Buying a Used Double Bass: What to Check

Short answer: A used double bass is a good buy when the top, back, ribs and neck joint are structurally sound. Anything that is only adjustment work (bridge, string height, fingerboard dressing, strings) is a predictable cost, while neck and glue problems are not. Budget for a setup after purchase, and for a higher-priced instrument have a bass luthier look at it before you pay.

Where to find a used double bass

Specialty bass shops and luthiers

Dedicated bass shops and violin shops with a bass department often stock used instruments and sometimes rent them. The bass has usually been looked over already, a setup may be included, and you can go back with problems. The price is higher than a private sale, but you also get a repair contact for later.

Music retailers and online

General retailers mostly carry plywood and student basses, often with a return window. That takes risk out of the purchase because you can check the bass at home. Returns, demos and trade-ins are often cheaper than new.

Private sales and classifieds

Private sales have the widest price range and the highest risk: history and repairs are poorly documented, and there is generally no return. See the bass in person, play it, ask about previous owners and repairs, and get claims in writing. Be careful with sellers who only offer shipping and prepayment. Overpayment scams, fake checks and payment before viewing are well-known problems in instrument sales. A bank can guarantee a check in writing, and the funds should only be considered yours once the check has actually cleared.

Bassist networks, society classifieds and schools

Bassist societies run classified listings for used basses and bows, and the asking prices cover a very wide range, from roughly 800 USD upward (Oct. 2026). Teachers, orchestras and university studios also pass on instruments, often with the full history, and an experienced player can come along for the viewing.

What condition to expect and what it costs

Prices depend heavily on construction (plywood, semi-solid with a solid top, fully solid, carbon) and on the market. For a used bass, price ranges vary by shop and instrument, so compare several listings and get a quote for any work you expect. A very cheap bass often has hidden costs. See carved versus laminated basses for the construction types and 3/4 versus 4/4 for size. Full-size scale lengths run about 104 to 106 cm for a 3/4 and about 107 to 110 cm for a 4/4.

Inspection: the checklist

Bring a flashlight, a tuner, a small inspection mirror and a ruler. Work through the instrument systematically and start with the structure, not the sound.

Top, back and ribs

Cracks are normal on older basses because the wood moves over decades. What matters is whether they were repaired properly and whether they are still active. Look closely at these spots:

• around the bass bar, sound post and bridge feet, where string tension concentrates,
• at the saddle, where the tailpiece wire crosses the top,
• on the back and ribs, especially at corners and curves,
• a sunken top beside the f-hole, which points to long-term overload or weak construction.

Open seams show up as a gap or by tapping: knock along the seam with a knuckle every couple of inches. A sudden dull or buzzing sound means the glue has let go. Regluing a seam is routine shop work, but a buzz should never be ignored. Shine the flashlight through the f-holes to see glue lines, cracks or loose parts inside. Fine bore dust and small round holes point to woodworm, which is a clear warning sign.

Neck heel and neck joint

The neck-to-body joint carries the full pull of the strings. Look for cracks, gaps and chipped varnish at the heel and at the transition to the scroll. A previous neck break is not an automatic dealbreaker if it was repaired professionally and reinforced inside, but ask for details. If the neck sits at the wrong angle, strings will be too high even with a low bridge, or the bridge has to be unusually tall. Only a shop can correct that angle.

Sound post, bass bar and bridge

You can only partly see the sound post (the small wooden dowel inside) and bass bar (the strip glued under the top) through the f-holes. Check that the post stands upright, sits firmly and does not rattle. It can fall if the strings are fully slackened. Setting or moving it is a specialist job, and a badly placed post can damage the top, so leave it to the shop. The same applies to a cracked bass bar or loose bar, which usually means opening the top.

The bridge should stand straight and perpendicular to the top, with both feet flat on the top and no gaps. A warped bridge points to neglect. If the bridge leans toward the fingerboard while tuning, you can gently straighten it in small steps, but anything more belongs with the luthier. Cutting a new bridge is a luthier job.

Tuning machines and endpin

Double basses use worm-gear machines. Tune all four strings, wait a few minutes, play them and check again. If a string drifts, the machine is worn, and replacing machines is comparatively expensive. Play with backlash or grinding is a wear sign. The endpin must clamp securely at every height and must not rattle, and the tailpiece wire should not be frayed.

Varnish, previous repairs and accessories

Visible repairs are fine when they are clean; a poorly done repair can be worse than the original damage. Ask who repaired what and when. Good, fairly new strings usually point to a well-kept bass. Treat accessories separately: bows often need rehairing (around 110 USD, Oct. 2026), and a good case can be a sizable extra.

