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

S

sajohnson504

Audiophyte
I will try and clarify a little bit. When I first received the speakers, I hooked them up and started playing different content. (Music, Movies) Everything seemed to sound good but, I wasn’t really paying attention and sitting in my chair. I was more concerned about following the break in period of 72 hours which is found in the manual before listening to anything above moderate levels. So, for the most part I just let them play while I was in the other room. On the second day I received my new cables from BJC, and I hooked them up and went back to playing content while I was in the other room. Saturday night, (4) days after receiving the speakers I finally sat down to watch a movie and was shocked that I was having troubles understanding the dialog. I adjusted the center channel higher in the avr setting and it was still hard to understand the dialog. So, I got up and checked the speaker with my ears and that’s when I noticed the difference in volume between drivers. So, was it like that from the beginning, maybe, not sure?
I am tempted to open the front and look but, I will wait until after I talk to support. However, in the manual it says if you cannot discern a tight, coherent image, you may need to reverse the (+) and (-) leads on one speaker to bring the system into proper polarity. Thought that was interesting after reading some of the comments. I have an idea of what they are talking about but, I am not an expert on this. I will get all this documented with support before I mess around and I will post what I find out.
 
lovinthehd

lovinthehd

Audioholic Slumlord
Looking at the manual it has two crossover points, 400 and 2600 Hz so a 2.5 or 3 way? Does the speaker on the right perhaps just sound limited in frequency range?
 
HTfreak2004

HTfreak2004

Senior Audioholic
I will try and clarify a little bit. When I first received the speakers, I hooked them up and started playing different content. (Music, Movies) Everything seemed to sound good but, I wasn’t really paying attention and sitting in my chair. I was more concerned about following the break in period of 72 hours which is found in the manual before listening to anything above moderate levels. So, for the most part I just let them play while I was in the other room. On the second day I received my new cables from BJC, and I hooked them up and went back to playing content while I was in the other room. Saturday night, (4) days after receiving the speakers I finally sat down to watch a movie and was shocked that I was having troubles understanding the dialog. I adjusted the center channel higher in the avr setting and it was still hard to understand the dialog. So, I got up and checked the speaker with my ears and that’s when I noticed the difference in volume between drivers. So, was it like that from the beginning, maybe, not sure?
I am tempted to open the front and look but, I will wait until after I talk to support. However, in the manual it says if you cannot discern a tight, coherent image, you may need to reverse the (+) and (-) leads on one speaker to bring the system into proper polarity. Thought that was interesting after reading some of the comments. I have an idea of what they are talking about but, I am not an expert on this. I will get all this documented with support before I mess around and I will post what I find out.
It won’t hurt the speaker to reverse the -/+ connections. What you don’t want is the woofers working against each other which would potentially reduce heat dissipation.

But to check if reversing your connection fixes the issue that’s no harm!
 
ryanosaur

ryanosaur

Audioholic Ninja
As I suspected.
I think disconnecting your center channel and using the 9 Volt battery is the way to confirm if your woofers are out of phase, which is pretty much what you are describing.
 
Hamid Khan

Hamid Khan

Junior Audioholic
I will try and clarify a little bit. When I first received the speakers, I hooked them up and started playing different content. (Music, Movies) Everything seemed to sound good but, I wasn’t really paying attention and sitting in my chair. I was more concerned about following the break in period of 72 hours which is found in the manual before listening to anything above moderate levels. So, for the most part I just let them play while I was in the other room. On the second day I received my new cables from BJC, and I hooked them up and went back to playing content while I was in the other room. Saturday night, (4) days after receiving the speakers I finally sat down to watch a movie and was shocked that I was having troubles understanding the dialog. I adjusted the center channel higher in the avr setting and it was still hard to understand the dialog. So, I got up and checked the speaker with my ears and that’s when I noticed the difference in volume between drivers. So, was it like that from the beginning, maybe, not sure?
I am tempted to open the front and look but, I will wait until after I talk to support. However, in the manual it says if you cannot discern a tight, coherent image, you may need to reverse the (+) and (-) leads on one speaker to bring the system into proper polarity. Thought that was interesting after reading some of the comments. I have an idea of what they are talking about but, I am not an expert on this. I will get all this documented with support before I mess around and I will post what I find out.
Thanks for clearing up your situation, I believe you was expressing that in the first statement, which lead me to the opinion of one of the drivers being out of phase. But do contact support, acknowledging them about your situation, if they gave you the thumbs to check polarity and a mistake has been made while doing so, they should not hold it against you.
 
