The rest of the comments are so far down the page I am starting a new one.
Thanks to everyone for coming and making it a fun event. These things don’t happen by themselves, so kudos to:
Bob for all the test equipment and switch boxes
Darren for the PE support and set up support.
Dennis for the snacks. Very good.
Brian Smith for the Woofer tester demo.
My wife for cleaning the house and letting it happen.
Everyone else who helped and brought stuff!
Hope I didn’t miss anyone.
Thanks!
My take on the demos:
1. The amplifier power demo was very interesting. I was pleased my Denon POA-2400 pulled the duty well. I wish I had yanked the Bryston out of the HT to check it alongside the others. I have always been one who thought that all you really need is a real 60 watts of power. Now I have to rethink this. As someone once said, “If you are going to maintain prejudices, it is best to rearrange them occasionally.”
Seeing the peak voltage pass 70 was absolutely amazing and the sound level and was not killer loud (but well above my normal listening level). The 40 volt (100 Watt) level was just not that loud. The average level was usually under 5 volts, rarely over 10 volts. It was interesting that the orchestra spectacular in the basement room clipped the Crest 300 a couple of times. Again, it was not *that* loud.
The speakers under test use the Peerless 850122 7” in a 24 liter box. The fb is about 40. The tweeter is a Seas H400 metal dome. The napkin calculation says this is an 85-86 dB sensitivity speaker. I don’t have an actual measurement. These speakers were setup in the room for the resistor test but they were used for the amp test as well. The speakers were selected because the crossover is in the 2500 Hz range and they tend toward the bright side. They measure almost dead flat, too bright for my tastes. In my mind, this is proof that sometimes a speaker which measures well does not sound that great to me. But a lot of people like them: “very revealing”. The amp was a Denon POA-2400 from about 1990. This *is* “your fathers” amplifier and nothing like the stuff Denon produces today. Another amp kudo was when we were setting up and touched some wires and the amp shut down. We thought for a moment the show was over, but the reset button brought it back. I know a lot of people would say “so what”, but I have seen too many amps give up on goofs like this.
A second part of the amp test was listening to the kit amp someone brought (I know who you are, but will withhold name). The amp was a gain clone rated at about 100 watts. We hooked it with the expectation that a good kit amp would run with the big boys and sound great. Right off, I thought the bass was recessed and it was not as loud as the Denon. We hooked up the power measurement and retested. The amp would not move past 32 peak volts in places the Denon would pass 60 volts. The more you turned it up past 32 volts, the harsher the highs got and the more recessed the bass. It took us a while to realize that was the total output and the rest was clipping. This was a much larger amp than most of us use on our HT or bedroom systems, yet it easily exceeded its limits.
The test music was RLJones Flying Cowboys track 3. This track has some mean snare drum peaks while the rest of the song is at a much lower level. That is why we were not driven out of the room at those levels.
2. The resistor test was about that same as all the other tests we have done on crossover components. Bob and I decided not to record results unless someone came forward and claimed to hear a difference but nobody did. I sometimes thought I could hear cleaner highs on the red side, but I know if the test were randomized, I would fail. The message here is that AB is really hard. If we knew which resistor was which, our brains jump to that side and we think we heard things. But the moment the test goes blind, it is really hard. For me, that is the core message; that AB blind testing is hard. I think if I set up something really obvious, it would still be very hard in a blind test. But I am no longer paying extra for expensive resistors.
Hey Bob, which color light had the good resistors? Time for all of us to say, “I knew it!”
3. The Linkwitz Pluto was an interesting and gutsy design. It sounded pretty good in the near field sweet spot but not so great beyond that. I am OK with this because I feel that if a speaker is designed for near field, than we should not criticize it in other conditions. Near field, it sounded a lot like headphones.
4. The woofer tester was a good tool and well thought out. I would like one someday. Thanks Brian!
5. The Dayton RS driver designs really came off well. I was worried about my unit as I really did not have time for a long audition or adjustments before the event. But people seemed to like it and I agree it needs just couple of dB drop in the 1000Hz area. Both the Dayton RS units really had a detailed lower section and a better separation of instruments. These drivers are very good.
6. Another interesting part of the day was ABing speakers. Bob’s AB level-matching preamp really helped with this. Being able to AB speakers, move them to the measurement station, back to he AB room, was quite an experience. Once one got the levels matched, many of the better speakers became simply different and not better or worse. This drives home the idea that a speaker has to be matched to the room and system. I cannot honestly say which of, say four, speakers were “best”. They all sounded very different but I would have to live with them to decide if I like them. We knew this heading into this experiment, but it is great to prove the theory.
Other threads on this topic:
http://www.pesupport.com/cgi-bin/config.pl?read=223785 trip report
http://www.madisound.com/cgi-bin/discuss.cgi?read=345303 Amp power testing
http://www.madisound.com/cgi-bin/discuss.cgi?read=345233 trip report
P
