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@Kini62, I see now that your experience with the MT110 is fully documented in the PSA thread. To briefly sum it up you said you were disappointed to find your MT110s to be less sensitive than your Klipsch RF62IIs the way you were running them in your room when you fully expected the PSA to be more sensitive than the Klipsch. This result was so unusual that many MT110 owners, including some who had switched from Klipsch, tried to help you identify the unique issue you had run into. You said you were so disappointed that you would return the MT110s if the shipping cost from Hawaii wasn't so high.

@Tom Vodhanel also tried to help you work through your issue and then generously offered to pick up any additional cost of shipping the speakers back to the mainland. You eventually took him up on that offer and expressed your gratitude to Tom and the whole PSA community for all the time and effort they put into trying to help you through a speaker sensitivity issue that no other PSA owner said they had experienced.

In conclusion it seems your experience with lower than expected MT110 speaker sensitivity was unique to the PSA community and would most likely not be applicable to others. We can only hope that someone like @bikinpunk will find a way to get hold of an MT110 or other PSA speaker, run it through his Klippel measuring device and share objective measurements of the performance including actual sensitivity so we don't have to rely exclusively on user listening impressions.
It was what it was. During speaker calibration the MT110s came back 2db less than the RF62IIs. Same distance, same tweeter height etc... I found that speaker sensitivity (which is what is measured) is different than in room efficiency. The RFs are ported with larger cabinets leading to greater overall in room efficiency. My Q750s are 4db less efficient than the RFs. Smaller cabinet, no horn, and passive radiators. Makes sense to me. YMMV.
 

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It was what it was. During speaker calibration the MT110s came back 2db less than the RF62IIs. Same distance, same tweeter height etc... I found that speaker sensitivity (which is what is measured) is different than in room efficiency. The RFs are ported with larger cabinets leading to greater overall in room efficiency. My Q750s are 4db less efficient than the RFs. Smaller cabinet, no horn, and passive radiators. Makes sense to me. YMMV.
Right, and multiple people in the PSA thread tried to explain to you how notoriously unreliable AVR auto calibration might come up with a false reading. Our speaker sensitivity mileage wouldn't vary if everyone used the industry standard for measuring speaker sensitivity. :)
 

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Right, and multiple people in the PSA thread tried to explain to you how notoriously unreliable AVR auto calibration might come up with a false reading. Our speaker sensitivity mileage wouldn't vary if everyone used the industry standard for measuring speaker sensitivity. :)
Doesn't matter if the speaker calibration is off or not as it would be off for both sets of speakers. Plus I verified it with a sound meter using the AVRs pink noise, playing music without changing the volume and the RFIIs were always 2db louder no matter the content.
 

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Doesn't matter if the speaker calibration is off or not as it would be off for both sets of speakers. Plus I verified it with a sound meter using the AVRs pink noise, playing music without changing the volume and the RFIIs were always 2db louder no matter the content.
As was explained in the PSA thread your method for comparing speaker sensitivity is not consistent with the industry standard so the results are not reliable. In terms of real world experience no one else has reported a similar result.
 

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Doesn't matter if the speaker calibration is off or not as it would be off for both sets of speakers. Plus I verified it with a sound meter using the AVRs pink noise, playing music without changing the volume and the RFIIs were always 2db louder no matter the content.
In brainstorming how this could have happened, my thought is that perhaps since the Klipsch are large full range speakers that play quite low, perhaps the higher SPL reading you got from them, playing wide band pink noise, was due to the elevated low end response resulting from significant room gain in the lower freqeuncies that the MT-110 would not get due to its much shallower roll off? I know my tower speakers have very significant low frequency room gain/room mode peaks that drastically boost SPL compared to a bookshelf that rolls off below 80 Hz. An AVR will be measuring full range SPL capability of each speaker when setting levels. Just a thought?

I dunno, on the other hand, surely an AVR is capable of detecting sensitivity in the 300-10 KHz region to get an accurate sense of how loud a speaker is playing…..
 

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As was explained in the PSA thread your method for comparing speaker sensitivity is not consistent with the industry standard so the results are not reliable. In terms of real world experience no one else has reported a similar result.
Don't really care. There is no other way to explain it. The RFs were always 2db louder, verified with a SPL meter, same source, same distance, same room, same equipment. You can keep on denying what it was and keep making excuses as to why I'm wrong but I don't care. The difference was noticeable, repeatable and without variation. Seems like a pretty good testing method to me with what I had available. Measuring the volume level of a speaker is not brain surgery.

As bear mentioned and as I've stated before there is a difference between measured sensitivity, you know the whole voltage in thing, anechoic testing and in room efficiency.
 

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Don't really care. There is no other way to explain it.
Yes there is, the correct way.

We had the mtm210 reviewed+measured a while back and the "sensitivity" clocked in at 98dB iirc, right on spec. That review is still up(home theater nirvana) somewhere in the archives but the graphs are all broken. If anyone has the time to try to "way back machine" them maybe that will convince you. Sensitivity is not efficiency and using a AVR to determine either may or may not give someone the results they expected or results that are accurate.



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More concise.

Hooking up ANY speaker to your AVR and running a calibration tone will NOT be an accurate way to gauge true "sensitivity" of the speaker---even if you keep all the AVR settings static. It MAY just happen to be close to accurate assuming both/all speakers are extremely similar "loads". Or it could be wildly inaccurate.

