HT Front stage coherence with a ML Center

[akm3]

Hey all!

One of the great tests of a "good" home theater setup is the ability for a character to be walking "across" the screen while talking and have their voice start on the left speaker, cross to the middle, and then over to the right speaker while talking.

On bad systems, this sometimes shows up as one or more of the locations the voice "shrinks" and becomes boxy or the tonal characteristics of the voice change, or whatever.

This is obviously why matched (or preferrably identical) front three is considered desireable.

With the Martin Logan line, there is no Identical choices, and all the current center channels use tweeters for their high end range. I have not had the delight of testing this out for myself, but I'm wondering if ML Center channel owners could comment on this, and I wonder if I could ask the community as a whole why ML left the seemingly superior Logos design (with no upper crossed-tweeter) for the current tweeter designs?

Another alternative I've seen some here explore is going without a center channel at all, but I'm worried that would impact the Home Theater sweetspot too negatively (possibly just ONE good seat in the house -- not good enough!)

Thanks!

Oh about me! I'm a former Aerius owner who is currently saving up -- if I save enough I'll purchase Vantages or Summits, and if I run across a good deal on Clarities/Aeons/Etc I may just purchase those ... I am just really stumped on this Center channel idea (no authorized dealers within 100 miles of me)

-Allen

-Allen

 

[akm3]

Actually, now that I think about it MORE ------


Why in the world doesn't Martin Logan make a center channel with woofer cones , ESL midrange and a RIBBON tweeter for the highs?

If the Ribbon is supposed to have the "ML" sound (as the advertising for the Frescos, Montages, etc would make us believe) it would HAVE to mate better in a ML theater then a Tweeter.

Plus, it would have the same diple radiation pattern...


I assume I will be told something about the purpose of the tweeter to increase vertical dispersion, which I'm sure it would do better then a ribbon but...what am I missing here?

-Allen

 

[ScottG]

You should check out JonFo's center channel DIY answer to this very problem

 

[Thai]

Is it because the ESL panel is not big enough??

 

[Chuck Lee]

HT front stage

I don't know why they did it like they did,but it does a good job with my CLS on each side and better than using a real mismatch all cone centre from someonelse., There is coherence the way they did it.I haven't tried any other centres except the Theatre with my CLS.I had a Mirage system of M3si and their m1 centre and crossover and BP210 sub.I believe in sticking with all the drivers from the same company, so when I went with Martin Logan, I went all the way around, 4 CLS,Depth sub and Theatre centre.
I would be curious about how the Magnepan centre would mesh with the Logans however.

 

[akm3]

I don't know why they did it like they did,but it does a good job with my CLS on each side and better than using a real mismatch all cone centre from someonelse., There is coherence the way they did it.I haven't tried any other centres except the Theatre with my CLS.I had a Mirage system of M3si and their m1 centre and crossover and BP210 sub.I believe in sticking with all the drivers from the same company, so when I went with Martin Logan, I went all the way around, 4 CLS,Depth sub and Theatre centre.
I would be curious about how the Magnepan centre would mesh with the Logans however.

How does your system sound when you do a test like I described (one example is on the DTS Dragonheart DVD where the Dragon files around two full circles with dialog panning from speaker to speaker -- with a non matched center (or surround, in that case) the realism of Sean Conneries voice collapses))

-Allen

 

[Robin]

ML Center Channel Speakers...

akm3,

Welcome to the ML Club!
My experience with my ML HT ~ specially with the Theater i center channel is that the capabilities of my HT are vastly improved with the Theater i as my center. So, taking your example, the film Dragonheart, when the dragon flaps around - the sound moves from the center channel around to all seven of my HT speakers as directed. It is wonderful. The Theater i handles all the center channel information, which in a DTS 5.1 or 6.1 or 7.1 system, 70 - 80% of the films sound is directed to go to the center channel. In the ML owners manual for my Theater i, ML clearly states unequivocally that the most important speaker in a 5.1 system is the center channel speaker.

One of the big selling points of the Theater i for me was the shear size and build quality of the Theater i. Most other center channel speakers I looked at like M&K, B&W and McIntosh where very much smaller but more importantly other enter channels did not sound as good as the ML Theater i. It has been my experience that with so many different and varied frequencies which are sent - at least initially to the center channel first, I can see why ML chose (for the Theater i) to employ two larger woofers, for all the deeper sounds as well as a three soft dome tweeter array, for all the frequencies above 20K. The large electrostatic panel of the Theater i is just unsurpassed in it's excellence for all the various mid-range sounds especially all the voices / vocals, which go to the center channel in a 5.1 set-up.

