Passive Crossover Question
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=59293
Printed Date: April 28, 2024 at 11:43 PM
Topic: Passive Crossover Question
Posted By: khsonic03
Subject: Passive Crossover Question
Date Posted: July 12, 2005 at 2:16 PM
Hello. I am having trouble finding an inline high-pass crossover at 8 or 10khz for an 8ohm load. I went to parts express, and the highest they have is a 5khz at 4ohm. I was told by a tech at Diamond Audio that the 5khz at 4ohm would crossover at roughly 8khz on an 8ohm load. Is this true? Or does anyone know where I can purchase a 10khz x-over at an 8ohm load? I went to the passive crossover section on this forum, and according to that (unless I'm misreading it), the 5khz at 4ohm would crossover at an even lower point for an 8ohm load (which is not what I want). I suppose I could make one, but I've never done anything like that, so I don't want to mess up! Thanks
Replies:
Posted By: Poormanq45
Date Posted: July 12, 2005 at 2:38 PM
Here you go, you can make your own
https://www.the12volt.com/caraudio/crosscalc.asp https://www.the12volt.com/caraudio/crosscalc.asp-------------
Posted By: khsonic03
Date Posted: July 12, 2005 at 3:40 PM
Yeah, I know. I went to that link earlier, but was hoping I could purchase one somewhere. Have you done it before? Is it difficult or more costly than buying some? I'm always up for trying new things, however I was hoping I could just purchase some because i am so busy with my fiberglass project right now.
Posted By: khsonic03
Date Posted: July 12, 2005 at 3:46 PM
Any good links for purchasing some parts for these? I looked at it again. It doesn't seem too difficult. I mean, I do know how to solder, and if it's just a matter of soldering a coil and a capacitor on a board, I think I can do that. Even though I have never worked with circuit boards.
Posted By: Steven Kephart
Date Posted: July 12, 2005 at 4:44 PM
So, what are you trying to do exactly? Are you trying to swap out the midrange or tweeters from an existing component set? Are you trying to make your own DIY speakers? If so, then you must realize that it is much more difficult than coming up with a textbook crossover and hoping that the speaker system will sound good. Steven Kephart Adire Audio -------------
Posted By: khsonic03
Date Posted: July 12, 2005 at 10:52 PM
Well, I currently have Diamond Audio M661's in the front. I have silk tweets in the mirror pods, and the woofers are down at the bottom of the door. There is a phase change from the woofer to the tweeter since they are so far apart. In short, I want to get the aluminum tweets, because I do prefer a brighter sound. I called Diamond to ask their suggestion, and they mentioned moving the silk tweets down by the woofer (within 4 inches), and putting the new aluminum tweets in the current pod locations (near the side mirrors). He stated that this would raise the sound stage slightly, and I could use the RAF off the current crossover to power the tweets up high. It is an attenuated channel -10dB, so the tweets would not be too overbearing. He mentioned that I would need a 10khz x-over. So that is where I currently stand (looking for an 8ohm 10khz x-over). Apparently he has done this before and has been pleased with the outcome. Worse comes to worse, I will stick with the aluminum tweets closer to the woofer. But I would still like to give this a shot.
Posted By: Steven Kephart
Date Posted: July 12, 2005 at 11:44 PM
Oh, ok. That's actually not a bad idea. You will get some lobing issues where the tweeters are playing the same frequencies. However if you use a really steep slope, that should be minimized. I'm not sure how well you could hear the lobing issues above 10kHz. And it's a much better solution than having the tweeters so far apart because that puts the lobing effects in a more critical band of frequencies. Steven Kephart Adire Audio -------------
Posted By: khsonic03
Date Posted: July 13, 2005 at 6:29 AM
OK, so my next question.....how do I increase the slope? I should be using the 12 dB formula for the crossovers, correct? Or are you thinking I should do an 18dB crossover?
Posted By: khsonic03
Date Posted: July 15, 2005 at 8:10 AM
Anyone? Should I use a higher slope? The Diamonds have 12 dB x-overs currently, so would it make sense to use the same, or go higher so the rolloff will be quicker?
Posted By: Poormanq45
Date Posted: July 15, 2005 at 10:37 AM
If you're using the same crossover frequency then you can use the same slope.
Sorry for not responding sooner
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Posted By: khsonic03
Date Posted: July 15, 2005 at 10:40 AM
Well, the crossover frequency is going to be aound 8-10 khz, as suggested by Diamond Audio. However, I'm not positive, but I know most tweets x-over at about 3khz. So, no--the x-over frequency would be different.
Posted By: stevdart
Date Posted: July 16, 2005 at 7:37 AM
khsonic, take a look at this, too: https://www.cdtaudio.com/cdt10lp.htm------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: khsonic03
Date Posted: July 16, 2005 at 8:23 AM
Hmm. Thanks. Essentially, thats what I will be doing. Except I just need to figure out where I should cross these over and the slope. I already have the tweets, so I was kinda hoping I wouldn't have to spend any more. I figure making/buying x-overs wont be too much. The Diamond Audio x-over has a -10dB attenuated channel that I will be using for these tweets.
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