Leema Tucana II Anniversary - initial impressions + measurements

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radiorog

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insider9 said:
Ok, as promised here are the measuremets as a way of comparison to Hegel Rost

Both speakers and mic are in the same postion, no DSP has been applied for comparison. Level matched conditions and no other significant variables. These are in room measurements of individual speakers and althought the room is treated you will see it obviously still impacts on frequency response. For ease of comparison I've used 1/6 smoothing.

Red is Hegel / Blue is Leema

LEFT SPEAKER 

RIGHT SPEAKER

From the above you can see how well the Leema controls the bass. Dips are nowhere near as big. And even though these are smoothed the diference is 3-5dB.
Hey insider. Could you roughly explain tomme what this graph is showing please? It seems frequency is on the horizontal axis, so what is the vertical? Where is time? Is it a piece of music or just a pulse of sound for a split second?
Cheers.
 

insider9

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Typing... :)

Measurement are of a frequency sweep from 20Hz to 24kHz. In real terms I'm measuring speakers and in room but worth looking how well the amp drives them. Blue line represents how Leema measured, Red how Hegel Rost did.

Y axis is in dB (linear scale by 5dB)
X axis is Hz (log scale)

In basic terms this shows how loud certain frequencies will be i relation to one another (as the overall level doesn't really matter).

So for example looking at a measurement between 500Hz and 24kHz the lines. Where room effect are less than below 500Hz. You see that both measurements are between two black horizontal lines. This means. That in this part of spectrum speakers measure within 5dB that's no more than +/- 2.5dB in room.

Now, looking at differences between Blue and Red lines indicates how amp is doing driving the speakers.

Left speaker at 141Hz Leema is better off (flatter by 3dB). Right speaker at 300Hz Leema is better by just over 5dB. These are substantial differences.

For higher res pictures go to my Flickr album is called Leema Measurements

https://flic.kr/s/aHsme7iVwh
 

radiorog

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insider9 said:
Typing... :)

Measurement are of a frequency sweep from 20Hz to 24kHz. In real terms I'm measuring speakers and in room but worth looking how well the amp drives them. Blue line represents how Leema measured, Red how Hegel Rost did.

Y axis is in dB (linear scale by 5dB)
X axis is Hz (log scale)

In basic terms this shows how loud certain frequencies will be i relation to one another (as the overall level doesn't really matter).

So for example looking at a measurement between 500Hz and 24kHz the lines. Where room effect are less than below 500Hz. You see that both measurements are between two black horizontal lines. This means. That in this part of spectrum speakers measure within 5dB that's no more than +/- 2.5dB in room.

Now, looking at differences between Blue and Red lines indicates how amp is doing driving the speakers.

Left speaker at 141Hz Leema is better off (flatter by 3dB). Right speaker at 300Hz Leema is better by just over 5dB. These are substantial differences.

For higher res pictures go to my Flickr album is called Leema Measurements

https://flic.kr/s/aHsme7iVwh
Mm, ok, cheers. I understand somebody that. :) What is a frequency sweep? Does it collect data from a piece of music, or is it something else?
 

insider9

Well-known member
No it's sort of a "chirping" noise similar to a sound you'd make if you were whistling from very low to very high.

I'm sure you've heard similar if you ever setup correction for home cinema, or done something similar.
 

insider9

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By the way should I use 1/3 smoothing, more or less industry standard the speakers measure in room (500Hz up) +/- 2dB. For comparison Kef Ref 3 anechoic chamber measurements show +/- 3dB :)

Only saying as there has been some criticism aimed at both my room and speakers. Oh, I wish I had an anechoic chamber to see how well they'd measure there.
 

insider9

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MajorFubar said:
insider9 said:
there has been some criticism aimed at both my room and speakers.

Treat it like water off a duck's back. Haters hate.
Thanks Major. No problem at all. Criticism is good. I don't claim to be right about a lot of things but spent a year reading about room acoustics and I'm continuously working to improve my listening environment.

It lead me to take another set of measurements which in turn made me realise I was using incorrect DSP filters. Which meant I wasn't getting the full benefit :) It's all good.
 

Andrewjvt

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insider9 said:
By the way should I use 1/3 smoothing, more or less industry standard the speakers measure in room (500Hz up) +/- 2dB. For comparison Kef Ref 3 anechoic chamber measurements show +/- 3dB :)

Only saying as there has been some criticism aimed at both my room and speakers. Oh, I wish I had an anechoic chamber to see how well they'd measure there.

name and shame so we can all gang up

only joking (for people that require yellow smiling men to believe)
 

Blacksabbath25

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Andrewjvt said:
insider9 said:
By the way should I use 1/3 smoothing, more or less industry standard the speakers measure in room (500Hz up) +/- 2dB. For comparison Kef Ref 3 anechoic chamber measurements show +/- 3dB :)

Only saying as there has been some criticism aimed at both my room and speakers. Oh, I wish I had an anechoic chamber to see how well they'd measure there.

name and shame so we can all gang up

only joking (for people that require yellow smiling men to believe)
the trouble is Andrew people take things the wrong way so easy so you need them to show that your being friendly and not being Evil *smile* yellow face
 

insider9

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CnoEvil said:
Indeed they are flatter up to 8kHz around +/- 1dB and that's extreme important but not above that. Above they're are +/- 3dB. And that's anechoic chamber.

