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Thread: The JL Audio CR-1 analog vs TacT digital crossover

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    Addicted to Best! marty's Avatar
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    The JL Audio CR-1 analog vs TacT digital crossover

    I recently installed a JL Audio CR-1 crossover in my system. As many of you know, my system has used a highly modified TacT 2.2 XP for many years, which served the dual purpose of providing DSP EQ as well as acting as the electronic crossover between my Pipedream Towers and JL Gotham subwoofers. System details can be found here:

    http://www.whatsbestforum.com/showth...ectrals+arrive

    Those of you who have followed my trials and tribulations also know that I have found the use of DSP extremely beneficial in solving what has been a number of difficult obstacles in trying to mate Pipedream Towers with a subwoofer from a different manufacturer. A detailed accounting of my rationale for the use of DSP can be found here:

    http://www.whatsbestforum.com/showth...highlight=tact

    So if I have championed DSP for so long, what on earth could have motivated me to even try the JL Audio CR-1 crossover? The answer is simple. One day, the TacT just up and died. When it did, I thought I was going to be sick. I actually had to turn the system on and off again several times and do some easy diagnostics to make sure that was the piece of gear that wasn’t working. Each time I turned the system off and on again, I closed my eyes hoping I would wake up from a bad dream. But unfortunately, it was not to be. The TacT really did go belly-up. For those of you that don’t know the TacT story, I’ll cut right to the chase. The company went out of business several years ago. Fortunately, there is a world of TacT devotees (on a well known Yahoo TacT forum) that have been instrumental in keeping owners informed and helping them with any technical issues and who have truly been selfless in helping those of us in need. Those folks are sort of a combination of a cult and service center created out of need, not unlike the folks who have maintained classic American cars in Cuba for several decades.

    I only had one chance and it was a long one. I contacted the often-elusive Anthony Padilla, who did my original mods and is considered the grand master of the TacT. Fortunately, Anthony replied to my request for servicing the unit and said he would do the best he could to fix it, but also warned me in advance that depending on what the problem was, it may not be fixable. More on that later. But in the meantime, I shipped of the TacT to Anthony in Las Vegas, and continued my rapid descent into 5 stages of mourning and grief described by Elisbeth Kubler-Ross in an effort to cope with my loss (denial, anger, bargaining, depression and acceptance). One can easily see my denial earlier (turning the system on and off hoping it was a bad dream). But anger (how can you possibly die on me, I’ve been so good to you?), bargaining (please, please work and I promise I will never play too loud again!) soon followed. Once the unit was shipped off, depression was a “gimme” as I sat looking at a system that I wasn’t sure would ever make joyous music again. Fortunately, acceptance soon followed as I realized there just might be light at the end of the tunnel. After all, didn’t I just read a glowing review by Jon Valin of the JL-CR-1 crossover? Hell, why not try it? What’s the worst that could happen? A phone call to one of my favorite dealers, Anthony Perotta soon followed with the arrival of a CR-1 at my door.

    I really am going to try and be very careful here and avoid the Valinisms that often plague reviews of high-end audio equipment. For quite a while, Jon Valin thought the latest thing he reviewed was the greatest thing he ever reviewed. If days of the week were audio gear and it was Friday, he would say that Friday was absolutely the greatest day of the week. It’s almost as if he didn’t read what he wrote about Thursday, a day before, when he proclaimed Thursday as the greatest day of the week, or about Wednesday, the day before that. You get the idea.

    Substituting the CR-1 for the TacT was a breeze. Hooking up the power cable, L/R inputs from the VTL 7.5III, L/R low pass output to the subs and L/R high pass output to the Spectral 400 driving the Pipedreams took about the same time a toasting a bagel. Then there was the moment of truth that always occurs turning on new gear and hoping that smoke doesn’t appear somewhere. And sure enough, there was none. In fact, it was so quiet I wasn't certain it was on at all. But it was!

