Electronic vs passive crossovers

[@sherrillshaffer579]

Nice explanation, but the original question was about electric versus acoustic crossovers, not active versus passive. Acoustic crossovers could describe a whizzer cone or dustcap that is mechanically decoupled from the larger woofer cone at higher frequencies, which is an older technology typically not used on high-end speakers now. Wiki has a good description of this.

[@maxb.simonsen2459]

To answer the questions about the different types of crossovers and terms. Passive crossover: Uses passive components e.g. capacitors, inductors and resistor. Used within a loudspeaker. Active crossover: Uses op amps, resistors and capacitors. Used before the amp, therefore also needing 1 amp per driver. Digital crossover: Uses math to change sample values. More info search for IIR or FIR filter. Used before the D/A converter, therefore needing 1 Dac and 1 amp per driver. Electronic/Electrical crossover, My interpretation: Only used to describe the passive or active crossover points and not looking at the drivers response. Acoustic crossover: Where the driver actually crossover over at. Since the drivers themselves has a phase and magnitude response the drivers will influence where the crossover point actually is. E.g. speaker with 2 drivers has a 1st order butterworth filter with a crossover point set at 2kHz. The drivers responses makes it so that the acoustic crossover point is at 2.2 kHz.

[@ThinkingBetter]

Yes, but the term "active crossover" means doing the filtering before the power amplifier. This can be done either using analog or digital (using DSP) circuitry.

[@maxb.simonsen2459]

@@ThinkingBetter Not in my book. If using DSP i would call it a digital crossover. DSP litterally means Digital signal processing

[@ThinkingBetter]

@@maxb.simonsen2459 Wikipedia: "Active crossovers are distinguished from passive crossovers in that they split up an audio signal prior to the power amplification stage, so that it can be sent to two or more power amplifiers, each of which is connected to a separate loudspeaker driver.". An active crossover can be either digital or analog. I agree if you use a DSP, you can call it a digital active crossover and since there is no digital passive crossover, you could just use the term "digital crossover" and people would know what you mean. BTW, a digital crossover could be done using a CPU also as digital audio processing doesn't require a dedicated DSP IC. For example, nowadays ARM CPUs are often used as DSPs.

[@BruceCross]

Active and passive crossovers aren't defined by whether they're placed before or after the amplifier, although it's how they're implemented. They're defined by whether the components of the circuit are electrically powered (active) or not electrically powered (passive). Passive is powered by the amplifier signal, but not by wall current. To reference Wikipedia again, "Active crossovers come in both digital and analog varieties." "Electronic crossover" usually refers to an active crossover, although a passive crossover uses electronic parts, too.

[@ThinkingBetter]

@@BruceCrossThere has been zero ambiguity in this topic in my career for decades and what Wikipedia says is aligned with that: "Active crossovers are distinguished from passive crossovers in that they split up an audio signal prior to the power amplification stage, so that it can be sent to two or more power amplifiers, each of which is connected to a separate loudspeaker driver". So even you use passive components that are not powered prior to the power amplifier (RLC), we will still call it an active crossover. I can agree this is a bit confusing (especially active crossover with passive components). Agree, electronic crossover usually refer to active crossover. I never use that term. When I worked at B&O we were pioneering the active crossover in speakers ages ago initially with passive components initially analog and later with DSP incl. IcePower (my colleagues started that, now used by PS Audio), e.g. the Beolab 90 that I have. Right now I'm listening to my KEF LS50W2 that also do active DSP crossover. Even my garage speakers are some decades old CX100s that I reworked with something called a "Beocreate 4" kit of a 4 channel amplifier with a Raspberry Pi doing the crossover (ARM CPU) and WiFi. I wouldn't call those garage speakers audiophile, but they sound better than ever. I have 8 stereo systems in this house (3 passive crossover).

[@andersbaptist976]

Well....in the Westminster there are a few different crossovers and some of them are acoustic ones. The handover between the front horn and the back loaded horn is the most obvious one and it is purely acoustic. The same goes for a full range driver in a box, from box to main cone, from main cone to whizzer and from whizzer to voice coil, no electrical components, passive or active are involved but it's a crossover just the same.

[@wilcalint]

See my post here on the Tannoy Acoustic crossovers designed for sound re-enforcement for movie theaters in the late 1920's. An Acoustic crossover is very different then a passive crossover.

