Why do so many audio (and video) cables have the same connector on both ends?

June 17, 2009 7:12 PM

Why do so many audio (and video) cables have the same connector on both ends?

After painting our living and installing new floors, I'm putting the whole A/V system back together and started to wonder why almost all video and audio connectors are the same on both ends (usually both male). RCA, coax, hdmi, fiber audio (OK this is probably a technical issue since you probably can't easily join these end to end anyway), maybe svideo I don't have on on hand to check.

There doesn't *really* seem to be an advantage to it, because in most cases a cord goes from an output on one device to an input on another. In the computer world, most cables seem to be male on one and end female on the other (parallel, serial, usb, firewire, vga, ps/2, etc)

The primary advantage of one male/one female is that you can easily make longer cables by joining shorter ones end-to-end. I can't think of any real advantages to both-ends-male. Is there one?

posted by RustyBrooks to technology (24 comments total)

Fewer different machines required to create a cable, leading to cheaper cables.

(also, not having to worry about which end you've just run through a wall - but the main reason has to be simplicity of production)
posted by pompomtom at 7:14 PM on June 17

Because you don't have to worry about which end is which when you run the cabling. Because component manufacturers only have to deal with one type of plug (female). Besides, a male-male plug can just as easily be extended with a male-female cable, which are also readily available.

Also, I disagree with your contention that "most" computer plugs are male-female; nearly all the cables I have are male-male, though I will admit they mostly have a different type of plug on one end (e.g., USB to micro-USB).

Overall, seems pretty arbitrary.
posted by rkent at 7:17 PM on June 17

Also, I disagree with your contention that "most" computer plugs are male-female; nearly all the cables I have are male-male, though I will admit they mostly have a different type of plug on one end (e.g., USB to micro-USB).


What? Almost all USB devices that I know of connect to the USB port of a computer using a male to female cable. You can connect them end to end or in a circle. A lot of USB cables do have different ends though, for a reason I don't fathom (speaking of the square instead of rectangle that a lot of printers, etc use, not the micro ones which are small for a reason)

Although you can GET female-to-female computer video cables, standard use from computer to monitor is male to female, same with parallel, serial, and firewire. I can't think of any computer cable that the normal usage (to connect a device to a computer) involves a male to male or female to female.

The cabling reason does make some sense
posted by RustyBrooks at 7:24 PM on June 17

Meh I might be wrong about USB, a brief survey of my cables is about half and half. The only usb devices I actually use are printers and I guess those would both be considered male, of different types.
posted by RustyBrooks at 7:26 PM on June 17

Really, look again at your cables. The DVI and FireWire cables I have right here are male on both ends, and they're totally standard.
posted by xil at 7:31 PM on June 17

What? Almost all USB devices that I know of connect to the USB port of a computer using a male to female cable. You can connect them end to end or in a circle. A lot of USB cables do have different ends though, for a reason I don't fathom

They're called A and B plugs and the small ones are Mini-B. They also have a Micro A and Micro B.

(Wikipedia link)
posted by delmoi at 7:42 PM on June 17

How would a female coax on a device even _work_?

I think the male end is more likely to break, and therefore better to attach to the cheaper, more replaceable part (the cable.)
posted by blenderfish at 7:43 PM on June 17

USB is different than a lot of cables. They use the shape to enforce power constraints; A plugs supply power, B plugs draw up to like 500 mA (USB 2.0). The point is you can't even try to connect a B device to a B device. In that sense, they are nearly all different connectors. If you try real hard you can get some A-A, but they violate the spec.

The question is, why do you want to partition devices like that? Home audio has no power constraints on it, and you'd either have to carry an assortment of cables or just rule out connecting your dvd player to your stereo directly.
posted by pwnguin at 8:02 PM on June 17

Also, a gender changer is very common among the PC technologies you mentioned. And you can get them for A/V cables too.

So basically, it's a matter of what's more common and using gender changers for the less common of: extending cable length, or connecting anything to anything.
posted by pwnguin at 8:09 PM on June 17

I can't think of any real advantages to both-ends-male.

Because a female end needs a housing to enclose it, and a male end doesn't. So the female end is more natural to be on the component side, which already has a "space" that the femal end can sit in.
posted by smackfu at 8:14 PM on June 17 [1 favorite]

One male/one female cables do let you make longer cables by connecting them together, but the primary reason they are built this way is to prevent you from connecting an input to an input or an output to an output. Depending on what the cable is being used for, considerable amounts of current may be flowing through the connectors and could damage the equipment its connected to. In contrast, with most audio/visual cables, nothing bad is probably going to happen if you connect an RCA output to another RCA output; it's not going to work, but it's unlikely to blow out your device so they save the expense of two different connectors.

Also, having the female socket on the device side makes it easier for one jack to serve multiple purposes (e.g. 3.5mm mono/stereo, Speakon + 1/4" combo jacks etc...)

Note that pro audio does use separate male/female connectors on each end for XLR cables, which may often need to be extended in a hurry.
posted by zachlipton at 8:19 PM on June 17

Network cables are all male-male- RJ45, RJ11, coax, & fiber optic. So is the ipod sync cable. And adding to smakfu's comment, putting the female end on the component makes it easier to have a smoother, flush-mount case.
posted by TDIpod at 8:53 PM on June 17

most cables seem to be male on one and end female on the other

And you'll notice too that computer cables (at least the older formats) have screw-in posts in an attempt to minimize bent pins and the like.

