The international standard symbol for a resistor is a box as shown near the woofer.
Measuring an inductor with a meter should be straightforward. Traditionally you combine an unknown inductor with a known capacitor and a resistor and apply a sine wave from a variable signal generator and vary the frequency while measuring the voltage to detect a change in impedance which represents resonance between the inductor and capacitor at that frequency, then use a calculator to find the inductor value.
Measuring an inductor with a meter should be straightforward. Traditionally you combine an unknown inductor with a known capacitor and a resistor and apply a sine wave from a variable signal generator and vary the frequency while measuring the voltage to detect a change in impedance which represents resonance between the inductor and capacitor at that frequency, then use a calculator to find the inductor value.
Resistor
I understand the Box symbol for a resistor, what I was trying say is I don't see a resistor in my tweeter circuit.
I am still learning how to read crossover diagrams.
I don't have a variable signal generator, so I tried the ebay tester.
I have watched the YouTube videos showing how to measure an inductor.
Thank You
I understand the Box symbol for a resistor, what I was trying say is I don't see a resistor in my tweeter circuit.
I am still learning how to read crossover diagrams.
I don't have a variable signal generator, so I tried the ebay tester.
I have watched the YouTube videos showing how to measure an inductor.
Thank You
I didn't see this as unusual. Even if a DIY crossover would normally use resistors. The three types of component can work to trim the highs, the lows, and all at the same time. There will always be more than one way to achieve the same result electrically. A manufacturer who finds a tweeter that plays at just the right level might decide that resistors are not necessary.
It follows that if you calibrated and used the device correctly then it may be defective.
Hello AllenB,
I have made some progress with the project, I did a full series of measurements today. The Tweeter is from owners manual that I traced using FPGraphTracer.
The woofer was measures at 1W at 1M without crossover (indoor) inside its chamber with the preferred gating from REW.
The picture is for both components. I am waiting for the frequency response graph for the midrange.
Woofer will need quite a bit in terms of crossover components, I will start building once I have the details for midrange.
Just wanted to share this with you to see if it makes sense? This is my first time measuring components.
I have made some progress with the project, I did a full series of measurements today. The Tweeter is from owners manual that I traced using FPGraphTracer.
The woofer was measures at 1W at 1M without crossover (indoor) inside its chamber with the preferred gating from REW.
The picture is for both components. I am waiting for the frequency response graph for the midrange.
Woofer will need quite a bit in terms of crossover components, I will start building once I have the details for midrange.
Just wanted to share this with you to see if it makes sense? This is my first time measuring components.
Added: Also guys when measuring component frequency response should it be done free air or inside enclosure? I selected frequency sweep of 20hz to 20Khz is that correct or should it be pink noise?
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It sounds as though you're ready for your own crossover thread. If you begin one I can move these responses over to it.
The usual approach is to have the driver mounted in the cabinet, and use a sweep.
The usual approach is to have the driver mounted in the cabinet, and use a sweep.
Yes AllenB I am waiting for the frequency response graphs for midranges to come through and i will make separate crossover thread.
Cheers
Cheers
Hello AllenB
Thank you for including the images with thumbnail on post.
Should I bump the post as I don't see anyone sharing feedback or do I proceed with the crossover buildup maybe I might get better support?
I just wanted to double check the frequency response before going into build.
What do you think?
Cheers
Thank you for including the images with thumbnail on post.
Should I bump the post as I don't see anyone sharing feedback or do I proceed with the crossover buildup maybe I might get better support?
I just wanted to double check the frequency response before going into build.
What do you think?
Cheers
Thank you, AlanB, for this post.
Recently, I bought a used pair of 2-way speakers that have no passive crossover. First time for me using an active crossover.
My mistake was connecting the active crossover like a passive crossover. In other words, preamp connected to the amp, speaker outputs to the crossover inputs, crossover outputs to the speakers. While it works and the crossover adjustments take affect, the sound is too low.
Note to self: the preamp outputs are connected to the crossover inputs.
Recently, I bought a used pair of 2-way speakers that have no passive crossover. First time for me using an active crossover.
My mistake was connecting the active crossover like a passive crossover. In other words, preamp connected to the amp, speaker outputs to the crossover inputs, crossover outputs to the speakers. While it works and the crossover adjustments take affect, the sound is too low.
Note to self: the preamp outputs are connected to the crossover inputs.
gain structure
Could you be so kind to explain your concept of *gain structure* in total.
I "think" I know where you are going with this, but my local audiophile community fails to grasp the idea.
thanks in advance
Could you be so kind to explain your concept of *gain structure* in total.
