Motion 30 Center Channel sounds muffled/dull out of one of the speakers.

HTfreak2004

HTfreak2004

Senior Audioholic
I should elaborate further. There is nothing inherently wrong with a 2.5 way design. I have designed quite a few. In fact my center is a 2.5 way and my surrounds are 2.5 ways. What I don't do with 2.5 way is use as MTM layout that is horizontal. To work it would have to be vertical. So if you want to salvage that center, then it needs to be turned vertical and not horizontal. Doing what they have done does nothing to solve the lobing issues of horizontal MTM centers, but off centers the acoustic axis, which in undesirable.

Now my 2.5 way center is not only vertical, but uses a coaxial driver.



The more I think about this, the more I think the BBC is correct. Because of the difficulty using properly designed centers under domestic conditions the center channel should be abandoned. In BBC mutichannel broadcasts there is no center channel.

Now in the townhome we are closing on next week, I used a single full range driver that was very satisfactory, like my coaxial.



For one of the systems in my new home I have designed the usual design to help overcome the lobing issue of MTM horizontal centers. That is the vertical mid and tweeter with woofer either side.



Crossover points are 400 Hz and 4000 Hz.

Whilst the results are fairly satisfactory, results are not ideal. The lobing issue is not entirely solved as there is a change in bass balance moving across the sound field.

So I now have come to the conclusion that a center speaker needs to use a coaxial driver or a full range driver if not to be a vertical array, which is seldom practical.

So the answer to the center conundrum is essentially no center, a coaxial or full ranger. Anything else is less than optimal.
Interesting concept!

This point I’m about to add is not based in science so bare with me here plz!

Based on what I perceive your trying to achieve it is my opinion that there is to much emphasis placed on the centre channel to begin with!

That emphasis is to make the centre channel a discrete channel while in reality it should support the main speakers not take over their roll in stereo or HT!

Assuming a centre channel may receive up to 80% of the responsibility for voicing dialogue in HT content and to a very large extent the vocals in 5.1 music videos, I would say the recording studio needs to reduced the emphasis placed on the centre’s channels roll by placing the bulk of the dialogue back in the main speakers mix like when a phantom centre is channel is used.

From there the centre channel only re-enforces the phantom centre similar as when bass management is used so a sub anchors the low end for the entire 5+ other channels.

That way more impact is given to the dialogue without it appearing to originate from the centre channel. A phantom centre seems to come from where we want it which is the actors or singers mouth. With a centre channel playing to large of a roll it appears disconnected from the screen which actually attracts attention to itself rather than the image on screen!
 
Pogre

Pogre

Audioholic Spartan
I should elaborate further. There is nothing inherently wrong with a 2.5 way design. I have designed quite a few. In fact my center is a 2.5 way and my surrounds are 2.5 ways. What I don't do with 2.5 way is use as MTM layout that is horizontal. To work it would have to be vertical. So if you want to salvage that center, then it needs to be turned vertical and not horizontal. Doing what they have done does nothing to solve the lobing issues of horizontal MTM centers, but off centers the acoustic axis, which in undesirable.

Now my 2.5 way center is not only vertical, but uses a coaxial driver.



The more I think about this, the more I think the BBC is correct. Because of the difficulty using properly designed centers under domestic conditions the center channel should be abandoned. In BBC mutichannel broadcasts there is no center channel.

Now in the townhome we are closing on next week, I used a single full range driver that was very satisfactory, like my coaxial.



For one of the systems in my new home I have designed the usual design to help overcome the lobing issue of MTM horizontal centers. That is the vertical mid and tweeter with woofer either side.



Crossover points are 400 Hz and 4000 Hz.

Whilst the results are fairly satisfactory, results are not ideal. The lobing issue is not entirely solved as there is a change in bass balance moving across the sound field.

So I now have come to the conclusion that a center speaker needs to use a coaxial driver or a full range driver if not to be a vertical array, which is seldom practical.

So the answer to the center conundrum is essentially no center, a coaxial or full ranger. Anything else is less than optimal.
That was the thought that popped into my head with a horizontal 2.5 way design. Wouldn't that make for uneven horizontal dispersion?
 
HTfreak2004

HTfreak2004

Senior Audioholic
I get that many hours on my system in 3 days. He just got the MLs he said. I didn't get what you are from the op either.
If my speakers were in my living room my wife would be on her 3rd pair with all her shows saved to the PVR:eek:
 
S

sajohnson504

Audiophyte
Update:

I called support today and discussed the center channel. The guy I spoke with was great and answered all my questions. He was aware of this concern with the speaker and other people thinking that it may be broken. He said it may create an uneven dispersion, however when working with the 40's in a proper setup ML says it will balance out.
 
TLS Guy

TLS Guy

Audioholic Slumlord
Update:

I called support today and discussed the center channel. The guy I spoke with was great and answered all my questions. He was aware of this concern with the speaker and other people thinking that it may be broken. He said it may create an uneven dispersion, however when working with the 40's in a proper setup ML says it will balance out.
Of course it will. Their speakers have magical powers that defy physical laws!

You need to turn up your BS alarms a few notches higher.
 
HTfreak2004

HTfreak2004

Senior Audioholic
Of course it will. Their speakers have magical powers that defy physical laws!

You need to turn up your BS alarms a few notches higher.
Perhaps the sign above the centre channel at the dealers should start with “Lead us not into temptation but deliver us fro the evil one” combined with an arrow pointing at the centre channel ;)
 

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