Active Crossovers

[Mike Lavigne]

I don't want to repeat my self, but please consider my old post. https://www.whatsbestforum.com/threads/active-vs-passive-speaker-set-ups.19082/post-355542

BTW, Jim Smith in his great book goes frontally against by-amping using SS on bass and SET on top.

All just IMO - others can disagree - just posting because I spend a lot of time in such approaches unsuccessfully in the past, I still have an Audio Research EC22 active crossover somewhere . A good local friend wanted to get it, I decided not to sell it to him, he would surely come asking for help sometime in the future ...

coherency first and foremost always to allow for the reproduction system to not call attention to itself and allow just the music to come thru. which is why my transparent in the bass class d amped active bass towers get their source signal from the passive main tower speaker terminals. so you are free to power the main passive speakers with any amp you prefer (whether darTZeel ss, Lamm SET, or VAC pp) as the bass towers will then mimic that type sound. all three approaches end up of a piece with a balanced character top to bottom.

i'm sure there are compromises in any approach to full frequency extension, but some much, much less than others.

 

[Kingrex]

Well,

I don't want to repeat my self, but please consider my old post. https://www.whatsbestforum.com/threads/active-vs-passive-speaker-set-ups.19082/post-355542

BTW, Jim Smith in his great book goes frontally against by-amping using SS on bass and SET on top.

All just IMO - others can disagree - just posting because I spend a lot of time in such approaches unsuccessfully in the past, I still have an Audio Research EC22 active crossover somewhere . A good local friend wanted to get it, I decided not to sell it to him, he would surely come asking for help sometime in the future ...

I 100% agree. See my next post. Might take an hour to get it out.

 

[Maril555]

Here is another idea. This is if I add subs. And possibly biamp.
Again. My speaker is a PAP Trio 15 with Coax. The stock passive crossover is biaampable.
My First Sound tube preamp wants to see greater than 20K.
My Blade KT88 PP amp is about 30K
The Sublime K235 is 75K
In this, there is not much to do accept hook it up and add the right cards to the Sublime active crossover.
I maybe want to limit the signal to the Class D Atmasphere powering the main speakers to 80 or 100 hertz through the Sublime active.
The card going to the subs would maybe limit at 20 to limit any rumble or subsonic noise.
I also have to consider I may have to limit the gain on the KT88. If that were the case, baring going through the Sublime to limit the gain, where would I add a resistor to limit the gain.

Am I on the right track?

I've consulted my crystal ball and I got a prediction- you are going to play with active amplification for a year and then will revert to a single amplifier arrangement.
How I know?
Been there, done that. but, as always, YMMV

 

[andromedaaudio]

Probably he does not have a substantial numbered account in a Swiss bank to pay for it , as well as for the future upgrades and repairs....

As you seem to know the brand pretty well, it would be great if you pointed us the prices of the gear you have been praising.

A collegue from.the netherlands always used to say jokingly .

Better very expensive then not for sale at all

 

[Atmasphere]

Well,

I 100% agree. See my next post. Might take an hour to get it out.

If I were you I'd consider just doing a two way.

The amp driving the tweeter will be making almost no power at all especially in a higher efficiency situation. If the speaker already has a passive crossover, it won't be any problem for an amp doing the mids to do the highs too unless its grossly incompetent.

This is a lot easier to blend than a 3 way setup is!

You can use a solid state amp on the bass. At those frequencies almost any solid state amp has enough feedback to sound right (its at higher frequencies many of them get in trouble). The lower you cross over the easier this gets. But if you are intent on an SET you'll want this to be about 200Hz or higher to get the most out of the SET.

In any event you need to be careful about the phase of the amps and their relative gain.

 

[Kingrex]

Scott of Found Music who made my amps knows what my stereo is doing.
Scott introduced me to a speaker designer (Johan) who is making a horn sub. I don't have all the details at this time. I will make a new thread as I dig deeper.

Scott has always disliked subs. Lack of coherence. Phase issues. Usually a sound that while being bass, is not recreating the tone of musical instruments. Lots of reasons to dislike a sub and prefer a good set of full range speakers. Scott reciently changed his opinion after hearing the latest iteration of Johan's horn loaded sub.

I have agreed to a purchase one of These subs. A 10" version. The sub is not a 20 hert sub. Its not trying to shake the room or take over where my mains let off. What it is supposed to be is a very fast, accurate and musical sub. Johan will bring the sub to my place and set it up.

I am pretty excited. I have heard horn based subs. The best Simon/Garfunkel and Bob Dylan playback I have ever heard was on a system with horn subs. One of the few systems I have ever teared up in front of.

I am going to attach everything directly to the First Sound. If the First Sound is not able to drive it, I will cross that bridge then. Maybe try an active analog crossover to alter the impedance the pre sees. If that does not work, I hate to say it, but I may have to consider a different pre. My Amps are the best piece of equipment I own. The pre is the second. Not sure what I would say is 3rd. Maybe my speakers. Maybe my vinyl or digital setup. I sort of think its the speakers. They really are very good.

