Keith aka Amfibius System
 

Hi all, by way of introduction I thought I would post a few things about my system. The whole system has been evolved around my speakers, a pair of Acapella High Violon 2001's. This is what the system looks like now:

http://www.pbase.com/amfibius/image/...8/original.jpg

http://www.pbase.com/amfibius/image/...7/original.jpg

http://www.pbase.com/amfibius/image/...9/original.jpg

And the current list of electronics:

Source
- Playback Designs MPS-5
- Micro-Seiki BL-99V, Micro-Seiki MA-505 Mk.2, Lyra Dorian, RCM Sensor Prelude

Amplification
- Cary SLP-05 preamp
- Cary CAD-211AE power amp
- SGR EL30S power amp
- Marchand XM44 active crossover

Speakers
- Acapella High Violon 2001
- JL Audio F110 subwoofers x2

The journey with the system has been rather long and involved. When I bought the speakers in 2007, I identified the bass as being a problem. It was slow, muddy, and sounded wrong compared to the rest of the system. On the other hand, the midrange and top end were exceptional - clear, precise, full of timbre, and incredibly dynamic. At the time, I thought that it would be relatively easy to fix the bass.

So out went my CAD-805AE 50W SET, and in came the 110W CAD-211AE's. For the loss of some midrange magic and transparency came much better bass control and even better dynamics, but it still did not sound right.

The next step was to buy a pair of JL Audio subwoofers, and use an active crossover to remove bass frequencies before the power amp. This has a number of theoretically positive effects - it reduces woofer cone excursion, therefore reducing break-up modes. The amplifier is free from working with bass frequencies, giving more apparent amplifier power. The subwoofer can be placed optimally to produce the most linear bass. All in all, I nearly achieved my aims of cleaning up the bass AND the midbass while giving a useful boost in dynamics as well.

But I was still not happy. The measurements indicated that everything was nice and flat with hardly any F/R anomalies. I could not see what was wrong, but I could hear it.

The next step was to buy a SGR EL30S power amp and a DEQX. The idea was to provide seperate amplification for the midrange/tweeter via the Cary, with the SGR solid state amp looking after the bass cabinet, with the DEQX working as a digital crossover, but also with the ability to provide room correction, speaker correction, group delay, etc.

Sadly, despite my best efforts I could not get the DEQX to sound good. There is something about redigitizing the sound which is horribly destructive for resolution and dynamics. It is without doubt a powerful development tool, but not something I could leave in my system long term.

I used the DEQX to simulate ideal crossover points, then ordered a Marchand XM-44 crossover. This was MUCH better - so much more transparent. But despite all this, the bass was still not right. So we decided to open up the speaker to have a look.

http://www.pbase.com/amfibius/image/...9/original.jpg

As you can see, there is an internal woofer mounted at 45 degrees, firing into the back of the external woofer which is mounted on a baffle (not shown). Strangely, the internal woofer comes off the binding posts FULL RANGE, while the external woofer goes through the crossover. The crossover appears to be a 1st order low pass with a couple of notch filters in place. This bizarre arrangement was responsible for muddying up the bass!

At least I could see where they had spent the money. The construction of the cabinet is incredible - double ply, then lined with lead, then stuffing material.

The obvious step would be to disconnect and remove the internal woofer, and bypass the crossover so that the bass cabinet is fully active. By this stage I had complete independent control over each driver in my system, so it was a simple matter of adjusting the crossover and taking new sims with the DEQX to get it to sound right. The system gained another useful step in resolution, but there was something that was still nagging me.

http://www.pbase.com/amfibius/image/...1/original.jpg

This is a shot of the backside of the external woofer. It is a SEAS CA 25 ACA, which you and I can buy as a replacement part for USD$70-80. Note the shallow voice coil, the stamped metal basket, and the generally flimsy construction. The Xmax can't be more than 10mm! Another bizarre design choice - why put such cheap woofers on a speaker that retails for USD$60k, especially when you have gone through the effort of building an incredibly solid cabinet for it?

Warning - speaker vandalism ahead!!

