How to best use REW to balance drivers

I just finished taking a new set of readings after visually making sure the woofers were properly wired. I made a few runs with the mic within a foot of the drivers, but I could never get a decent reading of the woofer performance relative to the entire speaker, so I moved the mic to about 3 feet back at tweeter and mid height, on axis. I will post some of the graphs, but also uploaded the entire REW file in case you have time to download it and play with the actual readings. The file can be found here http://prontoweb.com/rew/ and I would appreciate if you could help me determine the proper mid range setup for my system.

After my readings I am even more confused about the 'correct' polarity setup of the JBL driver vis a vis the woofer and tweeter. As I mentioned in previous comments, JBL says the driver is 'reversed' when compared to modern standard wiring due to the old JBL standard. So, I have set it up with + on the crossover to - on the driver and vice versa. I call that reverse polarity in my plots. The standard reference is + to + and - to -.

Here go the various plots:

Drivers only:

This is all three drivers with the JBL driver wired in standard configuration + to + etc. This graph looks correct to me when compared to the next one where I have the polarity reversed. This is why I am getting confused. The dark green line is the full spectrum graph.

This one shows the full response superimposed on the drivers but with the polarity on the JBL reversed, that is + to - etc. The Orange line is the full spectrum.

Finally, this one shows both full spectrum results with the JBL reversed in Orange and Standard in Green. I really would appreciate your suggestions. Thank you very much for your interest and time.

laser188139 said:

Neat, Rudy.

I am by no means an expert. Most of the advice I've seen on the internet as regards phase recommends that whatever sounds stronger is correct. As the green line meets this criterion and appears smoother, I would choose it. Does the transition from woofer to midrange sound smoother, too?

I made this suggestion because I have read the same thing about the CT125 tweeters. Someone pointed out on the Klipsch forum that the driver manufacturer documented the driver as having inverse polarity. Yet most appear to connect them normally. So I figured I would have to hear and measure them both ways to reach my own conclusion.

Taking the documentation on the ALK site as correct, that the low crossover is at 400Hz and the high crossover near 6kHz, it looks like the midrange is set nearly the same level as the woofer. I assume this is all with Audyssey equalization turned off, and the response will be smoother after equalization.

Bill

Click to expand...

Bill: I am having to revisit the whole polarity issue driver by driver. I have always hooked up the tweeter in standard manner, but need to see what the deal is with the tweeter. I have the mid level pretty well taken care of, and am just looking at the polarity issue. The woofers, btw, are Bob Crites woofers. I am in agreement with you that the green line, that is polarity in normal configuration, seems smoother in the transition. I hope Bruce chimes in and shares his wealth of knowledge on my issue. I just am not familiar enough with REW yet to properly interpret the data. That is why I made the original file available. I'm hoping Bruce or a more expert person can help me with some sage advice.

Yes, this was all with Audyssey bypassed. The plots with Audyssey on are amazingly flat! That was what convinced me that Audyssey does what it says it does. I don't even have the professional version of Audyssey, just 8 measurement points and it does a great job for the sweet spot.

I will upload it to the web site

Click to expand...

I looked at your new mdat (taken with calibration files) and I would say that the wiring of the JBL in the plot called Full range would be your best method.

The response called FR rev polarity shows a cancellation that would indicate the woofer and JBL are out of phase at the crossover.

If two signals are in phase as they cross (just like a subwoofer and mains at the crossover), the resulting signal should be about 6dB higher. If I look at your mdat and do some gating, and show them with an expanded axis at the crossover of the woofer and mid JBL driver, I would say the response that you call Full Range (green trace in the first jpg below) could be considered a classic 6dB mix, and the correct polarity. The second jpg shows a dip around the crossover (blue trace) and I would consider it the incorrect wiring of the driver.

Correct crossover

Incorrect crossover

brucek