Don Richard

Thanks, I have read some of these papers and it's nice to get all of them in one place.

I think Roy had a lot to do with it.

I suppose a person could hook a good AC voltmeter to the unused speaker's terminals. Read the voltage then calculate the SPL using the reading as if it were the voltage from an amp. I have never done this but I suspect the SPL would be pretty low.

Are you running phase traces when determining frequency response? Different filter settings that yield the same frequency response will not have the same phase response. Phase response is a very important factor when aligning a system and flattening frequency response without considering phase will not give the best sound.

I would go with the Luxman. Even if it had problems and had to be repaired it would be better than the Chinese piece.

The big thing about the Belles is the beautiful cabinet. Otherwise, it is basically a LaScala. If the cabinet is rough that will diminish their value considerably. 800 to 1000 bucks is about what they are worth. Make him an offer if you still want them.

http://www.marchandelec.com/xm26.html

The electronics in an active analog crossover are connected to circuitry powered by DC. The audio signal, which is alternating current, rides on the DC from the power supply and does not pass through zero. The current passing through coupling and time constant caps is low. ESR is of little consequence in low-current circuits, but more important where current is high and goes through a zero crossing such as caps in a passive crossover.

If one uses a DSP crossover there is less chance a bad cap will shift the crossover point. A bad cap in the power supply would probably affect both channels, caps associated with one channel would affect that channel. Generally, digital either works or doesn't. ESR is a factor that affects passive crossovers. Caps in electronic crossovers have DC biasing the caps so ESR is less of a factor.

Live sound engineers like to keep the stage volume as low as possible so that most of the sound you hear is going through the PA. When the stage wash is too loud the vocal mics pick up sound from the instruments that have their own mics, causing interference. "Line arrays" seem to be taking over the arena concert sound industry. Two people can hang a 16 box line system in an hour or so and the array prediction software is fairly good these days. The problem I see is that these hangs do not work well if you are sitting up close. Most providers use front fills in that case, which are basically like the smaller PAs used in clubs. If the provider doesn't use front fills, or doesn't do them properly, coverage suffers. Line source performance in the far field is excellent, however, with all of the large line systems I have heard.

Nothing much a few miles west of Baton Rouge, just on and off rain for the last 2 days, about 2 inches, very little wind. Just had a shower, sun's out now.

AV receivers are not rated the same as stereo equipment. Stereo equipment is rated by the FTC standards which were introduced in the 70's IIRC. These standards were implemented as a result of shady manufacturers fudging their specs. FTC testing requires running the amps at 1/3 power on both channels for an hour prior to power and distortion testing. It is a stringent test. AV receivers are not tested to FTC standards and will not perform at the same performance level as a stereo amplifier. Some AV receivers offer FTC ratings for 2 channel operation, but I know of none that can output full power on all channels simultaneously.

This is related to other auditory phenomena such as the McGurk Effect. Sight can affect hearing by influencing the perception of auditory input. It is, however, an illusion.

I thought you were referring to PWK's power requirements paper where he said the numbers allowed for 10 dB peaks. He wasn't needing 10 dB for sine wave test signals now, was he? If good numbers from a test are what you want, you probably want to use pink noise or music for a test signal. A true RMS meter with at least 20-20K frequency response is necessary for accuracy.

Not true RMS, insufficient frequency response for audio use.

You would need a good digital multimeter, signal generator, a dummy load, schematics, and possibly an oscilloscope to troubleshoot the amp. In addition to the output devices, the protection circuit and/or power supply could have failed.

Peavey amps are easy to repair. Some of the musicians who use those amps repair them themselves. Usually the output transistors IIRC. The local Peavey dealer should be able to handle repairs or send you to a repair facility. Just about any competent electronic technician should be able to fix this problem.

In my room going from 4 ft to 8 ft drops the SPL by 6 dB. From 8 ft to 16 ft it drops 4 dB. It depends on room gain, and generally the larger the room the less the gain. Acoustic absorption also has the effect of reducing room gain.

PZM mics are nearly worthless for sound reinforcement.

That's some lousy soldering on that amp. I am not surprised that it has issues.

Guitar and bass amps are usually sitting on top of the speakers, which play much louder than home speakers. Microphonics would be a bigger problem in this application than with home hifi systems. Maybe the musicians swap tubes frequently?

If a person is listening to 1 watt average power, the amplifier will need to put out 20 clean watts to pass peaks undistorted. Don't forget every time the listening distance is doubled SPL falls by 6 dB. ! watt average power into a Khorn is 92 dB SPL 16 feet away. Don't forget to allow for more power if EQ is employed. A 3 dB EQ bump doubles power requirements at that frequency.

Which partially explains the crappy quality of recordings these days, if you are referring to studio engineers. If you are talking about FOH engineers and touring sound providers, then speaker system comparisons are perfectly valid because the PA is the original sound that one hears at a large concert. If you are talking about hifi magazine reviewers, I can't consider any of these to be any more than professional shills and literary prostitutes who should be ignored.

I have a feeling this guy would be very happy with the sound from a 1960s jukebox. He sounds like an idiot, and probably is an idiot. Whenever a person compares one speaker with another, you have to consider that person's listening experience and qualifications. This guy does not appear to have the necessary bona fides for me to pay much attention to him. He says the Khorn isn't good because it only goes down to 33 Hz. At 33 Hz the Khorn can output a higher SPL with lower distortion than any commercially available home speaker, with a 100 watt amplifier. My guess is that he likes distorted bass because he compares speaker to speaker, not speaker to the original sound.

The Yamaha SP 2060 has two direct digital AES/EBU inputs, . Not sure about the others I recommended.