When adjusting slopes...?

[The Camry]

What does each slope sound like?

80prs is in the mail. doing my research now. What do you all set your slope at and why?

Click to read more...

 

[LosIsATool 5,000+ posts]

Slopes are used to build up valleys and drop peaks around your crossover points. You use them as a EQ.

 

[Jeffdachef 5,000+ posts]

Just get it in play around/get down and dirty with it until you like the sound! lol. Of course it'll be hours upon hours of tuning and fiddling around.

 

[The Camry]

any of you got a link or can explain to me the best way to tune and please dont just reply with "RTA" cuz i understand that but im not sure the exact way of going about things.

 

[keep_hope_alive Premium Member]

this is what changing slopes does to the frequency response

when adjusting points and slopes, you have control over how the speakers blend

but each slope has a different effect on phase.

6dB = 90 deg phase shift

12dB = 180 deg phase shift

18dB = 270 deg phase shift

24dB = 0 deg phase shift

30dB = 90 deg phase shift

36dB = 180 deg phase shift

i usually avoid 6dB and 18dB slopes because accounting for the phase shift is difficult unless you carry that through. if you have different slopes for each driver, you may need to change phase manually to keep the drivers in acoustic phase. if that sounds confusing, don't worry, very few people in car audio actually understand what crossovers do to phase.

the simple answer is stick with 24dB/oct and avoid phase shift issues.

if you use 12dB/oct you want to do that for both drivers or swap polarity on one of them. 12dB/oct lets more sound through.

by definition, a 12dB/oct HPF will result in a 12dB reduction at an octave below the crossover point.

and octave lower or higher is a halving or doubling of frequency at the crossover point, respectively.

so a 200Hz 12dB/oct HPF will result in a 12dB reduction at 100Hz and a 24dB reduction at 50Hz.

 

[keep_hope_alive Premium Member]

"what it sounds like" is as follows.

a 200Hz 6dB/oct HPF will still let the speaker play bass.

a 200Hz 12dB/oct HPF will reduce bass output noticeably.

a 200Hz 18dB/oct HPF will minimize bass output from the speaker.

a 200Hz 24dB/oct HPF will remove all audible bass from the speaker output

i do use an RTA when setting crossovers. i play each driver full range to see where their natural roll-off is at the listening position. this is important because it doesn't help to put a crossover outside of that range. then i adjust crossovers to within each driver's frequency response and listen for how they sound together. i will adjust slope of each driver as well as adjusting frequency to find the best balance, but keeping the natural roll-off in mind.

 

[The Camry]

I know quite a while ago you explained alot of that similarly to me. you said to use pink noise and then an rta. Look for where it starts to roll off and then set your x-over there or before that. Now assuming my rta is all over(was last time i checked), I should first use the EQ to make it all flat. Then find the natural roll off. Then set x overs then mess with EQ to find what sounds good to me then do TA

That right?

 

[The Camry]

lol oops. accidenttally posted