KZC-1 Speaker Project

[robwest]

A couple of cg pics (DOGA 2) of the KZC-1 speaker project I'm making for my brother. This is pretty-much the way they will be laid out. The outer dimensions will be 14"x20"x60". The bottom foot of the cabinets will be detatchable for mailing. Double gaskets and four bolts each will ensure air-tight fit. The edges and corners will all be rounded over and the finish will be white acrylic, (I like the contrast.). I haven't decided about grills yet. I like the look of the stand-off kind and am leaning in that direction.





And a look with bare wood, for grins.

[lunchmoney]

Re: KZC-1 Speaker Project

Very interesting layout. What drivers are you using?

[Æ]

Re: KZC-1 Speaker Project

The tweeters are too far apart, they should be as close as possible. Married, or stay single.

A couple of cg pics (DOGA 2) of the KZC-1 speaker project I'm making for my brother. This is pretty-much the way they will be laid out. The outer dimensions will be 14"x20"x60". The bottom foot of the cabinets will be detatchable for mailing. Double gaskets and four bolts each will ensure air-tight fit. The edges and corners will all be rounded over and the finish will be white acrylic, (I like the contrast.). I haven't decided about grills yet. I like the look of the stand-off kind and am leaning in that direction.





And a look with bare wood, for grins.

[martyh]

Re: KZC-1 Speaker Project

I'd stay single. Couples that are too much alike tend to creat their own brand of lobing and diffraction issues....(sorry, that's all I got).

[robwest]

Re: KZC-1 Speaker Project

Thanks, Lunchmoney.

The drivers are:

Tweeters

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-938

Mids

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-946

Woofer

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-106

Passive Radiator

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-492

This is meant to be a budget pair of towers and I guess the driver selection reflects that.

AE, what will be the effect of this separation? Don't line arrays have a bit of distance between the top and bottom tweeters?

[spasticteapot]

Re: KZC-1 Speaker Project

If you want "big sound", I'd suggest an Econo-waveguide implementation. Most of the work is done for you, and when used with a good 12" pro-style woofer (Eminence Beta/Delta/whatever), you can get some serious sound - especially if you corner-load it.

[Æ]

Re: KZC-1 Speaker Project

Yes, the upper most and lowest tweeters in a line array are separated by distance. . . but that distance is filled with additional tweeters. Unless you ears are precisely the same distance from both tweeters, your head at the right height there will be some problems. Better to use a single tweeter or place the tweeters absolutely as close together as possible, or fill the blank space with some additional tweeters. Comb filtering and frequency anomalies will occur with widely separated tweeters. The wave lengths of treble frequencies are much shorter than that of midrange and bass frequencies.

Thanks, Lunchmoney.

The drivers are:

Tweeters

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-938

Mids

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-946

Woofer

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-106

Passive Radiator

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-492

This is meant to be a budget pair of towers and I guess the driver selection reflects that.

AE, what will be the effect of this separation? Don't line arrays have a bit of distance between the top and bottom tweeters?

[robwest]

Re: KZC-1 Speaker Project

The deal is is that the drivers are already delivered except for the tweets. It works out that the sub's specs demand an 11 cu. ft. enclosure. That ain't gonna happen. They'll end up with about 5. If you notice, their xmax is 6mm. The PR's is 9mm. A flat 10" circle has about 2x the area of an 8" circle. So if the sub moves 1mm, the pr will move 2mm, theoretically. This would seem to mean that if the sub moves at 75% of excursion, 4.5mm, the pr will be at its fullest, 9mm. I'm also thinking that air pressure in the box and stiffness of the pr's spider will keep it from maxing out before the sub does. I hope.

I could live with this look if the tweeters have to be closer.

[tomzarbo]

Re: KZC-1 Speaker Project

Rob,

Those tweeters have lots of plastic on the flange before you get to the 'metal' of the magnet assembly. In order to get those tweeters closer together you could carefully sand off some of the mounting flange so they sit closer together.