Pogre

Pogre

Audioholic Spartan
I’m looking at the issue he has from the point of 55-60 hrs with no issue!

What would cause a speaker in phase without touching it to suddenly become out of phase without touching it?

Even if a connection came loose inside the enclosure the driver would simply stop working altogether not sound muffled. If a driver was out of phase the bass output would be affected more than the rest of the frequency range.

I’m asking as a question not to argue!
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.
 
S

sajohnson504

Audiophyte
Looking at the manual it has two crossover points, 400 and 2600 Hz so a 2.5 or 3 way? Does the speaker on the right perhaps just sound limited in frequency range?
It’s not as clear as the left. For the most part to my ear, it just sounds quieter and muffled.
 
Pogre

Pogre

Audioholic Spartan
I will try and clarify a little bit. When I first received the speakers, I hooked them up and started playing different content. (Music, Movies) Everything seemed to sound good but, I wasn’t really paying attention and sitting in my chair. I was more concerned about following the break in period of 72 hours which is found in the manual before listening to anything above moderate levels. So, for the most part I just let them play while I was in the other room. On the second day I received my new cables from BJC, and I hooked them up and went back to playing content while I was in the other room. Saturday night, (4) days after receiving the speakers I finally sat down to watch a movie and was shocked that I was having troubles understanding the dialog. I adjusted the center channel higher in the avr setting and it was still hard to understand the dialog. So, I got up and checked the speaker with my ears and that’s when I noticed the difference in volume between drivers. So, was it like that from the beginning, maybe, not sure?
I am tempted to open the front and look but, I will wait until after I talk to support. However, in the manual it says if you cannot discern a tight, coherent image, you may need to reverse the (+) and (-) leads on one speaker to bring the system into proper polarity. Thought that was interesting after reading some of the comments. I have an idea of what they are talking about but, I am not an expert on this. I will get all this documented with support before I mess around and I will post what I find out.
Man, it really sounds like a tweeter issue to me, which brings me back to where you have it located. When you contact them tell them where you have it and ask them about it. What you describe is exactly what I would expect from a ribbon tweeter positioned too high or too low. Did you try a temporary stand? Even a kitchen chair or something that will raise it up to ear level and get it out of that cubby? Try that, sit down and listen to some program material.

HD brings up a valid point also. If that is a 3 way or 2.5 way speaker then the woofers would not sound the same by design.
 
Pogre

Pogre

Audioholic Spartan
It’s not as clear as the left. For the most part to my ear, it just sounds quieter and muffled.
Like I said above, if it's a 2.5 or 3 way design that's how it's designed. My 6 1/2" woofers on my towers are identical but a 3.5 way speaker so they sound different. One is quieter than the other.
 
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.
No problem. He stated they were hooked up and had between 55-60 hrs use on them.

Later he admitted he had not sat for any critical listening so he made it clear the issue may have existed all along.

Then you stated with 2.5 and 3.5 way designs this is a common thing or at least with your 3.5 way tower.

I’m not aware of that with these design so I can’t comment on it from any experience.

In any case I had to reread his OP to be sure which was later clarified by him as his break in period and he wasn’t sure if the lack of output in the one driver was part of the break in he was applying.
 
Pogre

Pogre

Audioholic Spartan
No problem. He stated they were hooked up and had between 55-60 hrs use on them.

Later he admitted he had not sat for any critical listening so he made it clear the issue may have existed all along.

Then you stated with 2.5 and 3.5 way designs this is a common thing or at least with your 3.5 way tower.

I’m not aware of that with these design so I can’t comment on it from any experience.