All the while, I have been receiving help from SGR Audio, a speaker design company in Melbourne. They advised me that I had reached a dead end (and didn't I know that!). The only thing left to do is ... replace the woofer. I then did what no other Violon owner would do. I ordered a custom built high efficiency woofer to replace the stock drivers on the Violon. It would have to be of the same diameter and bolt pattern to ensure trouble free installation.

Here are a few comparison shots of the old and new woofers:

http://www.pbase.com/amfibius/image/...5/original.jpg
http://www.pbase.com/amfibius/image/...3/original.jpg

Arse end of both woofers. Note that the new woofer has a much more substantial build. The basket is cast steel and powdercoated, and the motor structure is bigger and deeper. Also note the cooling vent for the motor unit.

http://www.pbase.com/amfibius/image/...8/original.jpg
http://www.pbase.com/amfibius/image/...1/original.jpg

Front end of both woofers. I have to say that the new woofer looks quite sexy, even if it is going to be covered up in the end!

You may also have noticed that the new woofer is physically deeper than the old woofer. We immediately ran into a problem with the speaker cabinet. It contains a brace that secures the rear of the woofer. In fact, the woofer was glued to the speaker cabinet! To get it off, we had to tap it out with a hammer. So we had to do this:

http://www.pbase.com/amfibius/image/...5/original.jpg

By this stage, my heart was truly in my mouth. The sun was starting to set, and it was taking a VERY long time to mod the box given all the unexpected snags we kept running up against - hidden steel reinforcements, nails, and so on.

We got all the work done and replaced the speakers. Turned it on, did a few sweeps, and changed the crossover settings. We were ready to listen.

HOLY CRAP it's good! If you can imagine the power of a 300W solid state amp driving a high efficiency 8 Ohm woofer, with 110W of triode power running a high efficiency horn and tweeter - there is no shortage of power reserve. The speakers can go loud, loud, loud and even louder without a hint of strain. The dynamics of this thing are astonishing. The new driver goes about its business with a certain lightness and nimbleness, as opposed to the old driver which sounded heavy and plodding by comparison.

So after 4 years of development and thousands of dollars, I have finally reached the end of the road for the bass cabinet. When I bought my speakers, I thought that a change of amp would fix it - but it turned out to be more involved than that.

I then started to wonder what the horn would sound like if I removed its crossover :) The overall efficiency of the system is 92dB/W/m. Obviously, the horn is much more efficient than this so it HAD to be padded down to match the efficiency of the woofer. It should be a fairly simple matter to get at the internal crossover network, snip off a few wires, and then connect it directly to the Cary power amp, right?

WRONG!!! We manhandled the incredibly heavy horns off the box and I proceeded to undo the screws. The horn would not come off, so I thought it might be bolted in from the back. I undid the rear screw, only to be greeted by the sight of SAND pouring out the cabinet and onto my pristine living room rug made from genuine New Zealand lamb wool!! I quickly plugged the hole with my finger and replaced the bung (not easy when you have 40kg of horn cabinet on your lap!). Turns out the horn is screwed into the cabinet AND glued on. A sharp twist of the horn got it off, and this is what we saw:

http://www.pbase.com/amfibius/image/...0/original.jpg

http://www.pbase.com/amfibius/image/...1/original.jpg

http://www.pbase.com/amfibius/image/135560632/large.jpg

A Dynaudio D-52H midrange driver, customized for Acapella! Finally, a decent driver. The Thiel-Small parameters are here. Compare the F/R curve supplied by Dynaudio with my own measurement of the midrange horn F/R here. Obviously it looks different because it has the crossover in place and it is horn loaded.

After we drained all the sand out, we finally managed to get a good look at the horn crossover. It was sitting at the back of the box, covered in sand:

http://www.pbase.com/amfibius/image/...3/original.jpg

As expected, there are a few resistors to drop the efficiency of the horn to match the woofers. Check out the construction of the box:

http://www.pbase.com/amfibius/image/...4/original.jpg

As my friend said, it's very German in design. Only a bloody German would build a box out of double ply, then line it with lead. And then think to himself "hmm, maybe it's not dead enough. Let's fill it with sand!!".

