Why are active crossovers uncommon in home audio?

[Sweefu]

Hi All,

I've only discovered this awesome forum earlier in the year, it has been great fun reading through all the detailed reviews and forum discussions.

My background is in car audio (many years ago), which is probably why I am asking this question. About 6 months ago, I started researching home theatre/home hi-fi, while enjoying an old Yamaha RX-350 receiver and Richter Audio 2-way bookshelf speakers from the late 80's/early 90's.

I'm planning a basic setup using the Denon AVR-X1800h and some existing drivers I used in my last 2-way car setup (Usher Audio 8945P midwoofer and SB Acoustics SB29 tweeter). In car audio, active crossovers were (are?) very common, even fairly basic source units like the Alpine 9887r had a 3-way active crossover allowing you to bandpass the midwoofer, HPF the tweeter and LPF the sub. As most will know, there are now many dedicated active crossover/DSP options ranging from $500+. This meant it was simple and relatively easy to use high quality hi-fi components, if you were prepared to spend time on the installation, for a fraction of the cost compared to dedicated car audio drivers which was great.

I'd like to re-use my old drivers for a simple 2-way bookshelf speaker, but it seems like active crossover options are fairly limited in a home audio setting, and a lot more expensive. Mini-DSP looks like a popular option (as it was in cars too) but otherwise it looks like you need to spend several thousand dollars for any good options, compared to perhaps a few hundred dollars to build a reasonable 2-way passive crossover.

So my question is - why are active crossovers not more popular? Is it because most people are buying pre-made speakers, and DIY projects are not common/popular? Or if people are building their own speakers, are they instead using pre-made kits with passive crossover provided?

I'd prefer to use an active crossover so I can spend time adjusting and learning, as well as re-using the crossover later when I move to a different setup, but it looks like it will be an expensive/difficult option compared to building a pair of simple passive crossovers (particularly around trying to integrate mini-DSP with using the AVR amplifier etc).

Any thoughts or discussion on this topic would be great - thanks for your help.

 

[Roland68]

Hi All,

I've only discovered this awesome forum earlier in the year, it has been great fun reading through all the detailed reviews and forum discussions.

My background is in car audio (many years ago), which is probably why I am asking this question. About 6 months ago, I started researching home theatre/home hi-fi, while enjoying an old Yamaha RX-350 receiver and Richter Audio 2-way bookshelf speakers from the late 80's/early 90's.

I'm planning a basic setup using the Denon AVR-X1800h and some existing drivers I used in my last 2-way car setup (Usher Audio 8945P midwoofer and SB Acoustics SB29 tweeter). In car audio, active crossovers were (are?) very common, even fairly basic source units like the Alpine 9887r had a 3-way active crossover allowing you to bandpass the midwoofer, HPF the tweeter and LPF the sub. As most will know, there are now many dedicated active crossover/DSP options ranging from $500+. This meant it was simple and relatively easy to use high quality hi-fi components, if you were prepared to spend time on the installation, for a fraction of the cost compared to dedicated car audio drivers which was great.

I'd like to re-use my old drivers for a simple 2-way bookshelf speaker, but it seems like active crossover options are fairly limited in a home audio setting, and a lot more expensive. Mini-DSP looks like a popular option (as it was in cars too) but otherwise it looks like you need to spend several thousand dollars for any good options, compared to perhaps a few hundred dollars to build a reasonable 2-way passive crossover.

So my question is - why are active crossovers not more popular? Is it because most people are buying pre-made speakers, and DIY projects are not common/popular? Or if people are building their own speakers, are they instead using pre-made kits with passive crossover provided?

I'd prefer to use an active crossover so I can spend time adjusting and learning, as well as re-using the crossover later when I move to a different setup, but it looks like it will be an expensive/difficult option compared to building a pair of simple passive crossovers (particularly around trying to integrate mini-DSP with using the AVR amplifier etc).

Any thoughts or discussion on this topic would be great - thanks for your help.

Many cheap analog active crossovers have various errors and poor measurement values, so there are only a few really good ones. They're either expensive or/and DIY. Furthermore, the tuning effort is just as great as with conventional crossovers.
But nobody's stopping you from using active crossovers from car audio.

The situation is somewhat different with DSP-based solutions. In addition to MiniDSP, there's also Thomann's "the t.racks DSP" series, which is sufficient for a 4-channel/2-way stereo system at €119, or for 2 units (€238) for 3-way + subwoofer or 4-way speakers. Given the prices and relatively good measurement results, there's no reason to complain. However, there are also larger devices in the "the t.racks DSP" series.
Other manufacturers also offer such devices, even in very high-quality versions, such as the dspNexus.

There are also built-in amplifiers for speakers with DSP in various designs and with different numbers of channels.

A good, extremely versatile, and scalable solution is a PC or Mac-based FIR convolver, whose output is routed through a sound card or external DAC. It starts at pocket money and depends on requirements and performance. Acourate is one of many options; you can find a lot of information about it in the thread Multi-Channel, Multi-Amplifier Audio System Using Software Crossover and Multichannel-DAC.

 

[OldHvyMec]

Active XOs have been around in home use for a while, over 20 years for me and they are one of the cornerstones of most modern DIY projects.

First Watt; completely analog, no DSP, RCA only in and out. (12-1600.00 usd)

Pro; units like Behringer have been used a LOT in home use. I still use a DCX2496 in all my sub/bass management, and their NU12K for amps (bulletproof) XLR (3-400.00 usd)

DIY; Actives are available (I have to look up the manufactures/kits) SE (45-100.00 usd)

"mini"; is VERY popular. I have an HT8 that I'm currently tinkering with because it has XLR and (SE) RCA vs SE only. Not a fan of RCA except in turntable use. The HT8 isn't cheap either. (HTS 13-1500.00 usd)

Parts Express Dayton SE (2-300.00 usd) They have a few models and configurations, all with DSP. PE also has a few pro model active XOs.

Regards

 

[Sweefu]

Many cheap analog active crossovers have various errors and poor measurement values, so there are only a few really good ones. They're either expensive or/and DIY. Furthermore, the tuning effort is just as great as with conventional crossovers.
But nobody's stopping you from using active crossovers from car audio.

The situation is somewhat different with DSP-based solutions. In addition to MiniDSP, there's also Thomann's "the t.racks DSP" series, which is sufficient for a 4-channel/2-way stereo system at €119, or for 2 units (€238) for 3-way + subwoofer or 4-way speakers. Given the prices and relatively good measurement results, there's no reason to complain. However, there are also larger devices in the "the t.racks DSP" series.
Other manufacturers also offer such devices, even in very high-quality versions, such as the dspNexus.

There are also built-in amplifiers for speakers with DSP in various designs and with different numbers of channels.

A good, extremely versatile, and scalable solution is a PC or Mac-based FIR convolver, whose output is routed through a sound card or external DAC. It starts at pocket money and depends on requirements and performance. Acourate is one of many options; you can find a lot of information about it in the thread Multi-Channel, Multi-Amplifier Audio System Using Software Crossover and Multichannel-DAC.

Thanks for the info. I'll have a look into t.racks, sounds like a good option. Unfortunately being in Aus, everything ends up more expensive by the time you get it here.

Do you have any recommendations for amplifiers with built in DSP?

Active XOs have been around in home use for a while, over 20 years for me and they are one of the cornerstones of most modern DIY projects.

First Watt; completely analog, no DSP, RCA only in and out. (12-1600.00 usd)

Pro; units like Behringer have been used a LOT in home use. I still use a DCX2496 in all my sub/bass management, and their NU12K for amps (bulletproof) XLR (3-400.00 usd)

DIY; Actives are available (I have to look up the manufactures/kits) SE (45-100.00 usd)

"mini"; is VERY popular. I have an HT8 that I'm currently tinkering with because it has XLR and (SE) RCA vs SE only. Not a fan of RCA except in turntable use. The HT8 isn't cheap either. (HTS 13-1500.00 usd)

Parts Express Dayton SE (2-300.00 usd) They have a few models and configurations, all with DSP. PE also has a few pro model active XOs.

Regards

Thanks for your reply. I have had a look at the Dayton DSP also, it's not priced too badly here.

Is there any solution to using the internal amp of the AVR? From my view it seems like an external power amplifier will always need to be used (RCA out on the AVR -> input DSP -> output RCA to power amp -> power amp to speakers. This is annoying too, as I can't see a way around needing an AVR for Dolby Atmos, surround processing etc (which again makes passive seem like the popular option in this scenario).

cheers all

 

[Roland68]

Thanks for the info. I'll have a look into t.racks, sounds like a good option. Unfortunately being in Aus, everything ends up more expensive by the time you get it here.

Probably more expensive, but Thomann also ships to Australia and up to a certain amount there are no additional taxes or duties.

Special Rules for Australian Customers​

All our prices quoted on our online store contain both VAT and customs - so you will not incur any additional costs after the purchase unless the order total exceeds 1000 AUD, in this case we have to take off the VAT again and the Australian customs authorities might charge import fees separately.

Do you have any recommendations for amplifiers with built in DSP?

I can't give you a recommendation, as I wouldn't use something like that. I prefer separate components, but there are several manufacturers that offer them, even for something under €/$50.
wondom bru5 pc dsp configurable TPA 3255 "300w x 2" mini amplifier

By the way, you have something else on your doorstep Accuratesound CA

 

[chelgrian]

It’s quite odd that eliminating passive crossovers and requiring a specific cross over and amp per channel hasn’t taken off at the ‘high end’ of consumer audio since it represents the opportunity to sell the customer more stuff.

I guess one thing is that it’s fairly difficult to damage a speaker with a passive crossover where as it’s very easy to incorrectly connect a system that requires external crossovers and fry the speakers.

 

[raindance]

Personally, having seen many mis-wired stereo systems (an amp and two speakers that aren't wired in phase or with left and right swapped) I'd say that the problem is complexity. The average person just wouldn't be able to make it work.

 

[Roland68]

It’s quite odd that eliminating passive crossovers and requiring a specific cross over and amp per channel hasn’t taken off at the ‘high end’ of consumer audio since it represents the opportunity to sell the customer more stuff.

I guess one thing is that it’s fairly difficult to damage a speaker with a passive crossover where as it’s very easy to incorrectly connect a system that requires external crossovers and fry the speakers.

This has already been understood, but...
- the overall development effort is much higher.
- the material costs are much higher.
- shipping weight is much higher.
- the selling price is much higher than for individual components.
- the number of units is considerably smaller, which means all costs are spread over a much smaller number of units.
- changing individual components is very difficult.

For solutions with separate amplifiers and devices, the required space and a larger number of cables are also added.

An active loudspeaker is fundamentally no guarantee that it will sound better than the same loudspeaker with a standard crossover.
Today, for €/$200-600, you can get a DAC and amplifier package whose measured values are unmatched by most, even expensive, active systems. When combined with a DSP for further adjustments, the gap becomes even greater.

 

[DVDdoug]

The "average consumer" wouldn't be able to set-up a bi-amped or tri-amped system. And with few exceptions, most hi-fi and home theater speakers have to be disassembled and re-wired to be bi amped. Some speakers have separate woofer & tweeter terminals but they don't bypass the internal crossover.

Active bi-amped monitors & computer speakers are common.

There's a strong tradition of passive hi-fi/stereo speakers. And it's often difficult-enough to run wires to 5 or more pairs of speaker-wires for home theater. Active speakers would require power to all of them. The subwoofer is normally active so it has to be plugged-in, but placement isn't critical and there's usually only one.

...I put a tri-amped system in my van.

