Fred, I changed not because I did not love the Ultimates, but due to reliability issues. Finding a replacement for a single driver (crossover less) speaker is tough indeed.

The Dali Megaline is a two way with only two types of drivers and comes as close to single driver technology as I could find.

I just submitted a review of the Megalines to Positive Feedback Online where I was recently hired as a reviewer. The article and images should be posted soon.

albertporter April 12, 2005 20:38

Gee Albert,

I leave the scene for a few years and you go and change sytems. No Ultimates? I can only assume your ears found a new bliss. How is it holding up comparatively? It certainly turned out beautifully and the fit and finish on the Dali's is first rate-I heard a pair up here in Boston and was impressed dispite the poor choice in electronics and room they were set up in.

Hope all is well in Tejas,

Fred

cbird1 April 12, 2005 03:41

Speedball, thanks for the compliment. The Megaline integrated into the space very well. Better still, as they break in the sound is getting closer to what I want as a reference standard.

Nate, If your traveling this way again please do set aside time to visit. I think you would be surprised at the changes and YES, I have lots of good music, including a half dozen recently acquired master tape dupes that are stunning.

albertporter April 08, 2005 20:21

AP I gotta get back there. It looks too cool! Do you have any good music?

nrchy April 07, 2005 20:46

Those speakers are big but they do seem to have a nice clean...not too overpowering look about them. I bet they are a real conversation piece when the friends are over.

speedball April 07, 2005 15:11

System edited: Images edited

albertporter April 07, 2005 05:25

Eldartford,

I agree, having doors on the left side and opening to the kitchen on the right is not ideal. The only saving grace, the acoustical treatment was designed to help overcome those issues.

What else helps, although it does not look like it in my photo's (very wide lens). The distance between the wall with the speakers and the opening to the kitchen, is more than 14 feet.

That's the entire room length in some homes, so not as big a problem as might first appear.

Like most people, I bought the home I could afford, with a room suitable for music. Then I did everything possible to improve it, short of compromising the comfort of family and friends.

albertporter March 16, 2005 21:31

Slipnot1,

You are welcome anytime, let me know when your in the Dallas/Ft. Worth area and I will pick you up at the airport. If you want to meet the whole gang, make it a Tuesday when everyone is here for music night.

albertporter March 16, 2005 21:10

System edited: New room view showing HDTV

albertporter March 16, 2005 21:04

Very beautiful. I notice that you listening room is about as unsymmetrical as any room could be, which is contrary to what most audiophiles strive for. My room is also very unsymmetrical (except the ceiling is flat). Seeing yours, I feel less guilty.

eldartford March 16, 2005 15:40

Thanks for the new pictures Albert. I would love the opportunity to listen to some music with you, enjoy a bottle or two of Bordeaux and a couple of steaks......

slipknot1 March 16, 2005 14:34

System edited: Images edited

albertporter March 16, 2005 08:06

Amazing!!!

hifiblue March 09, 2005 16:04

That's good Albert. You sounded a little down when you ordered the crossover. I thought your silence might mean the dali's had reached a plateau.

gregadd March 08, 2005 02:30

Gregg, it has been a long haul.

When the Dali Megalines showed up at my door, they sounded absolutely awful. High frequencies were bright and there was NO bass below 60 HZ.

Fortunately they have improved steadily over the months, with (very) deep bass showing up at around 389 hours. They have 457.5 hours on them now and they are still improving every week.

To get the deep bass working, I ran (on repeat) the Purist Audio break in CD, and then the Ayre CD break in discs and pounded the bass, powering them with VTL 750 mono blocks.

It was amazing, particularly with the Ayre disc and its sweep tones, hearing the bass begin several seconds earlier as break in progressed. I don't know what frequency the Dali's begin responding to, but some notes are so deep they are most audible, fifty five feet away in the most distant part of our home.

The custom tube crossover is being assembled and I hope to have it within a few weeks. It will use 12-SN7 octal's and constructed in an aluminum chassis with outboard (tube rectified) power supply.

Once the crossover is in, I will experiment with four VTL 750's, four Air Tight ATM 3's and also my current configuration of VTL 750 (bass) Air Tight ATM3, (ribbons).

Three of my regular members feel the Dali's have surpassed my Soundlab Ultimates in almost every way. I will reserve final judgement until the crossover is replaced.

I will say I am feeling very positive at this point.

albertporter March 08, 2005 01:44

we know you have been busy with the show. we are waiting for an update on the progress of your speakers.

gregadd March 07, 2005 20:01

Craig,

Not knowing the sound of your Sim Moon gear it's difficult to know what direction I should suggest.

What cable is in the system now and what do you wish you could change about the sound your getting?

albertporter March 02, 2005 22:56

Albert-

I'm trying to find interconnects, speaker cables, and PCs for my system. I have the Dali Megaline's distant relative the Dali Euphonia MS-4 and I thought you might have a few suggestions on synergistic combinations. I'm using all Sim Moon gear (Limited Editions of their P-5 pre, W-5 amp, and Eclipse cdp). I'd like to stay below $6k.

