Hi Guys,
I have a small 3 way DIY speaker project going and I am having difficulty getting a balanced sound.
My woofer is 82db at 4.0 Ohm while my midrange and tweeter are 94db 3.5 Ohm (when I measure impedance using a multimeter). Consequently my highs are too great.
I seek your advice on how I can reduce or dampen the loudness of the midrange and tweeter without having to destroy the quality.
What type of component do I have to use? A resistor? Can someone help me with the value?
Many thanks in advance for your support.
I have a small 3 way DIY speaker project going and I am having difficulty getting a balanced sound.
My woofer is 82db at 4.0 Ohm while my midrange and tweeter are 94db 3.5 Ohm (when I measure impedance using a multimeter). Consequently my highs are too great.
I seek your advice on how I can reduce or dampen the loudness of the midrange and tweeter without having to destroy the quality.
What type of component do I have to use? A resistor? Can someone help me with the value?
Many thanks in advance for your support.
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If you're going purely passive you can use a resistor. I believe some have used a transformer as well. For the resistor you want to make an L-pad or voltage divider.
Have you modeled your crossover and drivers in X-sim? You can make them just match each other, but there is something called Baffle Step which you want to account for. I don't mean this as an insult but it sounds like you have some basic reading on crossover design.
To make them match at your specified Ohms and sensitivity, use a 2.62 Ohm resistor in series and right after it a 1.17 Ohm parallel resistor connected to negative. Of course those are the "ideal" and you need to find the closes E24 values (2.7 Ohm and 1.1 Ohm should probably work, again, simming in X-sim would let you know).
Have you modeled your crossover and drivers in X-sim? You can make them just match each other, but there is something called Baffle Step which you want to account for. I don't mean this as an insult but it sounds like you have some basic reading on crossover design.
To make them match at your specified Ohms and sensitivity, use a 2.62 Ohm resistor in series and right after it a 1.17 Ohm parallel resistor connected to negative. Of course those are the "ideal" and you need to find the closes E24 values (2.7 Ohm and 1.1 Ohm should probably work, again, simming in X-sim would let you know).
None taken mushroommunk my knowledge is very limited this is my first DIY speaker project.
I am not using any simulators as I don't have frequency & impedance measurements for my components. Just trying to do the best I can with what I have for balancing the sound passively.
Can I put the resistors at the end of the crossover just before single is driven into components?
I am not using any simulators as I don't have frequency & impedance measurements for my components. Just trying to do the best I can with what I have for balancing the sound passively.
Can I put the resistors at the end of the crossover just before single is driven into components?
Your multimeter does not measure the impedance of the drivers, but their dc resistance.
The nominal impedance will be higher by a couple of ohms so your drivers are likely all around 6 ohm nominal impedance. The manufacturer's specifications should confirm the nominal impedance.
Since you are obviously new to this, the simplest thing to do is use an L pad calculator like the one linked to below. Enter 6 ohm for the driver impedance, enter the number of dB attenution you require and the average power output of your amplifier.
The calculator will tell you the resistance and power rating of the wire wound resistors you will need. Use the nearest standard value for the resistors and the nearest power rating.
LPad Driver Attenuation Circuit Designer Calculator
The nominal impedance will be higher by a couple of ohms so your drivers are likely all around 6 ohm nominal impedance. The manufacturer's specifications should confirm the nominal impedance.
Since you are obviously new to this, the simplest thing to do is use an L pad calculator like the one linked to below. Enter 6 ohm for the driver impedance, enter the number of dB attenution you require and the average power output of your amplifier.
The calculator will tell you the resistance and power rating of the wire wound resistors you will need. Use the nearest standard value for the resistors and the nearest power rating.
LPad Driver Attenuation Circuit Designer Calculator
As a complete beginner it may be simpler and easier to purchase a variable L-Pad.
GA48528 LP-100-8 - SPEAKER L-PAD - MONO | eBay
You would need 4 of them however, one each for each driver that needs padding down, this isn't exactly cheap and often I work out that buying a better woofer is the preferred solution although 12dB would be extremely difficult to achieve and even more expensive.
Galu has good advice
What drivers are you using and what cross-overs?
GA48528 LP-100-8 - SPEAKER L-PAD - MONO | eBay
You would need 4 of them however, one each for each driver that needs padding down, this isn't exactly cheap and often I work out that buying a better woofer is the preferred solution although 12dB would be extremely difficult to achieve and even more expensive.
Galu has good advice
What drivers are you using and what cross-overs?
The tweeter handles less of the total amplifier power than the midrange which handles less than the woofer.
In order to suggest realistic power ratings to enter into the calculator for the midrange and the tweeter, please let me know the RMS power rating of each channel of your stereo amplifier.
Using the full amplifier output in the calcualtor will produce some unrealistically large calculated resistor wattages!
In order to suggest realistic power ratings to enter into the calculator for the midrange and the tweeter, please let me know the RMS power rating of each channel of your stereo amplifier.
Using the full amplifier output in the calcualtor will produce some unrealistically large calculated resistor wattages!
Ceramic wire wound resistors like the ones in your first pic are what you need, but see my previous post.
