I've been involved with DIY audio for the past year now, and I have completed one project. I've been contemplating a reference level loudspeaker on par with some of the big Wilson's or Tony Gee's Andromeda, and I have a question about speaker sensitivity.
I have been looking at the specifications for Wilson's X1 and it has a sensitivity of 95db/watt. That seems really high, considering none of the drivers used (in their DIY available incarnation) have a sensitivity that high. After researching the drivers it looks like Wilson is using (most likely in modified form) the following drivers:
Focal Audiom TD120 dx tweeter (93.5db)
2 Scan Speak 18W 8545K Midrange units (87.5db)
Focal Audiom 13VX woofer (89db)
Focal Audiom 15VX woofer (? most likely the same as the 13vX)
I'm not sure exactly which tweeters are used as the two rear-firing tweeters, but that is not important. what I am wondering about is how he is pairing the bass and midrange drivers together to get a sensitivity so high?! I imagine the midrange drivers are playing the same frequencies, so that should add 3db to the sensitivity in their range, from 87.5db to 90.5. It would also seem likely that the two bass drivers are working together as well, increasing their sensitivity to 92db. I'm guessing that since the X1's are ported that increases the sensitivity in that range too. I don't know how much though.
Is it possible to increase sensitivity anywhere in the crossover? I can't think of how that would be done, I only know how to use resistors to dampen my drivers.
I'm not actually trying to clone the X1's, I am just trying to get an understanding for how they function.
My sencond question is about power handling. In my speakers I am using a Vifa XG18 mid-bass driver as my Bass unit. They are listed as having a short term max power handling of 70w. In my sealed cabinet speakers they seem to move quite a lot at less than one watt of power. They seem to move most when I am listening to jazz and the bass player strums low notes. I understand they move the most at lower frequencies, but I just worry that they will break somehow. I don't really listen to music at high volume levels. I have my amplifier (Sony Str DB 780, rated at 100 wpc) playing at a maximum of -28db, and usually much less. I assume that 0db would be 100 Watts, but at -28db my amp should be putting out ~0.1953125 watts of power. Maybe I am just being paranoid, but I worry about my drivers! I would hate for one of them to exceed it's Xmax and ruin the voice coil.
There are still many holes in my knowledge of speaker building and techniques, so it wouldn't surprise me if some of what I have surmised here is incorrect, but hey, that's what these boards are for, right? I would appreciate any help you can give me! Just so this thread isn't just about questions, here is a picture the speakers that I made. They sound great!
Thanks,
Andrew
[IMGHTTPDEAD]http://www.andrewhasz.com/diy/top.jpg[/IMGHTTPDEAD]
I have been looking at the specifications for Wilson's X1 and it has a sensitivity of 95db/watt. That seems really high, considering none of the drivers used (in their DIY available incarnation) have a sensitivity that high. After researching the drivers it looks like Wilson is using (most likely in modified form) the following drivers:
Focal Audiom TD120 dx tweeter (93.5db)
2 Scan Speak 18W 8545K Midrange units (87.5db)
Focal Audiom 13VX woofer (89db)
Focal Audiom 15VX woofer (? most likely the same as the 13vX)
I'm not sure exactly which tweeters are used as the two rear-firing tweeters, but that is not important. what I am wondering about is how he is pairing the bass and midrange drivers together to get a sensitivity so high?! I imagine the midrange drivers are playing the same frequencies, so that should add 3db to the sensitivity in their range, from 87.5db to 90.5. It would also seem likely that the two bass drivers are working together as well, increasing their sensitivity to 92db. I'm guessing that since the X1's are ported that increases the sensitivity in that range too. I don't know how much though.
Is it possible to increase sensitivity anywhere in the crossover? I can't think of how that would be done, I only know how to use resistors to dampen my drivers.
I'm not actually trying to clone the X1's, I am just trying to get an understanding for how they function.
My sencond question is about power handling. In my speakers I am using a Vifa XG18 mid-bass driver as my Bass unit. They are listed as having a short term max power handling of 70w. In my sealed cabinet speakers they seem to move quite a lot at less than one watt of power. They seem to move most when I am listening to jazz and the bass player strums low notes. I understand they move the most at lower frequencies, but I just worry that they will break somehow. I don't really listen to music at high volume levels. I have my amplifier (Sony Str DB 780, rated at 100 wpc) playing at a maximum of -28db, and usually much less. I assume that 0db would be 100 Watts, but at -28db my amp should be putting out ~0.1953125 watts of power. Maybe I am just being paranoid, but I worry about my drivers! I would hate for one of them to exceed it's Xmax and ruin the voice coil.
There are still many holes in my knowledge of speaker building and techniques, so it wouldn't surprise me if some of what I have surmised here is incorrect, but hey, that's what these boards are for, right? I would appreciate any help you can give me! Just so this thread isn't just about questions, here is a picture the speakers that I made. They sound great!
Thanks,
Andrew
[IMGHTTPDEAD]http://www.andrewhasz.com/diy/top.jpg[/IMGHTTPDEAD]