There was a time when A/V equipment was considered "consumer" or for "at home" use while computers and the like were relegated to labs and industrial settings. Consumer form factors needed to be more user friendly, less prone to damaging hardware if tripped over or ripped out and bi-directional. Not so with VGA, serial, parallel cables and the like.

By comparison, check out older pro-level A/V equipment. You'll see the same computer-style treatment of the ports and cables along with uni-directional ends.
posted by wfrgms at 9:20 PM on June 17

Not to derail, but can I just register dislike for the "male/female " convention in naming cables? I'm sure it's old and all, but it just seems weird when we say it over and over. Maybe it should be "innie" and "outie"?
posted by Mngo at 10:31 PM on June 17

Good lord, I suppose you'll also take issue with my outboard digital convertors slaving themselves to the master word clock?
posted by Aquaman at 10:45 PM on June 17 [2 favorites]

Because a female end needs a housing to enclose it, and a male end doesn't.

This.
posted by lekvar at 11:12 PM on June 17

Not to derail, but can I just register dislike for the "male/female " convention in naming cables?

Here's an anecdote that might help you understand why this is a useful way to term the connector types.

Back in the early 90s, I worked on a crew that shot television coverage of sporting events. Part of our setup routine involved running long, heavy camera cables, 100' or more in length, throughout the facilities we were shooting in.

Unlike your standard consumer grade gear, the camera cables had a male connector at one end and a female connector at the other. The connectors themselves were very large, very expensive, and prone to damage from bent pins. A nice benefit to the male/female pairing on each cable was the ability to lock each cable's ends together to prevent pin damage during transit and handling.

However, it made for a very, very frustrating experience if you ran 600' of cable through a building, taped it down, and then discovered you'd ran it in the wrong direction. That's the kind of mistake you'd make once, and only once, because as soon as you did it some more experienced guy would walk up to you, clap his hand on your shoulder, and say "Fuck the truck."

That mnemonic was all you'd need¹; from that day forward you'd always remember that the truck would always have a female connection on it, and you'd always be running the male end of the cable into it. Even if you weren't hooking into a truck, you'd always know that the male end of the cable would go into the recording/transmitting equipment. If you visualized the signal as traveling down the cable, the female connector would be the input and the male connector would be the output. Not just for camera cables, either; the audio cables (with XLR connectors) work that way, too.

¹if you were a guy, anyway
posted by davejay at 2:04 AM on June 18 [3 favorites]

Because a female end needs a housing to enclose it, and a male end doesn't.

Depends on the connector type. The XLR connections I noted above are an example where this isn't true; a microphone has a male connector embedded in it, the mixing board will have a female connector embedded in it, and the cable will have one of each type.

I actually believe the reason consumer (ie cheap) gear uses one connector on the gear and another on the cable is for manufacturing efficiency: your cabling assembly process only need to be stocked with/built to assemble one type of connector, and the same applies for your circuit board assembly process. That the cables typically get male and the equipment typically gets female is likely a one-two punch of an inevitable drift towards standardization coupled¹ with the undeniable truth that male connectors break more easily while wires are cheaper to replace than equipment.

¹pun totally intended
posted by davejay at 2:12 AM on June 18

Er, forgot to add: whereas cheap consumer gear is built to efficiency, pro gear is typically used in a scenario where rapid, secure cable extensions need to be done (someone else mentioned this above), and the additional manufacturing cost is offset by that tangible benefit. Hence camera cables and XLR cables have male/female, and RCA and 1/4" and 1/8" cables have male/male.
posted by davejay at 2:15 AM on June 18

I'll wager an explanation for one.. the "F" connector used to pipe RF, such as that appearing on your cable box.

The male part of that connector is actually just the rigid center conductor of the cable. It has zero incremental cost and can be 'placed' anywhere along a cable. This isn't true of audio cables (e.g., RCA phono plugs/jacks), but boy, for RF cables it means fractional cents times billions of cables. A billion times anything is significant.

These cables are the type that are routinely customized for length, and an adjustment method that doesn't require solder or precision crimping is a good thing.

Again, economics appears in an engineering decision, where it often gets top billing.
posted by FauxScot at 4:13 AM on June 18

Its a design issue. Do you want to want to have a male jack sticking out of a device? Sure you could recess it, but then it would take up more internal space than a female jack.
posted by JJ86 at 6:02 AM on June 18

I know it's just linking to Wikipedia, but did you know they had an article on gender of connectors and fasteners?

It mentions out that in any case where you have dangerous levels of power, anything attached to the power source must expose female ends for safety. So the wall jack must be female, and the end of the cord must be female, so you end up with male-female cables.
posted by smackfu at 6:43 AM on June 18

can I just register dislike for the "male/female " convention in naming cables?

Noted. But if this nomenclature had been abandoned, I would never have had that amusing and very enlightening conversation with my father. You farm boys see it happening all the time but models for us city kids used to be uncommon. For me, connector gender was the beginning of a critical 'birds and bees' discussion.
posted by Rash at 10:44 AM on June 18

USB is different than a lot of cables. They use the shape to enforce power constraints.

Also electrical signalling and protocol constraints. USB always has a host at one end (the A-connector) and a device at the other end (the B-connector). The connector keying ensures that users can't accidentally, or deliberately, connect host-to-host or device-to-device.
posted by We had a deal, Kyle at 6:09 PM on June 19