what type of measurement is this? dBV?

[No_hair_left]

I have warrantied my atmos speakers as the crossover dip (rew photo) is considerably worse on 3 of the speakers when I take a measurement at the tweeter.

This translates in real world usage (dirac photo) as one speaker overtaking the other 3 whenever sound plays through them, they asked aperion and aperion concluded that they were out of phase from my measurements(even though mine showed in phase), sent the speakers off and the company I bought them with says they are fine and that I should measure from 0.5-1ft away instead, I ask for their measurements and they send me that.

What type of measurement is that? yellow one is inverted.(1st photo)

If I measure from the tweeter then wouldn't it be safe to assume they should all measure (within reason) without that dip or am I doing it wrong?

 

[egellings]

dBV is decibels, referenced to a 1 volt level. A 1 volt reading would register as 0dBV.

 

[levimax]

Can you explain in detail how you are taking your measurements?

 

[No_hair_left]

Can you explain in detail how you are taking your measurements?

speaker on table with mic directly at the tweeter. Then I put the speakers on a fixed ceiling mount (used the 90degree cal file) and pointed at the tweeter(about an inch away), both times shows the dip.

I did a test where I used a fixed speaker mount and didn't move the mic, same amp, wire,channel,spl which was 15 degrees off axis and 3 of them once again shows an dip that cant be changed.Dirac shows it, xt32 shows it, rew shows it, all with different mics too.

 

[No_hair_left]

dBV is decibels, referenced to a 1 volt level. A 1 volt reading would register as 0dBV.

Is there a reason they would show me this instead of a normal measurement or is it the exact same as one?

The yellow inverted one looks like what my speakers are doing but they say that its all
fine from checking.

 

[kyuu]

speaker on table with mic directly at the tweeter. Then I put the speakers on a fixed ceiling mount (used the 90degree cal file) and pointed at the tweeter(about an inch away), both times shows the dip.

Unless I'm misunderstanding what you're saying here, you should be using the 0-degree calibration file if you're pointing the microphone directly at the speaker. I also don't know why you're attempting to measure the speaker with the microphone essentially pressed up against the tweeter. That would only make sense, by my understanding, if you were attempting to isolate the tweeter's response.

 

[levimax]

F

speaker on table with mic directly at the tweeter. Then I put the speakers on a fixed ceiling mount (used the 90degree cal file) and pointed at the tweeter(about an inch away), both times shows the dip.

I did a test where I used a fixed speaker mount and didn't move the mic, same amp, wire,channel,spl which was 15 degrees off axis and 3 of them once again shows an dip that cant be changed.Dirac shows it, xt32 shows it, rew shows it, all with different mics too.

For valid nearfield measurements you need to disconnect the other drivers, you are most likely measuring some interfearance between tweeter and mid/woofer that may not really exist. For your purposes I would recomend some MMM measurements of the 4 speakers taken from 2 meters away. Make sure the speakers are in the same place and you stand in the same place when you take the measurements. If the speakers really are operating differently you will clearly see it.

 

[No_hair_left]

Unless I'm misunderstanding what you're saying here, you should be using the 0-degree calibration file if you're pointing the microphone directly at the speaker. I also don't know why you're attempting to measure the speaker with the microphone essentially pressed up against the tweeter. That would only make sense, by my understanding, if you were attempting to isolate the tweeter's response.

It was 0 degree when on the table, 90 degree when on the ceiling, was just trying to work out the dip in the response as it only gets wider the further back I move the mic

 

[No_hair_left]

F
For valid nearfield measurements you need to disconnect the other drivers, you are most likely measuring some interfearance between tweeter and mid/woofer that may not really exist. For your purposes I would recomend some MMM measurements of the 4 speakers taken from 2 meters away. Make sure the speakers are in the same place and you stand in the same place when you take the measurements. If the speakers really are operating differently you will clearly see it.

I did this without using the moving mic method at just over 5ft away and it showed the other 3 speakers being 3-7db down over the same frequencies, very odd.Angle was a fixed mount and mic was fixed position. Dirac art wont let me change the levels of the speakers so now one of them takes over.

 

[Hayabusa]

F
For valid nearfield measurements you need to disconnect the other drivers, you are most likely measuring some interfearance between tweeter and mid/woofer that may not really exist. For your purposes I would recomend some MMM measurements of the 4 speakers taken from 2 meters away. Make sure the speakers are in the same place and you stand in the same place when you take the measurements. If the speakers really are operating differently you will clearly see it.

