Quantcast
How to connect inline fuses to speaker cable? - Gearspace.com
The No.1 Website for Pro Audio
How to connect inline fuses to speaker cable?
Old 25th January 2013
  #1
234064
Guest
How to connect inline fuses to speaker cable?

So, I am installing inline fuses (1.5 amp fast blow) on each of my Yamaha NS10 speakers to prevent future tweeter damage.

What I did was cut a 1/4" shielded speaker cable in half so that I have two lengths of cable (one for each speaker).

On one end of a cable I have a 1/4" connector (plugged into a power amp) & on the other end I have two exposed wires (red & black) that I have been running into the speakers.

Ok, so I get that I only need to have a fuse on one of these exposed wires, I'm choosing to do it on the red wire.

Now, the inline fuse I have has an exposed wire on each side of the fuse, so how in the hell do I connect one side of the wire on the inline fuse to the red wire from the speaker cable? Is there a way to do it without soldering?
Is this a radioshack solution & if so what do I need to buy? I have been to told to 'crimp', honestly I don't know what the hell that is or how to do it in this situation, anybody have any tips or links? Thanks

I am a bit clueless about this stuff....
Old 25th January 2013
  #2
Lives for gear
 
Lotus 7's Avatar
Splicing 12 to 20 Ga speaker wire -101

Ideally, you should solder the end of the in-line fuse holder wire to the speaker cable wire and insulate it with some heat shrink tubing (placed on the cable before soldering). As suggested an alternative is to use a "crimped" in-line "electrical butt splice", but that requires the use of an crimping tool. The butt splice must be of the proper size for the wire gauge you are using. If you expect to do more wiring in the future, a crimping tool kit with connectors like the one in the link is a good investment. To use the butt-splice, you strip only 3/16 to 1/4 inch insulation, insert each bare end into the butt-splice and crimp each wire with the tool. If done properly, you should be able to pull strongly on each wire and not have it pull out of the splice. Using the crimping tool properly does take a little practice (mainly to know where the tool should be applied to the splice, and for many is actually more difficult then learning to solder.

Another possibility is to use a solderless wire quick-splice connector. The fully insulated wires (don't strip the ends at all) are placed in the adjacent slots of the connector. The connector metal tab is fully squeezed with a pair of plain pliers and it punctures the insulation and connects the two wires together electrically. The attached cover is then snapped in place to insulate the connection. These come in various sizes for different wire gauges. These are fast, clean, and easy and work well for the relatively low current flowing through speaker lines.

If you don't want to get involved with crimping or soldering, another possibility (although not as "neat") is to use conventional electrical "wire-nuts" The set in the link includes various sizes for all wire gauges. The two wire ends are stripped of insulation for approximately 3/4 inch. Then the two bare wires are twisted together into a "pigtail". Then a "wire-nut" is screwed onto the pigtail. It has an internal tapered coil spring that keeps the two wires connected securely and is insulated to prevent shorts. See example-5 in the drawing below for an example of a pigtail/wire-nut connection.

The least attractive solution, but one that will work if you can't try the others is to simply strip the bare wires, twist them together securely, and then insulate the "splice" by wrapping tightly with some vinyl electrical tape. Not "neat", but if the wires are clean and twisted tightly, will actually work fine.
Attached Thumbnails
How to connect inline fuses to speaker cable?-pigtail-splice.jpg  
Old 25th January 2013
  #3
Lives for gear
 
Frost's Avatar
 
🎧 15 years
This will negatively affect you speakers and not necessarily protect them. If it were this easy Yamaha would implement it in their design.

Can't solder but think you can design protection better than Yamaha? Hmmm.
Old 25th January 2013 | Show parent
  #4
234064
Guest
Quote:
Originally Posted by Frost ➡️
This will negatively affect you speakers and not necessarily protect them.
Care to elaborate on this point....?

A lot of people on this forum use this solution, from what I understand...

I know that most of the time tweeters blow due to a weak amp sending a clipped signal to the speakers...

However the tech I spoke with was a bit concerned that I'm using a 250w per channel amp (Yamaha P2500S) on speakers rated for 25w each. Of course you want an amp with more juice, however he was concerned that any small mistake (feedback, pop/clicks, any surge, etc) could potentially send that whole 250w to the speaker, that there's nothing protecting it... so I mentioned this solution & he seemed to think it would work fine (he's a speaker/amp technician). I looked around & saw a lot of people on here doing 1.5 amp fast blow inline fuses to protect these, so....

**why will this negatively affect my speakers & why will it not necessarily protect them???**
Old 25th January 2013
  #5
Lives for gear
 
Lotus 7's Avatar
Adding a fuse to a passive speaker is the most common way to provide some (not total) protection. A fuse will not protect a speaker from very short duration, high level transients like those caused by plugging/unplugging a mic or guitar pick up with the gain turned up high. It will also not protect the speaker from damage caused by driving a amplifier into "hard" chipping (which produces a high-level of harmonics that can damage the speaker's high-frequency driver (tweeter).

