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Crossover Network Comparison


muel

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I posted some comments on networks on Deans "Crossover Roadshow" thread but I thought I'd put this in a separate thread along with a few other thoughts.

I’d like to share my experience with different networks that I have tried on 1976 Lascalas and 1968 Cornwalls. I have used some of these with the stock horns but I first started looking into different networks due to my desire to attenuate the midrange after I started using wood horns.

Before I start, I’d like to mention that so often people discuss their opinions of equipment and they never mention other details that could be important variables to consider such as WHAT music? How LOUD? What size/dimensions of room? I think you should answer some of these kinds of questions so we will understand more about your motivation and we can relate to your position.

GOAL: Accurate reproduction of music but must be MUSICAL (adj. “having a pleasant sound”) to the point I forget the equipment and the room I am in and become immersed in music.

DETAILS:

Equipment used was a Scott 299b, VRD amps and a few different DACs including DacMagic, MHDT Havana, and Bel Canto. People often talk about their opinions about equipment and never mention what they listen to and how loud which I think is significant information. Music is mostly rock, jazz, blues, or classical. Mostly jazz these days but a lot of piano and guitar (acoustic and electric) as well. To keep the family happy I usually keep it around 70db or less but prefer 75db or more. My room is an odd shaped 19 x 16 with an offset vaulted ceiling that makes getting the soundstage straight difficult.

NOTE: These are impressions I had over time while swapping around equipment to see what I liked. I don’t have test equipment although I have played some with Studio Six “Audio Tools” on the iPhone without a proper microphone. I was not very scientific in my approach. I did not usually perform any precision tests between different equipment where I only changed one variable to draw a comparison. Most often there were other things that had changed over time such as K-55v driver might have been replaced with a K-55m or I was using them with a Fastrac Lascala, Fastrac Cornwall, or an Eliptrac with a 2” driver. Perhaps the speakers had been moved. Most of the time these wood horns were sitting on top of the cabinet which could also be a significant variable given their location relative to the other drivers. I have since learned to keep a log book of everything I do or change. I suggest this highly… I don’t remember every step I took along the way but this will be a nice reference to remind me in the future.

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Here is what I have used besides the stock networks (B networks and AA) with original caps as well as Sonicap replacements from Bob Crites.

ALK Cornwall B Series replacement Ver 2.

– Used in Cornwalls with stock horns and Cornwalls with Cornwall Fastracs.

  • To my ears a very even response top to bottom with stock horns. With Fastracs the mids were just too loud and I was going to have to find a way to attenuate.
  • These networks are still worth building if you are sticking with stock horns. Not very flexible though.

ALK ES-5800 and ES-500T networks

- Used in Lascalas with Cornwall Fastrac

  • Can attenuate highs and mids
  • Pinpoint accuracy – places each instrument precisely!
  • Very clear and holds up well to any volume you want. Drivers don’t seem to be working hard at all.
  • Much under 80db it starts sounding restrained or soft. Sound stage shrinks at lower volumes.
  • Great if you listen loud or like to have block parties. Probably better than the neighbors deserve.

ALK ES-5800 and AP12-500 networks

- Used in Cornwalls with Cornwall Fastrac and Lascalas with Lascala Fastracs and with Cornwall Fastracs

  • Can attenuate highs and mids
  • Pinpoint accuracy – a little more cohesive than the ES-500
    (ES are very nice above 80 db or so)
  • Good imaging – best at higher volume
  • Very clear at any volume.
  • I kept creeping the volume up to 75db or higher and didn’t even realize I had it that loud.
  • I liked the AP12-500 better than the ES-500. It would be interesting to hear this with really nice caps but that would be cost prohibitive.

ALK CornScala-Wall networks

- Used in Cornwalls with stock horns and Cornwalls with Cornwall Fastracs. Also used with Lascalas even though the crossover is a little high at around 600hz for the bass bins)

  • Can attenuate the highs (resistor based) and mids
  • Not quite the clarity or accuracy of the higher end ALK networks… more balance between the drivers.
  • Sounds open and still decent soundstage at lower volumes. Can play loud and doesn’t fall apart as quickly as stock networks but still no match for the steep slope ALK networks.
  • Impressive for the money. For late night listening on the Cornwalls with Fastracs these were my preferred networks.

- I recently replaced the stock capacitors on the ALK CornScala-Wall network with Mundorf MCap EVO Aluminum Oil caps. I tested for a short time on the LaScalas with Eliptracs and will be moving them to the Cornwalls soon

  • Initial impression is they have been opened up and there is improved resolution. If these need break-in time I’m pretty happy because they sound better from the beginning. I’ll have to wait to hear if I think they were worth the investment.

Aletheia Audio Super AA with VH Audio OIMP V-Caps

- Used on Lascalas with Eliptracs

  • Can attenuate the mids
  • Most cohesive I have heard… VERY balanced and even sound
  • Excellent resolution (hear it all… good and bad)
  • No harshness, not bright but still very clear
  • Can be pushed loud without falling apart but ALK ES networks still have the edge there.
  • My current network of choice.

I’m not leaving out Bob Crites crossovers… It is just that I wanted the ability to attenuate the mids. I’ve gotten a lot of parts from him over the last couple of years.

Bob, Al, and Dean have all been great to deal with and have been very patient and helpful to me. I have no problem suggesting you do business with any of them.

