Lonnie
Emo Staff 
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Pay no attention to the man behind the curtain
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Post by Lonnie on Nov 3, 2016 7:50:49 GMT -5
You make some very good points there Chuck.
If I could just through in my .02 here as well.
An all active system will always be superior in performance and if properly setup i.e. levels, crossover frequencies and such the system will be virtually bullet proof. All modern amps have multiple forms of protection and really should be the least of you concerns. Take your time setting it up properly. Use amplifiers with more power then you will ever need so you can take amplifier clipping out of the equation. Use the proper gear to set the levels for the entire audio chain so that none of the low level signals will clip. Properly select the frequency range for each driver and never use boost on an EQ, only cut and lastly set up the system so that even at max volume on the preamp, the over all output level of each amp will not exceed the thermal dissipation limits of the individual voice coils and that system will run forever.
Lonnie
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KeithL
Administrator
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Post by KeithL on Nov 3, 2016 10:38:30 GMT -5
Note that the capacitor also provides absolutely bulletproof DC protection. This thread has become a mix of different protection modes, including: Amp DC protection Peak-Limit protection Bandwidth protection Amp DC protection is present in almost all HQ amplifiers. This was an early problem with SS amps. Gone are the power-on thumps and the catastrophic failure modes that could put out rail DC voltages to the speakers. Peak-Limit protection is the light bulb solution although there are other ways to achieve the same result. Klipsch used back-to-back zener diodes to protect the K77 tweeter in some designs. Go above the zener voltage, blow a fuse. Bandwidth protection is the in-line capacitor solution. An in-line capacitor blocks frequencies that the driver cannot handle. This affords protection from wiring mistakes from an active crossover too. |
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Post by Wideawake on Nov 3, 2016 12:08:22 GMT -5
An all active system will always be superior in performance and if properly setup i.e. levels, crossover frequencies and such the system will be virtually bullet proof. All modern amps have multiple forms of protection and really should be the least of you concerns. Take your time setting it up properly. Use amplifiers with more power then you will ever need so you can take amplifier clipping out of the equation. Use the proper gear to set the levels for the entire audio chain so that none of the low level signals will clip. Properly select the frequency range for each driver and never use boost on an EQ, only cut and lastly set up the system so that even at max volume on the preamp, the over all output level of each amp will not exceed the thermal dissipation limits of the individual voice coils and that system will run forever. Lonnie Sage advice! I also believe that an all active system will be superior in performance when compared to a passive setup. One of these days I hope to find the time to test this hypothesis. |
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Post by pedrocols on Nov 3, 2016 13:16:03 GMT -5
An all active system will always be superior in performance and if properly setup i.e. levels, crossover frequencies and such the system will be virtually bullet proof. All modern amps have multiple forms of protection and really should be the least of you concerns. Take your time setting it up properly. Use amplifiers with more power then you will ever need so you can take amplifier clipping out of the equation. Use the proper gear to set the levels for the entire audio chain so that none of the low level signals will clip. Properly select the frequency range for each driver and never use boost on an EQ, only cut and lastly set up the system so that even at max volume on the preamp, the over all output level of each amp will not exceed the thermal dissipation limits of the individual voice coils and that system will run forever. Lonnie Sage advice! I also believe that an all active system will be superior in performance when compared to a passive setup. One of these days I hope to find the time to test this hypothesis. Howeever, even if you test this hypothesis and it becomes true in theory it will still be subjective like everything else in audio.... |
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Post by Wideawake on Nov 3, 2016 13:31:04 GMT -5
Howeever, even if you test this hypothesis and it becomes true in theory it will still be subjective like everything else in audio.... Well, there will be two parts to the testing. One will be via measurements and this part is objective. The other will be critical listening and that will be subjective. I suspect that the active system will likely measure better since it is relatively simple to correct. Whether or not we can hear the difference is to be seen (or heard  ) |
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Post by leonski on Nov 3, 2016 14:23:05 GMT -5
