Don Richard

The cost will have to come down on hybrids and electric vehicles before resistance to change by the public will vanish. There were small electric vehicles available 20 or more years ago but they were essientially modified golf carts that had about a 40 mile range. Of course, proper tire inflation increases the mileage/range of hybrids and electrics also.

I think the diaphragm for the T-35 and T-350 are the same. The T-350 has a larger magnet and horn lens but disassembly and reassembly is the same for both. BEC on this forum has diaphragms and rebuild services for K-77 (T-35) tweeters, perhaps he can chime in and clarify.

Because people like Robert Harley of TAS say that Khorns have "colored sound", whatever that means, and the lemmings follow the piper to the sea. I recently had the owner of a high end audio salon tell me the same thing, so I asked him if he had heard any of the newer horns to which he replied, "they sound the same". Funny, because exponentials, tractrixes, ind CD horns all sound different from each other to me. The new Palladium series fits the modern speaker design paradigm, so it might get reviewed by TAS. And I expect that they will say it would be better if the HF horns it uses were replaced by a Scanspeak Revelator tweeter, or a ribbon, or something (anything?) beside a horn.

It is better to vertically orient the MF & HF with the woofer for time alignment reasons. The sweet spot will be wider and the image will shift less if you move your head. If you have to locate the tweeter to the side, make the other box a mirror image.

www.audioroundtable.com/PiSpeakers/messages/13611.html At low frequencies we are not dealing with a simple 90 deg. trihedral corner. The ceiling also becomes a loading boundary, further constraining the radiation pattern at frequencies whose wavelength exceeds the ceiling height. Therefore, at those frequencies, <140 Hz for 8 ft,, it appears we are actually sitting in the horn mouth.

JBL lit on the 2380A says 100 deg +23, -23. It is >100 deg over most of its range, narrowing to <100 deg only in the top octave. That is also what the polar plots show. But the marketing dept. says 90x40 nominal. JBL is surely not the company it once was since becoming "Harmanized". They apparently can't even get their own specs to agree.

I have my Khorn system tri-amped. The greatest effect I observed was less lobing and a smoother sound throughout the room, due to the 24 dB/octave slopes. But one can accomplish that with passives at a lower cost. Time-aligning the drivers did make a clear (pun intended) difference. Transients such as drum hits come through with more realism and the system has a more coherent sound. IMO, polyamplification of Khorns is not worth the time or money unless you time-align the drivers.

The 2380 has 120 deg. horizontal polar response. This won't work well on a corner horn (too much hf energy hitting the walls). Then again, it doesn't look like you have to corner your setup.

Indy is a track designed over the years for 1500 lb. cars with over 4000 lbs. downforce. NASCAR "stock cars" weigh over double that and develop next to no downforce. The tires used in NASCAR are smaller than the tires on Indy cars. The result? The tires are overstressed and don't last 10 laps on that abrasive surface.[] But the show must go on. And on. And on. And on. I thought that race would never end.

The Founding Fathers of our great country, who ensured the opportunity for all of us to enjoy life.

There appears to be a typo in the JBL literature. I was looking at the horizontal polars plot, located immediately below the plot you referenced. On that plot, the scale jumps from 110 dB to 90 dB, instead of going from 110 to 100. Hmmm

Where are the acoustic center and acoustic origin of the tractrix horns? Is it astigmatic?

Amplifiers?

Could this be the source of the "bloom" spoken of by the audiophile press? The bass driver goes into power compression which reduces it's output, thus allowing the tweeter's output to "bloom", increasing the apparent "air" around the instruments. And they say this is a good thing.

This is why it is good to listen and compare equipment, particularly loudspeakers. Specs don't tell the whole story and reviews by others won't tell the whole story because you may value some characteristics differently than the reviewer.

Here's plans for a similar folded horn that is 37"W if laid on it's side. http://archives.telex.com/archives/EV/Speakers/EDS/Eliminator%20Series%20EDS.pdf

What are the dimensions of the K-402?

It is said that there is a sucker born every minute. Apparently the rate is much higher than that.

As power is applied in increasing amounts the voice coil heats, eventually to the point that it's resistance increases ind current into the driver is reduced, thus reducing it's output. This is called power compression, the degree of which is determined by the construction of that driver. One should not be running a driver into power compression - it is dangerously close to blowing at that point. Size the driver so that doesn't happen.

If you are not comparing a signal to another signal, or to a starting (reference) point, the concept of phase is meaningless.

If it is less than 180 deg. out of phase, when it gets to the ear it is a difference in amplitude. http://www.community.chester.pa.us/files/technote/polphase.pdf

Don Davis in the third edition of Sound System Engineering gives the whole story on this technique. Before TEF the front half was deadened as much as possible. When accurate measurements became possible it was found that selective application of absorptive material could be employed with good results. Further research using TEF resulted in the Reflection Free Zone (RFZ) technique. Russ Berger was a studio control room designer who developed much of this stuff.

You can. Some studios use the Live End Dead End technique - the half of the room with the speakers is dead which controls the early reflections. The other half is live and diffused which gives the room a pleasing sound. A room with excessive damping throughout the room can sound muffled in which case adding diffusers to the rear of the room can correct the problem. What you want to do is to avoid the early reflections - they cause time smear and compromise transient response. That is, if it is indeed the room causing the problem. If it is the speaker causing poor high frequency response, and it is operating properly, an EQ can be used to tune the speaker to taste.

Any speaker will sound the best in a room with the fewest problems. A room that seems bright is doing that because of reflected energy. Different frequencies will be reinforced or cut unpredictably. This condition tends to cause uneven frequency response, time smear and bad transient response. This could be caused either by the highs being reinforced or by the bass being reduced, and EQ doesn't do a good job of correcting this. Measurements should be taken to determine the exact cause which will point to the proper way to correct the problem.

The DRPA is a solid unit that should be reliable, as are all DBX products. However, it is not known for sonic excellence within the pro sound community. If you are looking for a unit to use at home the Behringer DCX-2496 would work better for that purpose. It sounds better, is cheaper, and there are many tweaks available to further improve performance.