Tweeter protection fuse question.

CH46E
CH46E Posts: 3,521
I have the RTA12B with the fuse. Does it really matter (as long as the values are the same) what fuse i use? I see some pretty pricey fuses on Partsconnexion.

Thanks

Comments

  • FestYboy
    FestYboy Posts: 3,861
    There ARE audio grade fuses out there, but the most important thing is clean contacts.
  • Schurkey
    Schurkey Posts: 2,100
    Tweeter protection fuses--are they fast-blow or slow-blow? Whichever they are, you'd want the same style in addition to the same amperage/voltage ratings.
  • F1nut
    F1nut Posts: 49,704
    Fast blow.

    If it was me I'd 86 the fuses and adjust the resistor value to compensate.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • CH46E
    CH46E Posts: 3,521
    F1nut wrote: »
    Fast blow.

    If it was me I'd 86 the fuses and adjust the resistor value to compensate.

    Was thinking about that. Just not sure about how to go at it.
  • F1nut
    F1nut Posts: 49,704
    It's easy. Measure the resistance of the fuse out of the block. Cut the leads to the fuse block and solder them to the leads on the new resistor. You may even be able to use the fuse block to hold the resistor. Make sure the resistor/wire leads do not touch anything else. Heatshrink would be a good idea.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • F1nut
    F1nut Posts: 49,704
    FYI.....do not apply heatshrink over the resistor, just the leads.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • CH46E
    CH46E Posts: 3,521
    A simple 10 watt Mills resistor should work once i get a ohm reading on a fuse? Or would the speaker rreally benifit from a higher quality like Deuland carbon or silver resistor?

    Thank you Jesse
  • F1nut
    F1nut Posts: 49,704
    Mills would be perfect.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • delkal
    delkal Posts: 764
    You are not going to be able to measure the resistance of a fuse with a DMM. It will usually read 0.4 ohms but that will be the same reading as when you short the leads.

    A fuse should have very little resistance, A typical one amp fuse will be close to 0.1 Ohms and you shouldn't have to compensate with a resistor. You will be getting more resistance in your speaker cables.

    If you have a polyswitch you are swapping out you usually need to add a 0.5 ohm resistor. But for a fuse you should not add a resistor.
  • F1nut
    F1nut Posts: 49,704
    I disagree.

    The original 3/4 amp 250V fuse out of a Monitor 11 sitting here it has a resistance of 0.6 ohms as measured on my Fluke.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • delkal
    delkal Posts: 764
    edited June 2018
    F1nut wrote: »
    I disagree.

    The original 3/4 amp 250V fuse out of a Monitor 11 sitting here it has a resistance of 0.6 ohms as measured on my Fluke.

    I don't know if fuses age but 0.6 ohms sounds way high. That fuse is even higher than a polyswitch! You should replace it.

    Here is the datasheet on a 1 amp glass fuse. 3/4 amp fuses have higher resistance than a 1 amp but it is typically 0.24 ohms. A one amp fuse is typically 0.19 ohms.

    It is easy enough for the OP to see if he needs a resistor. Just jump it and listen. People spend hundreds and thousands of dollars for speaker wire with a few 10's of an ohm less resistance. So why add it back if you don't need it?

    farnell.com/datasheets/2025718.pdf

  • F1nut
    F1nut Posts: 49,704
    The typical polyswitch used by Polk, which is nothing more than a re-settable fuse has a resistance of 0.5 ohms, so 0.6 ohms for a 3/4 amp fuse is not high.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • CH46E
    CH46E Posts: 3,521
    I did jump the right channel with a 2 strands of cat6e cable. The vocals shifted right. Had to go up 1 db on left and down 1 db on the right to even it out.
  • delkal
    delkal Posts: 764
    edited June 2018
    CH46E wrote: »
    I did jump the right channel with a 2 strands of cat6e cable. The vocals shifted right. Had to go up 1 db on left and down 1 db on the right to even it out.

    Jump both channels and see if you like it. You just got a free 2 db's There is a good chance it will open up your system but not make it too bright.
  • Schurkey
    Schurkey Posts: 2,100
    I'd call a little extra HF a gift from God--at least with my speakers. When I ripped out the polyswitches from my 1Bs, I did not install a resistor, just a jumper--and the top end could use just a bit more volume.

