Attenuate tweeter level by 2 db

bastek · 26th May 2008, 02:31 AM

I need to lower the highs by 1.5-2db without altering the crossover phase. I can use a 3R in series with the 13R, or a 25R in parallel with the tweeter. What's the best way to do it?

DAMIC · 26th May 2008, 08:38 AM

Hi,

http://www.carstereo.com/help/Articles.cfm?id=18

bastek · 26th May 2008, 05:39 PM

Thanks for the link, but i can't use the L-pad formula. I can only add one resistor in series or in parallel. What's the correct value for 2 db attenuation? The tweeter impedance is 7 ohms.

Inductor · 26th May 2008, 11:05 PM

Quote:

Originally posted by bastek
Thanks for the link, but i can't use the L-pad formula. I can only add one resistor in series or in parallel. What's the correct value for 2 db attenuation? The tweeter impedance is 7 ohms.

Why is that? What you are looking for, maybe is this.
http://www.troester.org/ls/lpad.html

But the model should be tested. You want to use your xover or similar (same results) with a different attenuation, if I'm right. If you need help just ask. What is your tweeter (besides the 7 thing)?

bastek · 27th May 2008, 12:21 AM

Hi. My tweeter is the Fountek NeoCD3.0 and the speaker is a little bright. That's why i want to bring the level down a bit 1-2 db will do it).
I want to use an external switch for original or -2 db setting.
thanks

djarchow · 27th May 2008, 03:08 AM

The 25 Ohm in parallel with the tweeter gives you the most even attenuation across the passband and keeps the phase closer to the original schematic.

regards,

Dennis

Inductor · 27th May 2008, 01:27 PM

Quote:

Originally posted by djarchow
The 25 Ohm in parallel with the tweeter gives you the most even attenuation across the passband and keeps the phase closer to the original schematic.

regards,

Dennis

Dennis, that gives a good attenuation of ~2dB.

bastek, I wouldn't be amazed if you find kind of a peak at ~15k of 6dB with this tweeter/xover, unless you have a fullrange kind of driver or a first order midwoofer with low roll-off + good integration. (Cons. xover at ~2K5 for the NeoCD).

bastek · 27th May 2008, 10:05 PM

I connected a 20ohm in series with the external switch, in parallel to tweeter, and they sound smoother in my larger room. I don't hear any peaks or dips in the highs, but i have to do some measurements. very satisfied with the sound for now. Thanks.

Inductor · 27th May 2008, 10:08 PM

Good. They also have a ~10dB attenuation/dumped (from 95) 8dB@5K/4.5dB@15K before the || resistor, so that might get smoothed (a little/bit).

27th May 2008, 10:08 PM	#9
Inductor diyAudio Member Join Date: Feb 2006 Location: Cascais	Good. They also have a ~10dB attenuation/dumped (from 95) 8dB@5K/4.5dB@15K before the \|\| resistor, so that might get smoothed (a little/bit). __________________ What the Hell is this crap?! It's not crap, it's muzak.

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26th May 2008, 08:38 AM	#2
DAMIC diyAudio Member Join Date: Jan 2006 Location: Beograd	Hi, http://www.carstereo.com/help/Articles.cfm?id=18

26th May 2008, 05:39 PM	#3
bastek diyAudio Member Join Date: Dec 2005 Location: NY	Thanks for the link, but i can't use the L-pad formula. I can only add one resistor in series or in parallel. What's the correct value for 2 db attenuation? The tweeter impedance is 7 ohms.

27th May 2008, 12:21 AM	#5
bastek diyAudio Member Join Date: Dec 2005 Location: NY	Hi. My tweeter is the Fountek NeoCD3.0 and the speaker is a little bright. That's why i want to bring the level down a bit 1-2 db will do it). I want to use an external switch for original or -2 db setting. thanks

27th May 2008, 03:08 AM	#6
djarchow diyAudio Member Join Date: Apr 2007	The 25 Ohm in parallel with the tweeter gives you the most even attenuation across the passband and keeps the phase closer to the original schematic. regards, Dennis

27th May 2008, 10:05 PM	#8
bastek diyAudio Member Join Date: Dec 2005 Location: NY	I connected a 20ohm in series with the external switch, in parallel to tweeter, and they sound smoother in my larger room. I don't hear any peaks or dips in the highs, but i have to do some measurements. very satisfied with the sound for now. Thanks.

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