# Tweeter Caps



## jimjam (Oct 5, 2009)

Searching some ms8 info. I came across "capacitor protection for tweeters in an active setup." I am surprised at what a universal standard this practice is and in the tons of reading I've done here in 2 yrs., I only barely recall stumbling on this issue before. I've never had any popping issues before but I just hooked up my ms8 (haven't turned it on yet) and I've read some popping issues associated with it (remote turn on delays etc.). Now, I am properly scared of having to pour further amounts of money into the enormous bottomless pit that has been my excursion into a good system to replace my L1 pros.

My system now lingers in limbo (off!) until I can protect myself, I suppose. I'm still just a novice to stereo tech. and I don't know crap about no cap. I've always searched FIRST and learned everything I've needed but, I really do not want to learn capacitors and all the associated nominclature (language of electronics) I'd need to feel confident I have it right. Then I'd have to order it and wait, damn!

Can some kind soul recommend the right size capacitor for me? I would like it to be far enough below my xover with minimal slope to have negligable effect on sound. I'm planning a cross at 4khz @ -24db with power at (below) 75w @ 4ohms. I wouldn't mind the freedom to play with a hi pass as low as 2.5khz. Bipolar, special materials, $5 or $15, Idk it's only two items. Could I get them from Radio Shack?

Finally, a cap goes in the pos+ wire on the tweet, right? Should it be close to the amp or to the speaker?

I'm sorry to ask this for an answer that surely exists here, in the forum but I'm going to be driving a lot this weekend and would hate to listen only to exhaust note the whole time while shipping my caps takes til next week.

thanks


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## dragonrage (Feb 14, 2007)

Get a non-polarized capacitor. A polarized one will work in either direction as long as there is no significant DC component to the amplifier - which there shouldn't be, but that's one of the protections that using the capacitor offers in the first place. It also helps protect against you accidentally hooking up the wires wrong (e.g. sending a woofer signal to a tweeter) or using the wrong filter frequency (e.g. 400Hz instead of 4kHz). It also helps prevent the tweeter from being damaged if you enter clipping because clipping redistributes the power into different frequency ranges than the non-clipped signal would be. It will not improve the sound quality when things work properly.

Passive Crossovers, Capacitor and Coil Calculator

Fill in the impedance and frequency; the value you want is C1 in the first-order crossover section.

Keep the frequency a good bit lower than the frequency you use in the MS8 or else you will audibly affect your sound with it. The lower you go, the less protection it offers, but the higher you go, the more audible and limiting it will be as far as changing things later - though you can always change the capacitor as well...

Another protection option: fuses or speaker circuit breakers from Parts Express. They don't offer the same exact protection as a capacitor but they also aren't as audible since they don't have much capacitance or inductance to modify the signal by a significant amount. (They do have a little bit of reactance - pretty much anything does - but again, much less than a capacitor as a capacitor is specifically meant to have reactance)


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## MadeByMonkey (Aug 31, 2010)

I suggest using the crossover on your Kenwood KAC-X4R to protect your tweeters because you already have it. I hate to break it to you but a cap is going to be completely useless if your MS-8 spazzes out and sends a full range signal to your tweeter.


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## sqshoestring (Jun 19, 2007)

MadeByMonkey said:


> I suggest using the crossover on your Kenwood KAC-X4R to protect your tweeters because you already have it. I hate to break it to you but a cap is going to be completely useless if your MS-8 spazzes out and sends a full range signal to your tweeter.


This is not true, the cap will keep DC power and low frequency out of the tweeter no matter what you send it....that is why people use them. An active xover will not protect the tweeter from what the amp sends such as a turn on pop or blown amp outputs, or anything else that could make the amp send those signals to the tweeter. Sometimes a failing ground can cause an amp to emit strange signals. The caps themselves cost nearly nothing, calculators are all over the net to tell you what ones you need, all you have to do is put them inline at the tweeter though you could put them anywhere after the amp far as I know.

You can still overdrive the tweeter and blow it up with normal high frequency the cap will pass to it. Some passive xover use a light bulb for this as it naturally limits with more current and does not blow like a fuse. However I don't know how you size a tiny lightbulb for that purpose, but it will limit power of any kind. DC might still blow the tweeter eventually with a lightbulb and no cap because it is constant full power, it would heat more than an alternating current from audio, at least at same peak voltage. Also DC makes no sound from the speaker so you don't know it is happening unless you see the cone stay in/out in its physical movement and that is hard to do with say, a dome tweeter.


