We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-22 · 6 min read · Independent comparison
If you want to repair a pair of wired headphones you already love and keep their original sound signature, choose SOULWIT 40mm; if you need a complete wireless setup for commuting, workouts and home listening without buying three separate things, choose Memorex 3-in-1.
• SOULWIT 40mm — biggest strength: a 32Ω dynamic driver with a stated OEM-like, balanced character, sold as a replacement part for a long list of popular over-ear models. It restores what you already own instead of replacing it.
• SOULWIT 40mm — biggest trade-off: installation requires soldering, and SOULWIT says so plainly. If you don't own an iron or have never opened a headphone cup, this is not a beginner project.
• Memorex 3-in-1 — biggest strength: three complete wireless devices in one box — over-ear Bluetooth headphones with 40mm drivers, true wireless earbuds, and a portable speaker — all on Bluetooth 5.1.
• Memorex 3-in-1 — biggest trade-off: the headphones are rated at about 4 hours of playtime at 50% volume, which is modest for a full day out, and there's no wired jack as a backup.
• Who each pick is for: SOULWIT for tinkerers and owners of broken wired headphones; Memorex for anyone who wants one purchase to cover the whole day.
This is a repair part, not a headphone. What you're buying is a matched pair of 32Ω dynamic drivers with a circular earpiece shape, built to drop into over-ear models across several brands — the QC35/QC45/QC25/QC15/QC2/QC3, AE2/OE2, Studio 2/3/Pro, Solo 2/3/4, Kraken 7.1, K55 and Major II families are all named on the spec sheet. If one channel of your headphones has gone silent, crackly, or noticeably quieter than the other, this is the kind of part that addresses the actual failure instead of sending the whole headset to a drawer.
The 32Ω impedance figure matters more than it looks. It's a common, easy-to-drive value, which is why SOULWIT can describe the output as clear, balanced and distortion-free "like the originals" — the goal here is to match what came out, not to upgrade it. Nobody should buy these expecting a soundstage transformation. You're buying your old headphones back.
In my opinion, the smartest buyer here is the person who already owns one of the compatible models and has opened electronics before. For everyone else, the honest advice is to weigh the effort against simply buying a new pair — and to check the current price on Amazon before deciding, since the math only works if the part is genuinely cheap relative to a replacement.
Memorex 3-in-1: Who It's For
The Memorex bundle attacks the problem from the opposite direction. Rather than fixing one thing, it hands you three: over-ear Bluetooth headphones with 40mm drivers, true wireless earbuds, and a compact Bluetooth speaker. All three run Bluetooth 5.1 with a stated range of about 10 meters, and the box includes three USB-C charging cables, spare earbud tips in S/M/L, and a one-year warranty.
The headphones are the anchor. They use a 40mm dynamic driver covering 20Hz–20,000Hz, with soft padded cushions, an adjustable headband, a 90-degree rotating design and a foldable structure, finished with a rubber-coated, fabric-and-rubber build in blue. They're rated at roughly 4 hours at 50% volume, and they charge in about 4 hours. That's the trade-off to go in with your eyes open: four hours is a commute and a chunk of an afternoon, not a full workday, and there's no headphone jack to fall back on when the battery runs down.
Where the bundle earns its keep is coverage. The TWS earbuds are rated up to 7.5 hours at 50% volume with touch controls, a built-in mic and three tip sizes — that's your gym and running option. The speaker handles hands-free calling and adds USB, TF card and FM inputs, so it works as a kitchen or backyard unit without a phone tethered to it. Everything is wireless, everything pairs the same way, and one set of cables charges the lot.
Who should buy it: a student, a frequent traveler, or a household that wants one audio kit covering desk, gym and living room. Who should skip it: an audiophile chasing the best possible sound from a single pair, or anyone who wants wired reliability. This is a convenience play, and it's a good one — as long as you accept the headphone battery figure as the real ceiling on your day.
Side-by-Side: Which Should You Choose?
• Best for someone who wants zero assembly → Memorex 3-in-1. Nothing to solder, nothing to open, everything pairs over Bluetooth 5.1.
• Best for all-day coverage → Memorex 3-in-1. Between the headphones, the 7.5-hour earbuds and the speaker, you always have something charged and ready.
• Best for long single-session listening → neither, strictly. SOULWIT's drivers are passive and run off whatever you plug them into; Memorex's headphones are rated about 4 hours at 50% volume.
• Best for hands-on hobbyists → SOULWIT 40mm. Soldering is the entry fee, and the spec sheet tells you so up front.
• Best for calls and mixed use → Memorex 3-in-1. Built-in mics on both the earbuds and the speaker, plus touch controls.
• Best for people who already love their current headphones → SOULWIT 40mm. You keep the fit, the pads and the tuning you're used to; only the driver changes.
• Best for a single-box gift or starter kit → Memorex 3-in-1. Headphones, earbuds, speaker, cables and manuals in one purchase.
If I had to pick one, I'd buy the Memorex 3-in-1. Not because it sounds better on paper — the spec sheets can't tell me that — but because it delivers a working, wireless, three-device setup with a one-year warranty and no soldering iron required. In my opinion, that's the safer purchase for most people reading this.
I'd only steer you to the SOULWIT 40mm if you own one of the compatible models, the driver has failed, and you're comfortable soldering. In that specific situation it's the more satisfying buy, because you keep the headphones you already like instead of starting over.
what is 40mm driver in headphones
A 40mm driver is the diameter of the speaker unit inside the earcup — the part that actually turns the electrical signal into sound. In the Memorex bundle, the over-ear headphones use a 40mm dynamic driver covering a 20Hz–20,000Hz frequency range. A larger driver generally moves more air, which is one reason the size gets mentioned on spec sheets.
what are 40mm drivers in headphones
They're dynamic drivers measuring 40 millimeters across, a very common size in over-ear and on-ear headphones. SOULWIT's replacement drivers are also dynamic, but the spec sheet lists impedance (32Ω) rather than diameter, so the two products aren't directly comparable on that number.
which driver is best for headphones
There's no single best size — it depends on the tuning, the enclosure and what you're driving them with. What matters practically is matching the driver to your setup: a 32Ω dynamic driver like SOULWIT's is easy to drive from a phone or laptop, while a 40mm driver in a wireless headphone is paired with its own built-in amplification.
is 40mm driver good for headphones
Yes, 40mm is a solid, widely used size for everyday over-ear listening, and it's what Memorex uses in the bundle's Bluetooth headphones. Whether it's "good" for you comes down to the whole design — cushions, fit, battery and tuning — not the number alone. Check the current price on Amazon and compare the full package before you commit.
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See also: 40mm driver headphones, Cowyawn Kids Headphones vs SOULWIT Cooling Gel Replacement, fast charge headphones