Hi all, 1st post here. Got a nice pair of refurbished 2805s from Kent, about three months ago. Really opened my world. I've have many decent dynamics in the past, meridian, bw and focal be, but this is it for me.
I use mainly a pair of 6 foot stereovox speaker cables, but I bought a pair of audioquest rocket 44 a while ago, never really liked them. There have been two major incidents, the only ones since I own my Quads.
1st one, I decided to give a chance to the neglected audioquest rocket 44s, which I hadn't really tried with the Quads. I did NOT turn the speakers off and proceeded to swap cables. Soon enough I noticed a lot of distortion, kind of what happens when a voice coil burns in a woofer. Something akin to putting a piece of paper on top of a snare drum. I freaked, turned them off and called Ken. Ken was patient and explained to me at length about the protection circuit. After turning them on again, they seemed fine, but there was a channel imbalance. Turned them off for a night. Came back to them and all was fine. Replaced stereovox cables and no issues.
I read some stuff online about the mogami coaxial cable being really good for Quads purportedly because of the capacity issues, etc. Not my field. I ordered a pair. Hated them but hooked them up upstairs in another system playing mostly npr all day, to burn in.
2nd episode. Just yesterday, I spent some time listening and decided that it was time to try the audioquest cables again, since I never seem to like them. I listened to some variety of stuff and then, the firebird suite from reference recordings, which has ridiculous DR. Sure enough at the 1st bass drum hits, right speaker shuts off and the voltage meter on my Pass xa 30.5 swings wildly to the right. I had never seen this. I freaked out again. I called Kent again and once again he explained all that stuff about DR and protection. But this time he sort of warned me about possibly perforating the panels once protection is activated too many times. So gave them a break for a few minutes and listened to something else. Again, the image drifted to the right with a difference of two notches on the balance control.
My questions,
Could this possibly had happened because of the cable? I am aware of Peter walker's opinion, but those audioquest cables seemed to be destabilizing to the Quads, twice. I know that playing that stravinsky pushed them too hard, but I generally had not experienced this kind of failure before.
It seemed like the protection lingered to the point that there was a channel imbalance. What is the right amount of time needed for them to come back healthy sounding?
The speakers seem fine now, but I am so paranoid about damaging them that I am considering crossing over and adding a subwoofer. This is not the way I want to go, but I also do not want to crate them back to Kansas anytime soon. Do you have recommendations for an economical xover and sw combo?
Thanks anticipated for your help.
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I use mainly a pair of 6 foot stereovox speaker cables, but I bought a pair of audioquest rocket 44 a while ago, never really liked them. There have been two major incidents, the only ones since I own my Quads.
1st one, I decided to give a chance to the neglected audioquest rocket 44s, which I hadn't really tried with the Quads. I did NOT turn the speakers off and proceeded to swap cables. Soon enough I noticed a lot of distortion, kind of what happens when a voice coil burns in a woofer. Something akin to putting a piece of paper on top of a snare drum. I freaked, turned them off and called Ken. Ken was patient and explained to me at length about the protection circuit. After turning them on again, they seemed fine, but there was a channel imbalance. Turned them off for a night. Came back to them and all was fine. Replaced stereovox cables and no issues.
I read some stuff online about the mogami coaxial cable being really good for Quads purportedly because of the capacity issues, etc. Not my field. I ordered a pair. Hated them but hooked them up upstairs in another system playing mostly npr all day, to burn in.
2nd episode. Just yesterday, I spent some time listening and decided that it was time to try the audioquest cables again, since I never seem to like them. I listened to some variety of stuff and then, the firebird suite from reference recordings, which has ridiculous DR. Sure enough at the 1st bass drum hits, right speaker shuts off and the voltage meter on my Pass xa 30.5 swings wildly to the right. I had never seen this. I freaked out again. I called Kent again and once again he explained all that stuff about DR and protection. But this time he sort of warned me about possibly perforating the panels once protection is activated too many times. So gave them a break for a few minutes and listened to something else. Again, the image drifted to the right with a difference of two notches on the balance control.
