Horn flare in Tannoy DCs is continued by flare of LF cone! Holes in pepper pot are phase compensating array!
That was for active tulip drivers, for a pepperpot you will need to equalize the treble.
I don't like 24dB passives as it puts more inductors into the audio path and the same goes for the SyncSource module.
For a long time the K2558 was the favourite monitor driver of George Massenburg and I am certainly not going to argue with a man of his credentials.
That said he used them in the Manley box with their passive xovers.
I don't like 24dB passives as it puts more inductors into the audio path and the same goes for the SyncSource module.
For a long time the K2558 was the favourite monitor driver of George Massenburg and I am certainly not going to argue with a man of his credentials.
That said he used them in the Manley box with their passive xovers.
Horn cut off frequency is 500Hz for 15" drivers and 800Hz for 12 and 10 inchers. So, overlapping should be excellent since xo is 1kHz for 15" and 1.2kHz for 12" and 10".
On a Tannoy? I would be very surprised if the HF can work down that low without distortion on that size cone/waveguide.
I'd cross the K2558 at 1400Hz.
THD on the 12" (K3149) is <0.5% for 96dBSPL with the passive 12dB xover so I wouldn't worry too much with a 24dB one.
You still need 6dB/oct boost from 5-6kHz on up and a slight notch at around 3k to take care of the horn honk.
THD on the 12" (K3149) is <0.5% for 96dBSPL with the passive 12dB xover so I wouldn't worry too much with a 24dB one.
You still need 6dB/oct boost from 5-6kHz on up and a slight notch at around 3k to take care of the horn honk.
Horn cut off is that low probably because LF cone counts as natural extension of pepper pot wg. It is similar with Tulips. Also very low xovers.
Bernie Grundman also liked Tannoy pepper pots a lot. Many years ago I possessed a big Tannoy poster with Bernie and gold records (Steely Dan Aja, etc). He used big FSM (15" woofer + 15" Dual Concentric) in his mastering lab. We used to joke here in my hometown of Cacak, that "every Serbian home should have a pair" (of FSMs).
Bernie Grundman also liked Tannoy pepper pots a lot. Many years ago I possessed a big Tannoy poster with Bernie and gold records (Steely Dan Aja, etc). He used big FSM (15" woofer + 15" Dual Concentric) in his mastering lab. We used to joke here in my hometown of Cacak, that "every Serbian home should have a pair" (of FSMs).
Ivan and Charles,
On the passive or active slope for the Tannoy I know that we can add the natural acoustical rolloff in conjunction to the electrical slope but my concern would be more to do with the electrical phase shift at crossover. That is why myself I favor the higher order crossovers of 4th order L-R crossovers. I just don't think that the problems of second order electrical summation are enough for me to look in that direction and I just think that first order crossovers are usually asking a bit much for most any driver thinking that the out of band response is going to be very smooth.
Ivan I would rather run up to a higher frequency on the compression driver and hear a bit of cone cry than hear the sound of a compression driver in its lower range. Trying to push the driver in this direction is just asking for to much excursion on the diaphragm and I wouldn't do that. Besides the 3Khz notch filter that Charles is suggesting most horn honk is lower in the band and why exasperate the situation. This is why so many complain about compression drivers on horns in the first place, not because of dispersion angles.
On the passive or active slope for the Tannoy I know that we can add the natural acoustical rolloff in conjunction to the electrical slope but my concern would be more to do with the electrical phase shift at crossover. That is why myself I favor the higher order crossovers of 4th order L-R crossovers. I just don't think that the problems of second order electrical summation are enough for me to look in that direction and I just think that first order crossovers are usually asking a bit much for most any driver thinking that the out of band response is going to be very smooth.
Ivan I would rather run up to a higher frequency on the compression driver and hear a bit of cone cry than hear the sound of a compression driver in its lower range. Trying to push the driver in this direction is just asking for to much excursion on the diaphragm and I wouldn't do that. Besides the 3Khz notch filter that Charles is suggesting most horn honk is lower in the band and why exasperate the situation. This is why so many complain about compression drivers on horns in the first place, not because of dispersion angles.
