Choosing new drivers/crossover in a speaker build

Do you have to tools to measure your loudspeaker?

Unfortunately, I do not. That is a very good question. It is likely that I will have to trust the design of the crossover that I choose, not to mention the tweeter. Looks like this may be over my head. I am a builder of speaker cabinets and 'proven' electronic kits. In the past, I have been fooled more than once.

1)

Unfortunately, I do not. That is a very good question. It is likely that I will have to trust the design of the crossover that I choose,...

2)

Looks like this may be over my head. I am a builder of speaker cabinets and 'proven' electronic kits. In the past, I have been fooled more than once.

If you have been fooled more than once (2), it seems like the tools (1) could start percolating up in importance...

Would it be easier to go with an active XO design? and then the crossover slopes and delays can be done without solder and electronics… or is that not as good?

If it is those wu18 SS drivers, then they are pretty renowned.
What are the dimensions of the horn loaded cabinets?
Do you know how low they go in terms of frequency in that arraingment?

A mic and IO device and REW would be a relatively cheap.
A D.A.T.S. could also be useful in the tool kit.

holmz,

 Points well taken. I really like your idea of an active crossover though. I have done it in the past, but not with quite as good results as I would have liked. The development was by engineer friend of mine who set the frequencies and slopes, etc.

  The cabinet is a model DNA2 by Decware Audio that I built a couple of years ago. It stands about 39" high X 10" wide X 17" deep. I'm kinda guessing here, but that is in the ballpark. The claims to frequency response by Decware are nearly realized, but I bet not down to the 20hz claimed. Seems like there was a bump at 40hz IIRC.

  The drivers are 18WU/8741T, which is a 7" midwoofer with a neodymium magnet. 

 FWIW, I have just received an email from the customer who has access to crossover information/design that will solve half of the problem. He will likely use passive for the design, but I will mention the electronic crossover idea anyway. Glad that you mentioned it.

  The cabinet may seem large, but actual area for a passive crossover would be right in the space behind the woofer. Not ideal if you ask me. I would rather run more wire and two more binding posts, and have a biamp situation. That way, I could go either way with a crossover.

 Thanks for helping me think this through. I'll sleep on it. 

I have a pair of those drivers, which were some of the lowest distortion ones available, but recently have been eclipsed by the newer Purifi units.
Still they are a super woofer.

A waveguide tweeter and with or without a MR (2 way or 3 way) they should be PDG.

I see it - but dimensions and where the woofer and the tweeter would go is uncertain. https://www.decware.com/newsite/DNA2.html

I think that the Hypex (maybe FA223 or FA123) is a something like 250W+250W+100W for the tweeter. And probably could be the easiest to do the bandpass XO. They also have 2 in 1 amps.

I might even take a crack at it as have most of what I need and other than the sheets of wood, I only need to figure out the diffraction and how to shape the cabinet not have it resonate. I have a pair of FA502s, and some 10” Earthquake SLAPS PRs that I could use.

I think I need to find a circle jig for the router.

whether those 3 in 1 amps with the DSP are sonically inferior to a passive XO and a larger is a question… But at the least the speaker cable questions go away.

DIYaudio.com is the best place to aask these kinds of questions.

I am a big fan of Scanspeak, but you are 100% going to be better off with a 3-way design here.  It also sounds like you are brand new to crossover design. That's it's own learning curve.  I suggest DIYaudio, but also maybe consider an active crossover with cheap amps to get started.  Lots less math that way.

holmz,

 You can see my build of the DNA2 on my systems page. There would be room for a tweeter at the top, above the woofer.

Jasper makes my favorite circle jig for routers.

erik_squires,

  Yah, that makes sense. I will continue with questions at that site.

  Much appreciated for the information. This will all have a great outcome.

As an ending statement, I would like to thank those who helped with this question. I remain fascinated by what I found at DIY Audio. Sometimes site will just supply an overwhelming amount of info, but that was not the case here! There is a very well written thread on the subject, hence my amazement, and not so much confusion. This will make my attempts completely more fun than frustrating.

     The End (remember when movies had to tell us when it was over?)

I just built a 12db active crossover and linear power supply from Elliott Sound Products.  I must admit that it made quite a difference.  I am using it to split the lows to the subwoofers/highs to the speakers.  I wasn't sure if I would like it, but my wife and I both agree it sounds significantly better.

A 2 way can be done reasonably well, but there is no way around it, you'll  be dealing with that huge peak. I have complete measuring equipment. Where are you located?

timlub,

As far away from society as possible, but not far enough. Actually, a little cow town near Cody Wyoming. Ok, I just gotta' say you got me interested. 

@jgoldrick do you have the specific URL?
Is it this one: 
https://sound-au.com/project81.htm

@holmz Yep, that's it.  #5 is a linear PS for it.  #9 is the same as #81, but 24db slope.

@4krowme .     I built a 15 inch 2 way. The 15 had a similar frequency curve. I did a fairly unorthodox design, but in the end it turnrd out to be an excellent  performing speaker.