DALI MEGALINE AMPS & CROSSOVER

ptheo:

For the sake of perfect continuity, *I* would probably stick with the same make of amplifier for top and bottom.

Haven't heard the BHK, but it is getting some nice reviews. A buddy of mine was actually considering the 250, but I think he's currently leaning toward Boulder.

I've heard the Megalines a total of three times , including twice at the same person's house. As I recall, he had them driven initially by pairs of Paraound JC1s, then by big Pass stereo amps. The other person was using Classe Omegas. In both cases, if I'm remembering correctly, the stock crossover was used. 

I remember the speakers sounded HUGE (at least compared with what I was running at the time), and that impressed me on some live Deep Purple, in particular. 

Funny... I just upgraded my modded by Audiosmiles in the UK  Behringer Ultra Pro for the DBX 360 (tweaked by Roger Sanders).  The Behringer/Audiosmiles unit is awesome. If you are interested, I can let it go pretty cheaply.  

I ran Dali Megaline for more than 10 years, tried multiple amps on them and got different results with each change. Short answer is you must use same amps on both top and bottom, otherwise nearly impossible to get fully integrated sound.  

I tried various amps, both solid state and tube and quickly found the big VTL 750 was was making better sound.   In fact, when the VTL 750 was on ribbons that is where the best sound was coming from.  Reverse and put the VTL 750 on bottom and it was better sound than top.

In other words if the woofers had the big tubes it sounded better than the ribbons (you could hear the mismatch).   Reversing got the same effect. Believe me, I was trying desperately to not buy two pair of big tube amps but that's what it took to get the Dali world class.  

My (now) Focal Grande EM are certainly better and simpler set up but I still have one guy in my group that misses my Dali Megalines with four VTL 750 and twin JL Audio subs.  

Solid state might exercise a little better grip on the woofers but they are only approx. 6” and very quick and controlled already.  They are more in need of what tubes do. 

I no longer own VTL but they were a great amp, especially for that time.   I ran VTL 750 on my Soundlabs, then the Dali Megaline and for the first year with big Focal Grande EM.

The new VTL Siegfied is better than the 750, and so is the Allnic M3000, Allnic M5000,  ARC Ref 250 and probably other more current design tube amps.   I would go for at least a couple of hundred watts on each of the four positions needed to operate the Megaline.

Last, the crossover that Tom Tutay builds is a huge upgrade over the stock one but does so without risk to the Dali design. The crossover point is indeed fixed but the flange point of Tutay crossover allows varying boost / cut of low frequencies via silver contact volume control switch, allowing you to tailor the sound to your room and compensate for distance from wall and corners.

Remember, there are capacitors in the base of the Dali Megaline that the signal passes through to make the crossover operate properly.  When you choose different EQ or crossover from factory specification you risk damage to the tweeter.

The 7 foot tweeter already dips below 1000 HZ which is very low frequency for a ribbon to have to operate.  I believe if you put in enough power and operate at frequencies below what it was designed for,  you might be inviting problems.

If you follow your own path to crossover points and EQ, I suggest you order replacement ribbons from Dali while they are still  available.  You probably already know this model is discontinued and is why I sold mine and went to Focal.

I agree lynott, one would expect going from digital amp(bass/mid- cone driver) to class- A amp(treble- ribbon) ones asking for trouble.  I’m sure any of the amp brands you mentioned above would sound great. Especially the Boulder & Classe Omega with their endless power reserves.

I can’t wait to hear some Deep Purple on these bad boys once properly setup! They were my first rock band back in ’72 at 10 years old! Highway Star!

Please send me info on the mods cerrot. I’m curious how much better/different the DBX 360 is?! I may even call Mr. Sanders since his speakers include an electronic crossover. Nice setup  

Thanks for chiming in Mr. Porter, I enjoy reading you thread very much! I have some many questions I want to ask you about the ML’s I don’t know where to start. But let me reply to a few comments you made. I know matching amps has to be better, but what’s amazing right now I have two different type/brand amps, two different length(4’ & 8’)/brand( MA-ANAP & AQ) speaker cables with cheap banana connectors, two different(one cheap, one good) interconnect brands, & last but not least the Beringer crossover & the system sounds AMAZING! The ease/clarity of the dipolar ribbon sound from the ground to the ceiling, the unlimited dynamic range sledgehammer bass, only one crossover electronic point adds up to the best speaker I have ever heard or owned. I can’t wait to get it all setup correct. How you ever went back to a point source speaker after the ML’s Mr. Porter I’ll never know.

Can you please explain to me why the 6” woofers are ‘more in need of what tubes do’? Never heard that before although I don’t doubt you for a moment!

Also, you mention the caps in the base are ‘to make the crossover operate properly’. I though the caps are to protect the ribbon from DC current back to it?

Regarding the lower crossover point with a stepper slope, if I’m not mistaken, my Apogee Stages crossed over at 800HZ at 6/12DB & My Apogee Studio Grands crossed over at 600HZ same slope with much smaller ribbons. Why can’t the Dali ribbon which is 91” tall do 800 say at 24DB?!

I will look into replacement ribbon for peace of mind because I don’t ever see me selling these speakers since that can’t be topped. Period.

Do you have any comments of me adding 3lbs of stuffing to each cabinet?

BTW- I did have them crossed over at 60HZ at 24DB with my subs, but didn’t like the bass. So now I’m running them full range & blended the subs in up to 50HZ. WOW is all I can say. I will be up again tonight until 3AM like every night for the past two weeks since I have had the speakers with my jaw ajar in disbelief!

 Check this out about the Beringer I’ve been disrespecting:

http://www.audioheritage.org/vbulletin/showthread.php?17457-Behringer-DCX2496-digital-x-over-any-good

http://freerider.dyndns.org/anlage/evaluierung.htm

Ptheo - here is a link to the modded Behringer.
http://www.behringermods.com/dcx2496.html

It is a sweet unit.  I upgraded to Rogers modded DBX as it has room correction (only used for 500 hz and below) and totally BLEW ME AWAY.