True sensitivity (1 W / 1 m)
–
Two ways to quote sensitivity
Speaker sensitivity tells you how loud a speaker plays for a given input at 1 meter. Manufacturers use two methods. dB/1 W/1 m measures the level with one watt of input. dB/2.83 V/1 m measures with 2.83 volts – which equals one watt only into 8 Ω. Into a 4 Ω speaker, 2.83 V delivers two watts, so the number looks 3 dB higher. Many manufacturers of 4 Ω speakers quote the voltage figure, which can make them seem more efficient than they are.
dB/W = dB/2.83 V − 10 × log10(8 ÷ impedance)
What sensitivity means in practice
| Sensitivity (1 W) | Typical speaker | Power for 100 dB at 1 m |
|---|
| 82 – 85 dB | Small bookshelf, sealed designs | 32 – 63 W |
| 86 – 89 dB | Most bookshelf and floorstanders | 13 – 25 W |
| 90 – 93 dB | Efficient floorstanders | 5 – 10 W |
| 94 – 100 dB+ | Horn-loaded, pro and high-efficiency | 1 – 4 W |
Every 3 dB of sensitivity halves the amplifier power needed for the same loudness, and every 10 dB more loudness needs ten times the power.
Maximum output at your seat
To estimate how loud a system can play, start with the 1 W sensitivity, add 10 × log10 of the usable power (the smaller of amplifier power and the speaker's power handling), subtract the distance loss of 20 × log10(meters), and add a few dB for multiple speakers and room reflections. For music with peaks 15 – 20 dB above the average, the average level you can enjoy is that much lower.
Choosing speakers and amplifiers together
- Low-sensitivity, low-impedance speakers need amplifiers that deliver high current into 4 Ω.
- High-sensitivity speakers reveal amplifier noise and hum – choose quiet electronics.
- Compare power handling with care: it says how much power a speaker survives, not how loud it gets.
- Impedance curves matter: a "6 Ω" speaker may dip below 3 Ω at some frequencies.
Frequently asked questions
What is a good speaker sensitivity?
Around 87 – 90 dB/W is typical for home speakers. Above 90 dB is efficient and works well with low-power amplifiers.
How do I convert dB/2.83V to dB/W?
Subtract 10 × log10(8 ÷ impedance). For 4 Ω speakers subtract 3 dB; for 8 Ω they are the same.
Does higher sensitivity mean better sound?
Not necessarily – it means the speaker plays louder with less power. Sound quality depends on many other factors.
How many watts for 100 dB?
At 1 m, a speaker with 90 dB/W sensitivity needs 10 W for 100 dB; with 87 dB/W it needs 20 W.
Why do 4 ohm speakers quote 2.83 V sensitivity?
Because 2.83 V into 4 Ω is 2 W, which makes the figure 3 dB higher than a 1 W rating.
About SensiSpec
SensiSpec is an independent, free calculator for comparing loudspeaker sensitivity specifications and estimating output. It uses standard electro-acoustic formulas. We are not affiliated with any loudspeaker brand.
Every formula on this page runs entirely in your web browser. The numbers you type are never uploaded, stored or shared. Our goal is simple: give you an honest starting point so you can compare product specifications with confidence and avoid paying for capacity you do not need – or buying something too small to do the job.
The methodology combines widely published engineering rules of thumb, manufacturer data sheets and the electrical code practices that installers use every day. We review the assumptions regularly and update the calculator when typical product specifications change.
Privacy Policy
Last updated: October 28, 2026
This Privacy Policy explains how SensiSpec ("we", "us") handles information when you visit this website. By using the site you agree to this policy.
Information we collect
We do not require registration and we do not ask for your name, address or payment details. Values entered into the calculator are processed locally in your browser and are not transmitted to our servers. Like most websites, our hosting provider may automatically record standard server log data such as IP address, browser type, referring page and time of visit for security and performance purposes.
Cookies and advertising
We use Google AdSense to show advertisements that keep this tool free. Third-party vendors, including Google, use cookies to serve ads based on a user's prior visits to this website or other websites. Google's use of advertising cookies enables it and its partners to serve ads to users based on their visit to this site and/or other sites on the Internet. You may opt out of personalized advertising by visiting Google Ads Settings, or opt out of some third-party vendors' use of cookies for personalized advertising at www.aboutads.info (US) or www.youronlinechoices.eu (Europe). To learn more, see How Google uses information from sites or apps that use its services.
Visitors from the European Economic Area, the United Kingdom and Switzerland are shown a consent message powered by a Google-certified consent management platform, where you can accept, reject or manage cookie choices. You can change your choices at any time from the privacy link displayed by that message. Some visitors may also be offered the option to view a short ad or complete another offer in exchange for access to the content; this choice is provided by Google and is entirely optional where alternatives are offered.
Analytics
We may use privacy-friendly, aggregated statistics to understand which features are used. These statistics do not identify you personally.
Your rights
Depending on where you live (for example under the GDPR or the CCPA/CPRA), you may have the right to access, correct or delete personal data and to object to certain processing. Because we do not keep personal data from the calculator, most requests can be handled by clearing cookies in your browser. For any other request, contact us at the address above.
Children
This site is intended for a general adult audience and is not directed at children under 13. We do not knowingly collect personal information from children.
Changes to this policy
We may update this policy from time to time. The date at the top of this section shows when it was last revised.
Terms of Use & Disclaimer
The calculator and articles on this website are provided free of charge for general information and educational purposes only. Results are estimates based on typical values and simplifying assumptions; real-world performance depends on the specific product, installation, climate, wiring and how you use your equipment.
Nothing on this site is professional engineering, electrical or financial advice. Always follow the manufacturer's instructions and local electrical codes, and have permanent installations, transfer switches and grid-connected systems designed and installed by a licensed electrician or qualified installer. Never operate fuel-burning generators indoors or in enclosed spaces – carbon monoxide can kill within minutes.
The site is provided "as is" without warranties of any kind. To the fullest extent permitted by law, SensiSpec is not liable for any loss or damage arising from the use of, or reliance on, the information or results provided. Product and brand names mentioned belong to their respective owners and are used for identification only. You may use the calculator for personal and commercial purposes, but you may not copy or republish the site content without permission.
SensiSpec