 

[Kingrex]

A collegue from.the netherlands always used to say jokingly .

Better very expensive then not for sale at all

Cheech and Chong said, time of weed and no money are better than times of money and no weed.

 

[Mike Lavigne]

Scott of Found Music who made my amps knows what my stereo is doing.
Scott introduced me to a speaker designer (Johan) who is making a horn sub. I don't have all the details at this time. I will make a new thread as I dig deeper.

Scott has always disliked subs. Lack of coherence. Phase issues. Usually a sound that while being bass, is not recreating the tone of musical instruments. Lots of reasons to dislike a sub and prefer a good set of full range speakers. Scott reciently changed his opinion after hearing the latest iteration of Johan's horn loaded sub.

I have agreed to a purchase one of These subs. A 10" version. The sub is not a 20 hert sub. Its not trying to shake the room or take over where my mains let off. What it is supposed to be is a very fast, accurate and musical sub. Johan will bring the sub to my place and set it up.

I am pretty excited. I have heard horn based subs. The best Simon/Garfunkel and Bob Dylan playback I have ever heard was on a system with horn subs. One of the few systems I have ever teared up in front of.

I am going to attach everything directly to the First Sound. If the First Sound is not able to drive it, I will cross that bridge then. Maybe try an active analog crossover to alter the impedance the pre sees. If that does not work, I hate to say it, but I may have to consider a different pre. My Amps are the best piece of equipment I own. The pre is the second. Not sure what I would say is 3rd. Maybe my speakers. Maybe my vinyl or digital setup. I sort of think its the speakers. They really are very good.

Scott is a very sharp guy. i spoke to him on the phone last week and he is pretty excited about these horns and Johan. could be awesome. best wishes with this Rex.

 

[Kingrex]

Scott is a very sharp guy. i spoke to him on the phone last week and he is pretty excited about these horns and Johan. could be awesome. best wishes with this Rex.

Johan sounds sharp too. Serious technology and tooling behind these subs. Its not a garage product. But I'm not allowed to discuss whats going on yet.
And no, I am not a dealer or distributor. Just an excited consumer.

 

[Newton John]

Been active for twenty five years. Wouldn't do it any other way.

Analogue at first then for past ten years digital with Linn Exaktboxes. Unlike the old analogue crossovers, these are not tied to one particular loudspeaker model. The only possible downside of Exakt I can see is that a Linn DSM is mandatory, so it is expensive.

 

[ajant]

I've consulted my crystal ball and I got a prediction- you are going to play with active amplification for a year and then will revert to a single amplifier arrangement.
How I know?
Been there, done that. but, as always, YMMV

If I were you I'd consider just doing a two way.

The amp driving the tweeter will be making almost no power at all especially in a higher efficiency situation. If the speaker already has a passive crossover, it won't be any problem for an amp doing the mids to do the highs too unless its grossly incompetent.

This is a lot easier to blend than a 3 way setup is!

You can use a solid state amp on the bass. At those frequencies almost any solid state amp has enough feedback to sound right (its at higher frequencies many of them get in trouble). The lower you cross over the easier this gets. But if you are intent on an SET you'll want this to be about 200Hz or higher to get the most out of the SET.

In any event you need to be careful about the phase of the amps and their relative gain.

Unfortunately, my woofers only play down to ~ 70Hz @ 80db/meter with low distortion. https://josephcrowe.com/blogs/news/altec-416-8b-in-100l-sealed

Therefore, I need to manage three or four of these subs. https://www.rythmikaudio.com/F12.html

I first thought of thought this DAC. https://www.merging.com/products/interfaces/hapi-mkIII

, using either of two 8 channel DAC cards (DSD optional)

But last year came this. https://danvillesignal.com/dspnexus-dsp-audio-processor

The dspNexus 2/8 with ADSP-21569 and AK4499EX is shipping - Danville Signal

Danville Signal Processing is a technology partner for high performance audio solutions. We provide SHARC-based DSP modules for a variety of OEMs, ODMs and oth

danvillesignal.com

with arguably better sounding AKM DAC chips, than those in the Merging Hapi, and presumably an equally well designed clocking, output stages and power supply. https://audioxpress.com/article/outboard-dsp-danville-signal-dspnexus

I like the option of potentially biamping two or three-way speakers, though I would need to rely on Danville’s partner Hollis Labs to design and install the crossovers on my Windows pc. And few horn speaker owners seemed to have used this DAC.

Furthermore, some have had issues with Danville’s replies or lack of same. https://www.audiocircle.com/index.php?topic=191930.msg2015596#msg2015596

Comments? Suggestions?

 

[tedevegas]

Am using the Sublime Acoustics K235 it's 3 way XO capable but am only using 2 way for my Silbatone & Diptyque Active Biamp/2 way.
I got it when they were first launched so i got it on the pre-order price but even at normal price it's quite decent. It's an analogue XO and you have to decide the XO point and slope am using 1600 hz, -12dB slope..