My measurements are respectable I believe for in room response. I wish I could have a possibility to measure them in an anechoic chamber.

But that's beside the point. Point was Leema gives measurable gains in bass control.
 

MajorFubar

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Wonder how my AVi's would measure in your room. I know what the official measurements look like, AVI made them public:

dm10-driver-measurements.jpg


(Apologies...that's probably quite off topic considering this thread is about an amp)
 

insider9

Well-known member
That would be a good test. When are you coming over, Major? :) I've have stands so no need for them.

It's all down to positioning. I take it the measurements you've posted is on axis, hence the horrendous 10dB spike in treble around 8kHz. And their off axis performance takes care of this. Otherwise they'd not only be unforgiving but also unlistenable :)

I guess with careful positioning we could get them to sound great with no need for DSP for bass.
 

MajorFubar

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insider9 said:
That would be a good test. When are you coming over, Major? :) I've have stands so no need for them.

It's all down to positioning. I take it the measurements you've posted is on axis, hence the horrendous 10dB spike in treble around 8kHz. And their off axis performance takes care of this. Otherwise they'd not only be unforgiving but also unlistenable :)

I guess with careful positioning we could get them to sound great with no need for DSP for bass.

Blue is on axis, red is 20 degrees off. Other than that, I don't know mate to be honest, they're the figures from AVI and I wouldn't know where to find the thread where they were published, which might shed light on how and where the measurements were taken. Certainly the 8k spike doesn't seem to manifest itself in actual listening tests. If anything they're quite dark speakers. Way darker than the EB2's
 

insider9

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I know very well. I'm doing all my DSP by hand so had to find everything out in both theory and through listening. I'd say 10kHz isn't so much a problem as boasting around the can add definition of done gently. Overdoing it might feel slightly grainy in treble. However 8kHz would just make it bright.

The two plots are interesting as on axis would make most ears bleed yet 20 degrees off would result in very early roll off around 9kHz.

And if your listening indicates they are dark then these are not their measurements.

Interesting and if I ever travel your way I'll make sure to put a mic in the car in case I'll end up paying you a visit :)
 

MajorFubar

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insider9 said:
I know very well. I'm doing all my DSP by hand so had to find everything out in both theory and through listening. I'd say 10kHz isn't so much a problem as boasting around the can add definition of done gently. Overdoing it might feel slightly grainy in treble. However 8kHz would just make it bright.

The two plots are interesting as on axis would make most ears bleed yet 20 degrees off would result in very early roll off around 9kHz.

And if your listening indicates they are dark then these are not their measurements.

Interesting and if I ever travel your way I'll make sure to put a mic in the car in case I'll end up paying you a visit :)

Sorry, I edited my post as you were replying because I originally thought the peak was at 10k, which is a lot higher than most people actually realise. You're always welcome to pop round, but to be honest my room is a lousy test chamber. No two positions sound the same.
 
It’s very interesting what you’re attempting, insider, but I’m not sure that you can necessarily attribute these slight changes to an amplifier having better control. You could just as easily look at damping factor/output impedance, but what you measure isn’t what you hear.

Maybe I’ve misread you, but these graphs are single sweeps aren’t they, not averages or multi point measurements? I’m assuming the speakers and mike are in unchanged positions throughout? What does it look like if moved forward or back a few cm? And are the measurements identical every day?

I think the reason speakers are tested anechoically is well established, but it can be replicated outdoors on a windless day, allegedly! Room averaged responses are used by Martin Colloms, whose book on High Performance Speakers I’ve recommended here before. It’s about £80 new but you can get an ex library copy for about twenty.

I’ll see if I can find something relevant to link here.
 

Craig M.

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MajorFubar said:
Wonder how my AVi's would measure in your room. I know what the official measurements look like, AVI made them public:

(Apologies...that's probably quite off topic considering this thread is about an amp)

If I remember correctly that graph is for the mid/bass only. I seem to recall Ash using it to show how well behaved it was till an octave past the crossover point. Or I’m remembering wrong. *wacko*
 

insider9

Well-known member
Craig M. said:
MajorFubar said:
Wonder how my AVi's would measure in your room. I know what the official measurements look like, AVI made them public:

(Apologies...that's probably quite off topic considering this thread is about an amp)

If I remember correctly that graph is for the mid/bass only. I seem to recall Ash using it to show how well behaved it was till an octave past the crossover point. Or I’m remembering wrong. *wacko*

That would explain a lot!
 

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