Welcome to Canadian Car Audio - Canada’s #1 Car Audio Forum   Members
 

Reply
 
LinkBack Thread Tools Display Modes
Old 04-03-2004, 11:05 AM   #1 (permalink)
Unhappy
CCA McKenzie
 
Mullen's Avatar
 
Join Date: Feb 2004
iTrader: (0)
Posts: 644
I am tring to use the Alpine I-personalize to fine tune my deck I understand gain and frequency I have set those but its asking me to set the slope

I have my gain set to "0" and Frequency set 31.5db (this example is for my sub) What should I set my slope at and what does it mean??

[img]graemlins/beer.gif[/img]
__________________
99 Accord EX
Alpine CDA-9815
Infinity Kappa perfect 6.1
Infinity Kappa 692.5i 6x9
RF 301x powers components
Memphis 15-ST124
Memphis 16-ST500D
Mullen is offline   Reply With Quote
Old 04-03-2004, 11:28 AM   #2 (permalink)
Post
Supporting Member
 
2 8's AKA Jeepbeats's Avatar
 
Join Date: May 2001
Location: Vancouver, B.C.
iTrader: (14)
Posts: 5,356
Does it give you a choice of 12/18/24? If so that would be the crossover slope, in db's/octave. http://www.bcae1.com/xovrslop.htm Someone else on here can explain this better than I can I am sure......
__________________
Location: Vancouver, B.C.
2 8's AKA Jeepbeats is offline   Reply With Quote
Old 04-03-2004, 11:38 AM   #3 (permalink)
Post
CCA McKenzie
 
Join Date: Jan 2004
iTrader: (1)
Posts: 572
Quote:
Originally posted by Mullen:
I am tring to use the Alpine I-personalize to fine tune my deck I understand gain and frequency I have set those but its asking me to set the slope

I have my gain set to "0" and Frequency set 31.5db (this example is for my sub) What should I set my slope at and what does it mean??

[img]graemlins/beer.gif[/img]
Ok from what I understand the slope is the point where you start to gradually cutout unwanted frequencies. The best way to describe this, that i can think of is to see an octave as a double of frequency. Like 40 to 80 hertz is an octave so is 300 to 600hz and 1000 to 2000hz and so on... you get the picture.
As for the db per octave part that is the amount of cutoff starting at your crossover point. So the higher the db the greater the cutoff. If your crossover was set at 200hz at 24 db per octave, you would have 24 db less signal at 100 hz.
Im also sure that someone here can put it a lot better than i did, but this should help you understand [img]graemlins/thumb.gif[/img]
__________________
I can hear pudding
152.5 is offline   Reply With Quote
Old 04-03-2004, 01:53 PM   #4 (permalink)
Post
CCA Hoser
 
Join Date: Mar 2004
iTrader: (0)
Posts: 146
Crossover slope is how much SOUND is filtered out ABOVE or BELLOW the CROSSOVER POINT...the steeper the SLOPE(24db) the less FREQUENCIES will be heard BELOW THAT X-over point.

If you pick a X-over Freq @ 100HZ--@--6db slope will allow FREQUNCIES DOWN to about 30HZ to be heard.(BARLEY).

If you pick same X-over freq @ 100hz--@--24db slope it will ATTENUATE MORE FREQUENCIES and nothing below about 80HZ would be heard. [img]graemlins/bump.gif[/img]
__________________
---___---
Halo1 is offline   Reply With Quote
Old 04-04-2004, 01:53 AM   #5 (permalink)
Post
CCA Hoser
 
Reider's Avatar
 
Join Date: Jul 2003
iTrader: (0)
Posts: 164
008, in your examples are you talking about the "roll off effect" that can still be heard beyond the X over point?
__________________
Eclipse 8443
Boston Pro 5.5 / Soundstream Rubicon 702
4 15" Rockford DVC's / 2 Rockford 800a2's
Reider is offline   Reply With Quote
Old 04-05-2004, 03:38 PM   #6 (permalink)
Post
CCA Golden Toque
 
Join Date: Jun 2001
iTrader: (0)
Posts: 3,261
ok...its really not that complicated people...think about this for a second..."dee-bee per octave"

ie. a 12 db/oct high pass crossover @ 100hz means that at 50 hz, the signal will be 12 db quieter then at 100hz.

if this was a 24 db/oct slope. then 50 hz would be 24 db quieter, and 25 hz would be 48 db quieter then 100hz.

If it was 12 db/oct low pass x-over at 100 hz, then 200 hz would be 12 db quieter then 100 hz.

[ April 05, 2004, 03:42 PM: Message edited by: Orion_95 ]
__________________
Tyler Johnstone<br />Orion_95@hotmail.com<br /><br />'Good judgement comes from experience. Experience comes from bad judgement'<br /><br />'Former' Install Manager - AVU Smithers
Orion_95 is offline   Reply With Quote
Old 04-05-2004, 03:42 PM   #7 (permalink)
Post
--SPECIAL ED--
 
Join Date: Dec 1969
iTrader: (0)
Posts: 0
It is the rate of rolloff from the crossover point in simple terms. Steeper the slope, the sharper the rolloff.
Kris Dancey is offline   Reply With Quote
Old 04-05-2004, 04:18 PM   #8 (permalink)
Post
CCA Hoser
 
Join Date: Mar 2003
iTrader: (0)
Posts: 355
Slope is determined by decibels/octave.

In terms of voltage the formula is

20 log vout/vin

-3db is equall to when .7071% of the input voltage reaches the output.

It is also the half power point.

For example a simple 6db/octave high pass filter
(capacitor) set for 100hz, 4 ohms

The amp puts out 20volts.

Impedance of 4ohm cap in series with 4 ohm speaker equalls Z=5.65ohms

20v/5.65 ohms=3.53 amps

3.53 amps* 4 ohms=14.15 volts

20 log 14.15/20 volts= -3db

At 50 hz speaker 4 ohm , cap is now 8ohm

Z=8.94

20/8.94ohms= 2.23amps

2.23 ampsx 4ohms=8.94 volts

20 log 8.94/20=-6.99 db
__________________
"I can taste the bubbles"..Stifler
abnormal72 is offline   Reply With Quote
Old 04-05-2004, 06:04 PM   #9 (permalink)
Post
CCA McKenzie
 
Join Date: Aug 2001
iTrader: (0)
Posts: 867
I am amazed that after Orion 95's explaination that it inst clear enough.


Why the replys after? [img]graemlins/dunno.gif[/img]
slow/n\low is offline   Reply With Quote
Old 04-05-2004, 08:52 PM   #10 (permalink)
Post
CCA Hoser
 
Reider's Avatar
 
Join Date: Jul 2003
iTrader: (0)
Posts: 164
Orions explanation was very clear and understandable to me..
__________________
Eclipse 8443
Boston Pro 5.5 / Soundstream Rubicon 702
4 15" Rockford DVC's / 2 Rockford 800a2's
Reider is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

» Advertisers










advertise here

» Recent Threads
Mobile Dynamics Closes Its Doors
Last post by [i]con
Today 08:20 PM
The car Fozz built!!!
Last post by Killer_klown187
Today 08:07 PM
Budget setup help required
Last post by Northside Taco
Today 08:02 PM
Urban Disturbance in Kitchener !
Last post by Father Yuli
Today 07:22 PM
Bad Credit Mortgages | Naruto Episodes | Books | Pacotes Porto Seguro | Mortgages

Powered by vBulletin® Version 3.7.3
Copyright ©2000 - 2008, Jelsoft Enterprises Ltd.
SEO by vBSEO 3.2.0
Canadian Car Audio
Page generated in 0.86673 seconds with 12 queries