I did something similar here:

I took a stationary belt sander to the flange of this neo tweeter in order to get them closer to the two RS-100 midranges. If you check out the pic of the back of that Jamo tweeter, you'll see a lot of material that can be removed. I would go right up to the gasket material. You could carefully with a thick metal straight edge and an Xacto knife, score a fairly deep line in the front of the tweeter faceplate so you know when to stop sanding. This would give you probably a good inch or so of closer proximity if you plan on using two tweeters.

Keep us posted, your mock-up pic looks cool!

TomZ

[donparsons]

Re: KZC-1 Speaker Project

I mounted the tweeter before cutting the through holes for my mids and used the router to cut the plastic flange. In this design by Wolf, the centers of the tweeters and mids needed to be close to avoid the mentioned lobing.

Rob,

Those tweeters have lots of plastic on the flange before you get to the 'metal' of the magnet assembly. In order to get those tweeters closer together you could carefully sand off some of the mounting flange so they sit closer together.

I did something similar here:

I took a stationary belt sander to the flange of this neo tweeter in order to get them closer to the two RS-100 midranges. If you check out the pic of the back of that Jamo tweeter, you'll see a lot of material that can be removed. I would go right up to the gasket material. You could carefully with a thick metal straight edge and an Xacto knife, score a fairly deep line in the front of the tweeter faceplate so you know when to stop sanding. This would give you probably a good inch or so of closer proximity if you plan on using two tweeters.

Keep us posted, your mock-up pic looks cool!

TomZ

[robwest]

Re: KZC-1 Speaker Project

Tom, Nice sander work on that. Plastic does funny things with the heat and grinding effects of a sander. Was that for a center channel?

Don, Beautiful burl on those. Nice back yard, too! How many clear coats?

These speakers will be about 12 feet from the couch, will the close spacing of the tweeters be that critical at that distance?

This just isn't as pleasant to look at, to me.

[donparsons]

Re: KZC-1 Speaker Project

I did 5-6 coats of clear poly on those. it was my first veneer job and came out pretty nice.

I believe you want to keep your tweeters in the original position, but place them as close as possible to one another.

You may have other significant issues here as well, but i am not the one to answer questions about them. My post was to demonstrate another way to get closer ctc spacing. I thought the trimmed flanges on those tweeters looked really good.

Tom, Nice sander work on that. Plastic does funny things with the heat and grinding effects of a sander. Was that for a center channel?

Don, Beautiful burl on those. Nice back yard, too! How many clear coats?

These speakers will be about 12 feet from the couch, will the close spacing of the tweeters be that critical at that distance?

This just isn't as pleasant to look at, to me.

[Wolf]

Re: KZC-1 Speaker Project

Side-by-side tweeters really isn't a good idea either.

I would recommend one, OR go vertical with 2- as close as possible.
Later,
Wolf

[rogoll]

Re: KZC-1 Speaker Project

I wounldn't trust the specs on the tweeter. FR is wrong, IMHO. You need to stay an octive away from the Fs (listed as 1,200 Hz), which would make the FR start at 2,400 Hz.

Are your drawings done in SketchUp?

[robwest]

Re: KZC-1 Speaker Project

I'm sure there's plenty more issues with these to crop up yet! Seems like every time I scratch, someone comes up with an entirely different train of thought I had never before considered. I'm enjoying this as it helps me learn.

I'm a firm believer in the 'Form follows function' principle. But I have to be practicle with these as well. These tweets have a convenient indentation a good way into the flange that I might be able to reduce them to if necessary. Then fill the back side (which I am sure is open with reinforcement ridges) with resin. Then tap for mounting. But again, at 12 feet, will an inch and a half matter?

Don: Yours DO look good. I was talking about the latest pic I cg'ed based on your and Tom's suggestions. Sorry you thought I meant yours.