    With the polyswitch, the HF was noticeably lacking.
  • CH46E
    CH46E Posts: 3,521
    edited June 2018
    Thanks for the info everyone. I think ( i have not jumped the other yet) but i have to agree with Schurkey, i could use a little of a brighter upper registry. My ears are not what they used to be. I can hardely hear anything over 15k to 15.5k hz. I used to be able to hear 21k hz. Not no more!

    What? Did someone say something? Im sorry what was that?
  • CH46E
    CH46E Posts: 3,521
    edited June 2018
    I did not know i could adjust the sound on these by simply putting something in place of the tweeter fuse.

    Ive got some other high end wire i may try in there and see what it does.

    I have about a foot of 40% silver wire, some 6% silver wire and several diff types of Audioquest PSC solid copper line.

    Maybe ill make a few jumpers and see if makes a noticeably different sound. Just an experiment??????

    Ill probaby just end up with resistors in there anyways!
  • CH46E
    CH46E Posts: 3,521
    I have a feeling it's going to have more to do with resistance of the material used, versus the material itself?
  • delkal
    delkal Posts: 764
    edited June 2018
    I don't think you will be able to hear the difference with different types of a 2 inch piece of wire. But people can hear anything so who am I to argue.

    What you are hearing (and it should be obvious) is the results of reducing the resistance for the signal going to your speakers from your amp. Just about everyone prefers the sound of larger gauge cables. They claim it opens up the highs and makes their system sound airy. Not many people complain it makes their system sound too bright.

    Check out this resistance calculator. Look up the resistance of a 20 foot piece of 24 ga wire. Its about 0,5 an ohm. Then look it up with 8 ga and its 0.01. About a 1/2 an ohm lower.

    Would you throw out your expensive large gauge cables and rewire your system with 20 feet of 24 gauge cables? That is basically what you are doing if you add a 0.5 ohm resistor.

    https://cirris.com/learning-center/calculators/133-wire-resistance-calculator-table
  • CH46E
    CH46E Posts: 3,521
    edited June 2018
    I unfortunately had to run about 300 feet of quad 16 awg wire for my HT. So i dont even get to use my AudioQuest Bedrock and CV8 cables. Equipment is in a wall cut out i did on the other side of the wall. For the mains i have 4 strands of 16 awg for each terminal. 4 positive and 4 neg. Best i can do for now. Each run is about 50 ft.

    I have been thinking about going back to a system with the equipment in a rack next to the tv so i can use my cables. Plus id be able to give my wife back part of her closet.

    The problem then would be that my dedicated 10 awg power feed on its own circuit breaker would not reach and id have to splice in extra footage and then have to deal with the exterior brick wall that is almost unreachable in the attic due to the slope of the roof.


    Awww, the struggles of a audiophile....
  • F1nut
    F1nut Posts: 49,704
    edited June 2018
    The main benefit of using larger gauge speaker cable is better bass, not treble. However, larger gauge speaker cable isn't all of the equation, far from it.

    By removing the fuse and not compensating for the original resistance of the circuit you are in fact changing the balance of the speaker by making it brighter because that circuit is for the tweeter alone. Now, maybe you think that's a good thing, but I sure as hell don't.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • Schurkey
    Schurkey Posts: 2,100
    F1nut wrote: »
    By removing the fuse and not compensating for the original resistance of the circuit you are in fact changing the balance of the speaker by making it brighter because that circuit is for the tweeter alone. Now, maybe you think that's a good thing, but I sure as hell don't.
    Kinda depends on whether you think the speaker was properly balanced to begin with.

    My 1Bs were lacking in treble from Day One.

    They're still lacking in treble, but not as much.
  • F1nut
    F1nut Posts: 49,704
    Schurkey wrote: »
    F1nut wrote: »
    By removing the fuse and not compensating for the original resistance of the circuit you are in fact changing the balance of the speaker by making it brighter because that circuit is for the tweeter alone. Now, maybe you think that's a good thing, but I sure as hell don't.
    Kinda depends on whether you think the speaker was properly balanced to begin with.

    My 1Bs were lacking in treble from Day One.

    They're still lacking in treble, but not as much.

    I'd have to say it's more a case of how you hear or perhaps you suffer hearing loss. I can't think of one SDA model that lacks treble.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk