Direct Coupled Drivers Vs Crossover

[Kingrex]

I am battling a crossover. It sucks so much power and adds a whole lot of haze. I have seen a lot of traction with multi amp direct coupled speakers. I am wondering what might truely make the most natural, alive and dynamic sound. A speaker with a crossover and appropriate amp, or a speaker with multiple amps, each attached directly to a driver with a active digital or analog crossover.

 

[Maril555]

I am battling a crossover. It sucks so much power and adds a whole lot of haze. I have seen a lot of traction with multi amp direct coupled speakers. I am wondering what might truely make the most natural, alive and dynamic sound. A speaker with a crossover and appropriate amp, or a speaker with multiple amps, each attached directly to a driver with a active digital or analog crossover.

In theory, active x-over and multiple dedicated amplifiers driving corresponding drivers seems to be a superior solution, but in practice results might be different. In solving one set of problems, it's likely introduces a different set of issues.
I have used both and ended up with a passive 1st order passive x-over.
I'm saying this with a full understanding of a possibility of a different outcome in someone else's system.
The longer I've been involved in the hobby, the more I'm becoming convinced that the right direction is directly correlated to the simplicity of the system.

 

[Kingrex]

Yea, I hear many people try DSP and quit. Thats a little different. But then again, as I listen more, I feel many of the name brand speakers with a high power amp lack heavily in area of musicality I gravitate too. They seem very powerful and rich with heavy bass. The more simple systems and ones with multiple amps seem more nimble and alive. They don't have the same bass. But I like the bass more as it carries leading edges and detail better. But, the only way I see playing this game is with Class D amps. I have 4 x 8 ohm drivers in my speakers. 2 x legacy 4 channel amps would work perfect. Yet my tube amp to me has far far superior tonality.

 

[Maril555]

Clarification: I didnt use DSP, I was referring to fully analog active x-over, Pass Labs XVR-1

 

[Robh3606]

I am battling a crossover. It sucks so much power and adds a whole lot of haze. I have seen a lot of traction with multi amp direct coupled speakers. I am wondering what might truely make the most natural, alive and dynamic sound. A speaker with a crossover and appropriate amp, or a speaker with multiple amps, each attached directly to a driver with a active digital or analog crossover.

Hello

I have had good results using both passive and active? You are using lower power SET? What does the speaker impendence curve look like? Those are 15's in parallel no?

Depending on the overall impendence level if it drops low and a high phase angle they could be a tuff load.'

With passive crossover in the bass leg there should be very little loss, the only series drops will occur in the inductors which should have low DCR values. If you use cheap higher wire gage inductors you can get a couple of dB of loss.

Rob

 

[Young Skywalker]

I am battling a crossover. It sucks so much power and adds a whole lot of haze. I have seen a lot of traction with multi amp direct coupled speakers. I am wondering what might truely make the most natural, alive and dynamic sound. A speaker with a crossover and appropriate amp, or a speaker with multiple amps, each attached directly to a driver with a active digital or analog crossover.

I have been using a line level analog active crossover and multiple amplifier channels for over 15 years now. I could never go back to a passive crossover loudspeaker which needs to be bossed into submission by an amplifier.

 

[Kingrex]

I gather Linkwitz are built with internal amps and an active analog crossover. I hear more and more about speakers with internal amps. They get good reviews. But they arn't catching on. I wonder if thats more a function of audiophile wanting a big amp to faun over more than good sound.

 

[Kingrex]

I have been using a line level analog active crossover and multiple amplifier channels for over 15 years now. I could never go back to a passive crossover loudspeaker which needs to be bossed into submission by an amplifier.

What amps do you use? Tell us more what you're doing.

 

[Young Skywalker]

What amps do you use? Tell us more what you're doing.

The loudspeaker system was designed to be active from the start. The loudspeaker cabinets (sealed), high excursion paper cone bass drivers, analog active crossover, and class A/B amplifiers are all designed and built in-house by SGR Audio in Melbourne, Australia. The tweeter is a modified Scanspeak Revelator and I do not know the manufacturing origins of the paper cone midrange but it is SGR's own design. The designer, Stuart Ralston, is young enough to have learned the digital world but old enough to have been mentored by over 50 years of old-school analog and driver design knowledge. The current incarnation of my loudspeaker had the electronics inside a smaller volume bass cabinet along with some additional features such as dual-band parametric EQ option (with variable Q-factor). They also make nice equipment racks that are distributed globally. The active speakers have a strong following here in Australia but as we know, the global audiophile market is much slower to adopt this superior approach.

 

[morricab]

I am battling a crossover. It sucks so much power and adds a whole lot of haze. I have seen a lot of traction with multi amp direct coupled speakers. I am wondering what might truely make the most natural, alive and dynamic sound. A speaker with a crossover and appropriate amp, or a speaker with multiple amps, each attached directly to a driver with a active digital or analog crossover.

I have a fully active 2nd system that is a 2-way horn design. I have done it two different ways: Digital crossover and Analog crossover.

With the digital crossover, I went with miniDSP but with digital in and out where I use my own DACs. This worked extremely well for digital but made analog viable only by AD conversion. Since I really wanted to use my turntable "as is" I went to an analog active crossover. However, there was also time alignment correction possible as well as some frequency response contouring that isn't possible with the analog crossover. The analog crossover requires better behaved drivers, which luckily I have.

The analog crossover I bought was an Accuphase F15L, which is an older but well regarded crossover. It has more limited slope options (2nd order and 3rd order) and no options for FR contouring or time alignement...this meant some changes in the driver positioning. IMO, the digital doesn't sound as good with this solution. This could be the lack of tailoring or it could be that the Accuphase is simply not the most transparent active crossover I could have gone with. Something like a Marchand tube crossover might be significantly better sounding and have more options with regard to crossover slopes. However, analog of course works better (my digitization of analog didn't sound very good and would have required the purchase of a studio quality AD converter) with the analog crossover...so a tradeoff, at least as implemented.

IMO, the digital implementation needs to be done with better DACs than one would get built into most "all-in-one" solutions. That is why I used a nanodigi, which is digital in and out only (no DAC installed) and I used my good tube DACs for much higher SQ.

The transparency vs. a passive crossover is clearly an advantage as are dynamics. If your drivers are pretty sensitive then you can use quite low powered SETs without the losses normally encountered.

 

[Kingrex]

I'm curious what the delta would be if you had say a Wilson speaker with a Dagostino amp vs the same Wilson and no crossover with say Legacy class D amps driving each speaker and a factory tuned analog active crossover driving it.

@SCAudiophile
Mark, is Legacy all direct coupled Amps? The Wavelet is the crossover? Does Legacy offer a active analog crossover for vinyl enthusiasts? Is the Wavelet analog or digital?

 

[morricab]

I'm curious what the delta would be if you had say a Wilson speaker with a Dagostino amp vs the same Wilson and no crossover with say Legacy class D amps driving each speaker and a factory tuned analog active crossover driving it.

@SCAudiophile
Mark, is Legacy all direct coupled Amps? The Wavelet is the crossover? Does Legacy offer a active analog crossover for vinyl enthusiasts? Is the Wavelet analog or digital?

lf you have sensitive drivers, why would you use Class D?

 

[Audiohertz2]

I am battling a crossover. It sucks so much power and adds a whole lot of haze. I have seen a lot of traction with multi amp direct coupled speakers. I am wondering what might truely make the most natural, alive and dynamic sound. A speaker with a crossover and appropriate amp, or a speaker with multiple amps, each attached directly to a driver with a active digital or analog crossover.

Passive on mids /highs active on bass will work over full active if you choose that route. Firstly you need to know ur xover insertion loss to really answer your question about power gains.

To know if ur system is underpowered or undersized for ur room , play one channel and lift the volume to a level which fills the room at a level u consider live to you liking if it cant then you require 4 times as much power as you currently have , active or not..!


Regards ..

 

[Kingrex]

lf you have sensitive drivers, why would you use Class D?

Because 6 x.class D amps is maybe $10k. 6 x low power SET is maybe $100k.

 

[Kingrex]

Passive on mids /highs active on bass will work over full active if you choose that route. Firstly you need to know ur xover insertion loss to really answer your question about power gains.

Are you saying use an active analog on the mid/highs and a full active on the woofers?

 

[adrianywu]

Most commercial loudspeakers have compromises that require tweeks in the crossover to work well. I have talked to Greg Timbers about the JBL DD67000 Everest, the last statement loudspeaker he designed at JBL before being forced out by the new owners. He said he was frustrated because the product design guys kept changing his design for their aesthetic goal. He therefore needed to design a crossover that is more complicated than necessary to compensate. He told my friend who owns a pair of these to remove the supertweeters and reposition them optimally to simplify the crossover, amongst other tweeks, to undo the problems introduced by the aesthetics of the design.
Therefore, it is not wise to try and modify commercial speakers for active crossover unless this is recommended by the manufacturer.
I build my speaker setup from the ground up with active crossovers in mind. I use an Accuphase F25 analog crossover, running 4th order L-R slope. I find this gives a cleaner result compared to 12dB slope. I have experimented with different amps before settling on a low powered class A transistor module for the Acapella plasma tweeters, 300B push-pull amps for the field coil midrange horns and Parasound transistor amp for the field coil woofers in ported enclosures. The field coils allow optimisation by adjusting the supply current to change the drive behaviour. I also physically time aligned the drivers. There are lots of variables but I am pretty settled now after experimenting over a span of a decade. The gain in clarity and dynamics by directly coupling the drivers with the amps are well worth the effort.

 

[morricab]

Because 6 x.class D amps is maybe $10k. 6 x low power SET is maybe $100k.

You need 6 stereo amps?? Or 6 monos? You could get 3 Aries Cerat Protos or Genus for well under 100K....You wouldn't even need a preamp as they are integrated. You could get 3 Ayon Crossfires used for about $15K. Just some examples... If you can't hear the difference that would bring compared to Class D...well...enjoy.

 

[audiobomber]

I am battling a crossover. It sucks so much power and adds a whole lot of haze. I have seen a lot of traction with multi amp direct coupled speakers. I am wondering what might truely make the most natural, alive and dynamic sound. A speaker with a crossover and appropriate amp, or a speaker with multiple amps, each attached directly to a driver with a active digital or analog crossover.

In theory, direct connection from a power amp to a driver is superior. Damping factor is optimal, resulting in greater dynamics and faster transients. As you mention, power requirement drops significantly. A passive crossover has to drop the level of each driver to match the least sensitive driver. For example, say your tweeter is 92dB/W/m, mid is 89dB, bass driver 86dB. You would lose 6dB to resistors, and instead of a 25W amp, you need 100W just to equalize driver sensitivity. Then you'll need baffle step correction, generally 4-6dB. Now you need ~300W for the same level as your crossover-less 25W system.

In the real world however, an active system is no panacea. I have tried to go active with a Marchand XM44 electronic crossover, Marchand XM46 passive line-level crossover and FMod modules. None were transparent, all compromised the sound of my amps. I then tried a single high quality cap on the input of my power amp to roll off the bottom end by 6dB/octave at 80Hz, relieving the monitors of the bass range to cross to a sub. The cap did what it was supposed to, it relieved the mid-woofers of deep bass, but caused grit at high frequencies, a bad trade. You are going to hear anything inserted between a preamp and power amp. The crossover had better be at least as good as your pre and power amplifiers.

You need to know something about speaker design to implement an active crossover. Simply ripping out a crossover and substituting an active crossover is almost guaranteed to fail. Mid and bass drivers often need a notch filter to deal with resonance above their operating range. Even with an active system, speakers need baffle step correction. Then there's time alignment, a tricky problem, compounded by the acoustic slope (natural roll-off) of the drivers and the electronic slope of the crossover. Speaker design is complicated, whether active or passive.

Amps are not cheap, nor are cables, and IME they need to extremely well matched for anything above the subwoofer range. Some people seem happy with different amps on their mid, tweeter and bass drivers. That was just awful to me. It was easy to get better bass and treble with non-identical amps, but coherence suffered; it was hi-fi sounding, not musical. I gave up on active crossovers. I run my main speakers full range, with subs connected in parallel and DSP corrections on the subs only.

A DSP solution with convolution filters, auto-eq software like REW or Accuphase and a USB microphone may be an ideal solution for someone with a fully digital system. I looked into it but haven't gone much further. It's a steep learning curve, and my system sounds so good to me right now that incentive is low for another audio system battle.

 

[Kingrex]

In theory, direct connection from a power amp to a driver is superior. Damping factor is optimal, resulting in greater dynamics and faster transients. As you mention, power requirement drops significantly. A passive crossover has to drop the level of each driver to match the least sensitive driver. For example, say your tweeter is 92dB/W/m, mid is 89dB, bass driver 86dB. You would lose 6dB to resistors, and instead of a 25W amp, you need 100W just to equalize driver sensitivity. Then you'll need baffle step correction, generally 4-6dB. Now you need ~300W for the same level as your crossover-less 25W system.

In the real world however, an active system is no panacea. I have tried to go active with a Marchand XM44 electronic crossover, Marchand XM46 passive line-level crossover and FMod modules. None were transparent, all compromised the sound of my amps. I then tried a single high quality cap on the input of my power amp to roll off the bottom end by 6dB/octave at 80Hz, relieving the monitors of the bass range to cross to a sub. The cap did what it was supposed to, it relieved the mid-woofers of deep bass, but caused grit at high frequencies, a bad trade. You are going to hear anything inserted between a preamp and power amp. The crossover had better be at least as good as your pre and power amplifiers.

You need to know something about speaker design to implement an active crossover. Simply ripping out a crossover and substituting an active crossover is almost guaranteed to fail. Mid and bass drivers often need a notch filter to deal with resonance above their operating range. Even with an active system, speakers need baffle step correction. Then there's time alignment, a tricky problem, compounded by the acoustic slope (natural roll-off) of the drivers and the electronic slope of the crossover. Speaker design is complicated, whether active or passive.

Amps are not cheap, nor are cables, and IME they need to extremely well matched for anything above the subwoofer range. Some people seem happy with different amps on their mid, tweeter and bass drivers. That was just awful to me. It was easy to get better bass and treble with non-identical amps, but coherence suffered; it was hi-fi sounding, not musical. I gave up on active crossovers. I run my main speakers full range, with subs connected in parallel and DSP corrections on the subs only.

A DSP solution with convolution filters, auto-eq software like REW or Accuphase and a USB microphone may be an ideal solution for someone with a fully digital system. I looked into it but haven't gone much further. It's a steep learning curve, and my system sounds so good to me right now that incentive is low for another audio system battle.

Sage advice.
Whats Baffle Step Correction? Is that another way to say time align?

 

[morricab]

In theory, direct connection from a power amp to a driver is superior. Damping factor is optimal, resulting in greater dynamics and faster transients. As you mention, power requirement drops significantly. A passive crossover has to drop the level of each driver to match the least sensitive driver. For example, say your tweeter is 92dB/W/m, mid is 89dB, bass driver 86dB. You would lose 6dB to resistors, and instead of a 25W amp, you need 100W just to equalize driver sensitivity. Then you'll need baffle step correction, generally 4-6dB. Now you need ~300W for the same level as your crossover-less 25W system.

In the real world however, an active system is no panacea. I have tried to go active with a Marchand XM44 electronic crossover, Marchand XM46 passive line-level crossover and FMod modules. None were transparent, all compromised the sound of my amps. I then tried a single high quality cap on the input of my power amp to roll off the bottom end by 6dB/octave at 80Hz, relieving the monitors of the bass range to cross to a sub. The cap did what it was supposed to, it relieved the mid-woofers of deep bass, but caused grit at high frequencies, a bad trade. You are going to hear anything inserted between a preamp and power amp. The crossover had better be at least as good as your pre and power amplifiers.

You need to know something about speaker design to implement an active crossover. Simply ripping out a crossover and substituting an active crossover is almost guaranteed to fail. Mid and bass drivers often need a notch filter to deal with resonance above their operating range. Even with an active system, speakers need baffle step correction. Then there's time alignment, a tricky problem, compounded by the acoustic slope (natural roll-off) of the drivers and the electronic slope of the crossover. Speaker design is complicated, whether active or passive.

Amps are not cheap, nor are cables, and IME they need to extremely well matched for anything above the subwoofer range. Some people seem happy with different amps on their mid, tweeter and bass drivers. That was just awful to me. It was easy to get better bass and treble with non-identical amps, but coherence suffered; it was hi-fi sounding, not musical. I gave up on active crossovers. I run my main speakers full range, with subs connected in parallel and DSP corrections on the subs only.

A DSP solution with convolution filters, auto-eq software like REW or Accuphase and a USB microphone may be an ideal solution for someone with a fully digital system. I looked into it but haven't gone much further. It's a steep learning curve, and my system sounds so good to me right now that incentive is low for another audio system battle.

I have considered the Marchand tube crossovers...I agree with you that I have yet to find a SS active xover that was truly transparent (two different Accuphases and a Bryston). The digital solution I came up with, where I use my own DACs that sound much better than what is typically integrated into all-in-one solutions was a very good all digital solution and was very clean and transparent.