
Frequency Response
Frequency Response / 频响曲线
Why 28mm Shows Up So Often
The 28mm mylar driver appears frequently in doorbells, intercoms, and alarms because several constraints balance out at this size:
- Enclosure space. A doorbell faceplate usually leaves roughly 30mm of diameter behind it, so 28mm fits while 35mm becomes a struggle.
- Output needs. 87±3dB sensitivity with 2W covers indoor distances of 3-5 meters comfortably.
- Cost position. Mylar diaphragm processing is mature, and tooling and material costs at 28mm sit low.
- Mounting. At 5.3mm thick it can clip directly into faceplate retainers without extra hardware.
An F0 of 600Hz means limited low-end extension, and deep bass is simply not available. Doorbell chimes and voice announcements carry their energy between roughly 300Hz and 3kHz, so 600Hz is sufficient for the job.
Applications and What to Watch
| Application | Key Requirement | Selection Note |
|---|---|---|
| Smart doorbell | Clear speech, compact | Cavity open-area ratio affects highs, aim for ≥15% |
| Building intercom | Midrange penetration | Pair with 2W amp, plan for mic echo cancellation |
| Alarm siren | High output, stability | Design around rated power, avoid sustained peak |
| Reading pen | Near-field clarity, low distortion | Close range needs only 1W, distortion matters more |
| Smart lock | Prompt tones, voice guidance | Waterproofing required, add acoustic membrane at outlet |
Handling Waterproofing
Doorbells and smart locks live outdoors, so ingress protection is not optional. Two locations need attention on a 28mm mylar unit:
- The diaphragm itself. Mylar material reaches IPX5 or better, which handles ordinary rain exposure.
- The sound outlet. Sound needs an opening and an opening admits water, so the standard approach is a waterproof acoustic membrane behind the hole.
One caveat: the membrane attenuates high frequencies, so the measured curve differs from the bare driver. Ask the supplier for post-membrane frequency data rather than evaluating the final product on a bare-unit curve.
Ordering Information
| Order Type | MOQ | Lead Time |
|---|---|---|
| Pilot Run | 500 pcs | 7 days |
| Standard Batch | 3,000 pcs | 15-20 days |
| Custom Spec | 10,000 pcs | 30+ days |
XDEC was founded in 2009 and has spent 17 years on speaker drivers, covering 7 product families from Φ3mm to Φ324mm with over 2,000 models shipped to 30+ countries. The factory holds ISO9001:2015 and IATF16949 certification.
Selection proposals return within 24 hours and datasheet review within 48. Production ships sorted into ±1.5dB tiers, with pairing available for stereo builds.
FAQ
| Question | Answer |
|---|---|
| What is the MOQ? | 500pcs pilot, 3,000pcs standard, 10,000pcs custom. |
| Can impedance be changed? | Yes. 4Ω, 8Ω, and 16Ω are all available as part of OEM winding work. |
| Is there a waterproof version? | Yes. The diaphragm reaches IPX5, with a waterproof acoustic membrane at the outlet. |
| Can the lead-out be customized? | Yes. Terminal wire, lead wire, and solder pad configurations can all be adjusted. |
| Do you provide SPL curves? | Yes, covering both bare-driver and in-cavity measurements. |
Contact Us
Contact Manager Yuan at +86 135 2888 3307 or xd12@xdec.cn. Include dimensions, impedance, power, and target application for a faster quote.