 

[Devnull]

Onkyo/Integra used to offer the the ability to set active xovers in their high end AVRs. They also had the ability to do physical driver offset. They would use one of the "zones" amp pair for the high frequencies. IIRC they also used to have the ability to drive passive subwoofers from the AVR directly.

 

[chelgrian]

This has already been understood, but...
- the overall development effort is much higher.
- the material costs are much higher.
- shipping weight is much higher.
- the selling price is much higher than for individual components.
- the number of units is considerably smaller, which means all costs are spread over a much smaller number of units.
- changing individual components is very difficult.

For solutions with separate amplifiers and devices, the required space and a larger number of cables are also added.

An active loudspeaker is fundamentally no guarantee that it will sound better than the same loudspeaker with a standard crossover.
Today, for €/$200-600, you can get a DAC and amplifier package whose measured values are unmatched by most, even expensive, active systems. When combined with a DSP for further adjustments, the gap becomes even greater.

Except that I’m talking about the high end and that is already tiny production runs already biamps so they already have most of the extra hardware boxes and wires removing the passive network from speakers and adding an active crossover before the amps would be a small step.

There’s no development work to do you just buy a off the shelf DSP from a pro audio supplier and put it in a shiny box and make a bunch of outlandish claims about it….

The pro audio market mostly eliminated passive crossovers networks years ago partially as they are a wicked waste of amplifier power.

 

[Keith_W]

I too have a car audio background Car audio and home audio are very different. Car audio people have a more DIY mindset, and home audio people mostly have a "consumer" mindset.

If you mount a tweeter in the A-pillar and a midwoofer in the side panel, there is no way they will play together properly unless they are bi-amped with a DSP setup. At the very least, the drivers need to have the volume trimmed so that they will match. The more advanced guys will try to time align the drivers. Most car audio guys recognize this. Some try passive XO's, but the results are rarely as good and requires a tonne of amplifier power.

Home audio is different - people buy finished speakers with XO's in place, plonk them in listening rooms, and most of the time they will get great sound. Follow some basic rules, and it is very difficult to mess it up. It's not like a car where you have no hope of great sound without involving yourself with XO's. XO design is seen as a dark art that only skilled designers are capable of. The overwhelming majority of the speakers on the market have passive XO's. Even the ones with active XO's give you very little opportunity to tune the XO. You buy the speaker, it's finished, don't touch it.

 

[Roland68]

Except that I’m talking about the high end and that is already tiny production runs already biamps so they already have most of the extra hardware boxes and wires removing the passive network from speakers and adding an active crossover before the amps would be a small step.

What exactly do you define as the high-end segment? If we're talking about the same buyer group, it's extremely difficult to sell an active system in this segment, as this buyer group is extremely conservative.
If I remember correctly, we have dealers/manufacturers in the forum who want to serve this segment. They can tell you a thing or two about it.

There’s no development work to do you just buy a off the shelf DSP from a pro audio supplier and put it in a shiny box and make a bunch of outlandish claims about it….

You really think that's all? Get yourself a pair of Elac Carina BS243.4s, or a similarly sophisticated speaker, and build an active system out of them that plays just as cleanly and noise-free in the near field as, say, a PA5 (II) amplifier, and achieves at least as good measured values as the original crossover. If you think you only need the hardware and that's it, you might be in for a surprise.
Various dealers/manufacturers can tell you a thing or two about that, too.
But if it's that easy, start your own business.

The pro audio market mostly eliminated passive crossovers networks years ago partially as they are a wicked waste of amplifier power.

The thing about wasted amplifier power is completely unfounded. Where does a normal crossover suffer a significant loss? That would be the first time, assuming the same technology, that two amplifiers consume less power than one.

With active monitors, you can find everything from passive crossovers and active analog crossovers to DSP-based and even mixed systems. Small chip amplifiers, DSP, and switching power supplies save weight, volume, and manufacturing costs, but the development effort remains.

By the way, I haven't been able to find a pair of active monitors for €1,000 that were sufficiently noise-free and sounded balanced to me. Noise-free performance, in particular, was a major problem.

