Building Passive Crossovers

BoneZ · 07-03-2015, 05:37 PM

OK, so I bought this pair of CDT HD-2BL Hybrid Mid-tweeters. Their frequency response is rated from 250Hz - 20kHz. I contacted CDT about the proper high pass frequency and they recommend 1500Hz at 24dB/Oct.

Now, building a 4th order passive crossover is easy enough, but my question for the audio gurus here is which style?

Bessel
Butterworth
Gaussian
Legendre
Linkwitz-Riley
Linear Phase

I never really knew the differences between these and I'm hoping someone here does.

tommyguns · 07-03-2015, 07:13 PM

Here's another source for that kind of help. diyAudio

RonRizz · 07-03-2015, 08:11 PM

Or why not look into Harrison Labs FMods, and do your crossover in the pre-amplified stage, where amplifier energy is not wasted.....

BoneZ · 07-03-2015, 08:12 PM

Quote:

Originally Posted by RonRizz

Or why not look into Harrison Labs FMods, and do your crossover in the pre-amplified stage, where amplifier energy is not wasted.....

Interesting. I wonder if the 3000/12 hp would be similar to the recommended 1500 / 24. I'll have to look into these. Thanks.

RonRizz · 07-03-2015, 08:20 PM

you can google it... They are inline crossovers that plug into your rcas, and the x over point chosen stays a constant, unlike in a passive setup, which fluctuates with the impedance of the driver while playing. Because it is done pre-amplified signal, there is no wasted power. Passive xovers burn energy filtering an already amplified signal, so you lose a slight amount of power when using them.
Also..... I am running a set of CDT ES-02's which also show a freq range of 250 - 20hz...
They recommend crossing at a higher freq for power handling purposes. I have crossed mine as low as 500hz at 100 watts, and had no issues with them.

RonRizz · 07-03-2015, 08:22 PM

I think they are like $25 a pair. Hell, I may have a set in the garage.... If they are the right freq Ill send em to you. Been YEARS since I had them in one of my cars.

BoneZ · 07-03-2015, 08:22 PM

Good to know. Thanks. I will probably go this route.

BoneZ · 07-03-2015, 08:23 PM

Quote:

Originally Posted by RonRizz

I think they are like $25 a pair. Hell, I may have a set in the garage.... If they are the right freq Ill send em to you. Been YEARS since I had them in one of my cars.

Hot damn in the city. Thank you.

RonRizz · 07-03-2015, 08:36 PM

found 2 sets..... just have to check the Harrison website to see what freq they are... I'll let you know. Leaving for tonight, gotta go set off some 4th of july fun!

RonRizz · 07-03-2015, 08:42 PM

just checked... the black lettered one is 1000hz LOW pass,
the red lettered is 100hz HIGH pass. The black set you could use for your midbass/subs, but you will need a 1000hz high pass for your cdts.

BoneZ · 07-03-2015, 08:42 PM

Many thanks friend.

BoneZ · 07-03-2015, 08:52 PM

I planned on just letting the woofers roll off naturally. I am going to order a set of these though. Hope they ship quick.

BoneZ · 07-03-2015, 09:08 PM

Is 1000Hz hp going to be high enough with only a 12dB/oct slope? CDT told me 1500 @ 24. I was almost inclined to get the 2500Hz.

RonRizz · 07-03-2015, 10:09 PM

Depends on the power you put in them...they are listed to go as low as 150hz, but not at rated power. I personally think 1000 is still too high, because your missing out on the lower midrange freq. That these speakers love.
I currently run mine at 630 with 100 watts, and they perform quite well.

BoneZ · 07-03-2015, 10:15 PM

I'm only going to be hitting mine with 60 watts each.

07-03-2015, 05:37 PM	#1 (permalink)
BoneZ A True Z Fanatic Join Date: May 2015 Location: Atlanta, GA Age: 53 Posts: 9,299 Drives: 2012 Blue BallZ Rep Power: 2684382	Building Passive Crossovers OK, so I bought this pair of CDT HD-2BL Hybrid Mid-tweeters. Their frequency response is rated from 250Hz - 20kHz. I contacted CDT about the proper high pass frequency and they recommend 1500Hz at 24dB/Oct. Now, building a 4th order passive crossover is easy enough, but my question for the audio gurus here is which style? Bessel Butterworth Gaussian Legendre Linkwitz-Riley Linear Phase I never really knew the differences between these and I'm hoping someone here does.

07-03-2015, 07:13 PM	#2 (permalink)
tommyguns Track Member Join Date: May 2009 Location: New York Age: 65 Posts: 914 Drives: 370Z/Sport/Black/MT Rep Power: 17	Here's another source for that kind of help. diyAudio BoneZ likes this. __________________ 09 Sport / MB / 6sd / Nismo"R" Intake / Eibach Pro Kit / Z1 25 row cooler / JWT LW FW / New Short Block 3/11/11 /H&R 15fr 20rr/DBA 4000/FI CB with 12"res./Morel/JL/"Division"mod/SPC/EcuTek/M370/ZEX C SHOT/ART's/NRG

07-03-2015, 08:11 PM	#3 (permalink)
RonRizz A True Z Fanatic Join Date: Aug 2011 Location: Pine grove, Pa Posts: 2,136 Drives: 2 feet, 3 pedals Rep Power: 6775	Or why not look into Harrison Labs FMods, and do your crossover in the pre-amplified stage, where amplifier energy is not wasted..... BoneZ likes this. __________________ P99rs Head Unit--- Amps- 2 Pioneer Prs800d --- Zapco ST1000MX---Zapco ST-4XSQ---- SI BM mk5 Subs---SI TM65v2 Midbass--- SI M3 mids--- SI M25 xbl2 tweeters ----- 2016 MECA street class 3rd place at world finals

