Nice thought there! But...

...I had a feeling it was something like this.


I've heard your idea work for speakers like Large Advents, though, John.

What is meant by "calibrated"... Each driver takes a different amp fuse?

Then the inline fuse could be the same rating as the lower rated fuse, right? Because if was gonna blow in the fuseholder on the DQ-10's anyway, why would it not blow at the same rating if 1 single fuse was used inline? Do the laws of the electrical universe somehow fail to apply to DQ-10's?

Correct me if I am wrong, but if you put a 3 amp fuse inline, and send 5 amps down the line, it is going to blow, right? So how does this putting an inline fuse, rated at the same amps as the lowest amp fuse that the DQ-10's use for the drivers, fail to provide the same protection as just using the 2 DQ-10 fuses?

I don't get it.

A 3 amp fuse is a 3 amp fuse... it's gonna pop when overloaded, if it's inline before ALL the drivers, or sitting in one of the DQ-10 fuse holders. Please explain how that is more likely to blow ALL the drivers, rather than an indivdual one.

Let's say if for instance you have a 2A fuse for tweeter a 3A for mids and a 5A for woofer.
If you choose to put the lower rated fuse - 2A - inline with the all the three drivers it simply blows, i mean the fuse.
If you choose to put the high rated fuse - 5A - in line with all the speaker drivers, if something wrong happens to the tweeter, where's the the tweeter protection? ...and where's the mids protection? You're only protect the woofer, you can say bye bye to the rest of the drivers...

Don't you have independent circuits at your main electric board at home? Certanly you do not have only one fuse or one circuit braker to all your appliances...
Well, it's the same here.

And, yes it's basic electricity.

Ummm, isn't that what I said? Use an inline fuse rated the same as the lowest rated fuse on the DQ's?

From the wonderful folks at Phasetek:

Q: What is the formula for calculating speaker fuses?

A: Below is a formula from the Series 2 amplifier operation manual. I = fuse value in amps, P = maximum power rating of your speakers, and R = nominal speaker impedance. For example: an 8 ohm speaker rated at 100 watts max would have a fuse value of about 1.75 A (square root of 100/32). You could safely use a 2 A fuse. Use fast acting fuses only. No Slo-Blo or time delay fuses.

Some good reading here about clipping, fuses, transients, etc. Specifically deals with AR speakers, but the rules are the same...

From the good folks at The Classic Speaker Pages website:

http://www.classicspeakerpages.net/library...aker_systems_1/

Now you must calculate with that same formula the other fuse rates for the other speaker drivers. Since each driver have a diferent current load - like emaidel says 3A for woofer and 0.8A for tweeters...for each load we must have a fuse rate.

You can use only one fuse inline if the current load in all the drivers where the same, which i think is not the case here.

And yes, because we are talking about continuous (or "rms" if you must) powers NOT peak power, slow blow type fuses are a pretty good idea for speaker protection.

Btw, even in this case fuses are more cheap than these speakers drivers.

I never said to use the higher rated fuse, the entire point of it was to use the LOWEST rated fuse, which in turn WILL protect ALL the drivers. The mids and woofs, as well as the tweets, would not see any current after the low rated inline fuse pops.

And, I asume that taking the fuse holders as well as thier associated wiring out of the picture, and direct wiring to a single fused lead, would help to eliminate any possible sonic shortcomings that may be caused by having that excess junk in the signal path. One may assume that the cleanest, shor-*test*-('"), simplest path would be the best way to approach this? Seems to be a fairly popular approach among audio enthusiasts.....

The point is rather useless anyway, as a fuse will not protect your speakers from every overload that is possible to be sent to them, but it is far better to have them fused for safety, especially for those that run underpowered amps and don't know when clipping is occuring, that's were most damage occurs.

And thats basic electricity....

You seem to be having a hard time grasping the concept...

If Dalqhuist recomends a 2 amp fuse for the tweeter, and that is the lowest rated fuse for all of the drivers, then a 2 amp fuse, when placed inline, and the other fuses/holders are bypassed, leaving ALL drivers fused to a single 2 amp fuse, then theoretically when the fuse reaches its thermal overload and blows, no current will reach any of the drivers at all.

And as far as your circuit breaker analogy goes, yes, I have a breaker box in my home, with many breakers. However, a single breaker can serve more than one outlet, which in turn can have more than one item plugged into it. Once the circuits overload point is reached, whether it is from one device plugged into the circuit, or from 5 devices, the breaker will trip. The breaker does not care what made it trip, be it a stereo, a washing machine, or a toaster oven. When the amp load is sensed, it trips. If you know the amp draw of the items you have plugged into any breaker protected circuit, and you follow common sense and do not run any combination of items that exceed the load rating of the circuit, you will not trip the breaker. In other words, don't use the toaster oven, the hair dryer, and the bread machine at the same time, plugged into a 15 amp circuit, or you will trip the breaker.

