This is a review of the Tannoy System 600 bookshelf speaker. It is rather old unit but since we have no Tannoy speakers in our database I thought it would be good to review. It is on kind loan from a member. I don't know what it cost when new.
The concentric driver sure looks weird:
It looks like it had a dust cap which was ripped out (but is not).
Funny bit is that when I was test it from some 6 feet away at high SPL, I was getting a strong breeze on my cheeks from the front ports! It also produced audible secondary tones during speaker sweeps.
Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.
All measurements are reference to tweeter axis with the grill removed. Frequency resolution is 0.7 Hz (yes, less than 1 Hz) and plots are at 20 points/octave. Spatial 3-D resolution is 1 degree.
Nearly1000 points around the speaker were measured (from 20 to 20 kHz) which resulted in well under 1% error in identification of the sound field until about 16 kHz. Error then rose up to 2% at 20 kHz. Final database of measurements and data is 1.4 Gigabytes in size.
In order to speed up the publication of these reports, this review is somewhat abbreviated. Full data is enclosed though.
Spinorama Audio Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker can be used. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:
I don't need to tell you that this is a very poor response. There is a huge suck out at the crossover frequency as the two drivers don't overlap properly. We also have peaking prior to that dip and general mismatch to higher frequencies. In essence, no measurement seems to have been used to optimize this design.
Predicted in-room response is therefore awful:
Here is the impedance measurement:
Speaker Distortion Measurements
I dedicated a couple of days to bettering the distortion measurements. First and foremost, I used the Klippel compensation system to produce anechoic distortion measurements from in-room! This means I can now show full spectrum of the distortion down to 20 Hz without any room modes or reflections messing up the display. It is not as useful in this instance but will be when we measure subwoofers.
Second bit was a suggestion by a member to also measure distortion at higher voltage. Up until now, I have only shown that at 2.83 volts at the speaker terminal. Now I am also measuring at four times that (around 10 volts). Here are the results:
We see that the level sensitive distortion is at lower frequencies. The rest are not scaling that much with level although there are differences.
Eye-candy Speaker Measurements
Because of the concentric driver, vertical and horizontal axis are quite similar. Similarly bad that is due to that suck out which you can clearly see in these graphs:
Speaker Listening Tests
No time as the big pile of speakers waiting to be reviewed is threatening to fall on me....
Conclusions
The Tannoy System 600 seems to have been designed based on ideas and principals, as opposed to verification with measurements. I am sure someone will educate me about the genius behind this design. The data shows the speaker to be highly colored and really not something you want to put in your system.
------------
As always, questions, comments, recommendations, etc. are welcome.
I was looking at my paypal balance on the computer today when my wife was walking by a floor down commented: "you seem to not have taken in enough donations!" You know how it is when the wife comments on something as she walks by. It is as good as gold. So please donate NOW using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
The concentric driver sure looks weird:
It looks like it had a dust cap which was ripped out (but is not).
Funny bit is that when I was test it from some 6 feet away at high SPL, I was getting a strong breeze on my cheeks from the front ports! It also produced audible secondary tones during speaker sweeps.
Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.
All measurements are reference to tweeter axis with the grill removed. Frequency resolution is 0.7 Hz (yes, less than 1 Hz) and plots are at 20 points/octave. Spatial 3-D resolution is 1 degree.
Nearly1000 points around the speaker were measured (from 20 to 20 kHz) which resulted in well under 1% error in identification of the sound field until about 16 kHz. Error then rose up to 2% at 20 kHz. Final database of measurements and data is 1.4 Gigabytes in size.
In order to speed up the publication of these reports, this review is somewhat abbreviated. Full data is enclosed though.
Spinorama Audio Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker can be used. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:
I don't need to tell you that this is a very poor response. There is a huge suck out at the crossover frequency as the two drivers don't overlap properly. We also have peaking prior to that dip and general mismatch to higher frequencies. In essence, no measurement seems to have been used to optimize this design.
Predicted in-room response is therefore awful:
Here is the impedance measurement:
Speaker Distortion Measurements
I dedicated a couple of days to bettering the distortion measurements. First and foremost, I used the Klippel compensation system to produce anechoic distortion measurements from in-room! This means I can now show full spectrum of the distortion down to 20 Hz without any room modes or reflections messing up the display. It is not as useful in this instance but will be when we measure subwoofers.
Second bit was a suggestion by a member to also measure distortion at higher voltage. Up until now, I have only shown that at 2.83 volts at the speaker terminal. Now I am also measuring at four times that (around 10 volts). Here are the results:
We see that the level sensitive distortion is at lower frequencies. The rest are not scaling that much with level although there are differences.
Eye-candy Speaker Measurements
Because of the concentric driver, vertical and horizontal axis are quite similar. Similarly bad that is due to that suck out which you can clearly see in these graphs:
Speaker Listening Tests
No time as the big pile of speakers waiting to be reviewed is threatening to fall on me....
Conclusions
The Tannoy System 600 seems to have been designed based on ideas and principals, as opposed to verification with measurements. I am sure someone will educate me about the genius behind this design. The data shows the speaker to be highly colored and really not something you want to put in your system.
------------
As always, questions, comments, recommendations, etc. are welcome.
I was looking at my paypal balance on the computer today when my wife was walking by a floor down commented: "you seem to not have taken in enough donations!" You know how it is when the wife comments on something as she walks by. It is as good as gold. So please donate NOW using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