[@montynorth3009]

The Westminster on the manufacturers site indicates passive Xover plus Bi- wiring.

[@wilcalint]

@@montynorth3009 I wouldn't doubt that today's Tannoy Speakers are using a discreet passive crossover. But back in the 1920's such things were not really available and cheap. So they went with an Acoustic crossover. I believe that Altec Lansing did simaler things.

[@marianneoelund2940]

The Tannoy Westminster is a huge (530 liter) folded-horn speaker which also uses a concentric HF driver (horn tweeter) that radiates from the center of the woofer cone. The woofer radiates forward through a medium-size horn structure, which has a cutoff around 200Hz, and it radiates to the rear through a large folded horn for the lower frequencies. That comprises an acoustic crossover between the two paths. But it's one driver, so this type of "crossover" is a fundamentally different concept, than crossing over between two separate drivers. There is still an electrical crossover for the tweeter.

[@jeremiahchamberlin4499]

You always make such helpful and informative comments. I immediately sensed that Paul should have referenced the particular speaker before launching his discussion of active vs. passive crossovers. Thank you for enlightening us all on the true nature of the question, and answering it. 👍

[@douglasbonner6543]

In a past system I had a Sumo Samson subwoofer and a Sumo Delilah electrictronic crossover set at 63hz. This combination worked like a charm. On the other hand if I had chosen a passive crossover the inductor would have been massive and heavy.

[@Acidrockracer]

Hey Paul, where do I submit questions? I have a question I hope you could answer.

[@jeremiahchamberlin4499]

Note: Tannoy Westminster Royal SE Speakers go for $25,000.00. Specs listed in advertise crossover as ‘B200 Hz acoustical, 1.0 kHz electrical.’

[@hugobloemers4425]

That's a nice story but I am not sure it was the question... Wasn't there the mention of acoustic cross over? I would consider that for instance a woofer that rolls off on the high side at relatively low frequencies. (SEAS has a 10" woofer that rolls off at 1,5 kHz so it does not need filter components and you end up with one capacitor for the tweeter. Though arguably even that is partially an electric cross over because of the high increase of the impedance curve.)

[@gregvisioninfosoft]

3 questions: a) I assume old fashioned active crossovers are still using capacitors and coils (merely optimized for the higher impedances of the pre amplifier stages, as opposed to the 8 ohms of a speaker coil) - hence using much smaller inductors. In any case, wont an active crossover still have the undesirable innate 'phase shifts' at the crossover points? b) is there any crossover technology that preserves the phase relationship across the full audio spectrum? If so what is the name of this constant phase solution? c) When one uses an active crossover, and the need for 6 amplifiers, I dont understand how one deals with the notion of turning the volume up and down. Must one adjust each of the 6 amplifiers individually every time they need to go from low volume to a higher volume (which implies a calibration step using a microphone and certain frequencies sent into the system)? This does not seem very efficient of ones time.

[@davidteague3849]

Paul. You got it wrong. The tannoy Westminster is a passive system and quotes the electrical transfer function as well as resulting acoustic crossover. The electrical is higher at 1Khz due to the horn loading of the compression driver boosting the low end thus arriving at an acoustic crossover to the 15" woofer at 200Hz as I read it Basically the acoustic crossover point is what really matters here

[@ThinkingBetter]

Acoustic crossover = filter the sound with acoustical means (tune driver, box, speaker mesh). Electronic crossover = filter the sound with electronic means, e.g. passive (after power amp) or active (before power amp).

[@wilcalint]

See my post here on the Tannoy Acoustic crossovers designed for sound re-enforcement for movie theaters in the late 1920's. An Acoustic crossover is very different then a passive crossover.

[@Harald_Reindl]

Digital crossovers are the future - no phase shifting, no bad capacitors, no wasted money

[@avro66]

Fantastic speakers, I've used many tannoy duel consentric speakers over the years, unfortunately I could never afford or acomidate the Westminster Royal speakers.

[@ThinkingBetter]

For serious audiophiles with a desire to maximally optimize their system, go active!

[@nikosidis]

Thanks Paul. Learned something from you again :)

[@truthnaut7829]

So from what Paul was saying, the crossover with mid and high attenuation knobs on the front of my Cerwin Vega's are an electronic crossover?

[@paran0ia7]

Those are just passive potentiometers, used for room/personal taste compensation. An active crossover will always be before the power amps, and likely have its own connection to mains power.