Getting the sand back in is a simple procedure of using the fill hole at the back, like this:

http://www.pbase.com/amfibius/image/...5/original.jpg

Right now, I have almost reached the end of the road. All the major modifications to the system have been completed. Things left to do:

- Subwoofer upgrade. The subs now sound slow compared to the rest of the system. Considering a Wilson-Benesch Torus, but it is a little bit too spendy. Might get a pair of custom built subs instead.
- Refine the crossover settings. Will be running more sweeps and more sims over the next few weeks. With the Marchand XM44 it is a simple matter of ordering plug-in cards. At some point, I will send the unit for upgrades to the op-amps.
- Don't need the 110W Cary's to drive the midrange horns any more, considering these are 98dB/W/m sensitivity. Ridiculously overpowered. Will probably welcome back the 50W Cary SET's into my system, or try the Einstein OTL.

Well, that is my journey. Hope you enjoyed reading.

Keith,

I had a Violin Mk IV in my possession for a while. That tweeter is really something but the bass was a little lacking. The ion tweeter and its potential for harming my son (who tried to stick stuff in whilst on) meant it couldn't stay :tears:

Love your setup though.

howie

Thanks Howie. What did you do with your Mk.IV Violons? Is the owner still on AA?

I maintain the Acapella mailing list and would like to get in touch with him :)

Great pics, and descriptions of your quest. :thumbsup:

Sorry went to a 2nd hand dealer. The previous owner was King Jerry, the Meridian Supremo, Leben Supremo and all round aficionado! (JSCC). We did a complete swap of gear from Hong Kong to Singapore. Jerry got my Meridian set up and I got his Acapella, Jeff Rowland and PS Audio set up. :yes:

howie

Hi Keith,

You got mail .... :D

And I am no "King Jerry" as Howie puts it ... maybe a hifi "dunce" more like it. :yes:

Enjoy the forum. A lot of nice guys around.

Cheers!

Amfibius, thanks for sharing the story and pics! :thumbsup: You don't give up easy, do you? :D I used to build my own speakers and crossovers back in the day but I wouldn't have the guts to rip into a $60k speaker like you did. I would have also given up and went with a two way speaker or horns and augmented them through an active crossover and a fast, musical sub like JL Audio. In fact I experimented with that setup much to my surprise and outstanding results. :yes:

Of course you now have a truly unique setup and sounds like you have just about reached nirvana. :thumbsup:

Congratulations! How many times did you go through your plan in your head before that 1st cut? Knowing there would be no going back once you did. Everything looks great.

Keith, awesome story and pics. It takes balls to open, much less modify, a $60,000 speaker. I am impressed that you could look at the components and know what to do. Congrats!!

Keith...welcome to AA :wave: and thx for subscribing and showing your support. Your system is superb. Your determination to get the sound you want is admirable. Great pics. Great story. Thanks for sharing. And here's hoping you get the last few % in your quest for the "perfect" sound. Enjoy :thumbsup:

Hi everyone, thanks for your comments.

PHC1 I think most people in this hobby have a certain tenacity :) I'm sure we all agree that the trick is to identify what you like and don't like, and then decide if you can do anything about it. If you can't, then it is time to change speakers. If you can, then it helps to know audio engineers who know what they are doing!

Everyone who has heard the standard Acapella knows that as shipped, they have certain compromises. 99% of audiophiles will expect to run them mono-amped via the passive crossover. Very few will bother with an active crossover, buy multiple amps, and not to mention - own the equipment needed to do sweeps and level match. If you are willing to bite the bullet, it is possible to get better sound than shipped from the factory.

chessman: like I said, I had a lot of help along the way. By myself I am an electronics dunce. I knew what I wanted, and I find that helps a lot!

howie and JSCC: you sold the Violons! That was one of the reasons I joined this forum! Violon owners are few and far between. I only know of 6 other Violon owners and we are in regular correspondence. Would you guys like to post pictures of your setup in here? Would be curious to look.