Thanks/Craig

cbd0815 March 02, 2005 00:09

Albert: I don't know the specifics of your speakers, but if their resonance point is noticeably above 12 Hz, and i suspect it is, introducing gain below that point will actually increase distortion, reduce transient response and lower the max spl ( dynamic range ) of the system.

In such a case, one might be better off limiting the bandwidth of the woofer section and lowering the gain at a higher frequency. This in turn reduces power draw from the amps, lowers the operating temperature of the woofers due to a reduction in power dissipation and increases the performance capacity of the system above the actively equalized cut-off frequency.

This is a common trick used by intelligent designers of vented speakers that are bandwidth limited i.e. using active equalization and a high-pass filter to both increase extension while lowering distortion. Bobby Palkovic of Merlin uses such an approach in his "BAM" module. Electro-Voice also used this approach in their "Interface" series of speakers back in the 1970's, which were the first vented designs based on Thiele-Small parameters.

As a side note, this type of circuitry is more effective with sealed designs as sealed designs have a shallower roll-off below resonance. In effect, they can get away with less active boost below resonance, therefore reducing power draw and thermal dissipation. On top of that, sealed designs maintain consistent damping characteristic below resonance, whereas vented designs lose any damping characteristics that the cabinet itself may have contributed. The lack of damping increases excursion and distortion as the driver is now "unloaded". This is where the high-pass filter comes in, limiting the lower frequencies and letting in the higher frequencies that won't cause as much excursion and distortion. Sean
>

sean January 02, 2005 23:08

I received a preliminary report from the analysis of my Dali Megaline's crossover.

There is more than 16 DB difference in gain between the ribbon, high frequency section and the 12 dynamic woofers.

The Dali crossover outputs (to the amps) are buffered and produce minimum + 2 DB gain over the input level from my Aesthetix.

In addition, there is an bass EQ curve that boosts output all the way down to 12 HZ (or below). It's possible that identical results are not obtainable in an all tube designed crossover. More measurements are being made and I will post numbers when I know.

albertporter January 02, 2005 22:11

...I can split hairs (all in the interest of science, you understand). A wave couldn't be perfectly square unless the leading edge went straight up (perpendicular to the time axis) and then executed a 90-degree corner at a point on that line. This is impossible in the real world of course, but in theory such a transient impulse would by mathematical definition be bandwidth-unlimited. Or so I thought. Mea culpa if I'm wrong. Sorry Albert. Sorry Sean; in my whole life this ugly mug has never darkened the window of an actual scope. Jes' funnin'. Happy New Year!

zaikesman January 01, 2005 21:29

Zaikesman: I never studied the patent on this design, so i can't tell you exactly how & why. All i know is that it works.

As to the bandwidth of a square wave, it wouldn't be a square wave if it required infinite response at high frequencies. That's because "everything" suffers from some type of bandwidth limiting. 10x the bandwidth of the primary signal will get you very slight but visible rounding of the leading edge and 15x will look "perfect" to the naked eye. If you really wanted to get technical, you might need wider bandwidth than 15x, but you're way more than splitting hairs by that point. Sean
>

sean January 01, 2005 04:17

Not to be pedantic (shyeah right), but I thought that in theory any perfectly square wave extended infinitely high in frequency... :-)

Anyway, about the Walsh driver design, is the basic reason for this performance attribute because it functions by travelling wave propagation rather than pistonic motion?

zaikesman December 31, 2004 23:02

El: I don't want to sidetrack this thread, but even the Ohm Walsh drivers will fall on their face with a square wave above a certain frequency. In order to produce a "reasonable" facsimile of a square wave, the circuit or driver has to have at least 10x the bandwidth of the center frequency used to generate the square wave. Given the limited high frequency extension and speed of this large cone, one would have to use a signal centered below 2 KHz ( at the utmost extreme ) in order to achieve a "decent" looking square wave. As one went down in frequency, the more articulate and square the wave would look using this driver. Given that most drivers can't do this at all at any given frequency, that says a lot about the potential of such a design.

This is one of the main reasons that this design approach has such a natural harmonic structure. Combine this with the very airy and ambient omni radiation pattern and you've got a one of a kind presentation. Now factor in that all of this eminates from a point source and you've got bass response that can shake the house and one might be able to understand why i like this design so much. Sean
>

PS... a "perfect" square wave requires a bandwidth that is at least 15x higher than that of the center frequency of the test signal. At 10x the bandwidth, it still looks quite good with a slight amount of rounding of the leading edge.

sean December 31, 2004 21:51

About the square wave as a test signal...its chief claim to fame is that it is very revealing of phase shift. If HF is shifted relative to LF the square becomes rounded. Now music is not a square wave, but I think that most will agree that phase integrity is one of the most important aspects of audio performance.

And, by the way, although your electronics may pump out beautiful square waves, few loudspeakers can reproduce it. The only one I know for sure (I have seen the scope photos) are the old OHM Walsh driver systems. And you could hear it.

eldartford December 31, 2004 18:57