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In brainstorming how this could have happened, my thought is that perhaps since the Klipsch are large full range speakers that play quite low, perhaps the higher SPL reading you got from them, playing wide band pink noise, was due to the elevated low end response resulting from significant room gain in the lower freqeuncies that the MT-110 would not get due to its much shallower roll off? I know my tower speakers have very significant low frequency room gain/room mode peaks that drastically boost SPL compared to a bookshelf that rolls off below 80 Hz. An AVR will be measuring full range SPL capability of each speaker when setting levels. Just a thought?

I dunno, on the other hand, surely an AVR is capable of detecting sensitivity in the 300-10 KHz region to get an accurate sense of how loud a speaker is playing…..
If worried about sensitivity op should had gotten duel woofer version, but turning the volume up 2db isn’t a big deal if it’s calibrated well . Does not automatically make it better then Klipch, sound quality is what matters .
 

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Discussion Starter · #30 ·
If worried about sensitivity op should had gotten duel woofer version, but turning the volume up 2db isn’t a big deal if it’s calibrated well . Does not automatically make it better then Klipch, sound quality is what matters .
If i was worried about sensitivity I would have indicated that but i'm not worried about anything other than if there was some unknown detriment to having a horizontal MT configuration.
 

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If i was worried about sensitivity I would have indicated that but i'm not worried about anything other than if there was some unknown detriment to having a horizontal MT configuration.
Once we rotate the horn everything is the same for the MT110(on/off axis).

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Discussion Starter · #32 ·
Once we rotate the horn everything is the same for the MT110(on/off axis).

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This make sense to me but you dont know what you dont know and it is so rare to see horizontal MT designs that I thought just maybe there was some small reason it is avoided. Thanks Tom.
 

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This make sense to me but you dont know what you dont know and it is so rare to see horizontal MT designs that I thought just maybe there was some small reason it is avoided. Thanks Tom.
It is mostly consumer perception driven. People expect to see a center channel that has a traditional front baffle ratio...much wider than tall.

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You should never measure sensitvity with full bandwidth pink noise and a SPL meter

The only thing you are getting is the peak SPL at a peak frequency, not the broadband sensitivity reading.

In the Klipsches case, it has an advantage because it can go to lower frequencies than the PSA which demands and is made specifically for subwoofers. Since low frequencies are room dependent, you have massive swings in frequency response so your SPL meter might be reading one of those big peaks caused by your room. The PSA by not generating deep bass will not excite those room modes so that throws off the SPL meter. Be aware that if the Klipsch is inaccurate or has rising response, the SPL meter wlll measure whatever the peak is.

The correct way would be to measure speakers outside and do a sweep from say 100Hz to 10KHz and get the frequency response measurement in there. A quickie in room I'd limit the sweep from 300Hz to 10KHz to minimize room issues when it comes to bass. Pink noise is used for Real Time Analyzers to measure all the frequencies at once as it graphs the full bandwidth from a minimum of 1 octave to 1/3rd octave or higher.

So if you care to get any form of accuracy, take the speakers out of the room and compare tone sweeps of the two speakers with the same bandwidth they are rated to do.

Why should you not put speakers horizontal? Well, speakers generate lobes and when they are vertically oriented, generate vertical lobes. Why don't humans generally don't hear those vertical lobes is because our ears, being on either sides of our heads are horizontal so both ears are on the same plane so are located in the same vertical lobe. You would have to do deep knee bends to move your ears vertically through the lobing to detect it. Lobing is a known problem for people that ride pogo sticks ;)

The issue arrises when you lay the speaker horizontal--now the vertical lobes become horizontal lobes so each ear can be (but not always) be in a different lobe. Human hearing is always on the hunt for differences in sound between our ears as that is how our brain calculates such things like how big something is, calculates distances and location of sound. Our HORIZONTAL hearing accuracy is very good, we are ground dwellers and stand upright and our enemies are on the ground. It makes sense that we hear that way and why our ears are not at the top of our heads like rabbits. After all, any sound from up in the air that will eat us is not as common as ground level enemies. Basically our vertical abilites are poor so when startled, we tend to look up to verify what we hear.

You might have noticed most multi-driver speakers are vertical, the most extreme of these are vertical line arrays--they even have vertical in the name! They throw up to dozens of vertical lobes which look nasty when testing with microphones and test gear. No problem though, they are vertical lobes so unless you use them with trampolines, you won't hear the lobes. However! You must never, ever lay them horizontal because those dozens of lobes will then be easily detected by the horizontall arangement of your ears. For this reason you'll never see a vertical line array laying on it's side above a stage--sure would save a ton of space if they could though.

You might have read the drama over horizontal "center" channels that are 2-way with the woofer/tweeter/woofer design. Those designs,when not done exacty right will throw horizontal lobes which can be heard by both ears as a difference in sound. Easy test to detect horizontal lobing. You can put someone talking through the speaker (in mono for accuracy) then slowly pivot your head side-to-side and if you hear the sound changing with your head movement, that is the horizontal lobing. So easy an audiophile can do it! ;)

Generally speaking, you should not lay a speaker on it's side unless it is specifcally designed correctly to do so. Coaxials, 3 way center channels and the rare 2-way can do this without issues. I saw a "horizontal line array" and it was curved inward to focus the energy together, it can be done...but answers a question kind of design (look cool and is LOUD for the win!)

For more information on vertical lobing, read about infinite line sources--the math/physics behind line arrays. To get actual test data, go to Audio Science Review and look at their speaker testing and compare vertical VS horizontal accuracy, for the most part the horizontal accuracy is far better than the vertical as that wiil give you an answer of what happens when you change from vertical to horizontal. Some speakers it won't make much difference but most speakers it will make a huge difference so let the measuremets be your guide.

Cheers! :)
 
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