Speaker hookup question

Those little speakers take 350w??? Is that peak? Not very efficient either at 88dB but you have been running them no problem so they must sound pretty darn good. What are you using for a sub Fred?
 
I know when Blackie was a Quasi, she did not like Infinity Quantum 5's at all when you started to move the volume up to high levels, it would blow fuses left and right
 
Northwinds said:
Those little speakers take 350w??? Is that peak? Not very efficient either at 88dB but you have been running them no problem so they must sound pretty darn good. What are you using for a sub Fred?
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I originally had the 5.1 system years ago but didn't like the other speakers. Loved the front left / right though and bought a bunch off ebay cheap. Woof is Klipsch 12" with the funky gold cone. Also a photo of the bookshelf stacks. Canted out as they have a dipole speaker in the back that bounces off the wall. Hopefully no earthquakes around here.

20170418_210526456_iOS.jpg20170418_210711392_iOS.jpg
 
Whether they could really take 350 watts without melting down, no idea. Never pushed them that hard.
 
You could test the 350 watt limit with your 400, it'll do 350 into 4 ohms I'm sure. Pretty sure the speakers will give up the ghost well before 350 watts. Manual says power requirements 50-350 watts. I don't think that means they can literally handle 350 watts. If signal was at 60 Hz am guessing they would break mechanically as well.
 
Gibsonian said:
You could test the 350 watt limit with your 400, it'll do 350 into 4 ohms I'm sure. Pretty sure the speakers will give up the ghost well before 350 watts. Manual says power requirements 50-350 watts. I don't think that means they can literally handle 350 watts. If signal was at 60 Hz am guessing they would break mechanically as well.
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I expect Lee would give it a go just to see if he could catch the voice coils on fire.
 
Northwinds said:
I know when Blackie was a Quasi, she did not like Infinity Quantum 5's at all when you started to move the volume up to high levels, it would blow fuses left and right
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Ron,

Your post got me to thinking.

I am not sure if you or some of the other folks out there have seen the Phase Linear 400 and 700B service bulletins that were issued on the "Infinity Quantum Line Source Speakers...." or "Infinity Speakers with Watkins woofer System". These service bulletins came out around 1980/1. (See attached pdf's.)

Decades ago, I first began replacing the older slower output transistors (FPL, and XPL series transistors) with newer faster MJ15024's. One day Dean showed me on a 400 series 1 amplifier how the older devices when being driven into a 4 ohm load into clipping above 8KHz would blow the fuses and the MJ15024's would not. He then began to explain to me common mode conduction.

Anyway, since these earlier amplifiers were quasi comp amps, my guess is that either the Infinity's were causing your problems or you were driving the amps into clipping into a 4 ohm load above 8 KHz (with the older slower output transistors which were common in the quasi comp amps).

It is interesting to note that the later 400 and 700 series II service manuals did not include any information about the Infinity's. Perhaps either Infinity fixed the problem on their end or there was some design change in the Phase Linear amps that prevented any issues when driving the Infinity's. Perhaps Joe has a thought or two on this?

Ed
 

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FredR said:
I expect Lee would give it a go just to see if he could catch the voice coils on fire.
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Fred,

Years ago (in 1981) after I quit doing sound for a Seattle band named Child, I turned my neighbor Steve onto doing sound for them.

I went to one of the shows to see how Steve was doing. Steve indicated that Jeff (the drummer) loved the way the bottom end sounded. I commented that I thought he was pushing the woofers a little too hard. (NOTE: The system Child was using was formerly part of the Heart P.A. system.) Some of the members of a band Steve formerly did sound for were also in attendance and on the dance floor at the time. The next thing I see is some smoke up near the ceiling next to the PAR lights which I had seen on occasion before (when a PAR light went out) and didn't think too much of it at the time. Right after that I look down and see FLAMES coming out of the (4) 15" woofers cabinets. Steve rushed to the back of the nightclub to grab a fire extinguisher. By the time Steve got back the flames had gone out. Fortunately the insulating material in the cabinets were flame retardant.

This same P.A. system also caught fire when Heart was using it (if my memory serves me correct) ---> in Portland Oregon (maybe Sept 2, 1978 at Portland International Raceway- Portland Jam '78). If my memory of the conversation with my friend Greg is correct, it happened during the performance of Barracuda as Mike Fisher had been holding back on going all-out until then. The audience thought it was part of the show. In this case it wasn't the 15" woofers that caught fire but instead a bunch or CTS 4-1/2 SR10-B upper mid-range drivers. It was a line-array Hi-Fi P.A. system. Long before line array P.A.'s became popular. It was discovered later that CTS had sub-contracted out some of the work on these drivers and some came with paper voice coils and others had aluminum voice coils. The ones with paper voice coils caught fire and the ones with aluminum didn't. After much wrangling with CTS and damage to my friends reputation all he got out of it was some replacements. If anyone out there has any photos of this show in Portland I would love to see them.

This video of Heart performing "Cook With Fire" may be from Portland Jam '78:
https://www.youtube.com/watch?v=ov1glkGWXgM
No FLAMES in this video. LOL!

Ed
 
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Hi Ed! I am not sure if the Infinity's had issues, they played great when they were not blowing fuses. Prior to Blackie, they ate a Pioneer Elite receiver but these speakers have long been know as amp killers. The Levinson never saw them as I had already sold it before I got the Q5's (Levinson was driving Infinity SM-150s). The Q5s are long gone now, way to heavy to ship so I just parted them out. I think I still have the grills and badges (somewhere)
 
I had a set of RSIIIb's that were hard on the 700 series II I had at the time. I'm thinking they were 4 ohm speakers. The only speaker protection I had was inline fuses that the instructions said would be wise to install. Thank God they worked!
 
I've seen it, to a lesser degree. My friend was running a college dance with a quad of Marantz HD880(?) from an Onkyo amp and I notice one had a smoking woofer. I pointed it out and he calmly walked over and disconnected it, finishing the night with three speakers.
 
laatsch55 said:
I expect Lee would if it would answer a question or two...
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Gotta break eggs to make omelets. What is it you said once Lee? You blow em up so we can't.
 
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Thinking a little Crown had some influence on your decision at that particular time...
 
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