07-03-2015, 08:20 PM	#5 (permalink)
RonRizz A True Z Fanatic Join Date: Aug 2011 Location: Pine grove, Pa Posts: 2,136 Drives: 2 feet, 3 pedals Rep Power: 6775	you can google it... They are inline crossovers that plug into your rcas, and the x over point chosen stays a constant, unlike in a passive setup, which fluctuates with the impedance of the driver while playing. Because it is done pre-amplified signal, there is no wasted power. Passive xovers burn energy filtering an already amplified signal, so you lose a slight amount of power when using them. Also..... I am running a set of CDT ES-02's which also show a freq range of 250 - 20hz... They recommend crossing at a higher freq for power handling purposes. I have crossed mine as low as 500hz at 100 watts, and had no issues with them. BoneZ likes this. __________________ P99rs Head Unit--- Amps- 2 Pioneer Prs800d --- Zapco ST1000MX---Zapco ST-4XSQ---- SI BM mk5 Subs---SI TM65v2 Midbass--- SI M3 mids--- SI M25 xbl2 tweeters ----- 2016 MECA street class 3rd place at world finals

07-03-2015, 08:22 PM	#6 (permalink)
RonRizz A True Z Fanatic Join Date: Aug 2011 Location: Pine grove, Pa Posts: 2,136 Drives: 2 feet, 3 pedals Rep Power: 6775	I think they are like $25 a pair. Hell, I may have a set in the garage.... If they are the right freq Ill send em to you. Been YEARS since I had them in one of my cars. BoneZ likes this. __________________ P99rs Head Unit--- Amps- 2 Pioneer Prs800d --- Zapco ST1000MX---Zapco ST-4XSQ---- SI BM mk5 Subs---SI TM65v2 Midbass--- SI M3 mids--- SI M25 xbl2 tweeters ----- 2016 MECA street class 3rd place at world finals

07-03-2015, 08:22 PM	#7 (permalink)
BoneZ A True Z Fanatic Join Date: May 2015 Location: Atlanta, GA Age: 53 Posts: 9,299 Drives: 2012 Blue BallZ Rep Power: 2684382	Good to know. Thanks. I will probably go this route. __________________ *“Happiness is having a large, loving, caring, close-knit family in another city.”*-George Burns

07-03-2015, 08:42 PM	#10 (permalink)
RonRizz A True Z Fanatic Join Date: Aug 2011 Location: Pine grove, Pa Posts: 2,136 Drives: 2 feet, 3 pedals Rep Power: 6775	just checked... the black lettered one is 1000hz LOW pass, the red lettered is 100hz HIGH pass. The black set you could use for your midbass/subs, but you will need a 1000hz high pass for your cdts. __________________ P99rs Head Unit--- Amps- 2 Pioneer Prs800d --- Zapco ST1000MX---Zapco ST-4XSQ---- SI BM mk5 Subs---SI TM65v2 Midbass--- SI M3 mids--- SI M25 xbl2 tweeters ----- 2016 MECA street class 3rd place at world finals

07-03-2015, 08:42 PM	#11 (permalink)
BoneZ A True Z Fanatic Join Date: May 2015 Location: Atlanta, GA Age: 53 Posts: 9,299 Drives: 2012 Blue BallZ Rep Power: 2684382	Many thanks friend. __________________ *“Happiness is having a large, loving, caring, close-knit family in another city.”*-George Burns

07-03-2015, 08:52 PM	#12 (permalink)
BoneZ A True Z Fanatic Join Date: May 2015 Location: Atlanta, GA Age: 53 Posts: 9,299 Drives: 2012 Blue BallZ Rep Power: 2684382	I planned on just letting the woofers roll off naturally. I am going to order a set of these though. Hope they ship quick. __________________ *“Happiness is having a large, loving, caring, close-knit family in another city.”*-George Burns

07-03-2015, 09:08 PM	#13 (permalink)
BoneZ A True Z Fanatic Join Date: May 2015 Location: Atlanta, GA Age: 53 Posts: 9,299 Drives: 2012 Blue BallZ Rep Power: 2684382	Is 1000Hz hp going to be high enough with only a 12dB/oct slope? CDT told me 1500 @ 24. I was almost inclined to get the 2500Hz. __________________ *“Happiness is having a large, loving, caring, close-knit family in another city.”*-George Burns

07-03-2015, 10:09 PM	#14 (permalink)
RonRizz A True Z Fanatic Join Date: Aug 2011 Location: Pine grove, Pa Posts: 2,136 Drives: 2 feet, 3 pedals Rep Power: 6775	Depends on the power you put in them...they are listed to go as low as 150hz, but not at rated power. I personally think 1000 is still too high, because your missing out on the lower midrange freq. That these speakers love. I currently run mine at 630 with 100 watts, and they perform quite well. __________________ P99rs Head Unit--- Amps- 2 Pioneer Prs800d --- Zapco ST1000MX---Zapco ST-4XSQ---- SI BM mk5 Subs---SI TM65v2 Midbass--- SI M3 mids--- SI M25 xbl2 tweeters ----- 2016 MECA street class 3rd place at world finals

07-03-2015, 10:15 PM	#15 (permalink)
BoneZ A True Z Fanatic Join Date: May 2015 Location: Atlanta, GA Age: 53 Posts: 9,299 Drives: 2012 Blue BallZ Rep Power: 2684382	I'm only going to be hitting mine with 60 watts each.

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