    It is the information I am about to reveal in this brief paragraph that in large part, summarizes the beauty of the work done by the CR-1’s designers. There are only two main rotary continuous controls for each channel; one that sets the crossover point (I set it at 80Hz; the same as I used for the TacT), and one to adjust the damping factor (the key to its ultimate performance). There is also a fixed switch that sets the slope of the crossover for both channels (12 dB or 24dB per octave; I chose the latter), and then one absolutely magnificent and ingenious rotary control that adjusts the level of the subs to the “satellites” of both channels simultaneously (no need to adjust 4 different levels independently). To understand why this design is so beautiful, let me put it this way. Getting my TacT to work really well took eight years (yes, sadly that’s very true). Getting the CR-1 to work well took about 8 minutes.

    Now the first thing I would be thinking if I were reading up to this point would be: how can this guy, who is giving up a device with basically unlimited tone shaping controls using DSP, possibly be happy with a device that now takes away all tone shaping from his system? To which I would say- damn good question indeed!

    But the truth is, I really do have a number of places in my system I can alter the overall frequency response of my system. First, there are tweeter level controls on the Pipedreams that allow the tweeters to by lowered or increased in two small increments in either direction. Next, recall I am using MIT interconnect cabling (necessitated by the Spectral amps) each of which employ little boxes with 5 position detents on each box that range from “less” to “more”. Less to more of what exactly, I have no freakin’ idea, but they’re there! And the MIT speaker wires (HD 90 rev 1) also have a 2-position switch on them (“normal” vs. “SHD”, whatever the hell that means. For the record, Bob Harley seems to think the SHD position works best. I think it’s a bit too “bright” and use the normal position). And don’t forget, the CR-1 allows the most basic function of setting the relative levels between the Gothams and the Towers. So all told, I have about 8 basic “tone shaping” controls per channel. (MIT adjustable interconnects run between the Meitner CD and the VTL pre-amp (1); VTL preamp to CR-1 (2); and CR-1 to Spectral 400 (3). MIT adjustable speaker cables from the Spectral to the Towers (4); the tweeter control on the Pipes (5) and the sub/sat level control on the CR-1 (6). In addition, there are two critical tone shaping controls; the remarkable damping control on the CR-1 (7) and the all important woofer phase control on the subs themselves (8).

    So, with only 8 “tonmeister” controls (borrowing the term from Deutche Gramophone’s engineers), can the system possibly sound as good as it did using the venerable TacT, with its virtually infinite level of adjustability? The answer is- perhaps somewhat surprisingly, yes and no. Let me share with you what the CR-1 does well. As many critics of DSP adamantly claim (although most of them have never used a good DSP unit, or for that fact, never heard a system where one is done well), only an analog system is capable of delivering all the nuance and subtlety inherent in the music, as that would be simply impossible using a signal processed in the digital domain. IMHO, that’s just not an accurate statement. What I can say is that in my system , having used both the TacT and the CR-1, is that digital conveys with an astonishing degree of verisimilitude, all that is rendered with the CR-1 as far as instrumental timbre. Now remember what Valin has said about the CR-1; namely that it was the first electronic crossover he has ever heard that basically had no sound of its own. I would largely concur. It is an amazingly superb transparent device. That said, I would have to say that the one area in which I think it is superior to the TacT is in the very top end of the treble range. This is most notable on instruments with prominent treble information; cymbals in particular shimmer with detail that I honestly think are more revealing than my TacT was able to reproduce. But most importantly, it is also apparent in its rendering of the “air” of the orchestra, which I have previously called the orchestra’s “penumbra” (roughly translated: an area that lies on the edge of something; a fringe; related to, connected to, and implied by, the existence of something else that is necessary for the second thing to be full and complete in its essential aspect). The other term I like to use for this is the orchestra’s “corona of energy”, but they both reflect a similar idea. Yup, I would have to say the CR-1 wins in this regard, but let me also say that the difference is hardly major. It is, in fact nominal, but it is there. I will also add that throughout the vast majority of the remaining frequency range, including the all important midrange, the argument of superiority of DSP vs analog using the two instruments described here (TacT vs. CR-1) is moot, at least to my ears. I would be hard pressed to pick them apart in a blind test on a wide variety of sources. (I know DSP believers are shaking their head up and down here, while the naysayers are shaking their head horizontally while muttering “this guy’s nuts”). Ah, the lively dialog we have among us as audiophiles.