You make some very good points there Chuck. If I could just through in my .02 here as well. An all active system will always be superior in performance and if properly setup i.e. levels, crossover frequencies and such the system will be virtually bullet proof. All modern amps have multiple forms of protection and really should be the least of you concerns. Take your time setting it up properly. Use amplifiers with more power then you will ever need so you can take amplifier clipping out of the equation. Use the proper gear to set the levels for the entire audio chain so that none of the low level signals will clip. Properly select the frequency range for each driver and never use boost on an EQ, only cut and lastly set up the system so that even at max volume on the preamp, the over all output level of each amp will not exceed the thermal dissipation limits of the individual voice coils and that system will run forever. Lonnie Power needed per 'way' really depends on crossover frequency. Crossing @say, 350hz is considered to be about 50:50 but if you cross at like 8khz to a 'super'tweeter, you may only need 10% or 15% of TOTAL power for that 'way'. The other advantage of an active crossover is that you, in effect, GAIN amp power since your amp is no longer called upon to reproduce out of band stuff. 'Best Case' is you gain about 3db of amp power which is like buying 2x the amp power. You can burn a tweeter with distortion OR too much power, Lonnie's right. Doing all that level setting might be a lot of work that pays off in the end. Don't forget that a speaker will change ELECTRICALLY as it warms. And generally not for the better. Even if not stressed to distortion, running a speaker to high levels on a regular basis will eventually take a toll. I heard some Paradigm Powered Atom speakers at a local shop. ALL matched internals and a great sound. Reasonably priced, for all they did so well. www.digitaltrends.com/pc-speaker-reviews/paradigm-a2-review/ |
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KeithL
Administrator
Posts: 10,261
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Post by KeithL on Nov 4, 2016 8:59:01 GMT -5
NOTE that our Airmotiv Stealth and Airmotiv "s series" powered monitors are all bi-amped - with active crossovers and individual amplifiers optimized for each driver  You make some very good points there Chuck. If I could just through in my .02 here as well. An all active system will always be superior in performance and if properly setup i.e. levels, crossover frequencies and such the system will be virtually bullet proof. All modern amps have multiple forms of protection and really should be the least of you concerns. Take your time setting it up properly. Use amplifiers with more power then you will ever need so you can take amplifier clipping out of the equation. Use the proper gear to set the levels for the entire audio chain so that none of the low level signals will clip. Properly select the frequency range for each driver and never use boost on an EQ, only cut and lastly set up the system so that even at max volume on the preamp, the over all output level of each amp will not exceed the thermal dissipation limits of the individual voice coils and that system will run forever. Lonnie Power needed per 'way' really depends on crossover frequency. Crossing @say, 350hz is considered to be about 50:50 but if you cross at like 8khz to a 'super'tweeter, you may only need 10% or 15% of TOTAL power for that 'way'. The other advantage of an active crossover is that you, in effect, GAIN amp power since your amp is no longer called upon to reproduce out of band stuff. 'Best Case' is you gain about 3db of amp power which is like buying 2x the amp power. You can burn a tweeter with distortion OR too much power, Lonnie's right. Doing all that level setting might be a lot of work that pays off in the end. Don't forget that a speaker will change ELECTRICALLY as it warms. And generally not for the better. Even if not stressed to distortion, running a speaker to high levels on a regular basis will eventually take a toll. I heard some Paradigm Powered Atom speakers at a local shop. ALL matched internals and a great sound. Reasonably priced, for all they did so well. www.digitaltrends.com/pc-speaker-reviews/paradigm-a2-review/
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Post by Chuck Elliot on Nov 4, 2016 14:31:34 GMT -5
One other feature that an active crossover gives you is the ability to time align the drivers in a speaker without staggering the mounting points on a very complex* baffle board.
This requires that the crossover be DSP based. This is very difficult to do in analog*, but rather simple in the digital world.
I have been a fan of time-aligned drivers since I heard the DQ10 speaker years ago.
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Post by leonski on Nov 4, 2016 16:37:57 GMT -5
I heard the Dahlquist speakers when new in shop. Haven't heard 'em in a couple decades. Are any still around? And yes, DSP is the way to go for time align. And with FIR filters, you can ALSO do away with in-band phase shift issues which can create destructive and Constructive interference. www.minidsp.com/images/documents/Product%20Brief-2x4%20HD1%20plugin.pdfLinked is the datasheet for the 2X4HD which has multiple Parametric EQ per input and output AND up to 80ms delay per output in 0.1ms increments. FIR filters are available, too, for the overachiever. www.minidsp.com/applications/dsp-basics/fir-vs-iir-filteringTo help us ALL thru the basics. The WIKI loses me after the first 5 words. |
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Post by Wideawake on Nov 7, 2016 13:33:34 GMT -5
One other feature that an active crossover gives you is the ability to time align the drivers in a speaker without staggering the mounting points on a very complex* baffle board. This requires that the crossover be DSP based. This is very difficult to do in analog*, but rather simple in the digital world. I have been a fan of time-aligned drivers since I heard the DQ10 speaker years ago. Yes, absolutely! Time and phase alignment makes a huge difference. I can attest to that from experience. It is difficult to setup using FIR filters but when you get it right the rewards are sweet. Anyone can build an active speaker but setting up the xo is an art that is worthwhile taking the time to master. Not to mention that it will take several months of tweaking a passive xo to get things dialed in just right and that passive xo will likely end up being very expensive but it will never be able to rival an active implementation. There are some things that just cannot be done using a passive xo. |
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