However, the most common cause of speaker damage when being driven from a amplifier with a much higher power output capability than the speaker is rated for is thermal overload cause by simply trying to push too much power through the speaker (playing at too high a level). Fuses are fine to protect from that sort of abuse and are an appropriate solution.

The idea the fuses can adversely affect the sound stems from the fact that it's usually best to provide as low a resistance path between the amplifier output stage and the speaker as is possible. Any significant extra resistance can reduce the damping factor and that may have an effect on the speaker's low frequency resonance peak. The series resistance includes the resistance of the connecting wires, any connector resistance, the resistance of the inductors in the speaker's crossover network. A 1.5 ampere fuse may add an additional resistance of 0.05 to 0.10 ohms to all the resistance in series with the speaker. For an 8 ohm speaker like a NS-10 (which in fact, has a much higher impedance at its bass resonance) the addition of a 0.1 ohm fuse will have a virtually unmeasurable effect, probably less than a few tenths of one dB at resonance. Using a speaker cable that a few meters longer would have a similar effect.

Adding 4 or 6 ohms in series with a speaker (reducing it's damping factor from 50 to 1.5 or 2 will have an audible effect on some speakers. Reducing the damping factor from 50 to 48 through the addition of a fuse is of no concern in the real world. Moving your head a few inches to a different position relative to the speaker will affect the sound more.

The other issue of using a series fuse is that when the fuse is being operated near it's maximum current limit for a long period of time, the fuse element heats up. As the fuse heats up its resistance increases slightly so slightly more voltage is lost across the fuse, reducing the speaker's level by a tiny amount. That's called "dynamic compression" and is touted as a reason to never use a series fuse. In reality, the amount of "dynamic-compression" signal loss is typically less than 0.3 dB and only occurs at a point just before the fuse "blows". Again with a speaker like a NS-10 the addition of the 0.05 to 0.1 ohm of added series resistance (slightly more just before it blows) will not have an audible effect. The effects mentioned are real and can be measured with the right instrumentation. That doesn't mean that in your situation they are anything to be concerned about.

I've routinely used series fuses in installations of 2-ohm M & K subwoofers (which are much more sensitive to amplifier damping than a NS-10) and have never been able to hear any audible effect on the sound.

Yamaha's solution to the problem is to add a caution note specifying use with an amplifier of "50 watts MAX" for the NS10M and "120 watts MAX" for the NS10M Studio. Adding a fuse will help protect the speakers from high average levels, but as Frost correctly stated and I explained above, it will not provide complete protection. You will still have to be careful about clipping and/or short-transient "spikes".
Old 25th January 2013 | Show parent
  #6
234064
Guest
Quote:
Originally Posted by Lotus 7 ➡️
Adding a fuse to a passive speaker is the most common way to provide some (not total) protection. A fuse will not protect a speaker from very short duration, high level transients like those caused by plugging/unplugging a mic or guitar pick up with the gain turned up high. It will also not protect the speaker from damage caused by driving a amplifier into "hard" chipping (which produces a high-level of harmonics that can damage the speaker's high-frequency driver (tweeter).

However, the most common cause of speaker damage when being driven from a amplifier with a much higher power output capability than the speaker is rated for is thermal overload cause by simply trying to push too much power through the speaker (playing at too high a level). Fuses are fine to protect from that sort of abuse and are an appropriate solution.

The idea the fuses can adversely affect the sound stems from the fact that it's usually best to provide as low a resistance path between the amplifier output stage and the speaker as is possible. Any significant extra resistance can reduce the damping factor and that may have an effect on the speaker's low frequency resonance peak. The series resistance includes the resistance of the connecting wires, any connector resistance, the resistance of the inductors in the speaker's crossover network. A 1.5 ampere fuse may add an additional resistance of 0.05 to 0.10 ohms to all the resistance in series with the speaker. For an 8 ohm speaker like a NS-10 (which in fact, has a much higher impedance at its bass resonance) the addition of a 0.1 ohm fuse will have a virtually unmeasurable effect, probably less than a few tenths of one dB at resonance. Using a speaker cable that a few meters longer would have a similar effect.

Adding 4 or 6 ohms in series with a speaker (reducing it's damping factor from 50 to 1.5 or 2 will have an audible effect on some speakers. Reducing the damping factor from 50 to 48 through the addition of a fuse is of no concern in the real world. Moving your head a few inches to a different position relative to the speaker will affect the sound more.