My questions,
Could this possibly had happened because of the cable? I am aware of Peter walker's opinion, but those audioquest cables seemed to be destabilizing to the Quads, twice. I know that playing that stravinsky pushed them too hard, but I generally had not experienced this kind of failure before.
It seemed like the protection lingered to the point that there was a channel imbalance. What is the right amount of time needed for them to come back healthy sounding?
The speakers seem fine now, but I am so paranoid about damaging them that I am considering crossing over and adding a subwoofer. This is not the way I want to go, but I also do not want to crate them back to Kansas anytime soon. Do you have recommendations for an economical xover and sw combo?
Thanks anticipated for your help.
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Thanks Max. Definitely, the behavior seemed to indicate it. The problem however, seems to be a little more complicated and I think I finally got to the bottom of it. I contacted some people, including one of the good guys here. After some backtracking and analysis of the past two months, it seems like, because I have been preparing my listening room by adding damping material on the walls, the room has become pretty dead, therefore leaving me wanting more sound. By raising the volume more than necessary, I have been clipping my pass labs 30.5. It didn't happen before because the room was completely untreated when we moved to the house (which we recently bought). I removed some damping material and moved the speakers closer, in near field position, almost. All seems good, but I feel like the amp is underpowered for the Quads. It drives my focal electra really well, however. I was worried that I had damaged the speakers, but briefly connecting my rogue pharaoh class D amp proved that the speakers are fine. At this point I am contemplating adding a sub to alleviate the load for both speakers and amp.
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Kent rebuilt a pair of ESL63 for me. With the Quad 909 amp, there's considerable bass response. I use an ancient run of Kimber Kable 8tc, and have done with three different amps.
With an amp built to handle their gyrating impedance, with them raised 12" off the floor, with them far enough from the rear wall to propagate a back eave, your 2805 shouldn't need help.
Have you run this by Kent? He will know a practical solution.
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With an amp built to handle their gyrating impedance, with them raised 12" off the floor, with them far enough from the rear wall to propagate a back eave, your 2805 shouldn't need help.
Have you run this by Kent? He will know a practical solution.
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I wonder if a 'test run' with something plain might be in order?
https://www.bluejeanscable.com/store
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https://www.bluejeanscable.com/store
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I'm not. I'm a happy hobbyist. I use Kimber 8TC to drive my Quads. I suspect the instability described stems from capacitance.
The BJC suggestion is basic, and a fair value.
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Pedro,
Good to hear your Quads are fine. Have you tried contacting Pass Labs about
this issue? ( service@passlabs.com ) They probably would be interested in
your experience. (Must have been some serious current draw for the meter on
the XA30.5 to swing wildly to the right)
Cheers,
Dennis
Good to hear your Quads are fine. Have you tried contacting Pass Labs about
this issue? ( service@passlabs.com ) They probably would be interested in
your experience. (Must have been some serious current draw for the meter on
the XA30.5 to swing wildly to the right)
Cheers,
Dennis
Thanks, I spoke with Kent McCollum, as well as Sheldon plus Mark from Reno HiFi. We came to the conclusion that I overdampened the room with acoustic material and trying to unconsciously make up for it, drove the amp to clipping. I ordered an svs sw and this should lighten the load for both amp and speakers. The AQ rocket 44 have destibilized the setup twice, but it was one element amongst others. Right now, there is no bass and don't really like the sound. Really need the sw.
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Your space appears half again larger than mine. I'm curious as to how you determine if the playback level is correct.
I try to attend live performances and get string bass recordings 'close'.
I added a DSPeaker 2.0 in parallel to my
preamp, to drive a few subs distributed around my room.
My Quads run full range, without additional crossover. It isn't often that the subs add much to the mix.
Personally, I don't like to have panels in line with dipoles; I want the backwave to freely propagate off the wall farthest from me to pressurize the room.