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## MadeByMonkey (Aug 31, 2010)

sqshoestring said:


> This is not true, the cap will keep DC power and low frequency out of the tweeter no matter what you send it....that is why people use them. An active xover will not protect the tweeter from what the amp sends such as a turn on pop or blown amp outputs, or anything else that could make the amp send those signals to the tweeter. Sometimes a failing ground can cause an amp to emit strange signals. The caps themselves cost nearly nothing, calculators are all over the net to tell you what ones you need, all you have to do is put them inline at the tweeter though you could put them anywhere after the amp far as I know.
> 
> You can still overdrive the tweeter and blow it up with normal high frequency the cap will pass to it. Some passive xover use a light bulb for this as it naturally limits with more current and does not blow like a fuse. However I don't know how you size a tiny lightbulb for that purpose, but it will limit power of any kind. DC might still blow the tweeter eventually with a lightbulb and no cap because it is constant full power, it would heat more than an alternating current from audio, at least at same peak voltage. Also DC makes no sound from the speaker so you don't know it is happening unless you see the cone stay in/out in its physical movement and that is hard to do with say, a dome tweeter.


So you are saying that all those drivers roasted as a result of tripping BitOnes and MS-8s would have been spared had the end user placed a simple cap in the circuitl? A simple cap protecting a tweeter at 400 Hz versus 4kHz as the Op wishes to do will still allow enough damaging frequencies through to roast the tweeter.


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## minbari (Mar 3, 2011)

MadeByMonkey said:


> I suggest using the crossover on your Kenwood KAC-X4R to protect your tweeters because you already have it. I hate to break it to you but a cap is going to be completely useless if your MS-8 spazzes out and sends a full range signal to your tweeter.


worst response ever! nothing here is true, please do not listen to any of it. 

listen to what shoestring said.



> So you are saying that all those drivers roasted as a result of tripping BitOnes and MS-8s would have been spared had the end user placed a simple cap in the circuitl? A simple cap protecting a tweeter at 400 Hz versus 4kHz as the Op wishes to do will still allow enough damaging frequencies through to roast the tweeter.


in most cases yes. although it may sound really bad, it will not instantly destroy a tweeter like a burst of DC or an electronic crossover on the blink would. for me personally I would not use 400hz for protection for a 4khz tweeter. if you are running a 4khz 24dB/oct slope, then an additonal 6db/oct at 2khz wont mess up your slope and 2khz should protect the tweeter against most any damage.


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## jimjam (Oct 5, 2009)

dragonrage said:


> Get a non-polarized capacitor. A polarized one will work in either direction as long as there is no significant DC component to the amplifier - which there shouldn't be, but that's one of the protections that using the capacitor offers in the first place. It also helps protect against you accidentally hooking up the wires wrong (e.g. sending a woofer signal to a tweeter) or using the wrong filter frequency (e.g. 400Hz instead of 4kHz). It also helps prevent the tweeter from being damaged if you enter clipping because clipping redistributes the power into different frequency ranges than the non-clipped signal would be. It will not improve the sound quality when things work properly.
> 
> Passive Crossovers, Capacitor and Coil Calculator
> 
> ...


Thanks dragonrage, heading to the calculator momentarily. Does "non-polarized" (doesn't work in either direction?) mean it should be in the pos+ only?

Thanks as well, to everybody else for the continued discussion, it's all been helpful!


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## t3sn4f2 (Jan 3, 2007)

POLYPROPYLENE CAPACITORS from Parts Express ship same day and come with 45 day money back guarantee. Free Shipping Available. Order free 10,000 product catalog.


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## minbari (Mar 3, 2011)

jimjam said:


> Thanks dragonrage, heading to the calculator momentarily. Does "non-polarized" (doesn't work in either direction?) mean it should be in the pos+ only?
> 
> Thanks as well, to everybody else for the continued discussion, it's all been helpful!


no nonpolarized means is has no polar direction (meaning it does not have a positive or negitive) you must get those kind for audio since you are using them with an AC signal.


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## gokiburi (Jul 20, 2007)

jimjam said:


> I am surprised at what a universal standard this practice is and in the tons of reading I've done here in 2 yrs., I only barely recall stumbling on this issue before.


Same here. *Now* I know how essential this is when running active, from my own tweeter destruction experience. I guess this topic is just not as exciting as sound deadening or whether Class D amps sound worse than A/B.  Live and learn, I guess.


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## jimjam (Oct 5, 2009)

Just to be certain here, the capacitor should be spliced directly in the pos+ wire?


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## jimjam (Oct 5, 2009)

t3sn4f2 said:


> POLYPROPYLENE CAPACITORS from Parts Express ship same day and come with 45 day money back guarantee. Free Shipping Available. Order free 10,000 product catalog.


Is this a non polarized cap? I noticed at PE they list caps that specifically are called "non polarized".


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## gokiburi (Jul 20, 2007)

jimjam said:


> Just to be certain here, the capacitor should be spliced directly in the pos+ wire? Is this a non polarized cap? I noticed at PE they list caps that specifically are called "non polarized".


