RS-P WWMTM 3 Way underway ( pic heavy )

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

rpb , these are really smooth speakers !!! i feel fortunate to listen to them everyday ! :D

[rpb]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

Thanks for all your help rpb , i really do appreciate it ... a couple things that may have thrown you off . going back through all my measurements (and a took a bunch) i noticed that i mixed up the top vertical with 45* left , that would explain why up and down were so drastically different . also i'm not worried about the polarity , i've ran enough sweeps and have watched them jump together that i am confident they are correct , also i did a triple check when wiring ... yesterdays measurements got us and specifically Josh what we needed to see . we are now discussing what changes may be made ...

again Thanks
Mark

Well that explains it. Also, that's a very smooth off axis!

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

and in case y'all missed them from a few pages back here is a raw driver from 36" ...

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

Thanks for all your help rpb , i really do appreciate it ... a couple things that may have thrown you off . going back through all my measurements (and a took a bunch) i noticed that i mixed up the top vertical with 45* left , that would explain why up and down were so drastically different . also i'm not worried about the polarity , i've ran enough sweeps and have watched them jump together that i am confident they are correct , also i did a triple check when wiring ... yesterdays measurements got us and specifically Josh what we needed to see . we are now discussing what changes may be made ...

again Thanks
Mark

[rpb]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

Here's an example of the vertical nulls of my mtm at about 45 and 60 degrees. http://i1221.photobucket.com/albums/...3/vertical.jpg As you can see, there's a lot of cancellation going on.

The nulls should be the same up and down since the mids are above, and below the tweeter. If one of the mids was wired with the incorrect polarity, I suspect that they would add off axis vertically instead of cancel, and possibly fill in the dip that was expected. The speaker may very well still sound excellent this way, but it could sound different, and possibly a little better if corrected. I've had polarity mistakes that sounded really good. Mistakes in wiring happen. Liking the result is nothing to be ashamed of if it turns out that's happened. I've been fooled more than once, although I usually suspect something is off after listening for a while. The trend seems to be that the speakers sound more spacious, and have a little less defined center image, or the image may sound shilted slightly to one side. You can measure again indoors pretty easily. If no null shows on the upper measurement, I'd pull a mid, and swap the polarity just to see if that changes things for the better. If everything gets really off, then you can figure it was right before checking. I'd measure the other speaker before trying the swap. See if it has the same response vertically.

[Navy Guy]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

i do . Josh has taught me if it sounds right , it is !

I have a pair that I designed for a friend using the RS28a and the curve looks almost identical to yours. I also thought it sounded too bright without the additional padding.

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

i'm now running different test ... close to 100db with my choice of music ... i could stop now and be happy !!! ;)

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

though i could be out all day my laptop shut down from heat from being in the sun and running ..

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

I just saw the thread. The new measurement looks really good, but confirms what I was hearing. I'll send you the 200uf- 10 ohm zobel to correct the 220 hz peak on the woofer. The 25 or 30 ohm parallel resistor for excursion control on the mids will also smooth the knee at 1200-1500. Everything will install post-x-o, so it shouldn't be hard to add. We will change to the 1.2mH tap on the mid inductor. If we need to adjust the tweeter due to these minor changes, it will be less than 1/2 of a dB and will be done with a parallel resistor post-crossover also. I'll send you everything you need. I'm not seeing the drastic top-octave drop you had before. It doesn't look bad if you consider the scale- it's only 2dB down now, it was like 5dB before. Remember, I compensated for the rising response in the x-o already, so the most you should expect is flat. If the measured response is real-world and not a mic effect, we can just take a few turns off the 0.04mH coil. Not a priority right now.

thanks Josh , i gotta admit i'm a lil dishearten ...

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

You should also measure the other speaker while you're setup.

ouch !!! these are big and heavy and i just moved back in ...

[rpb]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

You should also measure the other speaker while you're setup.

[rpb]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

That's strange. (The lack of a vertical null.)

If the x-over is accessisble, I'd disconnect the tweeter, and measure the mids. Then disconnect the mids, and woofer, and measure the tweeter. Then reverse the polarity of the tweeter. You should have a null vertically. Try about 30 degrees instead of 45. Somewhere there should be a null. It could be tilted higher or lower than 45 degrees. Knowing where it is will tell you a little about the tweeter and mid x-over.

What does the on axis phase look like? The impulse looks odd with the peak going downward. Try changing the entire speaker polarity at the amp, and remeasure. Then post the impulse. Lower the gating till it just almost touches the first reflection. Maybe below 250 hz. It should show in the impulse if you show a wider range on the chart.

[jbruner]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

I just saw the thread. The new measurement looks really good, but confirms what I was hearing. I'll send you the 200uf- 10 ohm zobel to correct the 220 hz peak on the woofer. The 25 or 30 ohm parallel resistor for excursion control on the mids will also smooth the knee at 1200-1500. Everything will install post-x-o, so it shouldn't be hard to add. We will change to the 1.2mH tap on the mid inductor. If we need to adjust the tweeter due to these minor changes, it will be less than 1/2 of a dB and will be done with a parallel resistor post-crossover also. I'll send you everything you need. I'm not seeing the drastic top-octave drop you had before. It doesn't look bad if you consider the scale- it's only 2dB down now, it was like 5dB before. Remember, I compensated for the rising response in the x-o already, so the most you should expect is flat. If the measured response is real-world and not a mic effect, we can just take a few turns off the 0.04mH coil. Not a priority right now.

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

up 45* ..




down ...

[rpb]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

where do you wan to see them ?

On axis wiil look the same above about 300 hz. The vertical off axis will probably show more of a null. Look at the impulse to see how low you can set the gating. Probably about 250 hz.

Try taking some measurements from about 6' and see if anything changes. Might smooth out a little. Diffraction effects will vary with distance. If you measure about 10 degrees off axis to the side, it may change a little as well. Also measure approximately 30, 45, and 60 to the side. Just estimate the angle. This will tell you what is going to bounce off the side walls in your room.