    Let’s turn our attention to the other side of the coin. Is there something the TacT does, that the CR-1 cannot do? You bet, and in fact it is two things. The first is that the ability to accurately equalize the bottom end is far superior with the TacT. Most room resonance lie below 400Hz, and that is where system EQ is most beneficial. As one would expect, the ability to make pinpoint adjustments in the frequency response, particularly below 150Hz, is a huge advantage for the TacT in that can provide an essentially flat and linear frequency response in this range, all but eliminating pernicious room boundary effects. Got a 7 dB peak at 80 Hz but a 5 dB dip at 76 Hz? No problem for the TacT as the bass EQ can be altered accordingly. You almost have to be a moron not to get great bass response using a DSP device that can make very small finite adjustments. As good as the CR-1 is, and it IS good, it simply cannot do that. Despite not having the ability to dial-in the bass response with ultra pin point accuracy and in accordance to the target curve of your preference, that limitation of the CR-1 is not a deal breaker for me. In fact, the bass response I can achieve with the CR-1 yields excellent bass in my room, and I suspect the phrase “in my room” is the key to that remark. I am fortunate to have a fairly large room, so my need to optimize the bass response may not be the same as if I were in a smaller room, where room boundary effects may argue more strongly for the need for the application of moderate to heavy EQ.

    But now comes feat number two, which gets right to the crux of the matter. As good as the CR-1 is, it simply does not have the ability to account for the inevitable difference in time arrival of the signal emitted from the Towers and the Gothams, which are located about 4 feet behind the Towers. The TacT allows the signal of the Towers to be retarded in the digital domain by approximately 8 msec. This allows the signals from the Gothams and the Towers to arrive at the listening position at the same time. There is simply no substitute for this requirement if one wishes to have the sound from both sources appear as though it was “cut from the same fabric” as HP would say. The phase control on the Gothams are indeed a critical component of getting the best sound, but there is no way on God’s green earth that any such analog control can act as a time machine and advance the waveform to where it needs to be to arrive at the same time as the sound coming from the Towers. The only way to do this correctly, is to retard the timing of the Towers, and as far as I know, that can only be achieved in the digital domain. Actually, I want to modify my remark to say that this is true if and only if the woofer is not in the same plane as the Towers. I have heard some system that use JL subs effectively as add-ons to a full range system that can achieve a near seamless time difference to the signal coming from the mains, but in these instances, the subs are always placed in the same plane as the mains. For all intent and purposes, if the subs are located behind the mains, it is physically impossible for the sound from both speaker sources to arrive the listener’s ears at the same time without DSP. I’m not saying that without DSP the sound will necessarily be terrible, and in fact it might actually be pretty good. But in this case, for the truly critical listener, good really is the enemy of near-perfect and the difference in the resultant sound is very noticeable between these two paradigms (DSP with timing correction and anything, digital or analog, without timing correction between the subs and the mains).

    Unfortunately, because the CR-1 does not perform the timing correction that I had when using the TacT, the resultant sound quality is very different psychoacoustically. With a well set up TacT, the sound stage and its penumbra was indeed seamless with respect to frequency, just as it would be if you were attending a concert. Again to borrow HP’s term, all the sound in the sound field seemed to be cut from the same cloth. The “corona of energy” from the lowest frequencies were perfectly in unison with the “corona of energy” produced by the highest frequencies. The psychoacoustic effect was profound. I was able to be transported into a very believable cogent sound field that in some very important ways, made me forget I was listening to a speaker system. And therein lies the rub when the CR-1 was substituted for the TacT as my crossover device. As good as the CR-1 is (and again,it IS indeed damn good!), there was always the sense that I was not listening to a performance in a hall, but a stereo system, albeit a very, very good one. Yes, some fine details were better rendered with the CR-1, but not the sense of wholeness for the psychoacoustic space over the full spectrum of sound that is most apparent on orchestral recordings. Now, if I played something like Adele 25 and you asked me which sounds better, I would say, who cares? I would be inclined to tell you that neither device would be able to get me interested in hearing the fine details of the air or top end in such a lifeless recording, and the lack of timing alignment of the bass wouldn’t bother me if the delay in arrival time were not compensated appropriately to the sound from my Pipes. So please consider that my remarks pertain only to source material of the highest caliber. Everything else is certainly listenable in relative terms, but the nuances I’ve described are really best observed with great source material.