You can splice it in on either lead. And yes, those are non-polarized.


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## minbari (Mar 3, 2011)

jimjam said:


> Is this a non polarized cap? I noticed at PE they list caps that specifically are called "non polarized".


I would hazard a guess and saw all the caps sold on Pe are non-polarized style.

and yes, polypropylene caps are certainly of that variety.


as gokiburi said, you can put it in either wire and it will be put "inline"


-------------[]-------------
like that


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## gokiburi (Jul 20, 2007)

They are indeed nonpolarized, I went to Solen's website to be sure. I don't want to lead anybody wrong.


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## sqshoestring (Jun 19, 2007)

You need non-polarized because the AC audio signal changes polarity all the time.

I size the cap to the lowest the tweeter should play, if you tweeter can go to 2K you may or may not (usually not in my case) run it that low, so I would size the cap for a 2K high pass. (This will give you -3dB at 2Khz, or 50% power there) I like to use larger dome tweeters. Its only a 6dB slope so it does not cut like higher slope does, you should make it high as you can. Your active xover will add its slope to this passive, once you get down to it, if you do. Yes it is still possible to blow the tweeter because if somehow you have no xover on it then it will be at its lowest xover (say 2K HP at 6dB). But if you get a pop or DC it will protect it, some failures you will hear it and turn it off, etc....so it is way better than nothing.

It is typical to put it on the tweeter +, but since it is AC power you don't have to.

Home speakers have always used caps, though some use second and better order xovers that have higher slope than just a simple cap. Most coax and some comps use only a cap on the tweeter for the xover it is very common.

Any capacitor that is polarized should have a big arrow on the side showing what lead is what: + or -. Non polarized do not.


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## jimjam (Oct 5, 2009)

gokiburi said:


> You can splice it in on either lead. And yes, those are non-polarized.


thanks


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## jimjam (Oct 5, 2009)

gokiburi said:


> They are indeed nonpolarized, I went to Solen's website to be sure. I don't want to lead anybody wrong.


much appreciated!


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## jimjam (Oct 5, 2009)

sqshoestring said:


> You need non-polarized because the AC audio signal changes polarity all the time.
> 
> I size the cap to the lowest the tweeter should play, if you tweeter can go to 2K you may or may not (usually not in my case) run it that low, so I would size the cap for a 2K high pass. (This will give you -3dB at 2Khz, or 50% power there) I like to use larger dome tweeters. Its only a 6dB slope so it does not cut like higher slope does, you should make it high as you can. Your active xover will add its slope to this passive, once you get down to it, if you do. Yes it is still possible to blow the tweeter because if somehow you have no xover on it then it will be at its lowest xover (say 2K HP at 6dB). But if you get a pop or DC it will protect it, some failures you will hear it and turn it off, etc....so it is way better than nothing.
> 
> ...


I'm looking at a 24uF. It covers 1500hz. My L1s have a resonance of 700hz. Doubled that's 1400hz. I've have had a good setup with my tweets crossed in the 2khz range before. Buwalda has made a convincing argument that this is a bad area to split up the vocals range but, I would still like the ability to play with it w/o interference. Opinions...


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## minbari (Mar 3, 2011)

I have heard many systems systems that were crossed at 2-2.5khz and sounded very nice. if you have an EQ, you can usually compensate, some, for the filter.


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## jimjam (Oct 5, 2009)

minbari said:


> I have heard many systems systems that were crossed at 2-2.5khz and sounded very nice. if you have an EQ, you can usually compensate, some, for the filter.


Am I getting into an increasingly dangerous zone to only block (by capacitor) 1500hz and below? Am I at a point of increased diminishing returns in this area? That is, is 2khz much, much more protection than 1.5khz or are they pretty close?


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## wooferdog (Mar 31, 2011)

don't a cap at 6db change the phase 90 degrees?


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## jimjam (Oct 5, 2009)

wooferdog said:


> don't a cap at 6db change the phase 90 degrees?


I think it's supposed to be low enough below the xover point that it is negligible but then again, that's my limited understanding.


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## Sarthos (Oct 29, 2010)

I'm too lazy to do the calculations, 90 degrees sounds high though, pretty sure that occurs at a frequency low enough to not matter.


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## dragonrage (Feb 14, 2007)

wooferdog said:


> don't a cap at 6db change the phase 90 degrees?


Up to 90* depending on the filter itself. But I'm not one to claim that you can hear such a change. It's certainly not ideal but oh well. You can use an all-pass circuit to modify the phase if you want. Linkwitz recommends that. In fact, he considers it a requirement.