[@mateodeo9161]

So active crossover delivers the best sound quality?

[@aaronsmith8265]

Great video! More curse words please! 😂

[@adityachatterjee4498]

How to divide wattage of the 3 way drivers in active crossover... like 150 watt stereo... how to divide wattage of the (high, mid & low) frequency drivers?

[@holliswong8519]

Got it!

[@thebearujb]

So what's your opinion Paul, which do you prefer, passive or electronic?

[@davebalfour6158]

Just to add to the confusion, or not. We have the LLCO or the line level crossover that's often inserted between pre amplifier and power amplifiers. How would this device be classified? It is passive after all.

[@ThinkingBetter]

Crossover before the power amp is active as the term active vs passive crossover is about where in the signal path the filter is located and not if it's based on active or passive circuitry. So you can have a passive filter working as an active crossover if you use capacitors, inductors and resistors in a circuit placed before the power amp. It seems this video made some people quite confused.

[@davebalfour6158]

@@ThinkingBetter the LLCO is not a powered crossover but operates at line level but I can see your point Maybe Paul could say a few words about these crossovers; benefits and disadvantages say.

[@wirelessdj]

What do you think of using capacitors for an active circuit as a crossover? I want built a high pass filter with capacitors using line level. Everyone I spoke to said it was not a good idea?

[@maxb.simonsen2459]

Np, just remember to include the acoustic response of the drivers when designing. Usually you would only use capacitors for active crossovers

[@ThinkingBetter]

It's not a bad idea to make the filtering before the power amp because it means the power amp can directly drive your speakers with best possible control and your crossover can be more optimized. The reason active crossover is less popular is that it is much harder to do as you now need to optimize the filter behavior outside the speaker that you purchased. For serious audiophiles with a desire to optimize their system, go active!

[@vessk000]

This is an active analogue crossover, it's NOT electronic!

[@zeusapollo8688]

Linkwitz-riley vs bessel vs Butterworth

[@johnsoprych483]

I thought "acoustic" crossover was like the enclosure dampening effect on the response curve (as opposed to passive/active electronic components) :\

[@mryoureauser6723]

Add another volt and three quarters to the voltage quadrupler in your watch and the brakes will come on to the squealing noise. An active crossover made from a scrap p.c.b can sure spank a power robbing passive version without the bad interactions with a voice coil.

[@montynorth3009]

Quite right. You get the full damping factor of the amp with active.

[@marianneoelund2940]

@@montynorth3009 No, because the voice coil also has significant resistance. System damping factor is never anywhere near the amplifier damping factor. It's almost impossible to exceed a system damping factor of 4, with copper voice coils. With graphene, you could go up to 6.

[@threatripper]

Question-----digital crossover?

[@andrewclough660]

meanwhile out in the factory........."hey anyone seen Paul ? Yeah he's holed up making bloody KZbin clips" Tell him we need more capacitors....

[@RudieVissenberg]

wow, the first one to watch the video. Interesting as usual

[@playbackvintagehifihunter9669]

🏅

[@artyfhartie2269]

The concept of straight wire with gain has been dumped for more and more electronic hardware especially when it comes to digital audio viz streamers, external DACs, USBs etc

[@rjlopez9358]

💯

[@phantom62]

When your watch went ding, I looked at my iPhone 😂

[@nicolasjoly1755]

the question was about acoustic crossover, which is weird

[@ThinkingBetter]

It's crossover by acoustic means. Tannoy is using that in their concentric sound driver, for example. I suspect that is what inspired this question.

[@montynorth3009]

I think the questioner was talking about a passive crossover but used the wrong terminology.

[@ThinkingBetter]

@@montynorth3009 Tannoy does acoustic crossover. Tannoy was mentioned in the question. Check "Tannoy Dual Concentric by Definition".

[@nicolasjoly1755]

@@ThinkingBetter so as Paul did not seem to know what may be acoustic filters, ,he gave a sidestepping answer

[@ThinkingBetter]

@@nicolasjoly1755 Perhaps, "acoustic crossover" is not a common term. Also "electronic crossover" is not a good term as I would argue that passive crossover is also electronic. Usually the terms "active" and "passive" are used to specify if the filtering is done before or after the power amplifier. Also, you can divide active crossover into DSP (digital) or analog.

[@NeilDSouza7]

And the First or Second one to comment as usual 😀

[@RoderikvanReekum]

This is not correct, you are THIRD to comment!