Motion 50Xti Frequency Dip - anybody having similar experience

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Fidji99

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Wanted to ask a specific question on Motion 50Xti - although I am happy with the sound, when measuring with REW, there is some weird dip around 200Hz
Is not room related, as other speakers do not suffer from the same room mode.

On top I can see quite high distortion peak in the same frequency - I suspect port resonance in some form, as when I block Bass Reflex , it improves slightly. I run it crossed over at 90Hz. Does not seem being caused by placement.

REW screen shot - FL&FR combined, for reference

1634127895128.png


DIstortion

1634127963514.png


1634128047783.png



Measurements from different positions - prior to DRC correction
1634128253136.png
 

ttocs

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If that green trace is just one 50Xti, and the purple trace is the other, then yes, might be something up with the speaker.

To check, move the mic to just a few feet away from the speaker and aim the mic at it between the woofer/mid and measure.
 

Fidji99

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so - it really seems to be some crazy comb filtering coming from adjustable sofa, this is how it looks 1m distance ungated. Crazy dip disappeared. I am bit limited in "change the position exercise" I will try to experiment with first reflection point on the floor

1634146753038.png


unfortunately distortion/resonance is still there [and you can hear at the sweep]

1634146919406.png


after some experimenting with tilt/angle and sofa position - it really seems to be caused by sofa & tilt combination - same speaker, same mic position,
brown - measured at LP normal tilt
blue - tilted upwards [2cds under front] sofa in upright position

Good news - will have something to do on the weekend ;-)

1634148024578.png
 

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ttocs

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My leather dual recliner is the same way. During measurements I recline and cover with blankets.

Glad you found the cause. It can be perplexing!
 

IEnjoyOLED

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My leather dual recliner is the same way. During measurements I recline and cover with blankets.
I don’t have an anomaly with my 50XTi in an exclusively home theater use room, but the next time I do an ARC sweep, I will place some blankets on the recliners. Good idea!

Btw, my theater is small, but I want to say that I have been delighted with how good the front speakers (LR: 35XTi and C: 50XTi) sound. Well done ML.
 

spkrdctr

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Yes, when I saw your graphs I was like that is 100% room response. By room I mean room and furniture etc. Now you figured it out. Good Work!
 
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