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## minbari (Mar 3, 2011)

wooferdog said:


> don't a cap at 6db change the phase 90 degrees?


yes, everything above the crossover point will experience a phase shift around 90° in general. as dragon said, you wont hear it though. plus with your MS8, the T/A abilities will compensate for it.


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## chad (Jun 30, 2005)

minbari said:


> yes, everything above the crossover point will experience a phase shift around 90° in general.


negative.. it "keeps shifting"


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## minbari (Mar 3, 2011)

I assume the tuning freq is 1 hz in that example?


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## chad (Jun 30, 2005)

why not, I need to tune low to get mad dee beez.

I was going for graph shape, it's only 90 degrees out at the -3 point, and only at a first order (series cap,) and in reality it's only 90 out of a driver with a like LPF


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## dragonrage (Feb 14, 2007)

minbari said:


> I assume the tuning freq is 1 hz in that example?


It's a relative graph. You can choose any center point you want. You can make the "1" 2500Hz and then modify all the surrounding numbers in the appropriate way if you want.


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## minbari (Mar 3, 2011)

dragonrage said:


> It's a relative graph. You can choose any center point you want. You can make the "1" 2500Hz and then modify all the surrounding numbers in the appropriate way if you want.


understand completely. just making sure I was looking at it correctly.


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## chad (Jun 30, 2005)

I like the 1 Hz thing.

Keeping with the theme of 1% 

One is the number of 2011.


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## sqshoestring (Jun 19, 2007)

jimjam said:


> I'm looking at a 24uF. It covers 1500hz. My L1s have a resonance of 700hz. Doubled that's 1400hz. I've have had a good setup with my tweets crossed in the 2khz range before. Buwalda has made a convincing argument that this is a bad area to split up the vocals range but, I would still like the ability to play with it w/o interference. Opinions...


I usually play with the system and if it bothers me I get a larger cap to move it down. If I never go down there I put a smaller cap on after some tuning. If you are going to run the tweeter rock bottom and make it lower it will offer less protection for over driving, but you do what you need to do, it will still help and help with other issues like a blown amp/etc. 

Note a xover is -3dB at that frequency if your impedance is right, so it is cutting at that point (say 2K) you would need it lower to not cut there. You can check them with tones to figure out where its at, and really it does not have to be exact anyway. Make sure you do check with tones to make sure its working.


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## jimjam (Oct 5, 2009)

I'm so proud, a query I began evolved into this wonderful technical discussion. Let me just dumb it back down a little though.

I have some 20uF caps coming. I just want be sure I don't ruin them. I plan to solder them on the pos+ line to my tweets (behind the plastic interior door panel/card). Any problem with soldering? Sometimes I can get a wire a little heated up when I solder. Risk of burning up cap?


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## minbari (Mar 3, 2011)

as with any soldering job. make sure the iron is hot enough for the job, but not overly hot. (you dont need a 100watt iron set to 900°) get the work hot quickly, solder it and get the heat off. caps are pretty forgiving when it comes to heat, but you dont want to melt them, lol.

if you are really worried about it, get a clip on heat sink and clip it on the lead as close to the cap as posible. this will keep heat from getting into the cap itself.


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## jimjam (Oct 5, 2009)

minbari said:


> if you are really worried about it, get a clip on heat sink and clip it on the lead as close to the cap as posible. this will keep heat from getting into the cap itself.


Good idea, thanks


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## chad (Jun 30, 2005)

My schematic that I use that has never lost a tweet.... (or horn driver for that matter)

Amp------------------------------------->Tweeter

(+)----------------------------------------(+)

(-)-----------------------------------------(-)


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## mmiller (Mar 7, 2008)

Great info guys!!!


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## jimjam (Oct 5, 2009)

chad said:


> My schematic that I use that has never lost a tweet.... (or horn driver for that matter)
> 
> Amp------------------------------------->Tweeter
> 
> ...


?

that is a diagram of just a wire from amp to tweet with nothing in between?


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## Jroo (May 24, 2006)

So on my infinity ribbons, I have been told several times to think about a cap on these. These would be xover somewhere around 8k to 10K, so I would look for a cap around 6k? I want to limit anything from getting into the tweeter that is lower than they truly like.


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## minbari (Mar 3, 2011)

Jroo said:


> So on my infinity ribbons, I have been told several times to think about a cap on these. These would be xover somewhere around 8k to 10K, so I would look for a cap around 6k? I want to limit anything from getting into the tweeter that is lower than they truly like.


for protection purposes, yes. 2-3x lower than your crossover point. if you have a steep slope, then you can lean closer to the 2x mark.


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## chad (Jun 30, 2005)

jimjam said:


> ?
> 
> that is a diagram of just a wire from amp to tweet with nothing in between?


that would be correct.