    To wrap up, there is unfortunately, no “best” here, rather only differences between a well optimized system employing either a DSP or an analog instrument to provide crossover capabilities and tone shaping. As to which sound I prefer, the truth is, at this point I’m not sure. There are clearly things about each piece of gear I like, as well as a few misgivings I have noted for both. One obvious solution to my dilemma is to wonder if there is a way to delay the arrival time of the Towers in some analog manner that could be incorporated into the CR-1 without mucking up its great sound. But then again, if it were easy, I’m sure it would have already been done by now.

    In the interim, what system am I going to use since I have the choice of using either? (The TacT was fortunately repaired by the great Padilla-a blown cap on one of the digital boards, I'm told). For the moment, I’m sticking to the CR-1 to see if I can further optimize its performance to capture that elusive psychoacoustic sense of sound field unity that the TacT provides so well due to its timing correction capabilities for my particular set-up. Perhaps unfortunately, stubbornness and perseverance have plagued me my entire professional career and although they can be Hyde-like qualities, my Jekyll persona acknowledges that they have been a tremendous asset as well. So has it been with my audio adventures as well. I mean really, nobody in their right mind fiddles with minor deviations on a TacT for eight years in the hope of achieving great sound, therefore it’s OK if you call me crazy. I am. But I truly enjoy the learning experience and will continue to do so by playing with the CR-1 for a while longer. TacT, the company, may be dead, and even though I consider the Padilla modified Tact 2.2 XP a sonic masterpiece, there are other modern variants of DSP that I might consider if I want to go down that road again. No need to tell me what they are- I think I know the current players. However, first hand comparative listening experiences would be more than welcome and eagerly received.

    Marty
    Last edited by marty; 12-26-2015 at 06:30 AM.

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    [WBF Founding Member] Moderator RBFC's Avatar
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    Marty,

    Great write-up. I've used the term "dome of ambiance" to describe an orchestral sound field. Have you spoken with Barry Ober of JL to get info about the group delay of their subs? Knowing that part of the equation may help with your eventual calculations, etc. I suspect you've done a great deal of homework here, so just offering a perhaps-redundant piece of the puzzle.

    Lee
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    Hi Marty, some questions on your system with TacT and without it, some of which we discussed over email but it might help to post here for the benefit of others.

    1. Your system had the best slam, speed and jumps I have seen alongwith the Trios and bass horns. How has this changed with the loss of the TacT but with the inclusion of the Cr1?

    2. The other thing I thought your system was excellent at is during crescendos on high volumes, the room would not feel overloaded. Normally with other systems, the volume gets set for one level, but as the decibel level swells due to the music, the room gets overloaded. I assumed the TacT was managing this in your system. Without the Tact, does the room get overloaded at any point?

    3. Has the tonality, soundstage, or imaging changed without the TacT?

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    Site Founder And Administrator Ron Resnick's Avatar
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    Dear Marty,

    I greatly enjoyed reading about your extensive experience with the CR-1! Thank you for the write-up!

    I am afraid you must have answered this already -- but since I see in the photo of your listening room space to the outside of each tower why don't you relocate the Gothams to the same plane as the towers and obviate the need for the digital time delay?
    Last edited by Ron Resnick; 12-26-2015 at 04:35 AM.
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    Addicted to Best! marty's Avatar
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    Quote Originally Posted by RBFC View Post
    "dome of ambiance"
    Lee, I love the term "dome of ambience". Whether we use that or "corona of energy" or "penumbra of the sound field", it sounds to me like we are talking about the same thing.

