My first 3 way speaker build

[Sydney]

Re: My first 3 way speaker build

...The hardest part for me to stomach at this point is how magical this sounds when I use it active....

gee there are worst things to happen :D

[mattsk8]

Re: My first 3 way speaker build

gee there are worst things to happen :D

I agree whole heartedly. Just not a fan of the reroute, I get an idea in my head and want to run with it

[Sydney]

Re: My first 3 way speaker build

At least you know what they are capable of.

[mattsk8]

Re: My first 3 way speaker build

At least you know what they are capable of.

Yes, active sounds better and is far and away easier. But, I wanted a challenge for myself and everyone around me :p.

Update #2...

I owe Craig Kinnison and Madisound more than one beer!! Craig found out that Madisound had used this woofer, and Madisound said it had to be a xover issue because what they had was magical (the guy I spoke with earlier today there must not have known). So Craig had me swap some things and add some other things on the shunt, and BAZINGA!!! They're alive!!! I'm so happy :D. I love stereos .

Next up... playing with mids and highs, right now they're pretty sharp but I can tell everything I need is there, I just need to tame these wild animals. More to come as things develop. Thanks for the help and suggestions everyone!!

[marvin]

Re: My first 3 way speaker build

Yes, active sounds better and is far and away easier. But, I wanted a challenge for myself and everyone around me :p.

Update #2...

I owe Craig Kinnison and Madisound more than one beer!! Craig found out that Madisound had used this woofer, and Madisound said it had to be a xover issue because what they had was magical (the guy I spoke with earlier today there must not have known). So Craig had me swap some things and add some other things on the shunt, and BAZINGA!!! They're alive!!! I'm so happy :D. I love stereos .

Next up... playing with mids and highs, right now they're pretty sharp but I can tell everything I need is there, I just need to tame these wild animals. More to come as things develop. Thanks for the help and suggestions everyone!!

Whew! I thought you were going to self fulfill your prophecy from post #1.....

My goal here is to prove that you can take fairly expensive, well received drivers and make them sound bad . Kidding, hopefully this doesn't play out that way;

Glad you didn't take the trouble to build curved cabs and be disappointed! More glad that you are on your way to a successful first 3 way build. :applause:

[mattsk8]

Re: My first 3 way speaker build

Whew! I thought you were going to self fulfill your prophecy from post #1.....

I definitely successfully completed that mission . I'm still deep into the woofer xover trying to find that fine line between bass and lower mids on the woofer. Getting closer though!

[mattsk8]

Re: My first 3 way speaker build

I've learned a lot. First, it's very easy to think speakers are no good simply because the xover needs a tweak or 5.

Second, I understand why 3 ways are so difficult. It's a combination of all the components, and how much there is going on in music between 200 and 400 Hz. So easy to get it all wrong.

Anyhow, I'm sitting in front of these right now, listening to Dan Fogelberg's song Nexus. They're magical, they have a glow in the mids and they miss absolutely nothing as far as soundstage and definition goes. Listening to beats and clicks pass from the right speaker to the left is almost eerie.

The bass isn't mind blowing, but it's very accurate. If I change anything, I might still replace the current woofer ported cabinet with a folded TL. Need to digest what I have now for a bit before I pull that trigger though.

I'm going to leave the xovers slobbed together for now, I need to spend some more time in front of them to make sure I won't want to tweak more.

[augerpro]

Re: My first 3 way speaker build

So what did you change? I'm guessing you didn't have the exact same response when translating from passive to active, and vice versa? I would think if you had the same transfer function regardless of crossover type they should sound pretty similar.

[mattsk8]

Re: My first 3 way speaker build

The biggest difference in bass was adding a resistor in the woofer shunt. But they still sounded kind of thin and shouty, so I swapped the 3.0 inductor with a 2.0 and it filled it in amazingly, w/out having an effect on the bottom end.

As far as the second part, yes and no. The end goal is ideally the same, but crossing active changes the signal before the amp sees it so you aren't necessarily manipulating electrical current. Changing things in the passive xover always opens a new can of worms. For example, swapping an inductor to try to pull midrange up could effect the bass too. With active xover, you can essentially just shut off whatever you don't want to hear.

[augerpro]

Re: My first 3 way speaker build

This was all measured and modeled? Could you post the predicted response and filter transfer functions of the active and passive versions?

[mattsk8]

Re: My first 3 way speaker build

This was all measured and modeled? Could you post the predicted response and filter transfer functions of the active and passive versions?

