Hello,
These speakers (dual concentric 3 way) seem to have a pronounced response around the crossover point at ~ 2.5kHz which I would like to address somehow. I have added extra damping material to the inside of the cabinet which has helped greatly with the upper mid range "hash" but I now need to sort out the tweeters filter.
So....my next move, I think, is to raise the tweeters crossover point slightly to equalise this peak and reduce this irritating sibilance. The user manual states that the crossover is entirely first order at 400Hz and 2.5kHz. Is this the right approach? Am I missing something here?
In the Tweeter's filter what is the function of the inductor?
I have (hopefully) posted a crossover schematic which I have labelled with the information that I have so far. I don't have any values for the inductors and only the measured DC resistance for he individual drivers.
Could I just change the 3u3 cap for a 2u2 or would this be a drastic change?
Overall the speakers are rated at 6 Ohms.
Any help would be very much appreciated.
These speakers (dual concentric 3 way) seem to have a pronounced response around the crossover point at ~ 2.5kHz which I would like to address somehow. I have added extra damping material to the inside of the cabinet which has helped greatly with the upper mid range "hash" but I now need to sort out the tweeters filter.
So....my next move, I think, is to raise the tweeters crossover point slightly to equalise this peak and reduce this irritating sibilance. The user manual states that the crossover is entirely first order at 400Hz and 2.5kHz. Is this the right approach? Am I missing something here?
In the Tweeter's filter what is the function of the inductor?
I have (hopefully) posted a crossover schematic which I have labelled with the information that I have so far. I don't have any values for the inductors and only the measured DC resistance for he individual drivers.
Could I just change the 3u3 cap for a 2u2 or would this be a drastic change?
Overall the speakers are rated at 6 Ohms.
Any help would be very much appreciated.
Attachments
It's only 1st order on the mid,
As a 1st step I'd try a Zobel on the mid.
Check out the on-line calculators here:
http://www.apicsllc.com/apics/Misc/filter2.html
That page will help you recalc xover values if you want to change them too.
Do you mave the model numbers of the drivers?
As a 1st step I'd try a Zobel on the mid.
Check out the on-line calculators here:
http://www.apicsllc.com/apics/Misc/filter2.html
That page will help you recalc xover values if you want to change them too.
Do you mave the model numbers of the drivers?
\Cheers Pete.
I'm pretty sure that the harshness is coming from the 1" HF horn. The internal foam damping has helped greatly with the mid but obviously the HF compression driver is unaffected by this.
How would a zobel on the mid help in this case?
The drivers are Tannnoys own :
Model: 611
Year: 1991-3
Dual Concentric: 2033
Dual Concentric Size: 8"
High Frequency: 1662/2033
High Frequency Size: 25mm
Low Frequency: 2035
Low Frequency Size: 8"
Second Low Frequency:
Crossover Code: 1127
I'm going to investigate further tommorrow but the weakness appears to be either an unwanted resonance in the horn or it is crossed too low to cope adequately. My thinking here is that if I cross it a bit higher then it may be under less strain and therefore sound better.
I'm having great difficulty with the online crossover simulators because I don't know the values of the inductor L1 ("66" is handwritten on it.) and also the true impedance of the HF driver (4.4 Ohms D.C. resistance).
I'm not sure how to fill in the gaps?
I'm pretty sure that the harshness is coming from the 1" HF horn. The internal foam damping has helped greatly with the mid but obviously the HF compression driver is unaffected by this.
How would a zobel on the mid help in this case?
The drivers are Tannnoys own :
Model: 611
Year: 1991-3
Dual Concentric: 2033
Dual Concentric Size: 8"
High Frequency: 1662/2033
High Frequency Size: 25mm
Low Frequency: 2035
Low Frequency Size: 8"
Second Low Frequency:
Crossover Code: 1127
I'm going to investigate further tommorrow but the weakness appears to be either an unwanted resonance in the horn or it is crossed too low to cope adequately. My thinking here is that if I cross it a bit higher then it may be under less strain and therefore sound better.
I'm having great difficulty with the online crossover simulators because I don't know the values of the inductor L1 ("66" is handwritten on it.) and also the true impedance of the HF driver (4.4 Ohms D.C. resistance).
I'm not sure how to fill in the gaps?
If you're sure it's the tweeter, a zobel on the mid won't help.
Using the calculator 'backwards' I get a value of 1.33mH for the inductor. (and a Z of around 10-11.5ohms).
Simplest thing to do is what you initially suggested, use a smaller cap, and see what happens (2u2 will get you up around 3KHz). Ideally you would need a change in inductor too, but only a small change downwards is indicated by the calculator.