I would have had to spend a lot more than I did with my two setups: the Elac Carina BS243.4 and DBR62 with PA5 II and A30a. But I still wouldn't have gained anything in terms of sound quality.

 

[chelgrian]

You really think that's all?

Yes technically that is all, BSS Audio and DBX were selling Loudspeaker Management Systems aka external DSP crossovers to everyone in the pro market before it went inside the box.

But if it's that easy, start your own business.

Selling to ‘audiophiles’ not likely. You need an established brand of the right sort to play off. Varèse could sell a £100 of DSP for £100,000 I can’t.

The thing about wasted amplifier power is completely unfounded. Where does a normal crossover suffer a significant loss? That would be the first time, assuming the same technology, that two amplifiers consume less power than one.

As heat in the cross over network, I’ve built multi kilowatt PA systems where I had to worry about it and the losses as heat in the speaker cables these days I just have to run mains and Ethercon to cabinets with DSP and Class D amps inside them.

At a few hundred watts on most home speakers on the other hand it’s irrelevant.

However that was not the point, the point is that the ‘high end’ where tens or hundreds of thousands of pounds are being spent has an obsession with extra boxes splitting PSUs out, splitting D/A converters out and then splitting the clock out from the D/A , splitting pre from power amps and then duplicating power amps by biamping and they come up with new ways to add extra boxes and extra tweaks all the time.

However the one thing they appear not to do is having a crossover before the power amps and eliminating the passive speaker level crossover network in the speaker and I find this *very* weird.

 

[Roland68]

Yes technically that is all, BSS Audio and DBX were selling Loudspeaker Management Systems aka external DSP crossovers to everyone in the pro market before it went inside the box.


Selling to ‘audiophiles’ not likely. You need an established brand of the right sort to play off. Varèse could sell a £100 of DSP for £100,000 I can’t.

As heat in the cross over network, I’ve built multi kilowatt PA systems where I had to worry about it and the losses as heat in the speaker cables these days I just have to run mains and Ethercon to cabinets with DSP and Class D amps inside them.

At a few hundred watts on most home speakers on the other hand it’s irrelevant.

However that was not the point, the point is that the ‘high end’ where tens or hundreds of thousands of pounds are being spent has an obsession with extra boxes splitting PSUs out, splitting D/A converters out and then splitting the clock out from the D/A , splitting pre from power amps and then duplicating power amps by biamping and they come up with new ways to add extra boxes and extra tweaks all the time.

However the one thing they appear not to do is having a crossover before the power amps and eliminating the passive speaker level crossover network in the speaker and I find this *very* weird.

You're ignoring several points, but one seems to be completely ignored. Who adjusts the active crossover? Where does the data for this come from, chassis adjustments, etc.?

 

[Chrispy]

The active crossover between speakers and subs with avrs is fairly vpcommon....

 

[kyuu]

The active crossover between speakers and subs with avrs is fairly vpcommon....

True, but a lot of the time that's just "set the xover at 80Hz and call it good". Sometimes that's fine, but there's probably a lot of setups where the integration between mains and sub is quite suboptimal.

 

[Chrispy]

True, but a lot of the time that's just "set the xover at 80Hz and call it good". Sometimes that's fine, but there's probably a lot of setups where the integration between mains and sub is quite suboptimal.

Still, a better starting point than most. Many just use too low a crossover IMO.

 

[chelgrian]

You're ignoring several points, but one seems to be completely ignored. Who adjusts the active crossover? Where does the data for this come from, chassis adjustments, etc.?

Again not the point but in the pro world speaker manufacturers provided the required information. These days the remaining vendors who do use external amplification and LMS tend to license and rebrand amplifiers with DSP in them and provide presets for all their products.

 

[Roland68]

Again not the point but in the pro world speaker manufacturers provided the required information. These days the remaining vendors who do use external amplification and LMS tend to license and rebrand amplifiers with DSP in them and provide presets for all their products.

Post a few companies and examples.