Thinking similiar to Statement/Khanspires but ...

[Kornbread]

Placed the mic as close as possible; just off center of the phase plug on all drivers, and came up with this. Then let REW 'average the responses.'

Also, there were some peaks laying ~25db down on the woofer and mid. Changed some xover slopes/types/points and now there ~45db down.



And then got [email protected] meter. [email protected] (floor bounce?) but looks like the first reflections was closer to 3.3?



What I should do is blend the gated response with the nearfield woofer response plus port? How do you get an accurate measurement at the port when it's on bottom of the cabinet ... and it's bloody heavy?

After some playing around, here's @1 meter gated @3.3ms. It still sounds hot in the lower treble ... ▼see note below.▼



Learned something today. The cheap android tablet was adding hash to the lower treble. The laptop with normal quality Spotify sounds better than the cheap android tablet set to extreme quality. Listening to cd's using an older Marantz setup, and flac files from Foobar>external dac>aune preamp I 'think' the speakers sound more like what the graph looks like. Not awesome, but getting better.

[Kornbread]

I don't know what app you are using to measure, but try to change the vertical scale for the distortion measurements.
And if you measure at too low of SPL, you will pick up room noise that messes with things.
Shoot for 80-85 dB on axis at 1 meter level. That's quite loud, but it works better than a low level.


Wolf and filmslayer, I find that measuring HD higher at 90-95dB at a meter is better than lower.

Been measuring with REW (room eq wizard and one of PE's calibrated? mics) quite low, doesn't bother the AWA as much. I'll remeasure at a higher level ... when she's not around.


rpb, It's about four feet into a somewhat irregular ~22'x26' room with sloping ceiling; think upstairs loft.

---k---Your impulse response definitely doesn't look good. I'm guessing this is related to measurement gating. Bad measurements makes everything difficult.

I'd be interested in seeing the individual drivers frequency response before/after crossover.

Did you unibox the Paper drivers box sizes? I never have, so don't know if the paper need bigger boxes. Your boxes look so darn similar to mine, I don't know if you built differently from the original to accommodate the paper versions.

It be interesting to see off axis response and a overall power response to better understand the treble hot issue. Toeing in or out or room may alter your opinion.

Played around with channel delay and never gained much with the impulse response. Key word ... played.

Read Bagby's white paper on measurement technique, sorry guys, it's above my head. Learning guys, maybe someday ... Did figure out how to gate the response and how to find where the first reflections appear in the impulse response. Hopefully, the next graphs should be gated correctly.

Would the individual driver response be ok from the same @1m, on tweeter position, or explain what you'd like and how, I'll give it a shot.

Yes, I did unibox the paper and metal woofers. IIRC, they were fairly close. Will try and find that, and post later.

The outer dimensions are the same as the Statement II, but the mid's enclosure changes the internal woofer volume. To me, the paper woofers looked fine in the larger box, and the cut sheet sealed the deal. No matter how many times I do the math, measure, and cut, I always screw some part of that up. Sooner or later, I'll get the dimensions up.

[---k---]

Your impulse response definitely doesn't look good. I'm guessing this is related to measurement gating. Bad measurements makes everything difficult.

I'd be interested in seeing the individual drivers frequency response before/after crossover.

Did you unibox the Paper drivers box sizes? I never have, so don't know if the paper need bigger boxes. Your boxes look so darn similar to mine, I don't know if you built differently from the original to accommodate the paper versions.

It be interesting to see off axis response and a overall power response to better understand the treble hot issue. Toeing in or out or room may alter your opinion.

[filmslayer]

I don't know what app you are using to measure, but try to change the vertical scale for the distortion measurements.
You want to focus on -40 to -60 dB down from your main frequency response line.
I think your distortion is OK, but it's a little hard to read.

And if you measure at too low of SPL, you will pick up room noise that messes with things.
Shoot for 80-85 dB on axis at 1 meter level. That's quite loud, but it works better than a low level.

i agree ... all my work with the RS family shows the paper cones to be in the -50 to -55 db 3rd HD . the aluminum versions just slightly better at -60 .

[Wolf]

I find that measuring HD higher at 90-95dB at a meter is better than lower. This offsets the noise floor substantially, but not all drivers can do that level in applied design.

Later,
Wolf

[rpb]

If you are listening to the speakers near a wall, try increasing the mid, and tweeter level about 3 dB.

[donradick]

I don't know what app you are using to measure, but try to change the vertical scale for the distortion measurements.
You want to focus on -40 to -60 dB down from your main frequency response line.
I think your distortion is OK, but it's a little hard to read.

And if you measure at too low of SPL, you will pick up room noise that messes with things.
Shoot for 80-85 dB on axis at 1 meter level. That's quite loud, but it works better than a low level.

[Kornbread]

i looked real quick and didn't see , what tweet did you go with ?

xt25tg30-04, had a new pair laying around.

Distortion decreased.

Before,



and after.

[filmslayer]

i looked real quick and didn't see , what tweet did you go with ?

[Kornbread]

Haven't had much time lately, but finally got around to stuffing the mid enclosure with denim, added a layer to the front panel of the bottom woofer, which was bare, and to the top panel of the top woofer. From what I could find, denim and mineral wool have nearly the same absorption properties and prices are also comparable. http://www.soundproofingtips.com/sou...ng-insulation/ Went with denim.

It will take some time before I understand Bagby's paper on how to take accurate measurements, but I 'think' the midrange sounds a bit muffled, but the measurements are nearly identical. Red is w/denim.



The upper midrange/lower treble sounds hot, but my probably inaccurate measurements show it's fine (REW freq. sweep, [email protected], on tweeter). Could this broad area of energy in the upper mid/lower treble be contributing to that?




What's all this hash mean, if anything? It didn't change after adding the denim insulation.

[Kornbread]

After a couple hours with the minidsp. Taken @ 1 meter, minidsp, all crossovers lr24. Didn't take much hammering. I'm guessing the low end is an effect of mic position and room?

jhollander, just now seen the post, guess it's time to do some reading. Is this the paper you were referring to? https://app.box.com/s/fefis558wna1d6pd07r3




What can I do with the impulse?



And this seems high, but my testing levels were fairly low. comments.....

[jhollander]

1 meter is good. You just really need to see the baffle effect. It's best to be as far away from other walls and furniture, so out in the middle of the room is my prefered location. You should not need the port for x-o work. You will need the near field and far field. Far field should be gated before the first reflection. Near field is not gated. Take some time to read up on Jeff B's measurement white paper if you haven't done that recently.

[Kornbread]

The neighbor helped schlep one tower upstairs.

How should I take measurements?

Normally, I take the speaker to the far side of the patio, and measure from 1 meter on tweeter axis. These are too big to move and I don't know if 1 meter is enough time to allow for all the drivers to integrate. Would it be best to place the mic next to each driver and measure? What about the port that's located on the bottom/center of the cabinet, how would I measure it? Should measurements be taken at the normal listening position?

Using REW and a PE usb mic.

[jhollander]

The Zinsser Bin is actually just shellac that is pigmented.

+1 in the Bin shellac based, water based not good imo

[davidroberts]

The Zinsser Bin is actually just shellac that is pigmented.You can use body filler to hide the seams. I have had better results with glazing putty.