Yep, there is a point below which a horn and driver don't work well. Response drops quickly and distortion goes up quickly. That point is directly related to the size of the horn mouth - if the driver can play that low.
Don't expect a "horn" the size of the cone in a 15" or 12" driver to play low.
Don't expect a "horn" the size of the cone in a 15" or 12" driver to play low.
Troels have some interesting graphs on his site
CD is going lower than I expected , even on 10"
CD is going lower than I expected , even on 10"
Zen Mod,
It isn't that you can't get the frequency down that low with the upper frequencies device, it is also what it sounds like. Also pay careful attention to those polar plots, they are most often done at 2.83volts which at 8 ohms is only 1 watt at one meter for a typical test. What do you think happens when you all the sudden start putting 20 or 30 watts of power into the device. The distortion numbers go up very quickly in the lower range.
It isn't that you can't get the frequency down that low with the upper frequencies device, it is also what it sounds like. Also pay careful attention to those polar plots, they are most often done at 2.83volts which at 8 ohms is only 1 watt at one meter for a typical test. What do you think happens when you all the sudden start putting 20 or 30 watts of power into the device. The distortion numbers go up very quickly in the lower range.
I'm not disputing that - just said that graphs are interesting ;
considering what I wrote few pages back - about Aleksandar's (RAAL) comments regarding xover - I'm not expecting 20W on squawkers , sitting 3,5m from them
considering what I wrote few pages back - about Aleksandar's (RAAL) comments regarding xover - I'm not expecting 20W on squawkers , sitting 3,5m from them
Zen,
Then surely don't spend time in most recording studios with the levels turned up, cause it does get loud in there...... Just saying, they do squawk as you would so nicely put it.....
Then surely don't spend time in most recording studios with the levels turned up, cause it does get loud in there...... Just saying, they do squawk as you would so nicely put it.....
sorry - didn't knew that we are talking about recording studios ......
in that case my approach will be active , probably with digital
in that case my approach will be active , probably with digital
Zen Mod,
You got me! Big Iskra VoT are "spitze". I do not understand how anybody could prefer loads of direct radiators in movie theaters when couple of VoTs behind the curtain sound so much better.
You got me! Big Iskra VoT are "spitze". I do not understand how anybody could prefer loads of direct radiators in movie theaters when couple of VoTs behind the curtain sound so much better.
It should be understood that the concept of Dual Concentrics date from the time when high power amps were rare beasts and loudspeakers had high efficiency, so low power was enough for relatively high SPLs. Therefore low cut off frequency and high distortions was not that much of concern.
Ivan.
You also have to remember that when these devices were first designed they were mostly used in movie theaters and were therefor behind a perforated screen that attenuated the sound. Frequency response was far from excellent, but for the time it was what there was. Sound was mostly from sound tracks on optical film, we are a world away from the original intent of the devices. And we aren't using vacuum tubes to drive them either, at least most of us aren't anymore. Nothing against a proper vacuum tube design, just not a single ended kind of guy here. And I don't want to have to run the air conditioning just to turn on a bunch of vacuum tubes....
You also have to remember that when these devices were first designed they were mostly used in movie theaters and were therefor behind a perforated screen that attenuated the sound. Frequency response was far from excellent, but for the time it was what there was. Sound was mostly from sound tracks on optical film, we are a world away from the original intent of the devices. And we aren't using vacuum tubes to drive them either, at least most of us aren't anymore. Nothing against a proper vacuum tube design, just not a single ended kind of guy here. And I don't want to have to run the air conditioning just to turn on a bunch of vacuum tubes....
I think that people who are interested in coaxials for home listening should try Adire 10 or 12 projects, or Cheap Trick CT235 from Klang und Ton since they use inexpensive Eminence drivers. Do not underestimate APT 50 tweeter and immediately try to replace it with better unit. This is decent phenolic driver. Discontinuity at 6kHz, caused by bullet shaped wg is obvious only on axis.
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