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I've always told people that the stock horn is the bottleneck, and that if they changed to a Fastrac, a Type AA can be run up almost as high as the Super AA without much of a problem. The Type AA has a hotter midrange, that's why I say "almost". I see some things in your notes about this that bother me, and now I'm wondering if I'm off on this one. The Super AA just adds a single coil in series with the mid-driver, it shouldn't be making the kind of difference your notes seem to indicate it does. OTOH, my experiences are tied to the experimentation I did in a room that by normal standards would be considered pretty small.

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Hi Cameron -- no, it's fine. The problem isn't with your experience or with what you wrote -- the problem is with what I'm telling people. When you say that the Super AA allows the speaker to be played louder "without falling apart", I'm assuming you are saying this in how they relate to the Type AA's you had. When I did these comparisons myself years ago, I found that with the Super AA set to 4 and 0, the upper SPL limit was about the same as the Type AA. Sitting 12 feet back in my small room, 95dB -100dB with peaks of 115dB was it. After that, distortion was clearly making it's presence known. If I lowered the midrange output a couple of dB, it helped a little, but not much. In short, your comments contradict my own experience, but then, my Type AAs were built quite a bit different than yours, and of course the room -- which always plays such an important role. I just need to provide more detail and add a caveat or two when I talk to people. Thanks for the much needed detailed evaluation of these various networks.

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Ok. That makes sense. I've done very little measuring of anything so I am just offering my impressions. I am not scientific about this stuff even though I find that side of things very interesting and useful. When I say "falling apart" I mean when anything unpleasant is happening. I don't know that I am neccesarily talking about distortion levels as much as my perceived level of harshness. I feel confident in saying that my Super AA's are more comfortable to listen to versus my Sonicap updated AA networks at louder volumes. Well... most any volume for that matter.

It is nice to be able to get to the level of "too fricken loud" before distortion becomes evident. I just don't listen at the level you describe (or maybe a little louder) for very long but it is fun sometimes in short durations.

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Sitting 12 feet back in my small room, 95dB -100dB with peaks of 115dB was it. After that, distortion was clearly making it's presence known.

Isn't that plenty loud enough? I think this is why I could use the JBL 2365 and not have it quack at me. I just don't listen at that high a level.

Bruce

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Thank you Cameron for the write up, really nice. I know you've been very helpful to me with your advice and it's really appreciated, probably saved me a bunch of cash because I didn't have to do all of the experimenting that you've done to find something that really worked well to my ears. I know that after I sent the ones that Dean is sharing with everyone to the next guy, that's when it set in just how darned good they sounded. I'm really anxious to get them from him when he gets them done because the cornscala walls just don't cut it in the La Scalas like I thought they did before I tried his out.

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I'm glad I helped! It is nice to save a step or two when you can! I could have spent many years and still not found the level of enjoyment I have now if not for the numerous contributions from others here at this forum.

You are right about the Cornscala-wall networks... they are better left for Cornwalls. Actually, for Cornwalls with Fastracs I think I'd prefer the crossover down a little lower. I have to admit though... I left the Cornscala-wall networks on the Lascalas for quite a while.

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I did a little surgery on my Cornscala-wall networks... swapped out the caps for Mundorf EVO aluminum oil. Only tested for a couple of hours on the Lascalas but hope to get them into the Cornwalls soon. I'm pretty encouraged by my first brief listen! I don't think you'd go wrong with these from Al or an "upscaled" version from Dean.

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I need to call Al tomorrow about that network. I just saw Dave Harris recommend it for a Belle user. I know what Al is thinking. The roll-off is so slow that the horn ends up determining the acoustic crossover - which is why he calls them "Universal". However, the electric and acoustic combine, and so the roll-off ends up being a little steeper than the electrical alone. The low pass coil is also half the size of the one used in the Universal Type A, which will have an impact on the upper midrange output. This is an area where Al and me still haven't come into perfect agreement -- I just don't like the idea of that thing in a Belle Klipsch or LaScala as a permanent arrangement. I think the answer is an economy version for the Klipschorn, LaScala, and Belle Klipsch, which can be done by simply adjusting two values: .62mH > 1.5mH and 33uF > 47uF. Those using the K-55 or BMS could use it as well. Those using drivers with titanium or aluminum should stay with the original design.

Edited by DeanG
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Hi Cameron -- no, it's fine. The problem isn't with your experience or with what you wrote -- the problem is with what I'm telling people. When you say that the Super AA allows the speaker to be played louder "without falling apart", I'm assuming you are saying this in how they relate to the Type AA's you had. When I did these comparisons myself years ago, I found that with the Super AA set to 4 and 0, the upper SPL limit was about the same as the Type AA. Sitting 12 feet back in my small room, 95dB -100dB with peaks of 115dB was it. After that, distortion was clearly making it's presence known. If I lowered the midrange output a couple of dB, it helped a little, but not much. In short, your comments contradict my own experience, but then, my Type AAs were built quite a bit different than yours, and of course the room -- which always plays such an important role. I just need to provide more detail and add a caveat or two when I talk to people. Thanks for the much needed detailed evaluation of these various networks.

Did you ever factor in the room you were in doing these comparisons was overloading?

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  • 5 months later...

My compliments to muel for this Crossover Network Comparison write-up. Gives me a quick focused lesson on a topic that is sometimes hard to follow on pages of comments in other threads about crossovers.

Thanks also to DeanG (and many other members) for providing this forum with so much information.

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