I’m using my k235 in stereo 3 way mode. I’m thrilled with it. Super high quality and exceptional fidelity. Highly recommend.

 

[Nuforce]

Glad to see another happy Sublime Audio owner! A really should sell my K231 and get the 235.

 

[Kingrex]

Unfortunately, my woofers only play down to ~ 70Hz @ 80db/meter with low distortion. https://josephcrowe.com/blogs/news/altec-416-8b-in-100l-sealed

Therefore, I need to manage three or four of these subs. https://www.rythmikaudio.com/F12.html

I first thought of thought this DAC. https://www.merging.com/products/interfaces/hapi-mkIII

, using either of two 8 channel DAC cards (DSD optional)

But last year came this. https://danvillesignal.com/dspnexus-dsp-audio-processor

The dspNexus 2/8 with ADSP-21569 and AK4499EX is shipping - Danville Signal

Danville Signal Processing is a technology partner for high performance audio solutions. We provide SHARC-based DSP modules for a variety of OEMs, ODMs and oth

danvillesignal.com

with arguably better sounding AKM DAC chips, than those in the Merging Hapi, and presumably an equally well designed clocking, output stages and power supply. https://audioxpress.com/article/outboard-dsp-danville-signal-dspnexus

I like the option of potentially biamping two or three-way speakers, though I would need to rely on Danville’s partner Hollis Labs to design and install the crossovers on my Windows pc. And few horn speaker owners seemed to have used this DAC.

Furthermore, some have had issues with Danville’s replies or lack of same. https://www.audiocircle.com/index.php?topic=191930.msg2015596#msg2015596

Comments? Suggestions?

Danville looks like a positive way to go. The only issue I have with it is, any change to the room may necessitate a change to the crossover. let say it get set up properly, but you decide to add a sub. You are going to have to go into the program to alter it. Not the end of the world. And the flexibility is nice. But its work that can be hard to master.

I was reading the Danville system is really built around taking a digital signal and sending it to the dspNexus. The Nexus then does its crossover work, then acts as a DAC to send the analog signal to a amplifier. No DAC is required. I get it. It may be superior on many levels. But is it always. And I did not see much about how to drive a analog system. My assumption is it has a DAC to turn the analog to digital, then back to analog again. Again, I get it. But its a bit to swallow. I would love to stay analog in analog. If I was most all digital, ditching a DAC would be a big money saver.

 

[Kingrex]

I am not sure how to purchase cards for the Sublime analog active crossover.

I want to continue to use my analog crossover for the mid and high frequency driver. This is in part because I have only 1 amp to drive the 2 drivers.

I figure I can use just the active crossover to control the woofers.

The question I have, what values do I want to get for the cards. I don't mean the actual values. I mean, I know roughly where the current crossover for the mid and high frequency cuts off. I can run pink noise and disconnect drivers and see where it falls away and picks up. I can also get some sense of the steepness. The question is, do I get a card that cuts off lower than the stock crossover. That way I know I have captured the total of the signal needed to fulfill the stock crossover needs.

What about the low end? I guess I need to nail that right on with the active crossover as it not cutting of the bottom. Only where it blends to the mid and highs.

At some point I am going to want to not use the stock crossover on the mid and highs and use the active, then use a inline filter to limit the frequency getting to the horn tweeter. But that is down the road,

 

[Nuforce]

I am not sure how to purchase cards for the Sublime analog active crossover.

Just email them. I've bought a few different cards. DM me if you want their email address.

 

[Kingrex]

Just email them. I've bought a few different cards. DM me if you want their email address.

Yea. I think I will run the sweeps and pink noise for each driver. Then send them the images. They can see the cutoffa d probably know the slope by how fast it drops off.

So, the 231 or 235? I'm just experimenting. And the specs are very similar. I doubt I will use the baffle step compensation. Sound like it an EQ to drop the high frequency output.

 

[tedevegas]

Just installed a Sublime Acoustic K235 in my system and wow, what an upgrade. The build is top notch and simplistic beauty. The sound is excellent, every ounce of hi fi. I use the low to feed 50hz and down to my powered subs. 50hz to 375hz to feed my woofs in my 3 way cabs. 375hz and up to feed the mid/highs. The 4 rotary controls are perfect for tweaking balance. Solid and quiet. The whole unit idles silent. It allows my subs to blend perfectly, I don’t hear the break between subs and my mains, which I love. This is an amazing upgrade for me and my system. Super value for what you get here. I’d highly recommend for anyone looking to take their system to the next level. Great piece!!

 

[Kingrex]

My sub is very adjustable on its own so I will cut it off around 120.

The woofers play from about 50 up to 600. The midrange is about 600 yo 1800. The horn tweetet is 1800 up to 20,000.

 

[Kingrex]

I sort of want to get a CJ Classic 62 amp. I would use my Blade on the horn tweeter. The Classic 62 on the midrange. And the Musical Fidelity on the woofers. I feel if I went fully active, no passive crossover that a CJ would come much closer to the Blade than a SS. My Audion SET 845 sounds like crap when paired with my Blade. Does not work at all.