Using the calculator 'backwards' I get a value of 1.33mH for the inductor. (and a Z of around 10-11.5ohms).
Simplest thing to do is what you initially suggested, use a smaller cap, and see what happens (2u2 will get you up around 3KHz). Ideally you would need a change in inductor too, but only a small change downwards is indicated by the calculator.
Hi,
Sorry for deleting my post but it was incorrect.
I had assumed what you label as the mid was the 0.5 way
bass and what you label as bass, is in fact the bass mid unit.
In this case the c/o is 2nd order electrical, though its possible
c/o slopes approximate 1st order acoustic is the c/o region.
I think your diagram is possibly wrong, but could be right,
overdamped 2nd order on the 0.5 way unit, 1st order on
the bass/mid unit, 2nd order on the tweeter.
Still it appears not to be a true 3-way.
Adding Zobels is NOT the way to go, c/o values would then
be completely wrong, including phase at the c/o point.
Reducing the tweeters capacitor is worth trying.
/sreten.
Sorry for deleting my post but it was incorrect.
I had assumed what you label as the mid was the 0.5 way
bass and what you label as bass, is in fact the bass mid unit.
In this case the c/o is 2nd order electrical, though its possible
c/o slopes approximate 1st order acoustic is the c/o region.
I think your diagram is possibly wrong, but could be right,
overdamped 2nd order on the 0.5 way unit, 1st order on
the bass/mid unit, 2nd order on the tweeter.
Still it appears not to be a true 3-way.
Adding Zobels is NOT the way to go, c/o values would then
be completely wrong, including phase at the c/o point.
Reducing the tweeters capacitor is worth trying.
/sreten.
Firstly, Thank you Auger, Pete and Sreten for your help.
It is really appreciated and I am learning alot through this. Also, I think it's amazing that I am gaining help from people who live on the opposite side of the world and also in the same city!
I have a simple simulation running now and can see graphically how changing components in the tweeter crossover affects the frequency curve. I am now fully realising that crossover tweaking is more about experience and perseverence than mathematics!
In the simulation I'm just looking at the frequency curve to gain a general understanding since I have no real values available for the inductors or driver impedance. I'm sure that I read somewhere that driver impedance is roughly 1.5 X DC Resistance??
I've ordered some components to reduce the Tweeters cap to 2u2F and then I'll go from there. If necessary I suppose that I could also unwind a few turns from the inductor. But I'll have to have a good listen first.
I'm pretty sure that my diagram is correct. I checked it many times because it did not seem to make any sense.
I had always assumed that these speakers were 3 ways with first order filters so you can understand the confusion I felt when I first saw the crossover.
After reviewing the user manual I now notice that it states "....secondary bass unit driven below 400Hz".
It does however definitely state on the spec sheet that it is "First order low pass, First order high pass". I guess you should never take manufacturers specs for granted.
Thanks once again for all your kind help and I will of course post my progress here soon.:
It is really appreciated and I am learning alot through this. Also, I think it's amazing that I am gaining help from people who live on the opposite side of the world and also in the same city!
I have a simple simulation running now and can see graphically how changing components in the tweeter crossover affects the frequency curve. I am now fully realising that crossover tweaking is more about experience and perseverence than mathematics!
In the simulation I'm just looking at the frequency curve to gain a general understanding since I have no real values available for the inductors or driver impedance. I'm sure that I read somewhere that driver impedance is roughly 1.5 X DC Resistance??
I've ordered some components to reduce the Tweeters cap to 2u2F and then I'll go from there. If necessary I suppose that I could also unwind a few turns from the inductor. But I'll have to have a good listen first.
I'm pretty sure that my diagram is correct. I checked it many times because it did not seem to make any sense.
I had always assumed that these speakers were 3 ways with first order filters so you can understand the confusion I felt when I first saw the crossover.
After reviewing the user manual I now notice that it states "....secondary bass unit driven below 400Hz".
It does however definitely state on the spec sheet that it is "First order low pass, First order high pass". I guess you should never take manufacturers specs for granted.
Thanks once again for all your kind help and I will of course post my progress here soon.
:
Hi,
There there seems to be a peak at the crossover frequency, it could be that the tweeter connections are out of phase. Try swapping the tweeter connections on both speakers and see if the peak goes away. Should be very easy to implement, and could save you a lot of effort later.
It won't be that the mid is out of phase, as you can easily test that with a 1.5V battery to check same phase with bass unit.