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## gokiburi (Jul 20, 2007)

chad said:


> My schematic that I use that has never lost a tweet.... (or horn driver for that matter)
> 
> Amp------------------------------------->Tweeter
> 
> ...


I would have said the same thing two months ago. Now, though, that is the schematic that has been successful in protecting my tweeters 80% of the time.


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## chad (Jun 30, 2005)

I have used thousands upon thousands of HF units without tweeter caps in an active setup without fail.....

Like every touring rig I have ever touched and everything else before it... for the past 20+ years. I suspect that goes beyond luck....


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## gokiburi (Jul 20, 2007)

I don't doubt it. I suspect you use better gear than me! :laugh: I never had any issues with my old school amps running active, but in this day and age, I'd say if someone buys a 125x4 Maxxsonics (or similar ilk) amp for $200, they might as well kick in a few extra $ for some caps. Or just stick to better, well-behaved, gear.


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## sqshoestring (Jun 19, 2007)

chad said:


> I have used thousands upon thousands of HF units without tweeter caps in an active setup without fail.....
> 
> Like every touring rig I have ever touched and everything else before it... for the past 20+ years. I suspect that goes beyond luck....


Yes but some people f things up more than you, or have 'friends' that do it for them, or have amps that do it, or make a mistake, or use a tweeter that can't take any extra abuse, or..... Sometimes I don't know how people blow up so much stuff as I never blew up much but it has happened. I learned to do that a long time ago when I installed, and so I just do it...but rarely run active tweets anymore. I'd rather swap tweets and change the install until I can get what I need, then have one less amp and wires in the car. I'd much rather have an active midbass amp than a tweeter amp. I'll try to install the tweets next to the mids for better TA and such.


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## jimjam (Oct 5, 2009)

sqshoestring said:


> Yes but some people f things up more than you, or have 'friends' that do it for them, or have amps that do it, or make a mistake, or use a tweeter that can't take any extra abuse, or..... Sometimes I don't know how people blow up so much stuff as I never blew up much but it has happened. I learned to do that a long time ago when I installed, and so I just do it...but rarely run active tweets anymore. I'd rather swap tweets and change the install until I can get what I need, then have one less amp and wires in the car. I'd much rather have an active midbass amp than a tweeter amp. I'll try to install the tweets next to the mids for better TA and such.


It was probably statements from authoratative folks like yourselves that reassured me, earlier in my learning, that I'd be ok w/o protection. Probably that, as well as, my speakers, at the time, cost a good bit less. My renewed consideration comes by way of the ms8. It just seems I've come across a number of people blaming the ms8 for blowing their speakers with only, various speculations for the causes. Though, it would be an excuse for some of those pretty looking L1 pro R2's, I just can't pour more RIDICULUS amounts of $ after what all started with a fairly simple goal of "a nice stereo".


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## Fricasseekid (Apr 19, 2011)

Great thread here! Seeing as how I'm about to go active for the first time myself, I'll be referencing this thread a bit. Thanks guys!


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## The Baron Groog (Mar 15, 2010)

What voltage do they need to be rated for?


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## sqshoestring (Jun 19, 2007)

jimjam said:


> It was probably statements from authoratative folks like yourselves that reassured me, earlier in my learning, that I'd be ok w/o protection. Probably that, as well as, my speakers, at the time, cost a good bit less. My renewed consideration comes by way of the ms8. It just seems I've come across a number of people blaming the ms8 for blowing their speakers with only, various speculations for the causes. Though, it would be an excuse for some of those pretty looking L1 pro R2's, I just can't pour more RIDICULUS amounts of $ after what all started with a fairly simple goal of "a nice stereo".


I've always told people to use caps on tweeters, but others don't use them and that is fine. To me there is no downside and they cost near nothing. I used to buy home tweeters that came with large ones that were too low for in the car and I used those often. The only real downside is phase issues from the xover you make, but it only affects when you get close to it so if you are worried then make the cap larger (lower HP).

Another part of the issue might be how people like to use huge amps on tweeters today, so if something does go wrong they go poof faster. I used a lot of 2x30rms amps but they were 12v rated so maybe 2x50 CEA. That was plenty of power for even large systems. But even then a bass note would smoke a tweeter if you screwed up, or the amp let go, etc.


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## jimjam (Oct 5, 2009)

The Baron Groog said:


> What voltage do they need to be rated for?


If you click on the link earlier in the thread for the caps at PE, they are rated at 400v. I suppose it would need to only be able to cover voltage your amp is delivering at the gain setting you're at. Probably at the max v your amp can deliver, just to be safe. Of course, I would confirm that with somebody who actually knows what the hell they are talking about first! 