In any case I had to reread his OP to be sure which was later clarified by him as his break in period and he wasn’t sure if the lack of output in the one driver was part of the break in he was applying.
I'm making assumptions that speaker is (maybe) 2.5 or 3 way design. If it is that means the woofers are crossed over at different frequencies. That can easily be perceived as a difference in volume between the 2.

I really have critically listened at low volume with my ear right next to each individual driver in the cabinets (I know, I know... get a life, lol). My upper woofer plays higher than the bottom one does and I perceive it as sounding louder.
 
HTfreak2004

HTfreak2004

Senior Audioholic
I'm making assumptions that speaker is (maybe) 2.5 or 3 way design. If it is that means the woofers are crossed over at different frequencies. That can easily be perceived as a difference in volume between the 2.

I really have critically listened at low volume with my ear right next to each individual driver in the cabinets (I know, I know... get a life, lol). My upper woofer plays higher than the bottom one does and I perceive it as sounding louder.
That’s because your ear is higher up above sea level for the upper driver and under the sea for the lower driver :) LMAO!
 
S

sajohnson504

Audiophyte
I'm making assumptions that speaker is (maybe) 2.5 or 3 way design. If it is that means the woofers are crossed over at different frequencies. That can easily be perceived as a difference in volume between the 2.

I really have critically listened at low volume with my ear right next to each individual driver in the cabinets (I know, I know... get a life, lol). My upper woofer plays higher than the bottom one does and I perceive it as sounding louder.
I'm not familiar with 2.5 or 3 way design but, what you are saying would make sense to me.
 
lovinthehd

lovinthehd

Audioholic Slumlord
It’s not as clear as the left. For the most part to my ear, it just sounds quieter and muffled.
That description could perhaps apply to a woofer crossed at 400hz vs one crossed at 2600hz, too....somewhat surprised you didn't catch such earlier, tho break-in doesn't necessarily need to be at low levels, and it doesn't take long anyways....it's mostly you breaking in.
 
Pogre

Pogre

Audioholic Spartan
I'm not familiar with 2.5 or 3 way design but, what you are saying would make sense to me.
Right. That's not to discount that you may have a polarity issue or loose connection, but my money is on the tweeter. Not that something is wrong, it's a totally different tweeter. Ribbon tweeters are very nice, but they're not as forgiving with placement like the dome tweeters you're coming from. Try an optimal placement, even if temporary, and give it another chance. Properly positioned a ribbon is hard to beat. If it still doesn't sound right give ML a call and go from there.
 
S

sajohnson504

Audiophyte
Thanks guys! Being unfamiliar with 2.5 and 3 way designs, i believed both of those woofers would have sounded the same. I appreciate all the feedback today! I'm still learning and I will get that center permanently moved up once I get my tv higher. I knew it would be a no, no watching one of Genes videos but had no choice at this time. For now, I will just move it up temporary and see how it sounds.

Thanks everyone!
 
ryanosaur

ryanosaur

Audioholic Ninja
It’s not as clear as the left. For the most part to my ear, it just sounds quieter and muffled.
I don't fully get 2.5-way mtm designs. Using the same driver at different xo points, as I understand, doesn't help things out, really. It would be interesting to see some really good tests of that speaker graphed out. It still seems like that woofer is out of phase. I could very well be wrong:D (and have no problems with that... in fact I would rather learn more through being wrong!),but as OP describes, the 'Left" side sounds muffled. I'm guessing that to be the Mid Woofer. A significant amount of the Vocal Band would be carried through that driver, bandpassed from 400-2600Hz (Vocal Band is 400-4000Hz).
Considering the quality for ML's Motion Series is generally good, this still strikes me as being a wiring issue in the XO or Driver connection of that particular speaker. Yes, in all fairness, it could be as simple as a poor XO design.

One other note... I know of good quality Ribbons and Planar drivers to be very good at wide dispersion performance. If you are within 30º of On-axis, up or down, I would expect to have good sound. Their website claims 80º: they give no description towards the quality of that dispersion.

