Choosing new drivers/crossover in a speaker build


This may not be the place for this thread, but I will take a chance. I am building a new set of speakers. Usually, I go with a full range driver and cabinet to match. This time around, I actually was paid in a pair of Scan Speak 8" drivers for my cabinet work. They cost $450 ea. or about that. I put them in a back loaded horn cabinet and couldn't be more impressed so far. Of course, these drivers are designed to work in multiway speaker design, and so I will be doing my best to find a good tweeter and crossover. I did see at Madisound, a 2 way crossover for about $600/pr. and so that likely will be the way I go for the crossover, or possibly build my own. Now, the usual tweeter used with this driver is also a Scan Speak, with a beryllium cone. At about $500 ea. I can't cut it. I will continue a search for a tweeter that can be crossed over at about 2khz.  

 Any ideas/experience with this?

128x1284krowme

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.