The right answer! Depending on objects in proximity I would also try 30 or 100cm

 

[No_hair_left]

Should we be careful when measuring old speakers? A not-too-faulty (but still faulty) speaker measured

After learning passive speakers can spoil too, I measured my pair of Diamond 8.2 that have sat in the living room for years Close mic of tweeter. The bad speaker was measured twice (orange and brown below) Hoo boy. My concern is that if we didn't have a second unit to compare against, we...

www.audiosciencereview.com

it reminds me if this post, drop off that recovers at the end, all tests show nothing seems to be wrong with polarity, his close up of the mic is the same as mine.

 

[levimax]

I did this without using the moving mic method at just over 5ft away and it showed the other 3 speakers being 3-7db down over the same frequencies, very odd.Angle was a fixed mount and mic was fixed position. Dirac art wont let me change the levels of the speakers so now one of them takes over.

Were the speaker and MIC in the exact same position when you took these two measurements? If not it doesn't really mean anything if yes then there is something wrong with the speakers. Just to clarify I am not saying the same distance from speaker to MIC but rather that both the speaker and the MIC are in the exact same position. The reason is room location can have a big effect on speakers FR even a few inches as these frequencies can make a big difference.

 

[mglobe]

If you want to be able to get them to replace the speakers, measure them exactly as they request.

 

[No_hair_left]

Were the speaker and MIC in the exact same position when you took these two measurements? If not it doesn't really mean anything if yes then there is something wrong with the speakers. Just to clarify I am not saying the same distance from speaker to MIC but rather that both the speaker and the MIC are in the exact same position. The reason is room location can have a big effect on speakers FR even a few inches as these frequencies can make a big difference.

Identical, mic didn't move and the mount I used is unmovable as its fixed. I doubt it was even mm out let alone inches.

 

[No_hair_left]

If you want to be able to get them to replace the speakers, measure them exactly as they request.

Guess I'll do this however I don't think they want to replace given they don't seem to want to share any other measurements.

In the uk the price of these has jumped considerably and they would have to import them from america again, they were the only company in the uk that were able to get these for me in the first place.

 

[levimax]

Guess I'll do this however I don't think they want to replace given they don't seem to want to share any other measurements.

In the uk the price of these has jumped considerably and they would have to import them from america again, they were the only company in the uk that were able to get these for me in the first place.

Not sure if you want to do it because it might make warranty issues for you but you could trying removing the tweeter and reversing the leads and measure again to see if response changes for the better or worse.

 

[No_hair_left]

Not sure if you want to do it because it might make warranty issues for you but you could trying removing the tweeter and reversing the leads and measure again to see if response changes for the better or worse.

They apparently did this already, he said the yellow one is what happens when he reverses it.

If I open the speakers they wont go near them again and they cost me over £1000 so cant afford that.

 

[Hayabusa]

They apparently did this already, he said the yellow one is what happens when he reverses it.

If I open the speakers they wont go near them again and they cost me over £1000 so cant afford that.

measure at bigger distance!

 

[No_hair_left]

Ill get the speakers back and do some measurements like suggested on here and the aperion suggested way.

This is one of those things where I just know there is a problem it's just trying to get everyone else to see it a bit better to try and work out what it is lol if one speaker measures fine but the other 3 show a huge dip at the crossover in rew, xt32 and dirac then it has to be the crossover.

Aperion say 0.5-1ft away from tweeter so ill try that.
Someone else said 6ft so i'll do that and 30-60cm.
Assuming I do all of that and the dip still persists in the 3 speakers vs 1 one good speaker that is normal Im assuming its the crossover? they are in phase and polarity is normal.

 

[No_hair_left]

Right one last time as got the speakers back today, sorry you all probably hate me.

The numbers are the end serial numbers so the pairs which the came as.

Is this a failed or failing tweeter in one of the speakers? One speaker still pulls ahead of all the rest but I did measurements at 4cm, 0.5 meters and 1 meter and they all show something wrong with one of the speakers. The one speaker is anywhere from -2db down to -10db down in all of the measurements and any distance. Identical speaker positions, spl and the mic was not moved once I measured the distance.

Polarity and phase were checked and fine.