Checking string height and neck relief

String height at the end of the fingerboard

String height (action) is the gap between strings and fingerboard. Too high makes a bass tiring and painful, especially for bowing and fast passages; too low causes buzzing. Measure with a ruler at the end of the fingerboard. As a rough guide for bowing, many players accept about 1 cm (about 3/8 inch) at the G string and about 1.5 cm (about 5/8 inch) at the E string, with lower values for pizzicato-oriented setups. Low action is easier to play but quieter and more prone to buzzing. High action is usually caused by a tall bridge or a worn fingerboard, both setup work rather than structural problems.

Sighting down the neck

A double bass has no truss rod, so a warped neck cannot simply be adjusted. Sight along the edge of the fingerboard from the scroll. A hand test also works: hold the G string down in first position and at the end of the fingerboard at the same time and look at the gap in the middle. About 2 mm is a common rule of thumb. A clearly stronger bow or a twist in the neck is more serious than high action alone.

Fingerboard condition

Ebony is the standard fingerboard wood. Cheap basses often have a dyed softwood board that wears grooves over time. Grooves cause buzzing, and dressing the board only works if enough wood is left. Ask a luthier before buying whether another dressing is possible. A new quality fingerboard can cost more than a budget bass.

Do it yourself or take it to a shop

You can do yourself: change strings (one at a time so the sound post stays put), tune, measure action, clean the fingerboard, and nudge a leaning bridge. Take to a luthier: fitting or cutting a bridge, dressing the fingerboard, setting the sound post, bass bar work, gluing, and anything about the neck angle or neck warp, which means a neck reset and an intervention in the structure.

Sound and trial playing

Play the bass yourself and, if possible, have an experienced bassist play it while you listen from a few steps away. Cover all strings up into the high positions, with bow and pizzicato. Listen for:

• Buzzes: do they come from the fingerboard, bridge, seams, endpin or accessories?
• Wolf tone: an unstable, beating note at a particular pitch. Many basses have one; luthiers often steer it toward a note that is seldom needed, frequently around G sharp. A strong wolf at several pitches is a minus.
• Evenness: do all strings and positions respond similarly, or are there dead spots?
• Feel: how do the scale, neck and string height fit your hand? Playability matters more than looks.

Setup costs and typical repairs

These are US shop prices in USD (Oct. 2026) and vary a lot between shops:

Hourly shop rates are in the 50 to 75 USD range, and a complete setup can take many hours. Tuning machine replacement, top removal and cracks depend on the damage: varies by shop, get a quote. A new string set is around 120 USD or more.

Appraisals and pre-purchase inspection

For basses above a mid-range price, a pre-purchase inspection by a bass luthier is worth it. A luthier can judge old repairs, check seams and neck and estimate what the setup will cost. Agree to the inspection before any money changes hands. A seller who refuses an inspection is a warning sign. A formal appraisal for insurance is a separate service, so ask the shop for a quote.

Transport, shipping, case and insurance

A double bass is bulky and fragile. For car transport you need at least a well-padded case or hard case, and you should never leave the bass in a hot or freezing car. Shipping brings shocks and climate swings; the sound post can fall and the bridge can shift. For more valuable basses, pickup or a carrier experienced with instruments is safer, and the bass should go to a shop for a check after arrival. Musical instrument insurance (a rider on a renter or homeowner policy, or a dedicated instrument policy) often covers transport damage and theft, but terms differ greatly, so ask before you buy.

Common mistakes when buying

• Buying from photos and description alone.
• Counting the price without follow-up costs (setup, strings, bow, case).
• Buying a cheap bass with a dyed softwood fingerboard or open seams because it "just needs a setup".
• Not asking about previous owners and repairs.
• Realizing too late that the size or scale length does not fit, see 3/4 versus 4/4.
• Buying an attic find without a check (woodworm, glue loss, cracks).

Myths

• "Cracks mean the bass is ruined": No. Properly repaired cracks are normal on old instruments.
• "Plywood always sounds bad": It is robust and stable for students; tone is less varied but not bad. See carved versus laminated.
• "A truss rod can fix the neck": A double bass has none. Neck warp is luthier work.
• "Older is always better": Age only helps if the structure is sound.

Dealbreakers

• Active, open cracks in the top, back or neck without a proper repair,
• a strongly warped or twisted neck,
• a softwood fingerboard with grooves that cannot be dressed,
• woodworm,
• a seller who refuses viewing, trial playing or an inspection.