Someone in the other thread asked how the Playback Designs MPS-5 compares to my previous CD player. Well, I am a very slow upgrader of CD players. This is my CD player history:

- Marantz CD-52 (1993-2000)
- Sony XB940ES SACD (2000-2006)
- Cary CD306 SACD (2006-2011)
- Playback Designs MPS-5 SACD (2011 ono)

As you can see, I am a believer in SACD. The first upgrade was driven by the need to get SACD. The second upgrade from the Sony to the Cary was because the Cary was simply superior to the Sony. I have compared the Cary to many other CD players, and it has held its own every time. It is superior to the Marantz, Ayre, Sony ES, and Musical Fidelity SACD players. It is equalled by the Esoteric but the Esoteric has a dryer sound than the Cary. On redbook, I preferred the Cary over nearly everything else.

It was always going to be difficult for anything to replace the Cary, and this was certainly the case with the MPS-5. I was decidedly unimpressed the first time I heard it. The dealer left it with me over the weekend and I told him that I was surprised that it sounded congested compared to the Cary, and lacked detail and dynamics. He came over and had a listen. I could see that he was struggling to contain his disbelief but eventually he did concede that the Cary ran the MPS-5 very close.

A couple of weeks later, he rang me up and said that the player he brought over was brand new. He had since been advised to give the player 500 hours of run-in which he had done. He offered to lend it to me again. I was unable to take him up on his offer for a good year - because by then he was starting to move them like hot cakes. He said to me "lesson learnt - never demonstrate anything until you know you can get the most out of it". Yes of course - particularly to someone with a critical ear and a reluctance to spend 15 big ones!

One year later he brought another demo unit to my place. This time, it had 500 hours of burn-in. The moment I pressed play, even without doing any direct A-B testing, I could hear the difference. This thing is so much better than the Cary! Instrumental seperation is amazing, instruments are full of life and timbre, and the soundstage was wide and expansive. The dynamics and bass were better, showing the superiority of the discrete output stage. The overall presentation was more dry than the Cary, but then the Cary always was a very sweet sounding CD player.

I decided I could get the tone back by playing with the valves, but things like detail retrieval and dynamics can never be improved if it is not there from the very beginning. So I opened my wallet and handed over 15 big ones.

Keith...it's clear you are a Cary fan. Have you tried other tube amplification in the past? Just curious on that front. Thx

cmalak I haven't actually owned any other tube gear apart from Cary. But I have borrowed stuff to listen to, yes.

Keith... In only 2 days, and 14 posts you've managed to move in, make friends, and get comfortable.

Congrad's you're one of us! :thumbsup:

Hi Keith,

Dan (Thanks Dan) would be helping to post the pictures - Before (where I owned the system) and After where Meridian is my main enjoyment today.

Basically, what you see would be the same as what Howie had cause we exchanged systems with one another. The end result being I upgraded every Meridian component he sent to the latest revision while Howie does a complete makeover with the SF Stradivari's, Soulution, etc, ....

Cheers!

Jerry.......Here are the photos of your Acapella's and Meridian speakers.


http://i453.photobucket.com/albums/q.../Acapella1.jpg


http://i453.photobucket.com/albums/q.../Meridian1.jpg

The Violins in my place

http://i165.photobucket.com/albums/u...u/R0011034.jpg

The Meridian in another place

http://i165.photobucket.com/albums/u...u/howieHT3.jpg

Thanks Howie, Dan, and Jerry for posting the pictures. Those pictures posted by Dan look like the Violons were being driven by Rowland Class D monoblock amplifiers? I have heard my speakers driven with a pair of Rowland 150W Class A/B amps, before they went Class D. Loved the sound!

Here are a few more pictures of my system:

http://www.pbase.com/amfibius/image/...9/original.jpg

http://www.pbase.com/amfibius/image/...0/original.jpg

And this is my music collection:

http://www.pbase.com/amfibius/image/...1/original.jpg

It is almost all classical. First 4 shelves are all Bach. Next 2 shelves are Beethoven. Schubert takes 1 1/2 shelves, Mahler takes 1 shelf. There is also 3/4 shelf of Prokofiev, and 1/2 shelf each of Wagner and Shostakovich. As you can tell, I like angst filled music (well, apart from Bach) - so frivolous composers like Mozart - 1/4 of a shelf :)

Here is a short clip from Youtube.

[ame="http://youtu.be/8zOSf7-6kVk"]Keith System[/ame]

Hmm, just happened on this thread. Keith, u are one persistent dude :thumbsup:. Lovely pics of your setup.

