Speaker Basics?

Ghostnuke

Well-known member
Joined
Jul 3, 2010
Messages
4,168
Reaction score
399
Location
Lawrence, Kansas
This is going to sound retarded, but I searched the forums and BR's site and didn't find anything. Is there a newbie's guide to speakers anywhere?

The situation that brings this up for me, is a project I'm currently working on. It's a cabinet that has one speaker in it already, but I'm wiring it to have two. When I was ordering the second speaker, I accidentally got the wrong one. The one in the cabinet already is 8 ohms, 10 watts. The one I ordered is 8 ohms, 15 watts.

Is this a problem, or can I use both at once? How would I have known which speaker to get if there was not one in there already?
 
Shouldn't be a problem. I believe the watts is the max it can handle.

As for which speaker to get if one is missing, th best way would be to check the parts listing in the manual if you can find it, or just ask someone here who has the same cabinet.

Of course, if you are converting the cabinet, then it's a moot point as to what was in there originally.

As for wiring them both up - if you're using a mono setup, then connect the same speaker wires to both. If you are using a stereo setup (board that puts out stereo sound), then you'll have separate wiring for each...
 
This is a Dynamo cabinet, so original parts are right out the window. :p I'm turning it into a Neo Geo wired for stereo. There was one speaker in the cabinet when I got it, looks like a 4x4 maybe. The one I ordered is a 6x9.

This should be ok? I guess the sound might be a little lopsided.
 
Just make sure it's shielded.

The tard that owned my Dynamo cabinet before me put an unshielded one in and it's messed up the picture on the monitor.
 
"modessitt" is correct. It is the MAX power (watts) the speaker can handle before the speaker will start to become damaged. If you want you could put a 100 watt speaker in there. It would just be a waste of money as your amplifier can't put near that much power out.

So... in the end it doesn't matter what size or wattage speaker you put in, as long as it is 8 ohm's and fits in the cabinet (and I think that ohms isn't even really that important, if using a 4 ohm speakers your current to the speaker would just be double, I think home audio is usually 8 ohms, and car audio is 4 ohms).
 
I'm turning it into a Neo Geo wired for stereo. There was one speaker in the cabinet when I got it, looks like a 4x4 maybe. The one I ordered is a 6x9. This should be ok? I guess the sound might be a little lopsided.

Ok, unless your Neo Geo came as stereo (I dont own one, so I dont know) technically you are not wiring it "stereo". Really you are wiring 2 mono speakers. Wiring two speakers alone does not make it stereo, and wiring only one mono. The difference between mono & stereo is that mono plays all sounds with no technical abilities. Stereo means that it is a "smart" system with technical capabilities. For example, lets say you have a left and right speaker set up for stereo. If a man walking down a hall from right to left came through your stereo setup, you'd hear the gradual loudness and fading of his foot steps start from the right speaker, and fade to the left speaker which would gradually get louder. If you have a mono setup, all you would hear is the sound coming out the same, no matter how many speakers you have. I think your neo geo is not capable of stereo. Instead you will have 2 speakers at mono, which is fine ( I have that in my dynamo and it sounds more balanced than just 1 center speaker).

In regards to the lop sided sound, in terms of volume it will be the same. However the quality might sound different. The shape of the driver (the cone part) is what pushes air through a series of pulsing vibrations to give you your sound. The shape of the drivers will push different amts of air, in your case it would be minor, and you would not hear much of a difference. If you do hear a difference, i'm guessing the 6x9 may be more bassy (deep rumble) than the 4x4 because of it's ability to push more air.

Just make sure it's shielded.
The tard that owned my Dynamo cabinet before me put an unshielded one in and it's messed up the picture on the monitor.

What demogo is referring to is shielded or foiled wire. That means there is a layer of foil or some other reflective material on top of the black and red wire to stop outside interference from messing with other electrical components. For example, if you have un-sheilded or non-foiled wire, the current in the speaker wire may pick up or send out signals, resulting in speaker distortion/crackling, monitor picture shaking, humming or buzzing. Were you ever near audio speakers and heard distortion (kind of like a modem sound) about 2 seconds before your cell phone rings? That's what happens with un-foiled wire.
You can identify foiled wire by the following.
You have the outer jacket (out most part of the wire). Now cut the outer jacket open. Inside you will have a 2 wires (typically red and black or white and black). Those 2 colored wires will be wrapped entirely in what looks like aluminum foil. You'd have to peel that foil back like a banana, and inside you'll have your 2 color wires. Unshielded or non foiled wire lacks that foil barrier.

"modessitt" is correct. It is the MAX power (watts) the speaker can handle before the speaker will start to become damaged. If you want you could put a 100 watt speaker in there. It would just be a waste of money as your amplifier can't put near that much power out.

