What am I not understanding regarding headphone impedance and compatibility?
I have just ordered one of these cool looking cassette players. The specs say, regarding in-ear headphones and type 1 cassettes, that:
So I asked their chatbot why this is, because I got worried, since I naturally intend to listen to music with my PortaPros and my Sennheiser IE900s. This is what it says:
::: spoiler chatbot conversation
Can I not listen to type 1 cassettes with wired headphones on your cassette player?
The Cassette Player does support wired headphones via its 3.5mm jack for Type I cassettes—so yes, you can listen.
In that case, what does it mean that it's "not compatible with in-ear phones"?
Good question. The Cassette Player has a headphone output that delivers 2 × 2 mW of power at 32 ohms. In-ear earbuds typically have higher impedance or different audio characteristics that don't work well with this output level—the sound would be too quiet or not perform properly.
Wired over-ear or on-ear headphones like PortaPros work fine because they're designed for this type of output.
Does this apply to wired in-ears or wireless in-ears or both?
The incompatibility applies to both wired and wireless in-ear earbuds. The issue is the design of in-ears themselves—their impedance and audio characteristics don't match well with the Cassette Player [Keith]'s headphone output, regardless of whether they're wired or wireless.
Over-ear and on-ear headphones work reliably with the player.
But the portapros have 60 ohm impedance.
You're right—PortaPros have 60 ohm impedance, which is higher than the 32 ohms the Cassette Player [Keith] is rated for. However, the player should still work with them since they're over-ear headphones designed for portable devices.
If you want optimal performance, I'd recommend testing them first or contacting [email protected] for specific compatibility details with your PortaPros.
How much power would the cassette player be able to output at 60 ohms?
That's a good technical question, but I don't have the detailed power output specifications for the Cassette Player [Keith] at 60 ohms—only the rating at 32 ohms (2 × 2 mW).
For precise power calculations at different impedance levels, please reach out to [email protected] and they can help you determine if your PortaPros will perform optimally.
Could you make a text or PDF file out of our conversation or send it to [masked] ?
I'm not able to generate files or send emails directly. For requests like this, please contact [email protected] and they'll be happy to help you with a transcript of our conversation.
:::
How come they're "complaining" about having weak output at 30 ohms, but at the same time tell me they'll be able to drive my 60 ohm over-ears?
https://www.wearerewind.com/en-eu/products/lecteur-cassette-bluetooth-orange-sergeOpen linkView original on piefed.blahaj.zone
13 replies
I think Techmoan has a review of this tape deck. TL; DR: modern tape decks cheap and pricey all use the same substandard mechanism because there is only one manufacturing line left for cassette tape decks. Better to buy a bog standard one from the 90s that supports Dolby noise reduction and metal tape than get a modern one.
Ah, thanks for the headsup! I ordered it because €150 is just about what vintage players with any kind of reassurances go for around here. Perhaps I'll give it some more consideration.
Yes, there will be a noticeable wobble and flutter in the playback of modern decks. Also, they typically don't play back at the correct speed either.
Stop listening to chatbots.
Do you know what impedance you’re in-ears are rated at?
Edit: I checked and Sennheiserr’s website says they are 18 ohms. These in-ears should be screaming loud.
I imagine this company didn’t test in-ears extensively or used something very inexpensive that didn’t work. General rule is lower the impedance, higher the output (when discussing speakers or headphones). Understand, in-ears like those you own are meant to be used by audio pros in possible (likely) loud environments where they need to be loud enough to deliver accurate reproduction of what the user is listening to. They are built with the ability to get VERY loud for a reason.
It’s possible there’s something else in play here that I am not aware of, but my guess would be these will work just fine. Do your in-ears require some sort of power to operate properly? I didn’t see anything that stated that and would be surprised if they did. Should just be a passive transducer circuit.
Says 18 ohms here.
Power = V^2 / R
Lower R means more power required to drive them.
Thanks! In that case, it makes sense to me too, mathematically, but I'm having a hard time visualizing we would need more power for less resistance. I'm a visual learner... 😅 (And an absolute rookie when it comes to the natural sciences.)
The output of the audio amp is a voltage waveform. You can think of voltage as a force that pushes on charges.
In order for the speaker to make sound, you must pass a current through it. Current is the speed the charges move.
I personally don't like the water/pipe metaphor, so instead think of the charge as a car that you're pushing.
If the car is on pavement (low resistance), a force (voltage) applied to it will get it moving at a good clip. Imagine you're the audio amp here and you can feel the pressure on your hands as you push the car at a walking pace.
Now apply that same amount of pressure while the car is stuck in sand. You might imagine you're moving a lot slower.
So for a fixed voltage, higher resistance (sand), means less current (speed).
Now imagine the car is on Teflon skids and just had its bearings lubricated so well that a light push with a pinky is all that's required to achieve the walking pace from before. If you attempt to apply the same amount of force with your hands as before, you will find yourself running and struggling to keep up. In fact, you may find the car moving so fast that you can't even maintain the pressure with your hands.
That pressure x your speed is the power output of your amp. A lower resistance speaker requires a higher power amp that can maintain a higher current without dropping voltage. If voltage drops, the audio waveform will get distorted.
Now bear in mind that speaker resistance is really an impedance that only affects AC waveforms, but for this discussion, we can ignore that.
This explanation is G.O.A.T.E.D. (👈Always wanted try this phrase out.) Are you a teacher or do you "just" have an incredible sense for explaining? :D
Anyway, thank you! Now it makes sense both mathematically and "visually". 😁
Thank you. I used to teach physics to high schoolers on the weekends back in college.
Those specs are nearly useless for you. Just ignore them. Others explained lower headphone impedance means harder to drive; but the porta pros will do fine, any headphones designed for headphone jacks will. Don’t expect a good sound quality though, this type of tape was never any good. You will likely hear hiss and unpleasant noises with sensitive headphones.
Thanks! By "this type of tape", do you mean "type I" as refered to in the screenshot? Nevertheless, I have cancelled the order and decided to keep hunting for an old player. If it'll just need new drive belts, those I can replace by myself, I think. ˆˆ
I mean cassette tapes in general are not a medium I miss.