Difference between -12dB and 24dB crossover

[tumpa]

Hi,
Can any one let me know the difference between 12dB and 24dB crossover in speakers, Which one is better in terms of 'bass' and overall performance ? Which is meant for 'fatigue free listening' ?

Thanks in advance

 

[ranjeetrain]

It tells you how fast the frequencies going in to certain driver rolls off. 24dB is steeper than 12 dB.

None is better than the other. Implement it well and both will work. Don't pay attention and none will work.

Also, crossover is just 1/3rd of speaker design. First is choice of drivers. Second choice of cabinet. Crossover is the last step.

Paying attention to crossover alone won't make a speaker great by itself.

Hope than helps.

 

[kapvin]

Hi,
Can any one let me know the difference between 12dB and 24dB crossover in speakers, Which one is better in terms of 'bass' and overall performance ? Which is meant for 'fatigue free listening' ?

Thanks in advance

There has been an increasing trend of forum members asking questions which have been answered elsewhere on the forum or are just a google search away.

Is it to increase post count, or just start a conversation, (the forum equivalent of chit chat about weather) or just because there is a selfish attitude (why search when i can ask a question). Maybe the forum admins can put up a wiki or FAQs so that such questions are not repeated ad nauseam.

It tells you how fast the frequencies going in to certain driver rolls off. 24dB is steeper than 12 dB.

None is better than the other. Implement it well and both will work. Don't pay attention and none will work.

Also, crossover is just 1/3rd of speaker design. First is choice of drivers. Second choice of cabinet. Crossover is the last step.

Paying attention to crossover alone won't make a speaker great by itself.

Hope than helps.

Ranjeet, thanks for answering; and your sequence is absolutely bangon. what I'd like to add is that drivers are the ingredients and your enclosure design depends on those. the crossover depends entirely on the combination of driver + enclosure (actually driver+baffle)

@OP; which is better depends on your design objectives and your drivers and your baffle (front panel) design. as ranjeet pointed out it a 12db crossover will attentuate the relevant driver by 12Db for each octave beyond the crossover frequency. for eg with a 2000hz crossover, the woofer level will lbe down by 12db at 4000hz and 24db at 8000hz. similarly the tweeter will be down by 12db at 1000hz and 24db at 500hz. for 24db design; the attenuation doubles.

Some simplistic points. please note the there is a phase shift of 90deg for each driver with a 12dB crossover; therefore they are out of phase at crossover point and will produce a deep null. therefore you need to invert the wiring of the tweeter to get them in phase and get a flat response. for a 24db crossover there is a phase shift of 180 degrees so total phase shift is 360 deg or zero phase. So you can wire them in phase (but remember the woofer is delayed by one whole cycle at crossover)
You can ideally slope the baffle to delay arrival (not launch as I had written earlier, sorry) of the tweeter wavefront

better depends on your application but here is a basic rule of thumb comparison.

12db will be cheaper than 24db (less parts count)
12Db requires good driver behaviour at least 2 octaves beyond crossover (no break ups , nulls etc) , with 24db you can get by with just 1 additional octave of good driver behaviour
12Db will put just a bit more strain on the tweeter (esp if you have chosen a lower crossover frequency)
12Db is a bit easier to get right. (this is an opinion, not a fact)