So... in the end it doesn't matter what size or wattage speaker you put in, as long as it is 8 ohm's and fits in the cabinet (and I think that ohms isn't even really that important, if using a 4 ohm speakers your current to the speaker would just be double, I think home audio is usually 8 ohms, and car audio is 4 ohms).

Right. Think of wattage as your reservoir amt before spilling over and causing a problem. On a mono system (stereo is a bit different, and i'll talk about that later if you want in this example) if the speaker is rated for 10 watts, and the most the amp on the game can put out is 6, then you have a safety buffer of 4 watts left over. You only have a problem if the amp puts out more watts than the rating of the speaker. For example if you have the amp pumping out 10 watts and the speaker is rated for 8, then you went over your limit by 2, and the speaker will distort and blow in a matter of time.
If you install a second speaker, you may have to raise the volume because now your amp has to divide up the power to feed 2 speakers. For example if you have a 5 amp game and 2 10watt speakers, now the amp has to divide up the power, so it becomes 2.5 watts for each speaker which is half the power and volume.

If you have a single 8ohm speaker set up now, you can do one of 2 things (Common Solution)

1) You can wire 2 4ohm speakers together in "series" which will give you your required 8ohms. Wiring in "series" is like leap frogging your wires from one speaker to the next.

2) You can wire 2 8ohm speakers together in "series" for a total of 16ohms. It's a 2 times the ohms, but half the "power". Only thing is you may have to turn up your volume a tad.

Your goal is to not go below 8 ohms. That's getting into the danger zone which could happen if you wire in parallel instead of series for this example.

As a beginner do not wire in PARALLEL! Make sure it's in SERIES!

You can see how simple "series" looks in google images. Just search "speakers in series" under google images. You can also see what parallel looks like which is what you don't want.

Is your brain fried yet? :D Take a break and read this again in 10 minutes if you still need to.

I'll be on still tonight or later tomorrow evening if you need more help.
 
Last edited:

Wow, that's a great post. Lots of information! I'll give you my specific plan here, and you can tell me if I'm ok.

What I have is an empty Dynamo cabinet, it just happened that the previous owner left a 4x4 speaker in it. I'm wiring the cabinet for MVS and will be using an MV-1 board in it. It should be capable of outputting stereo from what I've read.

Now, as I said before, I ordered a 6x9 and still have the 4x4 in the cabinet. Still all good?
 
What I have is an empty Dynamo cabinet, it just happened that the previous owner left a 4x4 speaker in it. I'm wiring the cabinet for MVS and will be using an MV-1 board in it. It should be capable of outputting stereo from what I've read.

Now, as I said before, I ordered a 6x9 and still have the 4x4 in the cabinet. Still all good?

I gave a quick read about MVS, and I could be wrong, but looks as if it could have stereo capabilities. I think there are actual NEOGEO forums like KLOV where you could get more specific info on that. I think it's 4" speakers 8 Ohm 5 Watt

Most arcade games are wired for 8ohm setups. I believe only the older ones like Pac-Man, etc are wired to handle 4ohm setups (which would be danger zone for you).

I think you'd be ok for an 8ohm setup. However i'd read any manuals you can find about the boards/slots(?) to confirm.

Ok, so the second part of this question would be. . .

1) Does it say what ohm rating is on the back of the speakers?

As long as both of them are at least 4 or 8 each, you'll be ok if you wire them in "series". Rememer for you it's SERIES!!!!
Try not to mix a 4ohm with an 8ohm. I don't know if it will make a great difference, but it's not how to do things the right way. That's just sloppy home rigging, could cause a long term issue. Try to match the ohms on the speakers like 2-4's or 2-8's. Wattage doesn't matter for matching purposes, just see if you can verify if they both are at least 10w each. Wattage on most speakers is at least 10w. So you'll be most likely fine if you can't find the wattage rating stamp on the back of the speaker since it looks like the NeoGeo MVS output is only 5watts.

Again, do a little research about the MVS ratings to verify. I looked quickly on NEO forums and that's where I got my info on it's specs, so I assume that it's truthful due to my experiences which is how I based my responses to you.
 
Last edited:
Actually I was talking about the speaker being magnetically shielded. If it isn't it'll throw off the colors on your monitor and can cause the effect to be permanent over time.
 
Actually I was talking about the speaker being magnetically shielded. If it isn't it'll throw off the colors on your monitor and can cause the effect to be permanent over time.

Oh ok. I don't have shielded speakers and i'm ok, but I bet that can be helpful too in certain setups. Also speaker placement makes a huge difference if you have that option. Here's a link how to rig a shielded setup if you need it http://www.clothedandy.com/Voight Pipes/shielding.html
 
Last edited:
Both speakers are 8 ohms, so should be ok there. MVS harnesses are made to have two speakers, L and 10 are left and right positive. You can see the difference from jamma here. Can I just run one ground wire up to both speakers and daisy chain them to get stereo?
 