JonFo's center channel (pictured above), as I understand it, and he can explain it much better than I, he just wanted much more of everything from the center channel but with ML's wonderful qualities - because it is so crucial in 5.1 HT systems. He made a fantastic DIY center with more of every thing I just described above and most importantly employing a much bigger ML ~ ESL panel, which is brilliant... I wish I could buy one like his... :cheers: I hope ML was paying attention to the wonders Jon accomplished...

Bottom line ~ IMHO, purchase a ML center channel, I highly recommend it for excellent complete sounding HT...

 

[ScottG]

akm3,

I wish I could buy one like his... :cheers: I hope ML was paying attention to the wonders Jon accomplished...

Bottom line ~ IMHO, purchase a ML center channel, I highly recommend it for excellent complete sounding HT...

I also hope that those lucky enough to attend the 2007 national get-together will deliver that feedback in person :guiness:

 

[JonFo]

...why ML left the seemingly superior Logos design (with no upper crossed-tweeter) for the current tweeter designs?

...
-Allen

-Allen

Allen,

As a prior Logos owner (and as noted above, center channel quality proponent ) I can observe the following:

- the Logos was great for the day, but it had significant issues due to the ESL being inches from the mid-bass box. This causes very short time reflections from the surface that come back through the ESL and 'smear' the image of the sound.

- The logos did use a tweeter to cover the upper registers, this was done to provide greater localization of the highs to the highs due to the spherical dispersion characteristics of a dome dynamic tweeter.

- All ML hybrids use some combo of dynamic high-frequency drivers to achieve that specific localization and dispersion.

- The logos suffered from power curve issues around the fact that it had a single 6.5” driver. Newer designs use two. (my design uses six 7” drivers and they suck dry a 200w channel to do their job).

Basically the new Stage (and to a large extent the Theater I) address the power curve issue with two mid-bass drivers, and provide excellent dispersion characteristics for a center. These will provide very good timbre match to the ESL line of speakers.

My only reservations is power curves, as I doubt they match a Summit past 100 dB SPL, but then, I’ve not measured one, so I don’t know.
(Scott, if I visit you this year, I’m taking the laptop and calibrated mic to measure your rig so we can settle that).

Final caveat, I mention power curves in the context of trying to match my Monoliths in a fairly large room. If matching a Stage to smaller units in a smaller room, that’s much less a concern, as it will likely keep up well. But in the end, the old saying about three identical speakers across the front has a lot of merit.

 

[akm3]

I do not have the acoustic or electrical design experience many here possess, but to overcome the "oomph" problem you describe, would it cause more harm then good to perhaps add a second Stage or Theater I speaker above the screen (one above one below) for extra center channel power?

Or would that cause undesirable interactions?

-Allen

 

[JonFo]

...
Or would that cause undesirable interactions?

-Allen

Bingo, it sure would.

particularly in the mids and highs as there would be sever comb filtering happening. This is manifested by unclear vocals and a ‘smeared’ soundstage. Not recommended.

Now, one could stack two Theater i’s one on top of the other (physically touching) and get additional SPL output with fewer side-effects. But I’m guessing no one has tried that

 

[Statman]

Just my 2 cents

I just wanted to add that the higher you can get the center off of the floor the front soundstage will be more cohesive when listening for a change between the front channels . I highly recommend an aftermarket stand, at least that worked for me! Thanks to Sound Anchors once again. I concur that the Theater i is beter in the dynamics due to the dual woofers compared to the single in the Logos. The Logos directly compared to the Theater i sounded "darker"? Must have been the tweeter and crossover used at that time. If I had it to do over I'd try to do what Jon Fo has done.:cheers:

 

[Pcar928fan]

I just wanted to add that the higher you can get the center off of the floor the front soundstage will be more cohesive when listening for a change between the front channels . I highly recommend an aftermarket stand, at least that worked for me! Thanks to Sound Anchors once again. I concur that the Theater i is beter in the dynamics due to the dual woofers compared to the single in the Logos. The Logos directly compared to the Theater i sounded "darker"? Must have been the tweeter and crossover used at that time. If I had it to do over I'd try to do what Jon Fo has done.:cheers:

I think that will work to a certain level, but after that you are going to loose ground, at least as far as being slightly outside the sweet spot is concerned. Think about it... ML's can be a bit beamy anyway and now you put it up high (like on top of a very big and tall TV) and the thing has to point down at a high angle of attack for the primary listening position, now all the people in front and behind will have a poorer sound quality by a big margin than the primary location. Put it at seated ear level shooting straight at you and guess what, EVERYONE gets a good sound... That is not practical in most cases of course so some compromise is required. I'll show you my compromise when I get my Sony 70" RPTV in a month or so...