Those particular Solen caps seem to be of a desireable construction according to a little searching I've done. By the way, the 20uF caps I bought (protection from 2000hz and down) are a touch larger than a C size battery. Just in case it matters to your install.


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## The Baron Groog (Mar 15, 2010)

Thanks, had a brain fart: watt/impedence=voltage so 125wrms on 8ohm driver = 15.63v or 4ohm driver = 31.25v.

Though as the amp can theoretically put out double that as "peak" output? SO would you need to consider 31.25v for 8ohm and 62.5v for 4ohm?


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## Fricasseekid (Apr 19, 2011)

The Baron Groog said:


> Thanks, had a brain fart: watt/impedence=voltage so 125wrms on 8ohm driver = 15.63v or 4ohm driver = 31.25v.
> 
> Though as the amp can theoretically put out double that as "peak" output? SO would you need to consider 31.25v for 8ohm and 62.5v for 4ohm?


This is not correct. It would take more voltage to supply 125 watts to an 8ohm driver than a 4ohm. 

The equation is. 

Sq Rt (watts x impedence) = voltage
or
v^2/ohms=watts

Also why even consider a peak power rating since every knows that it's just marketing anyways?


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## The Baron Groog (Mar 15, 2010)

More brain farts then! Damn, I didn't think I'd forgotten so much-but then high school was 16yrs ago...

Calculations voltage current resistance and electric power formula calculator electrical pie chart - electricity calculation - electrical power formula general ohms law physics electricity electronics formula wheel formulas amps watts volts ohms cosi

So: 
4ohm driver on 125wrms:22.36v
8ohm driver on 125wrms:31.62v

Or if you take the the RMS to be based on the voltage:


I'd consider peak power as the RMS stands for route mean square, an average power figure, so ultimately your amp could output more.

A bit more reading RMS is .707 of peak:
4ohm driver on 125wrms:22.36vrms = 31.62v peak=250w peak
8ohm driver on 125wrms:31.62v=44.73 peak=250w peak


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## minbari (Mar 3, 2011)

the kid is right. watts / resistance is not one of ohms or watts laws 

if you are looking to get max power out of an amplifier, then just set it up by adjusting the gains with your speakers connected. use a DMM or an o-scope. there is whole a thread on how to do this


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## chad (Jun 30, 2005)

If you run a tone thru your amp, with the tweeter connected, even in the tweeter's specified range, in an attempt to find where the amp clips... you will be buying new tweets, unless the amp is incredibly tiny.


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## Fricasseekid (Apr 19, 2011)

I think if you know your amp supplies more power than is needed to run your drivers then finding where it clips is irrelevant anyhow. 

In other words, the only time finding where your amp will clip is if you plan on supplying all the available power to said driver. Otherwise you could just set the gain with a DMM and be done with it.


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## evo9 (Jul 6, 2005)

MadeByMonkey said:


> I suggest using the crossover on your Kenwood KAC-X4R to protect your tweeters because you already have it. I hate to break it to you but a cap is going to be completely useless if your MS-8 spazzes out and sends a full range signal to your tweeter.




You dont know what you are talking about!

IN THE KNOW: Nov/Dec 2001

Question for Mr Clark "tweeter protection in active setup" - CARSOUND.COM Forum

.


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## chad (Jun 30, 2005)

evo9 said:


> You dont know what you are talking about!
> 
> IN THE KNOW: Nov/Dec 2001


Ahem....



> *Protecting Tweeters*
> Tweeters are expensive, and I’m sure that there’s nothing more frustrating than purchasing a pair of $200 tweeters and having one of them destroyed. Tweeters, and especially horn drivers, are extremely sensitive and fragile.


Actually compression drivers are MUCH more robust and capable of handling abuse than "tweeters..."


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## MadeByMonkey (Aug 31, 2010)

evo9 said:


> You dont know what you are talking about!
> 
> IN THE KNOW: Nov/Dec 2001
> 
> ...


All righty then. The fact is that many of the DIYMA folks pick an amplifier that is capable of roasting their tweeters. It is not unusual to see them powering tweeters with amplifiers capable of producing two to three times the RMS power handled by the tweeter.

Here is an experiment for you to try. Connect a 50 watt RMS tweeter to a 150 watt RMS amplifier, protect it with a capacitor, then make your MS-8 Spaz out or simulate a spazz out by sending a full range white noise signal at max power. Let me know if the tweeter survives.


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## jimjam (Oct 5, 2009)

MadeByMonkey said:


> All righty then. The fact is that many of the DIYMA folks pick an amplifier that is capable of roasting their tweeters. It is not unusual to see them powering tweeters with amplifiers capable of producing two to three times the RMS power handled by the tweeter.
> 
> Here is an experiment for you to try. Connect a 50 watt RMS tweeter to a 150 watt RMS amplifier, protect it with a capacitor, then make your MS-8 Spaz out or simulate a spazz out by sending a full range white noise signal at max power. Let me know if the tweeter survives.


