About AUDIOBOT 9000
AUDIOBOT 9000 is a resource for evaluating headphones and amps
Data
The headphone and amp data on this site comes from various sources: the manufacturer’s homepage, product listings from vendors like Amazon and B&H, owner’s manual PDFs, and reviews. In addition, John Seaber of
JDS Labs generously shared with me a data dump of several hundred headphone specs that his company gathered (this site is neither affiliated with John nor JDS Labs, but he is awesome nonetheless.)
The data is manually and tediously inputted by me, and I will continue to add more as new products are released and from your suggestions. I try to be as accurate as possible in presenting correct data for each product, but it can be difficult because manufacturers don’t always provide complete specs and figures can vary depending on where you look. There undoubtedly are errors on this site so feel free to alert
@audiobot9000 if you find any.
Methodology
This site calculates various interactions between each amp and headphone combination using the data gathered.
Peak SPL
How loud the headphones are in decibels when driven by the amp. Ranges between 110 and 120 dB are considered ideal. The value is calculated by first matching the headphone impedance with the amp’s power rating at that impedance, then using the following formula:
Code:
Peak SPL = (1000 * V_rms^2) / impedance V_rms = Math.sqrt( impedance * power)
If none of the amp’s listed power ratings matches the headphone impedance, the rating closest to the headphone impedance is chosen. Please note that the value returned is an estimate and may not be representative of the amp’s actual performance at that impedance.
Headphone Efficiency
The unit used by this site is dB SPL/mW to represent the efficiency. If the sensitivity (dB SPL/V) is listed instead, as is often the case with Sennheiser headphones, the value is converted to efficiency using the formula:
Code:
Efficiency = db SPL/V - 30 + 10 * log(headphone impedance)
If no units are listed next to the figure, then dB SPL/mW is assumed.
Damping Factor
This multiplier basically determines how much control the amp has over the movement of the headphone driver. Values over 10 are ideal. The formula used is:
Code:
Damping Factor = headphone impedance / amp output impedance
Planar Magnetics
Planar magnetic headphones are generally harder to drive than their dynamic counterparts. To be conservative, a multiplier of 1.5X has been applied, meaning they will require 1.5 times more power to drive. As newer and more efficient planars are released, this multiplier may be unnecessary and removed in the future.
Recommended amps
Recommendations are based on several considerations such as the amp’s ability to drive the headphones to the desired SPL range, to return a damping factor greater than 10, and to respond within or beyond the headphones frequency range. To a far lesser degree, pricing is also taken into account because it wouldn’t make much sense to match a $20 portable amp with a set of $2000 headphones. Or would it?
Product Links
Alongside each amp or headphone are a few links to third-party sites. For example, there are some to Amazon, which contain an affiliate tag so that I earn a commision — usually 4% to 6% — if you decide to buy that product. There are also links to eBay (useful for discontinued products), BestBuy, among others. I do not earn my income from these links nor do I expect to; this site is purely a hobby for me. However, it does generate enough to cover server costs with some left over for beer. If you find AUDIOBOT 9000 useful, buy something from one of those links so that I may continue to pay for hosting and alcohol. Thank you.
Disclaimer
The information you find on this website is for educational purposes only. There may be errors in the specs listed on the site, so use your own judgement (and ears) when evaluating or before purchasing something. Lastly, neither this site nor I are affiliated with any of the companies listed on this site. I'm just a guy who likes headphones.
About Me
My name is Jesse Young, and the first pair of good headphones I bought were the Grado SR60s from the now-closed Cambridge SoundWorks store in downtown Berkeley. A week later, I went back and bought the SR80s. That was almost a decade ago, and I think I’ve done a reasonablly good job keeping my addiction in check. I think.
I also built a
dog medication resource, which you might find useful if you're into those creatures.