Two me, knowing that the 2.5way design can "tilt" the radiation pattern upward in a vertical alignment assuming the mid-woofer is on top, I would expect some complications on its side. If the XO slope carries a particular tilt, that could cause even more inherent problems.
I would expect ML to be smart enough to not send that speaker to market, though. ;)

:)
 
TLS Guy

TLS Guy

Audioholic Slumlord
First off, I have to say I really appreciate this site, lots of great information!

I am currently upgrading my current home theater and a couple weeks ago I purchased the Motion 40 towers and a Motion 30 Center Channel on closeout. I’m happy about the towers but, my Motion 30 center channel sounds dull/muffled out of one of its speakers. The Motion 30 has (3) speakers. They consist of (2) 5.5” drivers and a Motion tweeter. The driver on the left sounds clear when I put my ear to it but the one on the right isn’t as loud and isn’t clear. It sounds dull /muffled.
Current system information:
  • Yamaha HTR-5250 receiver running 5.1 setup
  • Motion 40 L/R
  • Motion 30 Center
  • NS-A1638 (my old towers used as L/R rear
  • SW-4 Subwoofer (on the list to be replaced)
  • New wire to the fronts and center BJC 12 with spade Lugs
  • New Subwoofer Cable BJC LC-1
Here is what I have done to problem solve for the Motion 30
  • Plugged in old center (NS-AC143) with old wire to see if it had same issue. It did not, center sounded clearer than Motion 30
  • Using same old center wire connected the Motion 30. The right driver still sounded muffled, no change
  • Put receiver into 2ch mode and disconnected one tower and hooked Motion 30 to that wire. Right driver still sounded muffled.
These speakers are new, and I have about 55-60 hours on them. Does this have anything to do with a break-in period?
The specs on the HTR-5250 look better than I expected when I looked them up. It looks like the receiver can drive (4) ohm speakers and has enough wattage. Thoughts on this? I do plan on purchasing a Denon AVR-x4500h or maybe even the x3600h just waiting to see what happens on Cyber Monday.
I do plan to call support on this but wanted to reach out to the forum first. Any and all thoughts, suggestions are welcome!

Thanks in advance!
Your center 30 is working as the designer intended.

Your center is NOT a 2 way speaker it is a 2.5 way speaker. If you look at the specs you will see that it has crossovers at 400 Hz and 2,600 Hz. So the driver you noted to sound dull is the "fill" driver to the driver that does not sound dull. In other words the dull driver is providing the baffle step compensation to the driver crossed at 2,600 Hz. 400 Hz is just the point where you would expect the transition from half to full space radiator to occur.

If you then ask me if this is a sensible or intelligent way to design a center speaker, I would deliver a resounding no!

So if you don't like it ditch it and get something else. If you really want good results learn to design and build your own, and free yourself from a lot of crass commercial design.
 
HTfreak2004

HTfreak2004

Senior Audioholic
Your center 30 is working as the designer intended.

Your center is NOT a 2 way speaker it is a 2.5 way speaker. If you look at the specs you will see that it has crossovers at 400 Hz and 2,600 Hz. So the driver you noted to sound dull is the "fill" driver to the driver that does not sound dull. In other words the dull driver is providing the baffle step compensation to the driver crossed at 2,600 Hz. 400 Hz is just the point where you would expect the transition from half to full space radiator to occur.

If you then ask me if this is a sensible or intelligent way to design a center speaker, I would deliver a resounding no!

So if you don't like it ditch it and get something else. If you really want good results learn to design and build your own, and free yourself form a lot of crass commercial design.
Hence the saying,
Don’t stop halfway if your going to start something finish the job :D

What do you get when you add together a 2.5 way speaker and a 3.5 way speaker?
Two wrongs that don’t make a right:p
 
TLS Guy

TLS Guy

Audioholic Slumlord
Hence the saying,
Don’t stop halfway if your going to start something finish the job :D

What do you get when you add together a 2.5 way speaker and a 3.5 way speaker?
Two wrongs that don’t make a right:p
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.
 

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