Are saying that a cap _won't _ protect them.


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## MadeByMonkey (Aug 31, 2010)

jimjam said:


> Are saying that a cap _won't _ protect them.


It will protect them right up until the point when they fail!:laugh:


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## chad (Jun 30, 2005)

MadeByMonkey said:


> It will protect them right up until the point when they fail!:laugh:


as will a speaker wire


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## evo9 (Jul 6, 2005)

MadeByMonkey said:


> All righty then. The fact is that many of the DIYMA folks pick an amplifier that is capable of roasting their tweeters. It is not unusual to see them powering tweeters with amplifiers capable of producing two to three times the RMS power handled by the tweeter.
> 
> Here is an experiment for you to try. Connect a 50 watt RMS tweeter to a 150 watt RMS amplifier, protect it with a capacitor, then make your MS-8 Spaz out or simulate a spazz out by sending a full range white noise signal at max power. Let me know if the tweeter survives.




Guess what.................. Mine is still working after my HD900 **** its guts. 15MFD - 400 VDC solen cap did the trick! And that was NOT an experiment. It was real world event. 



.


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## evo9 (Jul 6, 2005)

MadeByMonkey said:


> It will protect them right up until the point when they fail!:laugh:




I guess you dont understand how to work the math of the formula!





.


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## sqshoestring (Jun 19, 2007)

You guys saying your processor is flipping out and sending a full voltage signal to the amps? Well, then its your fault for using crap equipment. If you run the tweeter hard enough in its recommended range the cap allows and blow it, well, then you roasted it of your own accord. If the amp sends DC to the speaker, or the xover somehow gets defeated, etc, you should notice that and have a good chance of cutting power/etc before it torches the tweeter....or a far better chance than wire only gives you. Just remember, this is a free market solution and nobody is forcing you to use a cap...lol.

Otherwise figure out what size bulb will limit power, a bulb and cap should do a very good job of protecting it.


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## MadeByMonkey (Aug 31, 2010)

evo9 said:


> Guess what.................. Mine is still working after my HD900 **** its guts. 15MFD - 400 VDC solen cap did the trick! And that was NOT an experiment. It was real world event.
> 
> 
> 
> .


So because your tweeter survived in that one instance means that a capacitor will protect ALL tweeters in ALL instances of equipment malfunction? Yeah.... NO!


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## dragonrage (Feb 14, 2007)

MadeByMonkey said:


> So because your tweeter survived in that one instance means that a capacitor will protect ALL tweeters in ALL instances of equipment malfunction? Yeah.... NO!


No protection is perfect. Just ask your parents about that one . But seriously, I have no idea why you are arguing against protection. If you don't want to run a capacitor then don't. I don't run one, either - at least not at the moment - but doing so is not a dumb idea.


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## evo9 (Jul 6, 2005)

MadeByMonkey said:


> So because your tweeter survived in that one instance means that a capacitor will protect ALL tweeters in ALL instances of equipment malfunction? Yeah.... NO!




Once again, you do NOT understand how to use the formula! 





.


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## chad (Jun 30, 2005)

evo9 said:


> Once again, you do NOT understand how to use the formula!
> 
> 
> 
> ...


whip it out, we will pick it apart. Or at least the theory of it.


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## MadeByMonkey (Aug 31, 2010)

I understand that if one sends more current than the tweeter can handle, it will go up in a blaze of glory, cap or no cap. Is there something else that I am missing? Search this forum and you shall see that there are plenty of Bit One and MS-8 horror stories causing the exact thing to happen!

I am not against using a cap but I am against the advise being given out suggesting that it is the ultimate failsafe protection against ALL equipment malfunctions. Sometimes Murphy will bite you in the ass just because he can.


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## ousooner2 (Jan 6, 2011)

Ok so I just read this thread, but I'm still a little confused. I will be running the Maxxsonics onx4.125 (125 @ 4ohms) for my tweeters so I'd like to protect them as my last MB Quart q4.150 popped a tweeter. I want to make sure I get this correct so I'm coming to you all...and I truly appreciate the help!!

It'll be crossing the ID xs28 tweeter anywhere from 3kHz to 3.5kHz and likely using a 24db slope (I have 12db available also from the 360.2 but I figure the higher slope is better on a tweet). SOO...since I'm using a high slope, I can just half the x-over freq. and pick up a cap that is recommended when I put those #'s into the "the12volt" website??

@ 3kHz.... I'm getting a 13ufd cap
@3.5kHz... I'm getting a 11ufd cap

Correct??