The other issue of using a series fuse is that when the fuse is being operated near it's maximum current limit for a long period of time, the fuse element heats up. As the fuse heats up its resistance increases slightly so slightly more voltage is lost across the fuse, reducing the speaker's level by a tiny amount. That's called "dynamic compression" and is touted as a reason to never use a series fuse. In reality, the amount of "dynamic-compression" signal loss is typically less than 0.3 dB and only occurs at a point just before the fuse "blows". Again with a speaker like a NS-10 the addition of the 0.05 to 0.1 ohm of added series resistance (slightly more just before it blows) will not have an audible effect. The effects mentioned are real and can be measured with the right instrumentation. That doesn't mean that in your situation they are anything to be concerned about.

I've routinely used series fuses in installations of 2-ohm M & K subwoofers (which are much more sensitive to amplifier damping than a NS-10) and have never been able to hear any audible effect on the sound.

Yamaha's solution to the problem is to add a caution note specifying use with an amplifier of "50 watts MAX" for the NS10M and "120 watts MAX" for the NS10M Studio. Adding a fuse will help protect the speakers from high average levels, but as Frost correctly stated and I explained above, it will not provide complete protection. You will still have to be careful about clipping and/or short-transient "spikes".

Ok, thank you so much for this info. I think I'm going to go ahead and install the fuses.

My concerns were A) short transient spikes (mics, guitars, etc.) Which, I guess, common-sense and being careful (turning the amp OFF, or the amp dials all the way down, before disconnecting or connecting ANYTHING to the preamps) are the solution to preventing this.

and B) driving the amp too hard, i.e. turning the speakers way the hell up. I, personally, don't monitor that loud (the dials on the amp are always between 10 and 11 o'clock) however, there might be some people using the amp at sessions I'm not at, that want to drive the things loud, or make that mistake, etc. and I don't want to be out a tweeter because somebody didn't know what they were doing! That's an unpleasant conversation. Thanks Lotus 7, as usual, for the great info. I'm going to now crimp my fuses to my speaker wires and (finally) use them!
Old 25th January 2013
  #7
Lives for gear
 
Lotus 7's Avatar
Just don't get a false sense of security because you have some protection. The fuses will only help in some of the many possible "bad" situations. Also please keep in mind that NS-10s are not the most efficient speakers (at their full rated average levels, being powered by 25 watts (50 watts peak) they're just not that loud. NS-10s can generate a SPL (sound pressure level) of about 103-105 dB [email protected] 1 meter before damage (at about 32 watts RMS). That's a lot less then the 111 dB(SPL) of a Neumann KH-120 or the 113 dB(SPL) of a Genelec 1032. At a reasonable mix/monitoring level of 85 to 90 dB peak, a NS-10 can be driven by only a couple of watts. It's the attempted rock-concert levels that will kill them.

If you have people using them who are trying to duplicate the levels of some of the popular contemporary powered monitors, you're headed for problems with or without fuses.

You'd better show your friends how to change the fuses so you won't know when they crank it up behind your back. You may sleep better.
Old 2nd August 2013
  #8
Here for the gear
 
🎧 5 years
So how did the fuses work out for you? Just interested to see if everything went to plan, or if you've had any troubles or saves from using the new fuses?
Old 2nd August 2013 | Show parent
  #9
234064
Guest
Quote:
Originally Posted by GlennimusPrime ➡️
So how did the fuses work out for you? Just interested to see if everything went to plan, or if you've had any troubles or saves from using the new fuses?
I just got some inline fuse holders from radio shack. some fuses, I forget the ampage, it was either 1.5 or 2.5. not a problem w/ em and cheap solution/safety for them

edit: as far as troubles/saves, never a problem. the speakers had a blown tweeter when i got them (happened in shipping i suspect) so i was a little paranoid about blowing the tweets since that was a $100+ problem, not to mention the paypal woes. however, as far as the new tweeter, no problem, never blown a fuse even. then again i listen EXTREMELY moderately. i never blast the things, EVER. honestly sometimes it's hard to listen to ns10s for hours and hours cuz of the midrange, that's my only complaint, however that's got nothing to do with fuses and it's probably doing my mixes some good!
Old 2nd August 2013
  #10
Lives for gear
 
Fizzyhair's Avatar
 
🎧 10 years
Cheaper option is to trust yourself to just turn the amp down lol :-)
📝 Reply

Similar Threads

Thread / Thread Starter Replies / Views Last Post
replies: 2966 views: 515489
Avatar for jeremy.c.
jeremy.c. 14th August 2020
replies: 698 views: 245534
Avatar for EffinPoop
EffinPoop 2 weeks ago
replies: 64 views: 15042
Avatar for akashpmp
akashpmp 22nd March 2021
Topic:
Post Reply

Welcome to the Gearspace Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…

Forum Jump
Forum Jump