I have some 8 ohm speakers that have a 1.5uf cap that is "factory installed". They are set up so that conections can be made to include or exclude the cap. From what I can tell from the tutorial on passive filtering, if I use the cap the speakers wont pass anything below about 13k, correct? Isn't this a little on the "high" side? These are going to be used for a surround system in the house.
Replies (5)
swez on 05/30/2005 12:15:06
A 1.5 uF cap on an 8 ohm speaker is about 13Khz HPF. That's fine for a super tweeter application. (12Khz and up) But lousy for a full or midrange driver.
What size speaker(s) is/are in this part of the system and how much power can they take at say 300 Hz.?
NOTE: Depending on the driver specs and enclosure size/design, power handling will decrease as we drop the usable frequency response. If these are basically "ambient tweeters" , dropping them to 5Khz will give them a wider range to operate within. (almost 2 octave lower), but power handling may fall as well.
Say more about what is in the box if you can tell,
Swez
gearhead on 05/30/2005 16:24:08
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=64618&item=5777663746&rd=1&ssPageName=WDVW
After looking at them & thinking about it, these are probably supposed to be used as full range speakers with the tweeter tapped off of the cap. These aren't in enclosures (yet). My system is going to consist of 4 of these speakers for the surround, 2 Sony 5 1/4"'s for the center, and 2 12" Infinity's for subs.
Victor on 05/30/2005 16:41:50
Hey wouldnt like to comment on anything except...
Those sony speakers are real good ones, I have used them in a friends home theater system and they perform really well in the range of 60Hz to 2500Hz.
Also they are very well magnetically shielded.
But I removed the Cap cause we desired a full range performance from them and they did not disappoint.
Also you would need a good powerful amp cause they are rated at 8ohms and will demand more power to get them working well.
We used it with an Onkyo amp which put out 160wrms @ 8ohms per channel.
gearhead on 05/30/2005 16:51:11
The speakers I originally purchased were rated at 130wrms but they were sold out. These are what they substituted. I'm not complaining for $10 ea. I've got an Onkyo TX-SV636, 100wrms per ch. minimum @ 8ohms, so I'm guessing that's going to be enough.
swez on 05/30/2005 17:55:57
That picture clears everything up. The tweeter is tapped off that Cap. Many low budget crossovers are done this way. Quick & easy.
Frankly, I would look for a tweeter that operates well in the 3-5Khz range and can still handle the power rating on that amp channel. If using an 8 ohm tweeter, a 4.7uF cap will filter below 4.2Khz. Needs to be non-polarized, electrolytic cap, 30 - 50 volts rated.
That should do ya,
Swez
PS The SPL/watt (eff. rating) should be close to the woofer ratings as possible so you get balanced sound from each driver.
Replies (5)
swez on 05/30/2005 12:15:06
A 1.5 uF cap on an 8 ohm speaker is about 13Khz HPF. That's fine for a super tweeter application. (12Khz and up) But lousy for a full or midrange driver.
What size speaker(s) is/are in this part of the system and how much power can they take at say 300 Hz.?
NOTE: Depending on the driver specs and enclosure size/design, power handling will decrease as we drop the usable frequency response. If these are basically "ambient tweeters" , dropping them to 5Khz will give them a wider range to operate within. (almost 2 octave lower), but power handling may fall as well.
Say more about what is in the box if you can tell,
Swez
gearhead on 05/30/2005 16:24:08
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=64618&item=5777663746&rd=1&ssPageName=WDVW
After looking at them & thinking about it, these are probably supposed to be used as full range speakers with the tweeter tapped off of the cap. These aren't in enclosures (yet). My system is going to consist of 4 of these speakers for the surround, 2 Sony 5 1/4"'s for the center, and 2 12" Infinity's for subs.
Victor on 05/30/2005 16:41:50
Hey wouldnt like to comment on anything except...
Those sony speakers are real good ones, I have used them in a friends home theater system and they perform really well in the range of 60Hz to 2500Hz.
Also they are very well magnetically shielded.
But I removed the Cap cause we desired a full range performance from them and they did not disappoint.
Also you would need a good powerful amp cause they are rated at 8ohms and will demand more power to get them working well.
We used it with an Onkyo amp which put out 160wrms @ 8ohms per channel.
gearhead on 05/30/2005 16:51:11
The speakers I originally purchased were rated at 130wrms but they were sold out. These are what they substituted. I'm not complaining for $10 ea. I've got an Onkyo TX-SV636, 100wrms per ch. minimum @ 8ohms, so I'm guessing that's going to be enough.
swez on 05/30/2005 17:55:57
That picture clears everything up. The tweeter is tapped off that Cap. Many low budget crossovers are done this way. Quick & easy.
Frankly, I would look for a tweeter that operates well in the 3-5Khz range and can still handle the power rating on that amp channel. If using an 8 ohm tweeter, a 4.7uF cap will filter below 4.2Khz. Needs to be non-polarized, electrolytic cap, 30 - 50 volts rated.
That should do ya,
Swez
PS The SPL/watt (eff. rating) should be close to the woofer ratings as possible so you get balanced sound from each driver.
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