I "think" I know where you are going with this, but my local audiophile community fails to grasp the idea.
thanks in advance
Gain structure problem or not- it was resolved when you connect the crossover as it was designed to be connected.
The first thing to know about gain structure is that when you pass a signal between stages, or components, there is an appropriate range of signal level. If you supply a signal which is too low, the result can be noisy. Everything produces noise, it's just a matter of how much.
If you supply a signal which is too large you can over-drive the next stage, causing distortion. In addition this may have the potential to cause damage.
Further to this, if you run the speaker directly from the crossover you can over-load it, considering its high impedance. This also has the potential to cause damage.
If you supply a signal which is too large you can over-drive the next stage, causing distortion. In addition this may have the potential to cause damage.
Further to this, if you run the speaker directly from the crossover you can over-load it, considering its high impedance. This also has the potential to cause damage.
Hello AllenB,
The 10/15/20 ohm R to flatten tweeter impedance, does it use the same value for 4 ohm tweeter?
Thanks.
Chandra
The 10/15/20 ohm R to flatten tweeter impedance, does it use the same value for 4 ohm tweeter?
Thanks.
Chandra
The example tweeter was around 6 ohms. The resistor value needs to go up or down along with the tweeter being used.
Hi AllenB,
Thanks for the response.
Forgive my ignorance if the issue below was already addressed.
I would like to mix a 4 ohm tweeter (92 db) with an 8 ohm woofer (90 db), can we do the same calculation?
What would be the trick to soften the 4 ohm tweeter (being 4 ohm, I am sure it will sound louder)?
Thanks.
Chandra
Thanks for the response.
Forgive my ignorance if the issue below was already addressed.
I would like to mix a 4 ohm tweeter (92 db) with an 8 ohm woofer (90 db), can we do the same calculation?
What would be the trick to soften the 4 ohm tweeter (being 4 ohm, I am sure it will sound louder)?
Thanks.
Chandra
A four ohm tweeter will not necessarily be more loud. A few different factors go in to its sensitivity being what it is.
Just use the right values in each calculation and it will work.
Just use the right values in each calculation and it will work.
Capasitor
I'm working on a Xover that troubles me in the high freq. My problem may not be a problem at all, but a matter of perception. I feel that when I choose a xover point of , say 2100Hz and think there is something amiss. Maybe it's the mid-woofer or not, but when I attempt to go lower in freg., say 1900Hz the top end sparkle previously enjoyed diminishes. Like I mentioned, 'Perception?' I have read that taking a very small capacitor in the 0.01 uf value and bypass the crossover direct from (+) source to Tweeter terminal. This will undo some of the work the crossover has done while restoring that sparkle. As I am writing this, I remember reading an article called "Look back impedance!" and it was in relation to series crossovers. Could this method arise only in series Xcovers? My present Xover is a parallel Xover. At any rate, what are your thoughts on this perceived/problem?
Francis
I'm working on a Xover that troubles me in the high freq. My problem may not be a problem at all, but a matter of perception. I feel that when I choose a xover point of , say 2100Hz and think there is something amiss. Maybe it's the mid-woofer or not, but when I attempt to go lower in freg., say 1900Hz the top end sparkle previously enjoyed diminishes. Like I mentioned, 'Perception?' I have read that taking a very small capacitor in the 0.01 uf value and bypass the crossover direct from (+) source to Tweeter terminal. This will undo some of the work the crossover has done while restoring that sparkle. As I am writing this, I remember reading an article called "Look back impedance!" and it was in relation to series crossovers. Could this method arise only in series Xcovers? My present Xover is a parallel Xover. At any rate, what are your thoughts on this perceived/problem?
Francis
Perception can be like that, and small changes can sometimes make a lot of difference. There have been times I wish I'd written down settings before making changes.. Sometimes you will not know why.
Moving from 2100 to 1900Hz is not a large change, but it could be enough to fix a specific woofer breakup issue. It might land upon the tweeter impedance peak to introduce a bump in the response. It may introduce a phase variation that results in a wiggle in the response. The same could cause variations in the level and tone of room reflections around the cross. Less often I discover I'm doing substitutions with a partly broken component.
Moving from 2100 to 1900Hz is not a large change, but it could be enough to fix a specific woofer breakup issue. It might land upon the tweeter impedance peak to introduce a bump in the response. It may introduce a phase variation that results in a wiggle in the response. The same could cause variations in the level and tone of room reflections around the cross. Less often I discover I'm doing substitutions with a partly broken component.