Last updated: August 13, 2026
By using Build My Box, you agree to these Terms of Use. If you don't agree, don't use the site.
Build My Box is a free set of car-audio subwoofer enclosure calculators. You pick a vehicle and a driver (or enter your own numbers), and the calculators compute box volume, port dimensions, tuning frequency, and related figures from the inputs you provide and from vehicle/driver data in our database. That's the entire scope of the service — there are no user accounts, no logins, and (as of this writing) no paid features are active. The one place money can change hands is the voluntary tip jar described in Section 7 — nothing on this site is sold, and no calculator is behind a payment.
Illustrative imagery on this site — hero and banner artwork, tool icons, and box-type renders — is AI-generated illustration, not photography of actual products or of any partner brand's products.
Every calculator on this site computes an estimate from the inputs and data available to it. These results are not a substitute for verifying your own measurements before cutting material, buying parts, or installing equipment. Vehicle cargo dimensions, driver specifications, and reference builds are sourced from manufacturer documentation, retailer listings, and community reporting — cross- checked where we can, but not independently lab-verified by us for every vehicle and driver in the database.
Build My Box is not liable for fitment errors, measurement errors, construction defects, property damage, or any other loss arising from reliance on a calculator result without independent verification. Always double-check dimensions against your actual vehicle and driver before cutting wood or spending money.
Nothing on this site is professional acoustic engineering, installation, legal, or purchasing advice. If you need a guaranteed-fit or warrantied design, consult a professional installer or enclosure manufacturer directly.
You agree not to:
If you send us information through the Shop Ticket form — a vehicle measurement, a correction, a missing driver, or anything else — you keep ownership of it. By sending it, you give Build My Box a non-exclusive, royalty-free, worldwide licence to use, adapt, and publish that information as part of the site's vehicle and driver database, including in features that generate revenue.
You also confirm that the information is yours to share — that you measured or observed it yourself, or that it's otherwise not copied from a source that forbids it. Please don't send us data lifted from a paid database or another company's research.
We may edit, verify, or decline any submission. We don't publish your email address or identify you as the source unless you ask us to.
There are no accounts to terminate — this site has no logins. That said, we reserve the right to block, rate-limit, or restrict access for anyone abusing the site (scraping, attacking the Shop Ticket form, or violating Section 5's acceptable-use rules), without notice. We also reserve the right to discontinue, modify, or restrict any calculator or feature at any time, for any reason, including the paid features described elsewhere on the site that aren't active yet.
This site links to third-party retailers, driver/box manufacturers, CNC flat-pack cutting services, and event listings for your convenience. We don't control, and aren't responsible for, the products, services, pricing, or policies of any third-party site you reach through a link here.
Event listings: the SPL meet and competition events shown on this site are sourced from third-party organizers and event calendars — including Sparked Builds, with each listing linking back to its original page — and are displayed with permission where required. We don't organize, host, sanction, or verify these events. Dates, times, locations, entry fees, and classes are set by the organizer and change or get cancelled without notice, and our copy may be out of date. Confirm every detail directly with the organizer before you travel. Build My Box is not liable for travel costs, entry fees, or any other loss arising from an event that was rescheduled, relocated, cancelled, or listed incorrectly here.
Affiliate disclosure: some outbound links on this site (including product links surfaced in vehicle research and banners labeled "Featured partner" or "Recommended gear") are affiliate links — if you make a purchase through one, Build My Box may earn a commission at no extra cost to you. As of this writing our affiliate relationships include Sundown Audio and DS18, with additional programs pending. This never affects which vehicles, drivers, or fitment data we cover, or what the calculators recommend.
The homepage "sticker wall" (the scattered brand names in the page margins) is decorative — it lists real car-audio brand names to reflect the industry this site serves, and is not an indication that every brand shown is a sponsor, partner, or affiliate of Build My Box. Only the relationships disclosed in this section are actual paid partnerships.
The homepage tip jar is a voluntary payment processed entirely by Stripe. Build My Box never receives or stores your card information — see Stripe's own privacy policy for how they handle payment data. Tips are voluntary and non-refundable.
The calculators, site design, and the vehicle/driver research database are owned by Build My Box. You're welcome to use the calculators and share your results (including the build-link/build-card features) for personal, non-commercial purposes.
This site is provided "as is," with no guarantee of uptime, accuracy, or fitness for any particular purpose. See Section 3 above for the specific accuracy disclaimer that applies to calculator results.
To the fullest extent permitted by law, Build My Box's total liability for any claim arising from your use of the site is limited to the greater of $50 or the amount (if any) you voluntarily paid through the site in the 12 months before the claim. Build My Box is not liable for indirect, incidental, or consequential damages of any kind.
We may update these terms as the site changes. The "Last updated" date at the top of this page reflects the most recent revision. Continued use of the site after a change means you accept the updated terms.
These terms are governed by the laws of the State of Kansas, without regard to conflict-of-law principles.
Questions about these terms? Use the Shop Ticket form on the homepage (pick "General feedback").