Last updated: 9 August 2026
This policy explains what HiFiSystems.net collects, why, and what you can do about it. It is written to be read, not to be survived.
The short version
We run privacy-respecting analytics, we email you about new guides only if you ask us to twice, and we use affiliate links that set cookies belonging to the retailer. We do not sell your data, we do not run advertising networks, and we do not have a login system, so we hold very little about you.
What we collect
Analytics. We use GA4 to understand which pages and tools people use. We have configured it to collect aggregate usage only: pages viewed, referring site, approximate country, device type and browser. We do not collect your IP address in a form that identifies you, and we do not build advertising profiles.
The calculators. Everything you type into a calculator on this site is processed in your browser. Room dimensions, equipment choices, listening distances: none of it is transmitted to us and none of it is stored anywhere. The tools have no server component. Close the tab and the data is gone, including from your own machine, because we do not use browser storage either.
Email, if you ask for it twice. There is a form at the foot of each guide. It has one field, and one field is all we take: your email address. No name, no country, no “how did you hear about us”.
The form is double opt-in. Submitting it does not subscribe you; it sends you a confirmation email, and nothing starts until you click the link in that email. If you never click it, the address is discarded. That click is also our record that you consented, which is what GDPR asks us to be able to show.
Once you have confirmed, Kit holds, alongside your address: the date you confirmed, which page you subscribed from, and — because this is how every email platform works, ours included — whether you opened an email and whether you clicked a link in it. We would rather tell you that than let you discover it. We use it for one thing: to notice if we are sending to an address that has stopped reading, so we can stop.
What we send. One email when a new guide is published, and one when a correction changes a figure we had already published. That is the whole list. There is no schedule, because we publish when the specifications give us something worth publishing: some weeks that is several guides, some months it is none. We will not email you about anything else, and we will never email you on someone else’s behalf.
Getting off the list. Every email carries an unsubscribe link. One click, no confirmation step, no “are you sure”, effective immediately. You can also email corrections@hifisystems.net and ask, and we will do it by hand. After you unsubscribe, Kit keeps a record that your address opted out — that record exists so that a later import cannot quietly put you back on. If you would rather be erased entirely instead, say so and we will delete the record too.
Correspondence. If you email us, we keep the email so we can reply and so we have a record of corrections we were asked to make.
What we do not collect. No accounts, no passwords, no payment details (we never handle a transaction; purchases happen entirely on the retailer’s site), no comments, no uploaded files, no location beyond approximate country.
Cookies
Our own: essential cookies only, for site function. We do not set advertising or profiling cookies.
Affiliate cookies: when you click a link to a retailer, that retailer may set a cookie so they can attribute a purchase to us. That cookie belongs to them and is governed by their privacy policy, not ours. The window varies by programme and is typically between 14 and 30 days. If you would rather not carry one, do not use our links; the site works identically without them and nothing is gated.
Analytics cookies: depending on how GA4 is configured, one may be set. If your browser sends a Do Not Track or Global Privacy Control signal, we honour it.
You can block or delete cookies in your browser settings. Nothing on this site stops working if you do.
Third parties who may receive data
- GA4 — aggregate usage analytics
- Kit — email delivery, only for confirmed subscribers, and only ever your address. Kit is a United States company and your address is stored on its servers there, which matters if you are writing from the EEA or the UK. Its own privacy policy governs what it does as our processor: <https://kit.com/privacy>
- Hostinger — web hosting, which necessarily processes server logs
- Affiliate networks and retailers — only when you click an affiliate link, and only what the retailer’s own cookie records
We do not sell, rent or trade personal information. We have no interest in doing so and no mechanism for it.
Your rights
Wherever you live, you can ask us to tell you what we hold about you, correct it, delete it, or stop emailing you. Email corrections@hifisystems.net and we will act on it within 30 days.
If you are in the European Economic Area or the United Kingdom, GDPR gives you the rights of access, rectification, erasure, restriction, portability and objection, and the right to complain to your national data protection authority. Our lawful basis is consent for the newsletter and legitimate interest for aggregate analytics.
If you are in California, the CCPA and CPRA give you the right to know what is collected, to have it deleted, and to opt out of sale or sharing. We do not sell or share personal information as those laws define it, so there is nothing to opt out of, but the request channel above works regardless.
Because we hold so little, most of these requests resolve to “we have your email address” or “we have nothing.”
Children
This site is not directed at children under 13 and we do not knowingly collect anything from them. If you believe a child has sent us personal information, email us and we will delete it.
Data retention
An unconfirmed subscription — you submitted the form but never clicked the confirmation link — is discarded rather than kept as a lead. A confirmed one is kept until you unsubscribe, and after that only as the opt-out record described above, which we will also delete on request. Analytics data is retained in aggregate for 14 months. Correspondence is kept as long as it is useful for handling corrections. Calculator inputs are never retained, because they never leave your browser.
Security
The site is served over HTTPS. We hold no payment data, no passwords and no accounts, which is the most effective security measure available to us: there is very little here worth stealing.
Changes
If this policy changes materially we will update the date at the top and note what changed. We will not make a change quietly and hope nobody notices.
9 August 2026. We added an email opt-in at the foot of each guide, so this page now says exactly what that form collects (an address, nothing else), that it is double opt-in, that Kit records opens and clicks, how long any of it is kept, and how to get off the list. Nothing was collected under the old wording that is not described here.
Contact
corrections@hifisystems.net
Emilio Goris, HiFiSystems.net
United States