A little interesting trivia for everyone here, Keith & myself went to the same high school & University in the same years. Only realised this very recenlty. Now, we live on different continents :hswhome:.

Regards,
Joe Ling

Hi Joe, we weren't in the same high school. My parents could not afford to send me to that expensive private school you went to! I went to a public school. And same university, yes - but different courses. Despite sharing the same circle of friends, and hanging out at the same hifi shop, somehow we never met!

Oh ya, details seemed to have been lost after so many years...

Nice video Keith. Somehow the ion tweeter effect is lost on my 2$ computer speakers! :yes:

howie

Keith
I just picked up on this thread this morning and enjoyed following your efforts to improve the sound of your Acapella's. A fun read to start the day.

Thanks for following up on the Playback Design question. It is a unit that seems to get good reviews on a regular basis.

I owned a Cary 303-300 player and awhile back and liked the options of changing selectable sample rates on the fly and HDCD decoding. Different discs sounded better at different rates. I replaced that with a Esoteric X03-se which not only played SACD's but generally sounded better all around to me.

Jim

Keith......I really like the CD/record shelving. Very functional, and attractive.

Thanks Dan, the shelves are from Ikea :) They come unfinished and look pretty horrible, but they take on a nice honey colour if you sand it, then use the right stain and varnish.

Still-One, the PBD MPS-5 is by far the best CD player I have ever owned. I have to admit that when I was evaluating it, it was sitting on a wooden shelf and was using my Transparent interconnects. The Cary was on my glass shelf and I was using Acrolink interconnects. I must say I have never been a big believer that shelves and interconnects made THAT much of a difference. I believed that longer I/C's benefited more, and these short run I/C's couldn't make much of a difference.

Anyway, after I sold the Cary, I moved the MPS-5 to pride of place on my shelf. Since the Acrolink was already wired up to my preamp, I plugged it in. Holy Moly ... my jaw dropped. Suddenly the MPS-5 sounded like the Cary! Had I just wasted $15,000 when it was the interconnect all along?

I swapped the I/C's back over and the magic came back. Yes, it is better than the Cary.

The second conclusion: Transparent I/C's are way superior to Acrolink.

I definitely agree with you on the benefits of Transparent cabling. :Yes:

One of the BEST sounding system at the Cal Audio Show last Sunday was an Acapella system and vinyl was the source.

http://farm7.static.flickr.com/6147/...2cf45793_b.jpg

Yeah, that's the Acapella Violon Cello. Bigger horns, better bass cabinet ... pity I won't get a chance to hear it unless I travel to one of the shows in Europe or USA!

Australia is a bit of a hi-fi wasteland. I am still a new member here and I am reading everyone's signatures in disbelief. I suppose it does not help that everything here costs 30% more. A 911 in the USA costs USD$100k. Our AUD$ is stronger than USD$ at the moment, and a 911 sells for AUD$230k. Our hifi is similarly overpriced.

Great thread Keith, I just saw this...so do you root for the Saints?

I don't care about Aussie Rules, my friend :)

Understood! I would rather listen to your system too!

Hopefully mine will make you feel a little more comfortable. Although, admittedly, they're not exactly household names.

No music for me this weekend :(

I think I mentioned earlier in this thread that my amp blew up a few months ago when my friend lent me his Shuguang 845B's. Took out a resistor, a bias pot, and spent a few weeks in amp hospital waiting for parts to arrive from the USA. At the time I thought that I mis-mounted the valve because I was a bit tipsy at the time.

Well, my silly mate keeps on going on about how good the Shuggy 845B's are - so I ordered a pair. I mounted them on the amp this morning, and they immediately went KABOOM! The fuse blew up so violently that it shattered the glass! I replaced the fuse, and ... uh, oh ... no bias current. Opened up the amp and everything looked OK - no obviously burnt parts.

My amp is back in amp hospital this weekend :(

Holy Moly Batman!

Sorry to hear that. You must have felt like me when my purepower blew up.

Good luck with your repairs. Need I suggest you don't try the Shuggy's again :nono:?

howie

Yeah, I haven't had much luck with Shuggy's :(

Oh dear... Keith and Andy, not much luck down under with hifi equipment nowadays... Good luck Keith!!