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Post by gus4emo on Jan 22, 2019 22:45:51 GMT -5
Hi all, so about a year ago I bought a pair of DefTech SM55 50% off from Crutchfield, I like to play them loud but not deafening, last November the woofer on the right speaker started rattling, was replaced by warranty, last weekend the woofer on the left speaker started rattling but this time the XPA7 went on protection mode, I could see the left channel light blinking, I turned the whole system off, unplugged everything, plugged everything back in, all electronics back to normal, I called Crutchfield, will replace the woofer under warranty, my weird thing is I switched the speakers to HSU MK2, play them as loud but they have no problem, even connecting an old pair of Bose 301s and pushing them hard still no problem, hence my question, is the XPA7 killing my SM55? OR, the pair SM55 I bought at half the price might already had issues, remember, tweeters are fine, and all speakers in the system, stereo or home theater are cut off at 80, thanks in advance for your feedback.....
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Post by donh50 on Jan 22, 2019 23:50:56 GMT -5
I would guess you are simply overdriving the speakers (playing them too loudly). They have a 6.5" woofer plus a passive radiator. Bookshelf speakers often attenuate the tweeter to provide more extended bass response and match the woofer but heavy bass can easily overpower the woofer. Try setting the crossover to 100 Hz. Or different speakers.
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Post by gus4emo on Jan 23, 2019 11:36:48 GMT -5
I would guess you are simply overdriving the speakers (playing them too loudly). They have a 6.5" woofer plus a passive radiator. Bookshelf speakers often attenuate the tweeter to provide more extended bass response and match the woofer but heavy bass can easily overpower the woofer. Try setting the crossover to 100 Hz. Or different speakers. The woofer that was replaced on the right speaker is doing fine, I was playing Salsa music which is not bass heavy, now, the XPA7 puts out 520 watts per in stereo, I might use my XPA200 to power the SM55 at 150 watts per, what do you think? |
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Post by Ex_Vintage on Jan 23, 2019 13:19:59 GMT -5
DC bias coming from Pre-Amp?
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Post by gus4emo on Jan 23, 2019 14:33:04 GMT -5
DC bias coming from Pre-Amp? This is only affecting the SM55. |
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Post by donh50 on Jan 23, 2019 14:35:56 GMT -5
DC bias coming from Pre-Amp? Possibly... Could measure it, and at the output of the power amp for that matter. But all the other speakers survived. "Not bass heavy" is subjective, and remember with the crossover set at X Hz there is still a goodly amount of energy at 1/2 X and 2 X on either side since it does not instantly drop to zero past the crossover frequency. I used to be a tech and saw lots of blown woofers in bookshelf systems. Manufacturer's power ratings can be very optimistic at times... |
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KeithL
Administrator 
Posts: 10,272
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Post by KeithL on Jan 23, 2019 14:58:09 GMT -5
Our XPA amps will not pass DC.
If there was DC coming from the preamp it would be blocked at the input. And, if there was DC coming out of the amp, it would trip the protection.
Odds are the speaker was simply overdriven. As someone else already mentioned, power ratings on small speakers are often quite optimistic.
It's also well worth noting that power ratings for speakers are based on a lot of assumptions. Most speakers can tolerate relatively large amounts of power short term... Yet many will still eventually overheat if fed even a moderate amount of power continuously for a long time.
When you see power ratings on a speaker.... You should always read them as: "The size of an amplifier you can safely connect to the speaker, when playing normal music, if you exercise a little common sense".
DC bias coming from Pre-Amp? |
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Post by gus4emo on Jan 23, 2019 15:01:01 GMT -5
DC bias coming from Pre-Amp? Possibly... Could measure it, and at the output of the power amp for that matter. But all the other speakers survived. "Not bass heavy" is subjective, and remember with the crossover set at X Hz there is still a goodly amount of energy at 1/2 X and 2 X on either side since it does not instantly drop to zero past the crossover frequency. I used to be a tech and saw lots of blown woofers in bookshelf systems. Manufacturer's power ratings can be very optimistic at times... I love the sound of the SM55, when I get the speaker back I will turn down the bass setting, or cut them at 100 like you suggested......then again my curiosity, the replacement for the right speaker is doing fine..... |
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Post by gus4emo on Jan 23, 2019 15:03:13 GMT -5
Our XPA amps will not pass DC.
If there was DC coming from the preamp it would be blocked at the input. And, if there was DC coming out of the amp, it would trip the protection.
Odds are the speaker was simply overdriven. As someone else already mentioned, power ratings on small speakers are often quite optimistic.
It's also well worth noting that power ratings for speakers are based on a lot of assumptions. Most speakers can tolerate relatively large amounts of power short term... Yet many will still eventually overheat if fed even a moderate amount of power continuously for a long time.
When you see power ratings on a speaker.... You should always read them as: "The size of an amplifier you can safely connect to the speaker, when playing normal music, if you exercise a little common sense".
DC bias coming from Pre-Amp? Would it be a good idea to use the XPA200 to drive the SM55 instead of the XPA7? |
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Post by garbulky on Jan 23, 2019 15:15:03 GMT -5
Our XPA amps will not pass DC. If there was DC coming from the preamp it would be blocked at the input. And, if there was DC coming out of the amp, it would trip the protection. Odds are the speaker was simply overdriven. As someone else already mentioned, power ratings on small speakers are often quite optimistic.