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## chad (Jun 30, 2005)

The cap will protect from a turn on thump or the amp making DC providing it does not oscillate.. That is it.

It does not protect from moron.


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## ousooner2 (Jan 6, 2011)

Wait...I think you're supposed to plug in 1/2 the value of the x-over you will use into the12volt calculator. That gives me a cap anywhere from 22-26ufd for these x-overs. Hopefully that seems correct. I just want to make sure there's nothing that will change SQ. 

..hope you're not calling me a moron..? I know what they protect from and that's what I'm looking for as that Q had a channel go bad and it sent DC. Got the magic white smoke. It also popped my right mid a few times but those are okay


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## chad (Jun 30, 2005)

not calling you a moron, but it will not protect from moron, because at 1/2 crossover freq, it takes one slip to blow that fuse... AKA voicecoil.


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## ousooner2 (Jan 6, 2011)

Right. But it will/should protect from DC and turn on/off pop. I just don't want to send it 1/2 the x-over freq. so that's why I wanted a cap to protect these guys. 

Looks like I'll order up the one for the 3250kHz/24db x-over which would be a 25ufd cap from PE. Maybe RatShack has them..hmm.


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## chad (Jun 30, 2005)

Ratshaq won't they may have lytics, don't use those, just order some daytons or solens from parts express.


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## ChrisB (Jul 3, 2008)

chad said:


> Ratshaq won't they may have lytics, don't use those, just order some daytons or solens from parts express.


I bet Ratshack tries to sell him a cell phone though.:laugh:


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## ousooner2 (Jan 6, 2011)

Lol. I was in there for a cheap Y-adapter a few months ago and they tried to get me to get an Iphone4. 

...I had an Iphone4 sitting on the counter right in front of them. :mean: So the 25ufd cap won't have any affect on SQ?? I can TA or EQ everything like the phase shift. Just want to make sure as I'm a broke college student and want to get it right the first time lol




ChrisB- Have anything done to the '06? I miss my '01 Cobra all the time. Had a lot of time and money into that car (low 12 sec car) but it started costing me too much in gas running 93 lol. Once I graduate..it's back into a '11 5.0 or c6


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## chad (Jun 30, 2005)

As long as it's WAY out of the way of the XO freq, and there are phase calculators on-line, then no, no SQ issues.

Again, in the 20+ years of doing this in car audio and professionally with a million+ dollars of line arrays hanging.. I never wished I had a cap... Any HF device blown was by accident or my own damn fault... And that amounts to like TWO of them.

Combined wattage per hang over 20 years, oh hell you don't even wanna know.

Measured in KW/H into speakers, I have poured millions of watts, easy. No caps on HF devices. TWO failures.


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## ChrisB (Jul 3, 2008)

ousooner2 said:


> ChrisB- Have anything done to the '06? I miss my '01 Cobra all the time. Had a lot of time and money into that car (low 12 sec car) but it started costing me too much in gas running 93 lol. Once I graduate..it's back into a '11 5.0 or c6


I did the cold air intake, 93 octane tune, sticky tires, and BMR rear lower control arms. The prior owner of the vehicle installed the Ford racing springs and shocks as well as some Ford racing axle backs. Now, I need to address the front because one of the strut mounts is going bad. So I'll probably do K member, A-Arms and strut mounts at that time. Then I will finish off the rear with an upper control arm, upper control arm mount and Fays2 watts link.

After I address all the suspension issues, I'll consider more power which will be subject to my mood at the time. One of my friends owns a salvage yard, so if he can find a 2011+ 5.0 or GT500 for a decent price that I can pillage donor parts out of, I'll consider going that route too.

Finally, the car will need some paint and body work because the prior owner had gone with a Razzi body kit and it scuffed up the factory paint underneath it. Whoever installed it also drilled into the sill area. It was a horrible hack job.


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## random.precision (Jan 8, 2012)

I am a bit confused about something...

Let's say I want to actively cross my tweeters over at 2 kHz @ 24dB. Now, if I add inline a 6dB protection cap for one octave of 2 kHz (1 kHz), what will the final slope be? I've read conflicting info about this. Some say that the 6dB slope adds to the active's 24dB slope yielding a final 30dB slope, yet others say that the final slope is dictated by the active crossover yielding a slope of 24dB. Which is correct?


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## Jroo (May 24, 2006)

I want to finally use my Infinity Ribbons actively. Since they are so hard to find I was looking at the cap as additional protection. I will crossing them over in the 8k to 10k range. I will play with that some when the install happens. So worst case scenario, at 8k xover point, what cap value should I be looking at?


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## The Baron Groog (Mar 15, 2010)

2-Way Crossover Designer / Calculator

4.97 uF to crossover at 8k
9.94 uF to crossover 1 octave down, 4k

What's their Fs?


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