I'm not sure what you mean by "transfer functions" regarding the active xover; you just dial the preamp to 200 Hz (as high as mine would go), I set the slope at 24, then attenuated it with the subwoofer volume setting in the preamp. The only transfer function is the dial on the preamp. I didn't spend any time measuring, because I don't want active. The only reason I did that was to see if the woofer was capable all by itself, which it definitely is, so that told me something in the xover is stifling the bass.

As far as modeling the xover goes, I basically pick the points based on the measurements, and I have someone that understands these a lot more than I do model the rough xover for me. I know how they work, but don't want to spend the time learning the design software, it's a lot easier to things this way. I'd post, but they'd rather stay anonymous. Once I get the parts he tells me to use roughed in, I tweak everything.

I guess I'm not really sure what you're looking for, or more, why you're wondering. The TM is crossed at 2.3, and the mid/woofer is crossed at about 225. I have also measured them done, and they're very flat now, thanks to Chuck Morris helping me understand reverse null. I had a decent bump at 1.8k, Chuck helped me figure that out.

That said, if you have something I should try different on the woofer, I'm all ears.

[augerpro]

Re: My first 3 way speaker build

I just thought there would be something to learn here by understanding what "went wrong"? Just the OCD troubleshooter in me

[mattsk8]

Re: My first 3 way speaker build

I just thought there would be something to learn here by understanding what "went wrong"? Just the OCD troubleshooter in me

That I understand completely! I was hoping you'd say something along the lines of "just bump this value and move that piece, then they'll pound like a pair of 12" subs in the back of a station wagon" .

There was another guy on the forum here that tried using these woofers too and had the same issue, he ended up going active (don't remember his name, something Dunn?). What I have now is very respectable, but still not what you'd expect from a 10" woofer from a SPL perspective. They're very musical, the sound is exceptional. They don't miss anything, the bass is very smooth and accurate. I just wish I could pull a db or 2 more out of them.

I'm at the point now where I think I need to step back from tweaking and just listen for a week or so.

[chrisn]

Re: My first 3 way speaker build

A 2mh inductor seems rather small for a 200~hz crossover, 4-6mh is more "normal". 250uf cap could be too big, try a lower value (68-200) if you can. Are you listening to just one woofer or both? Sometimes just one will sound a little weak, if two, one could be wired out of phase from the other woofer. You have a nice selection of drivers, a little fine tuning and you'll have a very nice set of speakers.

[mattsk8]

Re: My first 3 way speaker build

A 2mh inductor seems rather small for a 200~hz crossover, 4-6mh is more "normal". 250uf cap could be too big, try a lower value (68-200) if you can. Are you listening to just one woofer or both? Sometimes just one will sound a little weak, if two, one could be wired out of phase from the other woofer. You have a nice selection of drivers, a little fine tuning and you'll have a very nice set of speakers.

Thank you very much for the suggestions. I started with a 3mh inductor, I swapped that to the 2 just to see what would happen and it didn't really have much effect on the bass (it did pull the lower mid up a tad, as you would expect). I haven't tried going higher than 3.0 yet though, maybe that should be my next move. I did try a 200uf cap in place of the 250, and that didn't help. What did make a difference was putting a 50watt, 2.4 ohm resistor on the negative wire side of that 250uf cap, that pulled the slope down even more. I will try a higher inductor and see what happens, but here's what I think is going on...

I've been playing with these a lot, and short of going higher than 3.0mh on the inductor I've tried everything I can think of. The thing with speakers is, you can always pad to make them quieter, but you can't make them play louder. I think the issue is that even though the SB29 woofer is rated at 88 db sensitivity and the SS 18w mid is rated for 90 (these should technically work together), they aren't even close. I think in the frequency range I'm using this woofer, the sensitivity is just plain awful, I'd say 86 db is a stretch.

To make these really sound good, I had to pad the mid with 7.7 ohms of resistance, and the tweeter with 11 ohms. Now they sound perfectly magical, but I don't think my amp can handle what I'm doing. These are terribly inefficient, after I listened to them for about 2 hours last night I could fry eggs on the amp I'm using to voice these (Adcom GFA-5500), it was almost too hot to touch. I wasn't listening at insane volume levels either, it wasn't quiet but it definitely wasn't overly loud. I think I might be in the market for a different pair of 10" woofers, only I'm going to use something that has a good history this time, rather than being a guinea pig.