Adrian
There there seems to be a peak at the crossover frequency, it could be that the tweeter connections are out of phase. Try swapping the tweeter connections on both speakers and see if the peak goes away. Should be very easy to implement, and could save you a lot of effort later.
It won't be that the mid is out of phase, as you can easily test that with a 1.5V battery to check same phase with bass unit.
Adrian
Sonusthree , email a copy of your cross-over schematic diagram to Tannoy and ask them to tell you whether that inductor is there to compensate for a rise in the output of the horn loaded tweeter at the low end of its bandwidth , as such is possible with horn loaded tweeters .
Alternately , it may be there to reduce the effect of the electrical interaction between the series capacitor's reactance and the high Q impedance spike at the tweeters Fs - that is to cause a parallel low impedance across the Fs caused impedance spike .
For either above case the value of the inductor would have been chosen to reduce output at the low end only sufficiently to allow the series capacitor to cause a first order roll-off , however , do ask Tannoy , they should happily tell you , and particually as it is an old model speaker and likely no longer of commercial concern for them .
Alternately , it may be there to reduce the effect of the electrical interaction between the series capacitor's reactance and the high Q impedance spike at the tweeters Fs - that is to cause a parallel low impedance across the Fs caused impedance spike .
For either above case the value of the inductor would have been chosen to reduce output at the low end only sufficiently to allow the series capacitor to cause a first order roll-off , however , do ask Tannoy , they should happily tell you , and particually as it is an old model speaker and likely no longer of commercial concern for them .
Hi Kiwi,
I've already tried reversing the HF polarity with no luck. Apparently the polarity of these dual concentrics are set to maintain correct phase across the crossover band and the time alignment of the D.C. arrangement makes this easier than conventional drivers and even other co-axials?
I'm not entirely trustworthy of manufacturers quotes but I have heard other people say this also.
Hi Alan,
I have sent an Email to Tannoy and will wait patiently for a reply. Whilst messing about I managed to inadvertantly disconnect an inductor (L1) in one cabinet. At first listen this brought some relief but after more than 2 minutes it became clear that the sound had lost it's sparkle (Is that the campest description you've heard on this forum? )
I've recently moved house but when I can find the laptop power supply I'm going to set up a frequency sweep to give me a better idea of what's going on here.
The later MK11 version is reputed to sound less forward. The crossover points are quoted as being the same. I wonder how they managed it? I should probably ask Tannoy about that too.
Thanks everyone,
S3.
I've already tried reversing the HF polarity with no luck. Apparently the polarity of these dual concentrics are set to maintain correct phase across the crossover band and the time alignment of the D.C. arrangement makes this easier than conventional drivers and even other co-axials?
I'm not entirely trustworthy of manufacturers quotes but I have heard other people say this also.
Hi Alan,
I have sent an Email to Tannoy and will wait patiently for a reply. Whilst messing about I managed to inadvertantly disconnect an inductor (L1) in one cabinet. At first listen this brought some relief but after more than 2 minutes it became clear that the sound had lost it's sparkle (Is that the campest description you've heard on this forum? )
I've recently moved house but when I can find the laptop power supply I'm going to set up a frequency sweep to give me a better idea of what's going on here.
The later MK11 version is reputed to sound less forward. The crossover points are quoted as being the same. I wonder how they managed it? I should probably ask Tannoy about that too.
Thanks everyone,
S3.
Sonusthree said:Hi Kiwi,
I've already tried reversing the HF polarity with no luck. Apparently the polarity of these dual concentrics are set to maintain correct phase across the crossover band and the time alignment of the D.C. arrangement makes this easier than conventional drivers and even other co-axials?
I'm not entirely trustworthy of manufacturers quotes but I have heard other people say this also.
------> comment added by Alan ----> The relative polarity and phase variations around it between the outer cone and inner horn from both the electrical connections and the effect of the distance between the 2 radiating points can be correct only for a single frequency in the cross-over band -{think Wavelength and Half-wavelength = Distance for particular frequency/ies}- and usually the nominal cross-over frequency is the one chosen . As result of the wavelength/distance effect there will be ripple errors in the summed frequency response both above and below the chosen effective frequency - larger depth ripples for low-slope filters than for high-slope filters . Tannoy know this , but do not mention it in their products' owners' manuals .
Hi Alan,
I have sent an Email to Tannoy and will wait patiently for a reply. Whilst messing about I managed to inadvertantly disconnect an inductor (L1) in one cabinet. At first listen this brought some relief but after more than 2 minutes it became clear that the sound had lost it's sparkle (Is that the campest description you've heard on this forum? )
I've recently moved house but when I can find the laptop power supply I'm going to set up a frequency sweep to give me a better idea of what's going on here.