The 2 amp fuse is the same... it will (Should!) trip at its specified rating, regardless of the overload that came down the line, or what is inline after the fuse, the current stops there. The fuse does not care that it may be a tweeter , or a hot-tub that is placed in the circuit path after it. There is no alternative veiw to be voiced on this, when the fuse blows, the circuit path is no longer complete, and I don't think that it can be explained much simpler than that.

Yes, using the formula will give you a net result to protect all the drivers, not just a single driver, but if the tweeter fuse is for example already a 2 amp fuse, please explain to me how more than the rated amperage of the fuse is going to reach any of the drivers?

Using the formula, you may actually end up with a higher recommended fuse rating than the 2 amps for the DQ-10's (Can't tell with having the numbers here...) but the 2 amp should suffice, if a 2 amp was recommended, I would start at a lower amp rating to be safe, and see if I have any issues with the fuse popping at non-clipping levels.

If you do not drive the amps to clipping, barring any other issues, such as failure of internal amplifier components that sends an unavoidable excessive load to your speakers, you should never even have the need for a fuse. Fuses are not 100% capable of protecting your speakers, and can be done away with if you know how to use your equipment. Look around and see the amount of vintage loudspeakers that have survived 40+ years of abuse and neglect without ever having a fuse applied to them.

I do recommend using fuses though, as they may just save your drivers in just about any overload situation that you may encounter, besides the above mentioned excessive unavoidable loads. Even the expensive fuses that are the subject of these posts, are a far cheaper alternative to replacing drivers in most cases.

I'm Spanish but i certainly can read a little English...............

And yes everybody knows at ST that i'm a bit slow................. and a complete zero concerning electricity or electronics, you see i'm a carpenter not an electric engineer.
Believe me i'm doing my best to learn and to understand the basics of this think called sound.....you know, all electromechanical processes where the amplified audio signal must move a cone or other mechanical device to produce sound...i find that so amazing...how is this possible.............?!
I promisse you that i will do my best to understand.

Hey, Paul. I wasn't promoting running fuseless, at least not intentionally. I was just asking questions of people who actually know something on the topic, such as you. I have always marveled at what people will do to machines that perfectly qualified engineers have spent years refining. I know that these gadgets are designed to a certain dollar spec, and are subject to mods that improve them over stock. However, I also buy into the "equal and opposite reaction" theory, and believe that if someone removes the suspension from his car, it's unlikely to handle challenges, like bumps and dips. And if he adds mondo tires without beefing up the suspension, he's in for a world of hurt, too.

I also have a philosophical point. Socrates was a Greek...
No, not that one. I think it's easy to say, "It's JUST fuse, and spending $160 on fuses is exorbitant. But the real question to me is if you have speakers that already sound amazing, and you can enhance the sound by 10-20 percent, what's to lose?

Now the tidbit for perspective: I paid $150 for my DQ-10s a month ago. So, I could approach it from two angles:
--I am going to have a pair of 150-dollar DQ-10s, dammit.
--I only paid 150 dollars for DQ-10s, so I can afford to trick them out to maximize performance.

You know, I'm no pro when it comes to electronics either, and I am (was) in construction for many years as well. I have picked up a few basic skills, but that is about it.

I could be way off in my thinking about the fuses. Now that I understand that the Dahlquists do have a main fuse, and a separate fuse for the tweeter, rather than just fuses for separate drivers, without a main fuse, that may be the best way to go, offering the tweeter a little extra protection with the .8 amp fuse.

The .8 amp fuse would fail at current loads that will pass right through the 3 amp main fuse. I am going to assume that the Dahlquist's tweeter would be damaged by a load greater than .8 amps, and therefore needed to add this protection that would not be covered by the main 3 amp fuse. If they used a .8 amp fuse as a single main fuse, the thing would pop every time you played it at even a reasonable listening level, or less.

Still, I think the best policy is to get an amplifier that produces clean power, and is rated for twice the recommended power handling level of your speakers, and don't turn it up to or past the point of clipping, and you should be able to relax and not worry about it!

Though it's nice to see that this thread has generated some interest, the purpose wasn't to discuss whether or not a fuse is necessary, but that the Hi-Fi Tuning fuses actually improved the sound of the DQ-10, and by a noticeable amount.

If anyone goes online to investigate user comments on these fuses, there is a plethora of posts from people genuinely delighted with the difference these little buggers make, though all of those posts are for electronic components, and not loudspeakers.

I purchased these from thecableco.com, who highly recommended using them in the DQ-10's in the first place. I notified them afterwards of my delight in their benefits, and the response was something like, "people don't realize how much difference something as simple as a fuse can make." And that's the truth, for sure.

Stereophile highly recommended the fuses as a relatively cheap investment, and while $40 for just a fuse seems awfully high, I can't think of anything else approaching such a price that has made such an improvement.

Rather than argue over the need for fuses, or perhaps even eliminating them altogether, why not just buy a few and find out for yourselves?