    As far as group delay of the subs, I don't think that's going to do it as it's not the subs that need to be delayed but rather the Towers (mains). The TacT does this in its initial set-up by using impulse signals to calculate time arrivals from the subs and then delays the arrival time of the mains to match it. This is confirmed and validated by measurements you can see on your computer using the TacT software. Its really a beautifully done system, which as many know, was derived from the original Lyngdorf system when Boz and Peter Lyngdorf were partners. Too bad Boz (TacT) went bust.
    Last edited by marty; 12-26-2015 at 06:14 AM.

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    Addicted to Best! marty's Avatar
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    Quote Originally Posted by bonzo75 View Post
    Hi Marty, some questions on your system with TacT and without it, some of which we discussed over email but it might help to post here for the benefit of others.

    1. Your system had the best slam, speed and jumps I have seen alongwith the Trios and bass horns. How has this changed with the loss of the TacT but with the inclusion of the Cr1?

    As I tried to suggest in the OP, its close, but its not exactly the same. How can it be if the signal from the subs lag behind the Towers by 8 msec? its the difference between "you are there" and "you are almost there but you are listening to a stereo system". For most material, you may not notice much difference. On the other hand if your a little obsessional, you might.

    2. The other thing I thought your system was excellent at is during crescendos on high volumes, the room would not feel overloaded. Normally with other systems, the volume gets set for one level, but as the decibel level swells due to the music, the room gets overloaded. I assumed the TacT was managing this in your system. Without the Tact, does the room get overloaded at any point?

    The room performance never changes and never overloads. This is not a feature of the TacT, but of the room itself.

    3. Has the tonality, soundstage, or imaging changed without the TacT?
    Re #3. Fortunately, these have not changed.

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    Addicted to Best! marty's Avatar
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    Quote Originally Posted by Ron Resnick View Post
    why don't you relocate the Gothams to the same plane as the towers and obviate the need for the digital time delay?
    Great question. Ron. Pics can be deceiving. There just isn't enough room. Locating the subs outboard of the Pipes would not allow me to access my CD rack on the right, or my turntable on the left. I also think they would be too close the side wall, particularly on the right.

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    Site Founder And Administrator Steve Williams's Avatar
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    Terrific write up Marty and knowing you as I do I am betting that you have pretty much everything worked out but I do believe that you will not be completely satisfied and will return to TacT
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    [WBF Founding Member] Moderator RBFC's Avatar
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    Quote Originally Posted by marty View Post
    Lee, I love the term "dome of ambience". Whether we use that or "corona of energy" or "penumbra of the sound field", it sounds to me like we are talking about the same thing.

    As far as group delay of the subs, I don't think that's going to do it as it's not the subs that need to be delayed but rather the Towers (mains). The TacT does this in its initial set-up by using impulse signals to calculate time arrivals from the subs and then delays the arrival time of the mains to match it. This is confirmed and validated by measurements you can see on your computer using the TacT software. Its really a beautifully done system, which as many know, was derived from the original Lyngdorf system when Boz and Peter Lyngdorf were partners. Too bad Boz (TacT) went bust.
    Marty,

    I completely understand regarding the need to delay the towers, not the subs. I mentioned group delay since it may provide you a way to know how much to add to the distance-related delay of the towers. If you end up using something that is not like your old unit, I thought it might be useful for you to have a "total ms delay figure" that described the positional and the electrical characteristics of your current setup. I guess my first response was poorly worded.

    You might find a device that offers basic delay, such as the typical audio-video synchronization functions in receivers, that is very transparent due to its simplicity. I wish you luck!

    Lee
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    Member Sponsor Addicted to Best! mauidan's Avatar
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    Marty,

    Nice to read that AP was able to repair your RCS 2.2XP.

    I still think you try using the Meitner on the HP output instead of the TacT DAC card.
    Dan

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