Oh ok. I don't have shielded speakers and i'm ok, but I bet that can be helpful too in certain setups. Also speaker placement makes a huge difference if you have that option. Here's a link how to rig a shielded setup if you need it http://www.clothedandy.com/Voight Pipes/shielding.html

Interesting links. I didn't know the details but became painfully aware of the impact of the unshielded speaker on the monitor.

I just ordered a replacement shielded speaker from Bob Roberts and have been very happy with that one.

I think a lot depends on how close the speaker is to the monitor and with the monitor mounted vertically, it's pretty close -- too close.
 
Both speakers are 8 ohms, so should be ok there. MVS harnesses are made to have two speakers, L and 10 are left and right positive. You can see the difference from jamma here. Can I just run one ground wire up to both speakers and daisy chain them to get stereo?

Ahh ok. So you actually have 2 spots on the harness, 1 pos for each speaker. Then don't series the speakers (I was thinking jamma). Again, don't series the speakers!

Just run one separate positive wire to each speaker positive terminal.

Great question about the neg to neg daisy chain, Im not 100% sure but I can find out tomorrow. You can't daisy chain one negative terminal directly to the other in a straight line without grounding somewhere. You still need an end point ground somewhere like metal (although one may argue that daisy chaining won't make a difference). If you did do daisy chain, make a "Y" connection having 2 ends of the Y, one on each of the speakers negs, and the 3rd/last point of the Y to a common ground somewhere on the metal frame or screw. I don't know if it's safe to tap into the ground on your MVS harness, but if you could that would be a dandy thing. I'd personally run each negative terminal to a piece of nearby metal separately to help handle the load. I'll check tomorrow, maybe it's no big deal.

Just as a bonus tip I personally use 18 gauge foiled wire to handle the load of the speakers for both the positive and ground.
 
Last edited:
Great question about the neg to neg daisy chain, Im not 100% sure but I can find out tomorrow. You can't daisy chain one negative terminal directly to the other in a straight line without grounding somewhere. You still need an end point ground somewhere like metal (although one may argue that daisy chaining won't make a difference). If you did do daisy chain, make a "Y" connection having 2 ends of the Y, one on each of the speakers negs, and the 3rd/last point of the Y to a common ground somewhere on the metal frame or screw. I don't know if it's safe to tap into the ground on your MVS harness, but if you could that would be a dandy thing. I'd personally run each negative terminal to a piece of nearby metal separately to help handle the load. I'll check tomorrow, maybe it's no big deal.

Just as a bonus tip I personally use 18 gauge foiled wire to handle the load of the speakers for both the positive and ground.

I'm thinking I'll run 1 ground wire up and then Y it off so that each speaker is has its own connection to the ground. Would that be better or should I just run 2 ground wires up?
 
Yeah, you can chain the grounds just fine.
Do run a line back to PCB GND.
Don't just connect to a metal part nearby (as it may or may not have a good path back to ground).
I don't really think shielded wire is needed here. If we were talking about a low-level, unamplified audio signal, then yes, use shielded wire. But the amplified output signal? I don't think shielding is needed. If you're worried about EMI, twist the wires on their way up to the speakers.
 
I'm thinking I'll run 1 ground wire up and then Y it off so that each speaker is has its own connection to the ground. Would that be better or should I just run 2 ground wires up?
I'd end it on 1 ground wire after it had been "Y'ed". DarrenF says you need to ground it on the PCB Ground so i'd do that since I personally have no knowledge of the MVS setup. Also like Darren said below foiling may not be necessary, but if you have it available you could use it to be on the good side of the fence (even though it may be overkill).

Yeah, you can chain the grounds just fine.
Do run a line back to PCB GND.
Don't just connect to a metal part nearby (as it may or may not have a good path back to ground).
I don't really think shielded wire is needed here. If we were talking about a low-level, unamplified audio signal, then yes, use shielded wire. But the amplified output signal? I don't think shielding is needed. If you're worried about EMI, twist the wires on their way up to the speakers.
You're probably right. I just always use foiled because it's readily available to me. Murphy's Law says you'll need it after you decide not to initially use it.
 
My knowledge isn't MVS-specific either; just that if the audio signals originate on the PCB, they need to form a complete circuit to the PCB. If they don't provide a specific return path for each audio channel, then I'd assume it to be common with the rest of the PCB ground.

One side note about shielded cable... for it to be effective, connect the metalic foil to ground on ONE END (only) of the cable. Grounding both ends can lead to undesirable ground loops. If an end isn't grounded, it doesn't "do it's thing," acting as a "Faraday cage" around the wires inside to prevent interference.

Note that my opinion regarding the un-necessity of shielded wires to the speakers doesn't extend to shielded speakers. Those may be valuable for a totally different reason: protecting the monitor from the speaker magnet's field if they are sufficiently close.
 
Back
Top Bottom