Hi All,
My name is Alex and this is my first post.
I have very basic knowledge of electronics, but 25 years ago, I built my hi-end speakers from a well know company who published their own kits.
The speakers are 3.5 ways: 2 woofers + 1midrange + 1 tweeter ( 2 x front ported)
The cabinet was very difficult to make, in fact, I was helped by a wood craftsman, and the speakers were lacquered.
The company who supplied me with all the components, suggested to make a different (and more elaborated) crossover, compared to the one proposed in the original project.
Image is attached.
When I listened to the speakers the first time, I soon realized that the high frequencies were too bright, and therefore they suggested to change the value of the resistor on the tweeter from 1.0 to 1.8 Ohm.
That worked fine.
However, since then many things changed in my gear, I also moved to a new home and I have a much bigger room.
As a result, I find the need to apply a further cut to the high frequencies, and wanted to ask you if the way I should do this is the same, (increasing the value of the resistor).
If that is the case, which value should I use for the new resistor?
Thank you!
Alex
My name is Alex and this is my first post.
I have very basic knowledge of electronics, but 25 years ago, I built my hi-end speakers from a well know company who published their own kits.
The speakers are 3.5 ways: 2 woofers + 1midrange + 1 tweeter ( 2 x front ported)
The cabinet was very difficult to make, in fact, I was helped by a wood craftsman, and the speakers were lacquered.
The company who supplied me with all the components, suggested to make a different (and more elaborated) crossover, compared to the one proposed in the original project.
Image is attached.
When I listened to the speakers the first time, I soon realized that the high frequencies were too bright, and therefore they suggested to change the value of the resistor on the tweeter from 1.0 to 1.8 Ohm.
That worked fine.
However, since then many things changed in my gear, I also moved to a new home and I have a much bigger room.
As a result, I find the need to apply a further cut to the high frequencies, and wanted to ask you if the way I should do this is the same, (increasing the value of the resistor).
If that is the case, which value should I use for the new resistor?
Thank you!
Alex
Attachments
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i can't help with your request but I'd be really interested to see the speakers that you built they sound interesting
Note that doubling the resistor halves the drive level which is -3dB in sound level, which is just about discernable.
So in your tests it's most efficient to double the resistor value, then if the sound is still to bright, double again, etc. Once you get in the ballpark you can backtrack a bit to finetune.
Jan
So in your tests it's most efficient to double the resistor value, then if the sound is still to bright, double again, etc. Once you get in the ballpark you can backtrack a bit to finetune.
Jan
I have attached some images, so to give you a good idea 🙂
Attachments
Hi,
Thank you for all your replies and suggestions.
Now, I just want to take a step back and ask the following:
All the drivers of my speakers are rated 8 Ohm, however, the speaker itself was rated for a nominal impedance of 6 Ohm.
Of course, this is with the original crossover, which I assume has an impact over the declared impedance.
For convenience, I attach an image of the original crossover.
My question to you is the following:
Is there a way to know what would is the nominal impedance of my speakers, with the customized crossover I have?
Thank you,
Alex
Thank you for all your replies and suggestions.
Now, I just want to take a step back and ask the following:
All the drivers of my speakers are rated 8 Ohm, however, the speaker itself was rated for a nominal impedance of 6 Ohm.
Of course, this is with the original crossover, which I assume has an impact over the declared impedance.
For convenience, I attach an image of the original crossover.
My question to you is the following:
Is there a way to know what would is the nominal impedance of my speakers, with the customized crossover I have?
Thank you,
Alex
Attachments
The impedance of the individual drivers, and of your loudspeaker system as a whole, varies widely with frequency.
The nominal impedance figure usually represents the impedance of the complete loudspeaker system somewhere in the region of 400 Hz, but the impedance will be found to be different at different frequencies.
You have nothing to worry about here.
The nominal impedance figure usually represents the impedance of the complete loudspeaker system somewhere in the region of 400 Hz, but the impedance will be found to be different at different frequencies.
You have nothing to worry about here.
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Here's an illustration of how a speaker system's impedance can vary with frequency.
The impedance is 6 ohm around 500 Hz and that could be described as the nominal value.
The impedance is 6 ohm around 500 Hz and that could be described as the nominal value.
To be more technically accurate:
"According to IEC-268-5 the nominal impedance is found by multiplying the minima of the curve (within the pass band of the loudspeaker) by 1.25. Said another way, the minima of the loudspeaker impedance shall not be less than 80 percent of its nominal value."
https://www.prosoundtraining.com/2010/03/17/which-impedance-nominal-minimum-maximum-average/
"According to IEC-268-5 the nominal impedance is found by multiplying the minima of the curve (within the pass band of the loudspeaker) by 1.25. Said another way, the minima of the loudspeaker impedance shall not be less than 80 percent of its nominal value."
https://www.prosoundtraining.com/2010/03/17/which-impedance-nominal-minimum-maximum-average/
Thank you guys.
So if I want to measure the nominal impedance of my speakers, I would need to know the minima of the curve, which I should measure some way, but I do not know how.
I was kind of curious to know as I have a Mcintosh amp with autoformers, I tried to connect the speakers to both 8 and 4 ohms, (I decided then to leave them connected to 4 Ohms) because I hear not difference, so I was looking for an empiric confirmation that 4 Ohms is correct.
Going back to my original question, also based on what Jan.Didden mentioned:
Would you recommend as a first attempt to try a resistor of 3.9 Ohms, then if not enough, simply go up to 4.7, 5.6 etc. rather than doubling?
Any specific type of resistor is recommended here?
For instance: here I can find many, but is there any specific tolerance, power or composition that would work better?
Thank you 🙂
Alex
So if I want to measure the nominal impedance of my speakers, I would need to know the minima of the curve, which I should measure some way, but I do not know how.
I was kind of curious to know as I have a Mcintosh amp with autoformers, I tried to connect the speakers to both 8 and 4 ohms, (I decided then to leave them connected to 4 Ohms) because I hear not difference, so I was looking for an empiric confirmation that 4 Ohms is correct.
Going back to my original question, also based on what Jan.Didden mentioned:
Would you recommend as a first attempt to try a resistor of 3.9 Ohms, then if not enough, simply go up to 4.7, 5.6 etc. rather than doubling?
Any specific type of resistor is recommended here?
For instance: here I can find many, but is there any specific tolerance, power or composition that would work better?
Thank you 🙂
Alex
Just pick a value and try. I merely suggested doubling because that gets you to the sweet spot fastest, but if you want to spend a few days doing it by stepping small increases, knock yourself out!
Look for noninductive resistors, for a tweeter, 5 to 10W would be enough, as there is never that much going into a tweeter continuously.
Jan
Look for noninductive resistors, for a tweeter, 5 to 10W would be enough, as there is never that much going into a tweeter continuously.
Jan
I wonder what type the present 1.8 ohm resistor is?
I suggest at least a 5 W rating for a tweeter.
I would use a ceramic (wire wound) resistor, but there are other types that some say "sound" better.
Good question with regards to the type, I do not remember what I used at the time. I need to remove the tweeter PCB, which will take me some time, due to many factors, including the fact that I have to lift the speakers and put them down horizontally to work on them.
This is the Digi-Key page you are looking for: https://www.digikey.ca/en/products/...AIA8gAsAtpgMzGyQIACq-LwsXsgAstiomACu3NiiIiJAA
LOL so I can only choose among the first three as all the others have zero stock 🙂
Although you selected wirewound, the third one down seems ceramic from the image.🙄