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Discussion Starter · #1 ·
Greetings.

I'll run active my tweeters (directly from the amplifier), and I'm looking into what would be the best way to protect them against a technical failure of my dsp (because of my amp does not have any integrated crossover). My installer tells me that I can not run them without some protection, and tells me that he can install a 4.7uF capacitors (@ 4 ohms). However, I have read on these forums that this method actually degrades its SQ.

I could think of placing a "Fmods" (from Harrison Labs) hp 2500 hz /12dB crossover to filter the minimum frequency in the event of failure dsp. According to the manufacturer, these are made with hi-grade components and produce virtually no noise. Do you think these Fmods would be sufficient protection? (I do not want to spoil my new morel tweeters!)
 

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You don't want to have the filter cut anywhere close to the point you are using
 

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if you plan on crossing at 2500hz, have the inline cap cross at 1000hz. you want something that will protect it just enough in case of failure but not cross high enough to mess with the sound
 

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Discussion Starter · #4 ·
You don't want to have the filter cut anywhere close to the point you are using
How much "close" should be ok?

I'm planning to cross them at 3000~2800 /18~12db with the dsp.

I haven't bought any fmod yet and they have many custom freqs fmod. (12db is the only slope available)
 

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800ish
 

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Discussion Starter · #6 ·
if you plan on crossing at 2500hz, have the inline cap cross at 1000hz. you want something that will protect it just enough in case of failure but not cross high enough to mess with the sound
Thanks for your response, very helpful!


Do you use any "back up" passive tweeter protection?

Are that "Fmods" really worth it (25.00 pair shipped) or Should I get the cheap 4.7uF filters (4.00 for the pair)?

If you will run a crossover-less amplifier... Which TW protection would you choose?
 

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I did a good bit of looking into this recently and from what I've gathered you want to be a good 1.5 to 2 octaves below the pass band to avoid phase issues. I went with 100 uF caps @ around 500 Hz @ 4 ohms with a 2.5 kHz 12 db/oct tweeter crossover point...~2.25 octaves below the crossover point. The caps are pretty big FWIW and had to be mounted at the amp.
 

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Discussion Starter · #10 ·
No, they (the F-Mods) will not do anything to protect your tweeters from DC offset and pops.
So... What can you do to protect tweeters against any electronic devices failure? :confused:

Should you just cross fingers and hope nothing goes bad?

Is that most "full active system" users do? :confused::confused::confused:
 

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I don't use any additional tweeter protection besides the crossover set on my head unit. I know a lot of people fear some crazy malfunction, but I think those types of equipment failure are very, very uncommon.
 

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I go in raw dog
 

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Thanks for your response, very helpful!


Do you use any "back up" passive tweeter protection?

Are that "Fmods" really worth it (25.00 pair shipped) or Should I get the cheap 4.7uF filters (4.00 for the pair)?

If you will run a crossover-less amplifier... Which TW protection would you choose?
yes i do. in my 300zx i have a cap that crosses at around 700-800hz, and in my daily i have a cap that crosses at around 850hz
 

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So... What can you do to protect tweeters against any electronic devices failure? :confused:

Should you just cross fingers and hope nothing goes bad?

Is that most "full active system" users do? :confused::confused::confused:
put capacitors in line with the speaker wire. not rca's
 

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Because it works
 

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Discussion Starter · #17 ·
I don't use any additional tweeter protection besides the crossover set on my head unit. I know a lot of people fear some crazy malfunction, but I think those types of equipment failure are very, very uncommon.
Some installers I have inquired think diferent! :p

May be it is because the PRS99 you have... here, I´m using factory HU, and a A/D/S PH15 old school 6ch amp with no crossover. I mean... I have no crossovers network but my Helix DSP.
And, I am pretty sure they can fail and they does :worried:
 

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Can you explain me the reason for?

(because of better TW protection?, Because ofbetter SQ?, Because of better Cost/bennefit relationship???)

(Thank´s in advance ;) )
capacitors are first order crossovers (-6db slope). this means if the actual active crossover fails, itll still have some protection. also, they block dc current which could come from amp failure, or turn on/off pops. with the inline-rca plug, they wont block anything that is from the amplifier, only something from before the amplifier (or where ever you install it). theyre just a failsafe to protect your tweeters in case of equipment failure or a simple mistake in wiring or dsp programming


Because it works
why even bother posting if your help is this half assed?
 

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Some installers I have inquired think diferent! :p

May be it is because the PRS99 you have... here, I´m using factory HU, and a A/D/S PH15 old school 6ch amp with no crossover. I mean... I have no crossovers network but my Helix DSP.
And, I am pretty sure they can fail and they does :worried:
I didn't say that it doesn't happen, but I don't think it happens often. What I do think happens often is user error. Someone starts messing with things and blowing tweeters. I think these spontaneous failures that just so happen to either send a full range signal, or DC to tweeters are something pretty rare.

By all means, add a cap if it makes you feel better. I've never used them, and I've never had a problem. Purely anecdotal, but you did ask what most users do, and I responded with what I do (nothing).
 

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Why bother posting asking me why I posted?
I haven't seen you tell anyone to buy only Scanspeak. Did you jump ship?
 
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