The later MK11 version is reputed to sound less forward. The crossover points are quoted as being the same. I wonder how they managed it? I should probably ask Tannoy about that too.
Thanks everyone,
S3.
Tannoy make ongoing refinements to the horn profile and sound dispersing/phase affecting piece inside it to reduce the resonant colouration in its low-treble response -{its Horn-shout effect}- thus they may have for the MkII version . Alternately they may have changed one or more components in the cross-over to reduce the 2k5 area prominence , still keeping the same X-over point - such is possible . Ask Tannoy - they may sell you a MkII X-over , if applicable , or at least inform you of the component values for it .
When you are able , measure the response of both the inner horn and outer cone separately to each other - with the X-over bypassed completely . The 2k5 region is one where break-up often occurrs in that diameter size plastic-cone driver type , and is also a region where prominence can occurr in small horns . Which-ever , or what degree in both , driver/s it is in needs to be discovered before you can usefully decide how to mod. the X-over .
2u2 series cap. to tweeter will give different sound , but not neccessarily more accurate , though you seem to have realized this .
Post your results and any comments from Tannoy - forum members may be able to develop this mod. further ! , and its interesting !!
best wishes ,
Hi everyone,
I've owned a pair of 611's (Mk1) for a few months now and i'm happy with the high frequencies but the bass seems a little thick at times (Odd for an Acoustic suspension design)
I had a look at the crossover and the inductor in series with the bass driver measures the same as the one in series with the midbass driver. The DC resistance of the probes on my multimeter are 00.4 and the Inductor measures 00.9. So if I take the 00.4 from the 00.9, the DC resistance is 00.5. Does this sound correct? (Not my maths)
They are both 1.00mH.
From what I understand, the lower the DC resistance, the tighter the bass. Should I replace the Steel core (It looks like steel from the end) with a low DCR Air core?
I've owned a pair of 611's (Mk1) for a few months now and i'm happy with the high frequencies but the bass seems a little thick at times (Odd for an Acoustic suspension design)
I had a look at the crossover and the inductor in series with the bass driver measures the same as the one in series with the midbass driver. The DC resistance of the probes on my multimeter are 00.4 and the Inductor measures 00.9. So if I take the 00.4 from the 00.9, the DC resistance is 00.5. Does this sound correct? (Not my maths
)They are both 1.00mH.
From what I understand, the lower the DC resistance, the tighter the bass. Should I replace the Steel core (It looks like steel from the end) with a low DCR Air core?
Lookat driver connections, and ...
(1) - look at the Drivers' connections to the x-over.
Are all 3 drivers, including the high frequency, connected in the same Polarity ?,
or is one connected in reverse Polarity ?
-{ie:- in what some people refer to as "out of phase" or "reversed phase"}.
I do mean the actual Drivers' connections and NOT simply the Inputs to the x-over as connected to the Input terminals on the back of the cabinet.
(2) - 0.5ohm is not unusually high DCR for 1mH inductors, but lower ohm can be made or bought.
What is your budget if buying ?
(3) - is this thick bass sound only when you drive the speakers to high volume levels, or does it also occur sometimes at low volume levels ?
Hi everyone,
I've owned a pair of 611's (Mk1) for a few months now and i'm happy with the high frequencies but the bass seems a little thick at times (Odd for an Acoustic suspension design)
I had a look at the crossover and the inductor in series with the bass driver measures the same as the one in series with the midbass driver. The DC resistance of the probes on my multimeter are 00.4 and the Inductor measures 00.9. So if I take the 00.4 from the 00.9, the DC resistance is 00.5. Does this sound correct? (Not my maths
They are both 1.00mH.
From what I understand, the lower the DC resistance, the tighter the bass. Should I replace the Steel core (It looks like steel from the end) with a low DCR Air core?
(1) - look at the Drivers' connections to the x-over.
Are all 3 drivers, including the high frequency, connected in the same Polarity ?,
or is one connected in reverse Polarity ?
-{ie:- in what some people refer to as "out of phase" or "reversed phase"}.
I do mean the actual Drivers' connections and NOT simply the Inputs to the x-over as connected to the Input terminals on the back of the cabinet.
(2) - 0.5ohm is not unusually high DCR for 1mH inductors, but lower ohm can be made or bought.
What is your budget if buying ?
(3) - is this thick bass sound only when you drive the speakers to high volume levels, or does it also occur sometimes at low volume levels ?
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