toddalin
01-03-2008, 03:07 PM
As many who follow my threads are aware, I've been re-doing my Cerwin Vega 10" 3-way front and rear surround speakers.
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/room4.jpg
This was brought about for two reasons.
First, one of the speakers back had pulled off almost letting the speaker fall 16 feet to its demise (as well as everything below it). :spchless: Luckily, it had wedged itself inplace rather than fall.
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/Carnage.jpg
The other reason was that the foams were shot and rather than refoam them, I opted to replace them with speakers that would never need to come down again (which requires outside contractors). To which, the woofers were replaced with the W10GTIs and the cone midrange/dome tweeters with 2425s/P.Audio PH-230 horns.
The W10s barely fit in the cabinets and their backs are <1/4" from the rear cabinet wall. I thought this could hinder air movement from the rear vent of the woofer. Also, the old port was on the back of the cabinet and would need to be removed and sealed as it interferred with the woofer placement. I figured that as long as I needed to put a "patch" on the rear from the old port, I may as well drill another hole in the back at the point of the woofer vent and reseal it from the back to provide a small recess in which the air could effectively vent and "get around" the woofer.
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/index_0046.jpg
Crossovers were designed and constructed, based on modifications of the "Keeper" crossovers so that the surrounds would have similar internal electronics (and hopefully sound) to the L/C/R.
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/index_0071.jpg
To preclude the cabinets coming apart and falling (especially since they picked up about 30 pounds each!), 1/4" steel, "allthread" rods were placed through the cabinets that tie the backs to the fronts. The two rods along the top serve as a continuation of the eye-bolts that hang the cabinets from the rear. Additionally, a lower rod at the center was added so that the bottom of the baffleboard doesn't "pull out" and swing forward. The rods were then wrapped with duct tape to dampen any "ringing." Note that there was not enough room for the L-pads on the baffles so they were relegated to the lower side at the front. This will also let them be accessable with the speakers hanging in place.
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/index_0065.jpg
And Voila!
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/index_0101.jpg
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/index_009.jpg
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/index_011.jpg
I still need to make new "stand-offs" for the grills (and put in the rest of the horn screws), but that's being taken care of.
And, as always, the bottom line is how they sound. Recognize that my room has profound influence of whatever speaker is in it. The reading was obtained on axis at about 1 meter. I believe that the peak just below 2.5K is a room node as both the woofer and horn show it when used individually. Irregularities in the lower end are probably mostly due to the room and floor bounce too. Depending on mic placement, I can get the bass flat to ~40 Hz before it rolls off.
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/index_012.jpg
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/room4.jpg
This was brought about for two reasons.
First, one of the speakers back had pulled off almost letting the speaker fall 16 feet to its demise (as well as everything below it). :spchless: Luckily, it had wedged itself inplace rather than fall.
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/Carnage.jpg
The other reason was that the foams were shot and rather than refoam them, I opted to replace them with speakers that would never need to come down again (which requires outside contractors). To which, the woofers were replaced with the W10GTIs and the cone midrange/dome tweeters with 2425s/P.Audio PH-230 horns.
The W10s barely fit in the cabinets and their backs are <1/4" from the rear cabinet wall. I thought this could hinder air movement from the rear vent of the woofer. Also, the old port was on the back of the cabinet and would need to be removed and sealed as it interferred with the woofer placement. I figured that as long as I needed to put a "patch" on the rear from the old port, I may as well drill another hole in the back at the point of the woofer vent and reseal it from the back to provide a small recess in which the air could effectively vent and "get around" the woofer.
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/index_0046.jpg
Crossovers were designed and constructed, based on modifications of the "Keeper" crossovers so that the surrounds would have similar internal electronics (and hopefully sound) to the L/C/R.
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/index_0071.jpg
To preclude the cabinets coming apart and falling (especially since they picked up about 30 pounds each!), 1/4" steel, "allthread" rods were placed through the cabinets that tie the backs to the fronts. The two rods along the top serve as a continuation of the eye-bolts that hang the cabinets from the rear. Additionally, a lower rod at the center was added so that the bottom of the baffleboard doesn't "pull out" and swing forward. The rods were then wrapped with duct tape to dampen any "ringing." Note that there was not enough room for the L-pads on the baffles so they were relegated to the lower side at the front. This will also let them be accessable with the speakers hanging in place.
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/index_0065.jpg
And Voila!
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/index_0101.jpg
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/index_009.jpg
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/index_011.jpg
I still need to make new "stand-offs" for the grills (and put in the rest of the horn screws), but that's being taken care of.
And, as always, the bottom line is how they sound. Recognize that my room has profound influence of whatever speaker is in it. The reading was obtained on axis at about 1 meter. I believe that the peak just below 2.5K is a room node as both the woofer and horn show it when used individually. Irregularities in the lower end are probably mostly due to the room and floor bounce too. Depending on mic placement, I can get the bass flat to ~40 Hz before it rolls off.
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/index_012.jpg