pinkmouse said:
Yes. Polarity is correct.
After changing the 5.6ohm (the one in front in series with the tweeter xover NOT the one in the L pad) to 2.2 ohm, the sound though is more of what I would like but is a little forward and treble a little harsh.
Therefore I will increase the 2.2ohm to about 3 or 3.3ohm then move the low pass 3db point a little further by reducing the 2.2mh inductor. I have no measurement equipment (since all my money went into the drivers ... 🙂 ) so I have to do it all by ears.
The port is 78mm x 200mm. Since the depth of the cab is about 240mm and I can't increase the port length, I bought a 90 degree angle pipe and make a L shape port instead.
andy2 said:
I think what PinkMouse was referring to was the possibility that the driver may be *marked* incorrectly. This could be by design (for years, JBL marked the terminal that moved the diaphragm outwards *black*) or by accident (that pesky QC thing). The only way to tell this is to "pop" each driver with a battery and note which way the diaphragm moves.
Or I guess you could just deliberately invert the phase of the tweeters and see how it changes the sound. If it gets more muffled (due to cancellation at the crossover point), it was correct before. If it gets less muffled, then you've found your problem.
andy2 said:
You have already changed your crossover point significantly by changing the value of that resistor. Do a simulation of the x-over network with the two different resistor values and you will surprised to see how big the difference is.
That's why the L-pad is nice -- you can change just one variable at a time. By changing both resistors so as to keep the impedance constant, you can change just the level of the tweeter without changing the x-over frequency or effective slope.
Don't forget to try experimenting with the feet of the speaker. In my experience this can make quite a difference to the sound, especially on wooden floors. You could try two spikes at the rear and soft feet at the front.
A little joke.....
If you want your speakers to sound more "forward" put a Diode in the signal path so that the cones only move... forward
If you want your speakers to sound more "forward" put a Diode in the signal path so that the cones only move... forward
Charles Hansen said:
Ah.... this brings back memories and much head scratching at the time.
Definitely sounds like a driver dip or a crossover underlap to me as is probably the effect the designer wanted. The only way to properly fix something like that is a crossover re-design.
Have you actually asked the designer as he has probably has several different sounding variations he used during testing.
rabbitz said:
From reading some of his writing, I think he might have designed all his speakers with his measurement equipment instead of his ears and heart. His design philosophy tends to emphasize measurement neutralilty over musicality/character. I was looking at most of the xover he designed and they are so busy with notch filter, extra components ... while most others nowaday trying to achieve simple xover design.
Anyway, I was doing some spice simulation on the woofer xover and it appears that the combination of the .68mh inductor and 2.2mh L acts as some sort of baffle step adjustment but i think it may have attenuated the mid more that I would like.
I was playing around with the component values and spice simulation shows that if I reduce the .68mh to .5mh and 2.2mh to 2mh, I can bring the mid up a little while still preserve the same approximate oxver point.
Good way to go. This will lift up the speaker of its overgineered bass anchor, and give it a sense of projection. Alas it will sound soft if you dont get sure to do something with the presence range (4-8kHz) that I saw it lacks on the graph. This must follow too. Only a speaker with a nicely judged presence range can cut through and project the mix right in your listening space.
Dont forget that using a ribbon (especially a short one) can be ok for avoiding floor and ceiling reflections hence gaining in clarity, but the power response of the speaker goes into an abrupt lowering especially when taking over @ 2600. Maybe you will see a need for more spl from the ribbon on axis than flat. Good luck.
Dont forget that using a ribbon (especially a short one) can be ok for avoiding floor and ceiling reflections hence gaining in clarity, but the power response of the speaker goes into an abrupt lowering especially when taking over @ 2600. Maybe you will see a need for more spl from the ribbon on axis than flat. Good luck.
I did a quick look at the TJL link and see the SPL graph of system crossed at 2K6. And you are mentioning about a dip in the 1K to 3K range, correct? I don't really know the situation, but I will tell you how I will intuitively solve similar problem (based on quick guess only!)...
With fourth order at 2K6, the vocal you are looking for is under the tweeter responsibility. You should not change the lowpass inductors unless you intend to reinvent the wheel redesigning new speaker.
What I would do is simply to lengthen the spread of the tweeter roll-off up to about 1KHz. In your case, you could increase the 0.47mH (the last inductor in the hipass) up to about 1mH.
You should increase gradually. Every increase will for sure makes the vocal comes out of the tweeter, but there will be 'instability' (sorry for the unintelligent phrase 😀) but by increasing further you will come to a 'stable' state. Whether it is at 1mH or 0.9mH or 0.8mH I don't know. You need your ears, please don't ask me to elaborate the instability issue
Afterall this is only a quick guess to resolve the problem.
Don't worry, increasing the 0.47 inductor won't hurt the woofer (I'm not referring to the whole system performance).
With fourth order at 2K6, the vocal you are looking for is under the tweeter responsibility. You should not change the lowpass inductors unless you intend to reinvent the wheel redesigning new speaker.
What I would do is simply to lengthen the spread of the tweeter roll-off up to about 1KHz. In your case, you could increase the 0.47mH (the last inductor in the hipass) up to about 1mH.
You should increase gradually. Every increase will for sure makes the vocal comes out of the tweeter, but there will be 'instability' (sorry for the unintelligent phrase 😀) but by increasing further you will come to a 'stable' state. Whether it is at 1mH or 0.9mH or 0.8mH I don't know. You need your ears, please don't ask me to elaborate the instability issue
Afterall this is only a quick guess to resolve the problem.Don't worry, increasing the 0.47 inductor won't hurt the woofer (I'm not referring to the whole system performance).
Oh, I'm sorry I have no experience with ribbons...
But it should have a spec or something specifying this, correct? If 1kH tail will fry the ribbon I believe there are thousand of ribbons fried already
This is not because of the tail (aka 0.47) but the first cap (4.7uF)!
If 1kH is harmful, you could calculate the maximum L first (which I guess is close to 1mH???). I always use low power amplifier when working with speaker (design).
But it should have a spec or something specifying this, correct? If 1kH tail will fry the ribbon I believe there are thousand of ribbons fried already
This is not because of the tail (aka 0.47) but the first cap (4.7uF)!If 1kH is harmful, you could calculate the maximum L first (which I guess is close to 1mH???). I always use low power amplifier when working with speaker (design).
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