New project - Seas U16RCY/P with SB26STCN or SB21SDC

[Jakes_dad]

So I want to build a 2-way with the Seas UR16RCY/P.

They will be built into an entertainment center flanking the TV Screen.

Kind of like this (not to scale):

​

I have a maximum baffle width of 7".

They will be used for music, mostly background and casual listening, and TV.

They will be in a fairly large great room and we listen off axis more often than not.

I did some work in Xsim with that woofer and both tweeters( I used the woofer data from the Zaph audio site and tweeter data is from HIFi compass) I also did not apply any baffle step as these will be basically wall mounted (not sure if this is correct or if I should have a couple db)

SB21:




​

SB26:

​


Pros for the SB21 for me:

1. A little better off axis
2. I already own a pair

Pros for the SB26 for me:

1. Appears a little easier to work with
2. Seems people like this tweeter a lot, not many opinions on the SB21

Please let me know what you all think about tweeter choice and also any comments you may have on my sims.

Thanks,

Richard

[tomzarbo]

Richard,

It might just be me, but I can't see any of the pics for some reason.

TomZ

[Jakes_dad]

Tom,

I can see them on my PC, but not on my phone. Not sure what is causing that.

I uploaded my photos again, I think that fixed it.

[a4eaudio]

I cannot see them either.

[Jakes_dad]

Not sure what is going on, I see them on my PC and phone and checked on another PC and see them there as well. I don't know how to fix it at this point.

[Chris Roemer]

I can see 'em on an OLD PC using Firefox (on Vista).

[Wolf]

Did you adapt the responses to your baffles and location or use them as they were?
If you did not, then this is all a wash and is neither a valid Sim or a good example of the upcoming build.

My thoughts, are that you should be able to go 1st order electrical on the woofer,, as the U Series is known for it. You should likely be okay with either tweeter. I would go sb26 for an easier xover, and likely better sound than the more unknown sb21, but you do have a pair already to use.

Wolf

[Jakes_dad]

Wolf,

"Did you adapt the responses to your baffles and location or use them as they were?"

I modeled the baffle size and driver position in Response Modeler to incorporate diffraction and derived minimum phase. Is this what you were referring to?

[Wolf]

Sounds like you prepared well. I look forward to your progress...

[a4eaudio]

I can now see the pics on my phone and pc.

If you go with the SB26 I have a brand new pair that I'm not going to use as planned.

[ernperkins]

The traced Infinite Baffle (IB) responses are probably OK if you're mounting them on the wall. I see you included some estimate for delay in the woofer, but can't tell if you created minimum phase versions of your traced files. If not, none of your files have any phase information (if you open a frequency response or impedance file in notepad you'll see the 3rd parameter in each line is 0). If that's the case, use the "derived" option in the XSim driver "Tune" window to create minimum phase versions of all your frequency response and impedance files.

[Jakes_dad]

I created minimum phase versions in Response Modeler and estimated .75' delay in XSim.

[Jakes_dad]

Been away from this for a bit, but I built some test cabinets a while back:

​​ ​
I have been listening to them quite a bit with crossovers that I built with parts I had on hand and came up with this:

​​

These are the actual measurements in room placed next to the TV as in the first pic:

​




Modelled impedance:



These are designed to be listened to off axis, and the dip around 3.5-4k smooths out once you get 15 degrees or so off axis.

So what do you think?

Any suggestions before I order the final parts for the crossovers?

Thanks,

Richard
​

[Jakes_dad]

This is the 15 degree off-axis measurment:

[ernperkins]

The more important question is what do you think?

Here are two other approaches using the U16RCY/P you might consider:

1. Using LR2 slopes and a single inductor on the U16 (as Ben mentioned): http://www.audioexcite.com/?page_id=2386

2. Special attention on the U16 crossover (interesting reading): http://www.troelsgravesen.dk/SEAS-CURV.htm

Also: Your FR plot would be more informative if it wasn't so compressed. How about vertical step size = 2 dB and then adjust vertical center?

[Jakes_dad]

The more important question is what do you think?

Here are two other approaches using the U16RCY/P you might consider:

1. Using LR2 slopes and a single inductor on the U16 (as Ben mentioned): http://www.audioexcite.com/?page_id=2386I

2. Special attention on the U16 crossover (interesting reading): http://www.troelsgravesen.dk/SEAS-CURV.htm

Also: Your FR plot would be more informative if it wasn't so compressed. How about vertical step size = 2 dB and then adjust vertical center?

I have both of those projects bookmarked and couldn't get the single inductor to work very well, it's either my low crossover point or my lack of crossover skills.

I revisited what Troels did and made another attempt, thanks for the nudge.

I am now listening to this:



FR - in room, 24th octave smoothing, warts and all, including my super cool wall bounce



Pretty happy at this point, gonna listen to this for a while and see.

Any other input would be appreciated.

Thanks,

Richard

[rpb]

This is the best / most fun part of building speakers! Make a x-over, and then listen to lots of music until you get the urge to alter it. Then listen more to the revised x-over. Eventually, you decide which you like the best.

For measurements, I use gated. I want to see what the speaker is doing, not what the room is doing. Yes, the room can change the sound, but I would not try to fix that with the x-over. Changing tonal balance is done, but not based on a room measurement. Instead it is based on how I think it should sound.

[Jakes_dad]

We have these are set up as our main speakers in our family room. They were playing from about 8 this morning until about 7 tonight, so I had lots of time to listen and tweak. I think I am getting close, but still have a couple of things I want to try.

[craigk]

Interesting. My last 3 ways took 8 months for me to tweak.

[rpb]

Although it's pretty easy to create a functional speaker x-over in a few days, it's fun to obsess over it for much longer!

[Jakes_dad]

We have been listening to these for about a month or so and have gone through a lot of changes to the crossovers. We are going to listen for a while longer and see how it goes, but I think we are headed in the right direction.

[ernperkins]

OCD Craig, OCD. Good to see you around again. :-)

[rpb]

I have both of those projects bookmarked and couldn't get the single inductor to work very well, it's either my low crossover point or my lack of crossover skills.

I revisited what Troels did and made another attempt, thanks for the nudge.

I am now listening to this:



FR - in room, 24th octave smoothing, warts and all, including my super cool wall bounce



Pretty happy at this point, gonna listen to this for a while and see.

Any other input would be appreciated.

Thanks,

Richard

I rely on gated measurements of the speaker. I know that the room, and placement affect the sound, but I generally don't measure that. I have measured my speaker, and room together before, but it did not measure flat. A measurement like that does not tell me anything useful. If I hear something that I think is off, I can usually look at my gated measurements, and see where I need, or want, to make a change. Or I can speculate where to make the change, and then listen some more. A one dB difference over an octave is significant enough to hear. After a point, there's no right or wrong, there's just what you want.

[Jakes_dad]

I used a longer gate time on that one just to see where the overall balance was. I used a shorter gate time on the plots I posted earlier in this thread, but t wanted to get an idea of how they measured below 200 to confirm what I was hearing. Next time I make measurements I will go back to the shorter gate time.

[Jakes_dad]

Two months later and this is where I ended up. Pretty happy with this.

2 dB step size:

[Wolf]

Looks good, hope it sounds good!
Wolf

[Jakes_dad]

They sound pretty darn good to me, but I might be a bit biased.

For their intended purpose, they don't leave me wanting anything.

Thanks for checking my work, I am still not very confident in what I am doing.