That is patently obvious! 😀
I suggest you try being more acceptive of advice instead of merely seeking confirmation that your somewhat questionable ideas are runners.
Ok, this’s clear enough. 😉
I won’t go for that path again — the idea of paralleling a resistor to a driver.
Yet, I doubt on Allen’s reply that if a resistor is serially connected instead, the sensitivity will be the same as none resistor connected. For the tweeter, simply place a resistor serially before or after a filter will result in an attenuation. But why doing the same thing on woofer won’t get similar result. I know that there’s a method to change Q of drivers by using serial resistor. How can we distinct between attenuating and adjusting Q?
Last edited:
Could you help to explain more in detail, please? Why placing a series resistor is a bad idea? The attenuation of sensitivity and adjusting Q are general methods that people always apply them, aren’t they?
For adjustment of Qts, we are talking about only placing a small resistance in series with the bass driver. The resultant attenuation and power loss is low.
For attenuation purposes, we are talking about placing a large resistance in series with the bass driver. The resulting power loss is high (electrical energy being turned into heat in the resistor rather than into sound in the bass driver) and the change in Qts more severe.
For attenuation purposes, we are talking about placing a large resistance in series with the bass driver. The resulting power loss is high (electrical energy being turned into heat in the resistor rather than into sound in the bass driver) and the change in Qts more severe.
Last edited:
Why do any of these combinations? All your amps are 8 ohm rated, so go series for best impedance match and be done with it.
@OP why did you make a new thread for the same topic.
You are still looking for someone to tell you its OK to buy 20USD bass drivers so you can afford more expensive 100Hz crossover, now you want to reduce impedance to save money on crossover parts. Why not just get a proper 12" to begin with and cross it higher. Either 2x4ohm in series or 1 8ohm. And for the love of god find something with more sensitivity with those amps of yours.
Were you not happy with the advice in this thread:
Infinite baffle woofers in an enclosure
@mods: why not merge these threads.
You are still looking for someone to tell you its OK to buy 20USD bass drivers so you can afford more expensive 100Hz crossover, now you want to reduce impedance to save money on crossover parts. Why not just get a proper 12" to begin with and cross it higher. Either 2x4ohm in series or 1 8ohm. And for the love of god find something with more sensitivity with those amps of yours.
Were you not happy with the advice in this thread:
Infinite baffle woofers in an enclosure
@mods: why not merge these threads.
You would need a resistor of 1000s of watts costing more than the coil you try to avoid using and end up with 70dB sensitivity making you also need an amp of 10000 watt to even hear anything.
@OP I suggest you read all the stickies before making any more threads asking for confirmation on crazy ideas.
So you want to design your own speaker from scratch!
Introduction to designing crossovers without measurement
So you want to design your own speaker from scratch!
Introduction to designing crossovers without measurement
What if I go with paralleling an 8 Ohms resistor to two 4 ohms woofers being serially wired, but I’ll use a large resistor i.e. 100W resistors, as pic attached? Is it acceptable?
I see some crossovers of sonus faber speakers don’t use any caps, instead, they use these heatsink resistors.
I see some crossovers of sonus faber speakers don’t use any caps, instead, they use these heatsink resistors.
Attachments
Last edited:
The reason this does not help is because you are using a Voltage source amplifier. Resistance in parallel does not help.
I’m trying to let the low pass filter virtually see the woofers 4 Ohms, not an amp.
Two 4 Ohms woofers serially wired, then, parallel connecting to an 8 Ohms resistor, resulting in 4 Ohms total seen by the crossover. Am I correct?
A speaker varies its impedance along the frequency it plays; a resistor is linear.
Not quite mixing apples and pears, but close ( I guess).
Not quite mixing apples and pears, but close ( I guess).
Why do you think it will help.. Is it because of the inductor values? Is is because you already have a crossover? Is it what pico said?
How can you reconcile these two statements?
It's quite usual for young guys in their 20s to want to rewrite the rule book, but one day you will find it pays to listen to the voices of experience. 😉
I have such a loudspeaker going to 2 ohms around 100 Hz. you need atomic centrral to move them well. Chord amps for instance and equivalent !
Better to design with two of these drivers in serie to double your impedance.
But how can he save money on crossover parts then?
100Hz at 8 ohm Lol (I no longer know why this is an objective though but it seems it’s the most critical aspect of the design, and that everything else comes second).
I suggest OP you parallel the two 12” and serial with a 1000 watt 2 ohm. You will have a nice sensitivity of 70 dB and you need a 1000 watt amp at steady
4 ohm load to get close to 100dB perceived SPL.
10000 watts peaks if you want to have +10dB dynamic headroom but by then that resistor will probably set your cabinet on fire.
This is a very good idea. Who needs sensitivity when power is so cheap?
That is why nobody else have done it, because only real creative minds can come up with it.
Or just get a proper 12” 8 ohm single woofer, cross at sensible frequency and use your existing amps.
Why anyone wants cross at 100hz passive is beyond me.
Why anyone wants to have 4 ohm only to save some money on crossover parts are even more weird.
Why anyone wants to reduce sensitivity only for the purpose of saving money on the two above points is just crazy.
Can’t wait to see the project complete and the measurements.
100Hz at 8 ohm Lol (I no longer know why this is an objective though but it seems it’s the most critical aspect of the design, and that everything else comes second).
I suggest OP you parallel the two 12” and serial with a 1000 watt 2 ohm. You will have a nice sensitivity of 70 dB and you need a 1000 watt amp at steady
4 ohm load to get close to 100dB perceived SPL.
10000 watts peaks if you want to have +10dB dynamic headroom but by then that resistor will probably set your cabinet on fire.
This is a very good idea. Who needs sensitivity when power is so cheap?
That is why nobody else have done it, because only real creative minds can come up with it.
Or just get a proper 12” 8 ohm single woofer, cross at sensible frequency and use your existing amps.
Why anyone wants cross at 100hz passive is beyond me.
Why anyone wants to have 4 ohm only to save some money on crossover parts are even more weird.
Why anyone wants to reduce sensitivity only for the purpose of saving money on the two above points is just crazy.
Can’t wait to see the project complete and the measurements.
Last edited:
- Status
- Not open for further replies.