It's also well worth noting that power ratings for speakers are based on a lot of assumptions. Most speakers can tolerate relatively large amounts of power short term... Yet many will still eventually overheat if fed even a moderate amount of power continuously for a long time. When you see power ratings on a speaker.... You should always read them as: "The size of an amplifier you can safely connect to the speaker, when playing normal music, if you exercise a little common sense".
Would it be a good idea to use the XPA200 to drive the SM55 instead of the XPA7? Actually which amp you use has little impact on how loud you would drive it. They can both push a large amount of power. The difference is the XPA-200 clips sooner (which is more unhealthy for the speaker if it does). Maybe ease off on the volume. |
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Post by gus4emo on Jan 23, 2019 16:30:55 GMT -5
Would it be a good idea to use the XPA200 to drive the SM55 instead of the XPA7? Actually which amp you use has little impact on how loud you would drive it. They can both push a large amount of power. The difference is the XPA-200 clips sooner (which is more unhealthy for the speaker if it does). Maybe ease off on the volume. Years ago I was driving Bose 301s at or higher volume for hours at a time, same XPA7, the 301s never budged... |
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Post by garbulky on Jan 23, 2019 16:42:04 GMT -5
Actually which amp you use has little impact on how loud you would drive it. They can both push a large amount of power. The difference is the XPA-200 clips sooner (which is more unhealthy for the speaker if it does). Maybe ease off on the volume. Years ago I was driving Bose 301s at or higher volume for hours at a time, same XPA7, the 301s never budged... I have no idea why your speakers failed. Perhaps it wasn’t because of high volume. I can’t think of a more likely reason though Maybe you need to send it in to get it checked out |
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Post by gus4emo on Jan 23, 2019 18:11:48 GMT -5
Years ago I was driving Bose 301s at or higher volume for hours at a time, same XPA7, the 301s never budged... I have no idea why your speakers failed. Perhaps it wasn’t because of high volume. I can’t think of a more likely reason though Maybe you need to send it in to get it checked out Remember, those woofers have double surrounds... |
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bootman
Emo VIPs 
Typing useless posts on internet forums....
Posts: 9,358
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Post by bootman on Jan 24, 2019 12:00:32 GMT -5
If other speakers at the same volume have no ill affects, why would you still think its the amp? That ins't logical. I blew a SM55 also years ago and it is still sitting in the basement. They are just too fragile of a speaker and I moved on. When orb audios can safely handle a X series amp and another speaker can't.....well you be the judge.  |
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Post by gus4emo on Jan 24, 2019 14:36:43 GMT -5
If other speakers at the same volume have no ill affects, why would you still think its the amp? That ins't logical. I blew a SM55 also years ago and it is still sitting in the basement. They are just too fragile of a speaker and I moved on. When orb audios can safely handle a X series amp and another speaker can't.....well you be the judge. What would you recommend to replace them with, I love the sound of the SM55. |
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Post by garbulky on Jan 24, 2019 15:05:04 GMT -5
If other speakers at the same volume have no ill affects, why would you still think its the amp? That ins't logical. I blew a SM55 also years ago and it is still sitting in the basement. They are just too fragile of a speaker and I moved on. When orb audios can safely handle a X series amp and another speaker can't.....well you be the judge. What would you recommend to replace them with, I love the sound of the SM55. What are the speakers do you have and have used and like |
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Post by leonski on Jan 24, 2019 16:12:02 GMT -5
First? Changing amps won't help. You (the OP) like it loud. You'll just keep turning it up, anyway. Damage to speakers is sort of 'cumulative'...that means every abuse Adds Up to a shorter lifespan for the speakers. Start listening around. Maybe get some Cerwin Vega, which are VERY durable and loud. www.cerwinvega.com/home-audio/floorstanding-speakers/xls-215.htmlWithin its limits, I'm sure its a very nice speaker. Learn to HEAR distortion.....which the ear is fairly insensitive to in the low frequencies. Work on building a system.....And a proper place to install it. I don't know how much $$ the Cerwin Vega is these days, but I'll bet you Can't Break It. |
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Post by indyscammer on Jan 24, 2019 16:19:49 GMT -5
I blew one of my Paradigm speakers I use for surround duty several years ago. Root cause was the wire soldered between the connector and the driver BROKE just from the movement/vibration of the cone. Speakers fail. It would be interesting to see what or how they fix it.
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Post by DavidR on Jan 24, 2019 16:35:12 GMT -5
My guess is defective voice coils or You may have bottomed out the voice coil and damaged the vc former and/or windings.
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Post by gus4emo on Jan 24, 2019 16:53:35 GMT -5
First? Changing amps won't help. You (the OP) like it loud. You'll just keep turning it up, anyway. Damage to speakers is sort of 'cumulative'...that means every abuse Adds Up to a shorter lifespan for the speakers. Start listening around. Maybe get some Cerwin Vega, which are VERY durable and loud. www.cerwinvega.com/home-audio/floorstanding-speakers/xls-215.htmlWithin its limits, I'm sure its a very nice speaker. Learn to HEAR distortion.....which the ear is fairly insensitive to in the low frequencies. Work on building a system.....And a proper place to install it. I don't know how much $$ the Cerwin Vega is these days, but I'll bet you Can't Break It. I'm thinking about replacing the SM55, but they're going to be bookshelves speakers. |
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