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I try to attend live performances and get string bass recordings 'close'.
I added a DSPeaker 2.0 in parallel to my
preamp, to drive a few subs distributed around my room.
My Quads run full range, without additional crossover. It isn't often that the subs add much to the mix.
Personally, I don't like to have panels in line with dipoles; I want the backwave to freely propagate off the wall farthest from me to pressurize the room.
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Last edited:
Thanks for the heads up. I did remove most of the the panels behind the speakers and gained some bass and volume back. It's starting to feel much better. I only added behind the speakers because it seems that everyone suggests to do so, to minimize standing waves and improve imaging. I think I am making progress. I might actually have a pair of canare cable somewhere. I also have a short run of mogami coaxial that I bought based on recommendation, but I did not like at first. It's on a secondary system getting "burned".
Any opinions on the mogami coaxial speaker cables?
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The Mogami line is excellent quality. I had an extension for my Headphones made with their Quad core.
You should be aware that you are devoting more money to our hobby than I can consider; so my choices may appear cheap in comparison.
I like the previously mentioned BJC products because they will make interconnects to any requested length.
My hearing is no longer so acute that I can make fine distinctions beyween cables. I can hear gross distortions and smeared timing from secondary reflections.
If you attend to Kent's suggestions, you'll get the best possible results.
I know I did.
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You should be aware that you are devoting more money to our hobby than I can consider; so my choices may appear cheap in comparison.
I like the previously mentioned BJC products because they will make interconnects to any requested length.
My hearing is no longer so acute that I can make fine distinctions beyween cables. I can hear gross distortions and smeared timing from secondary reflections.
If you attend to Kent's suggestions, you'll get the best possible results.
I know I did.
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The protection circuit most likely kicked in after he arced a panel. The 63's and later have an antenna and crude receiver consisting of an inductor and rectifier which turns on a transistor which triggers a 555 based one-shot. This one shot turns on a TRIAC which shorts the input of the speaker.
The input consists of a 220uF cap in parallel with a 1.5ohm resistor. so at frequencies above DC, the input is damn near a short. That's why the meter on the amp was flying to the right. There is a polyfuse that should trigger and disconnect the input from the rest of the speaker. However when hit hard, I've seen the TRIACS fail before the polyfuse can kick in. The speaker will play very quietly after that.
What happened to these quads and that PASS amp really sound to me like you've overloaded the speakers and the protection circuit kicked in. Not that the amp couldn't handle the Quad's load.
Sheldon
quadesl.com
The input consists of a 220uF cap in parallel with a 1.5ohm resistor. so at frequencies above DC, the input is damn near a short. That's why the meter on the amp was flying to the right. There is a polyfuse that should trigger and disconnect the input from the rest of the speaker. However when hit hard, I've seen the TRIACS fail before the polyfuse can kick in. The speaker will play very quietly after that.
What happened to these quads and that PASS amp really sound to me like you've overloaded the speakers and the protection circuit kicked in. Not that the amp couldn't handle the Quad's load.
Sheldon
quadesl.com
(30W class A, beyond class A a whole lot more than that. Not driven to clipping, but overloaded)
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Who's speakers arced? Yikes, I hope not mine!
Today was a good day. I removed more foam tiles and messed with back and forth movement in relation to the walls. There was a hole in the mid bass that was driving me nuts. I think I got a sweet spot. Further careful testing yielded decent volume, better bass (almost too much in some cases!) and no sign of weakness, although I am not ready to test that. Sound levels are satisfactory for most orchestral music and definitely vocal, pop. I played a few LPs, CD and my roon/microrendu /mytek setup. Sound is glorious, as I remembered.
As if it wasn't enough, I discovered that my stereovox colibrí xlr interconnect that goes from preamp to amp, has a tendency to loosen itself out of a secure connection and this explains the channel imbalance. When it rains it pours. I should be getting the svs sb13 on Thursday.
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