JBL 2470 - are they superior to the K 55?

[tigerwoodKhorns]

DC Frequency = 0hz - lol. OK I should have known.

So will any capacitor work as long as it does not filter the signal sent to the tweeter at too high of a frequency.

Chris

[sunnysal]

I meant delay the tweeter and the mid a bit...mix up...I am glad others feel the same way I do, I did not mean to suggest anyone did not.

I think there is no doubt that I will be buying an electronic crossover with delay as soon as they are available with RCA plugs and expect consumer voltages at input and output. right now the only unit I can find with that setup is the clarity DEQX and I am a bit afraid of the room and driver correction interface. I am waiting for them to get into future, easier revisions of software before taking the leap. Tony

[sfogg]

Tony,

"I think there is no doubt that I will be buying an electronic

crossover with delay as soon as they are available with RCA plugs and

expect consumer voltages at input and output."

That really isn't all that big of a deal to work around on a pro unit.

My pre-amp could drive the Behringer to full scale on the input on its

own. On the output I just need to add some attenuation between the

crossover and the amps to drop the levels down. I could have just used

the input level adjustments on the amps but I wanted to get them

matched exactly between the three amps.

Shawn

[Deang]

It's been a while with these in the system -- it sounds good, but I'm tired of riding on the edge with them and not knowing what's going on as far as loading and distortion goes.

Chris -- did you ever put the 2470's you bought into your Klipschorns? If not, would you be willing to send one to Al so we can get some distortion measurements? I'll cover all shipping expenses.

[Deang]

Most here know the following, but I'm going to drop it into the thread anyways:

"A compression driver depends upon the acoustical coupling of the horn for it to operate properly. The reason that compression drivers are called compression drivers is because, when the diaphragm moves, it compresses the air in front of it. There has to be a certain amount of acoustical impedance, or resistance, provided by the air in the throat of the horn for the diaphragm to push against. This acoustical loading is designed into the horn, and every horn has a specific low frequency cut-off point, below which that loading characteristic disappears, or is greatly reduced. Sometimes this is referred to as the usable low frequency limit or, more accurately, lowest frequency for full driver loading. That frequency can be determined best by referring to the manufacturers specifications for the particular model of interest. If the horn and driver are operated at frequencies below that point, then the diaphragms movement is no longer limited by that acoustical resistance."

[tigerwoodKhorns]

It's been a while with these in the system -- it sounds good, but I'm tired of riding on the edge with them and not knowing what's going on as far as loading and distortion goes.

Chris -- did you ever put the 2470's you bought into your Klipschorns? If not, would you be willing to send one to Al so we can get some distortion measurements? I'll cover all shipping expenses.

Dean,

They are sitting in a box unused and will be for a while. I tried so hard to get these things shipped to AL and it just didn't happen. I don't mind shipping to AL if you want to ship them there. I'll send the both if he wants to listen for a while.

But are you sure you need to worry about this? In my experience as an engineer, there are not many "brick walls" and most everything has a rolloff or taper zone (except for real brick walls). I know that you are aware of this. The other thing is that these are really heavy duty drivers. They look like they are designed for abuse they will never see in a home system (well, except maybe for Deaf Jeff).

In any event, I can send them if you like. Email me. I wouldn't mind getting some testing done and I am curious about Al's impressions of them.

Chris

[Deang]

"I don't mind shipping to AL if you want to ship them there. I'll send them both if he wants to listen for a while."

We really need to nail down its behavior on the K-400/401 and the Trachorn. It's a very good sounding driver, but it would be nice to have confirmation that it's loading properly and that distortion is within acceptable limits.

I took my Klipschorns back in time Friday and dropped my K-55-V's back in. I've been telling people that the move to the driver wasn't anything near as dramatic as moving to the Trachorn -- I probably shouldn't have been doing that. Sometimes going backwards can tell you quite a bit about what you have. I used to do it with the RF-7's constantly -- dropping the stock networks back in to compare to what I was doing. I have no idea why I didn't do it in this case until now.

".. are you sure you need to worry about this? In my experience as an engineer, there are not many "brick walls" and most everything has a rolloff or taper zone (except for real brick walls)."

The RTA shows response is down a bit at the low end. Because of this, I'm curious about the loading and distortion. I don't hear anything objectionable, on the contrary -- it sounds excellent. However, I'm worried!

"In any event, I can send them if you like. Email me. I wouldn't mind getting some testing done and I am curious about Al's impressions of them."

Will do.