What Galu said above, a general "Rule of thumb " is that the half way point for music power is about 300Hz, half the power below that frequency and the other half above it and I think above 300Hz it is 10% or so
I am using the following components:
Midrange & Tweeter Set
Cerwin-Vega(R) Mobile V465C Vega Series 6.5" 400-Watt 2-Way Component Speaker... 847169019982 | eBay
Woofer
Cerwin Vega's Mobile Vega V84d Woofer - 250 W Rms - 4 Ohm (v84d) 847169019555 | eBay
Crossover (i know laughable
2 Pack 3 way Crossover CRX-303 300W Passive Crossover Car Audio Tweeter 685650080253 | eBay
I suppose it would be better to change the woofer, as a beginners tip is it better for the woofer to be higher sensitivity than midrange/tweeter?
Midrange & Tweeter Set
Cerwin-Vega(R) Mobile V465C Vega Series 6.5" 400-Watt 2-Way Component Speaker... 847169019982 | eBay
Woofer
Cerwin Vega's Mobile Vega V84d Woofer - 250 W Rms - 4 Ohm (v84d) 847169019555 | eBay
Crossover (i know laughable
2 Pack 3 way Crossover CRX-303 300W Passive Crossover Car Audio Tweeter 685650080253 | eBay
I suppose it would be better to change the woofer, as a beginners tip is it better for the woofer to be higher sensitivity than midrange/tweeter?
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M & T = 100W rms; Impedance is probably 4 ohm (mobile speakers); don't see a sensitivity figure? These will need their own separate enclosure within the woofer enclosure.
W = 250W RMS; 4 ohm; 82dB/W/m
Where did you get the sensitivity rating for the mid/tweeter units?
It is normal for the mid/tweeter to be the same as or a few dB higher than the woofer.
W = 250W RMS; 4 ohm; 82dB/W/m
Where did you get the sensitivity rating for the mid/tweeter units?
It is normal for the mid/tweeter to be the same as or a few dB higher than the woofer.
Galu & Moon I am using car audio components to make home speakers. I have a Marantz Marantz SR6012 which is 110W rms at 8 Ohm. The sensitivity details I got from the CV website and other online sources. The woofer is DVC yes although I am wiring it to 4 Ohm. The midrange will be in separate enclosure as I already feel woofer interference at high levels.
Would this woofer be better with the midrange and tweeter:
Replacement Super Bass woofer sub speaker Cerwin Vega 12" AT-12 D7 600W/pgm | eBay
Would this woofer be better with the midrange and tweeter:
Replacement Super Bass woofer sub speaker Cerwin Vega 12" AT-12 D7 600W/pgm | eBay
Attachments
That makes thngs a bit clearer!
Your new woofer choice is a touch too sensitive at 86dB/W/m - see post #13. However it may match the 84 dB/W/m midrange/tweeter unit pretty well and avoid the need to add resistors to attenuate the mid/tweeter unit.
(Note that you have to ask for a 4 ohm version 'by request' to match your mid/tweeter unit if it is 4 ohm rated).
Remember, you can attenuate the mid/tweeter unit, but you can't attenuate the woofer.
It appears that the mid/tweeter unit includes its own mid/high frequency crossover, so you may only have to use a two way crossover in order to match the woofer to the mid/tweeter unit.
Your new woofer choice is a touch too sensitive at 86dB/W/m - see post #13. However it may match the 84 dB/W/m midrange/tweeter unit pretty well and avoid the need to add resistors to attenuate the mid/tweeter unit.
(Note that you have to ask for a 4 ohm version 'by request' to match your mid/tweeter unit if it is 4 ohm rated).
Remember, you can attenuate the mid/tweeter unit, but you can't attenuate the woofer.
It appears that the mid/tweeter unit includes its own mid/high frequency crossover, so you may only have to use a two way crossover in order to match the woofer to the mid/tweeter unit.
Basically, I do not recommend using car speakers in the home. The response of car speakers is balanced for the confined space in a car, so how they will sound in the home is unpredictable. Still, since you have bought the drivers, you can but find out!
Regarding sensitivity matching - sorry, I got confused! Mid/tweeter unit is 94dB and proposed woofer is 86dB.
The proposed woofer is still insensitive compared to the mid/tweeter unit which will still require you to do lots of attenuation using high power resistors.
It has little advantage, sensitivity wise, over the 84dB one you already have and I wouldn't advise spending the extra money on it.
Go ahead and use the L pad calculator which I recommended earlier. You don't have to attenuate the mid and tweeter seperately - you just need one L pad to attenute the composite mid'tweeter unit. Enter 4 ohm, 50W and the number of dB you need to attenuate by. Let us know the resistances and power ratings of the two resitors which are calculated and I can help from there.
Regarding sensitivity matching - sorry, I got confused! Mid/tweeter unit is 94dB and proposed woofer is 86dB.
The proposed woofer is still insensitive compared to the mid/tweeter unit which will still require you to do lots of attenuation using high power resistors.
It has little advantage, sensitivity wise, over the 84dB one you already have and I wouldn't advise spending the extra money on it.
Go ahead and use the L pad calculator which I recommended earlier. You don't have to attenuate the mid and tweeter seperately - you just need one L pad to attenute the composite mid'tweeter unit. Enter 4 ohm, 50W and the number of dB you need to attenuate by. Let us know the resistances and power ratings of the two resitors which are calculated and I can help from there.
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