8"+1" two-way DIY speakers

[crazyhub]

Hi all,

I know of a lot 7" or smaller mid-woofers matted with 1" or smaller tweeters but very few using a bigger woofer...Do you know of?

Thanks!

 

[JRace]

Reference 3a uses an 8" (without any crossover) mated to a 1" tweet, and a supertweet. They do refer to it as a 2-way.
Reference 3A Loudspeakers

A two way design utilizing our own directly coupled (no crossover) hyper exponential 8" (20 cm.) woven carbon-fiber main driver, superb 1" (24mm.) soft textile dome tweeter and a gold coated fine ceramic super high frequency exciter.

Front baffle is tilted back at a critical angle and the drivers are positioned precisely for correct time alignment and sound wave propagation.

Cabinet panels are constructed with varying thicknesses of 1½" (39mm. to 1" (25 mm.) to drastically reduce resonances.

Highest quality components with very advance technologies are used for enhanced refinement (Bybee Quantum Purifiers, Mundorf silver capacitors, Murata super tweeters and AVM fluid, Van den Hul wires, etc…).

An externally hosted image should be here but it was not working when we last tested it.

And they do make a stand-mount 2way:
http://reference3a.com/mmdecapo.htm

TWEETER
Custom designed and pair matched.
27 mm. textile dome,
Non-resonant rear chamber.
Un-damped, dual suspension.
Low resonant frequency, 600Hz,
Cut off frequency 300Hz.
High pass frequency, 6dB/octave

MAIN DRIVER
8 ¼" diameter, designed and build by Reference 3A.
Designed not to require cross-overs.
Very wide frequency response.
Hyper exponential shaped woven carbon cone.
Exclusive Vibra-Puck treated driver structure.
Precisely shaped phase plug.

An externally hosted image should be here but it was not working when we last tested it.

 

[JRace]

oopps
you did ask for DIY...

 

[crazyhub]

oopps
you did ask for DIY...

Yes but only because my real interest is about the used slopes and Fx on such 2-way...Otherwise thanks for your input

 

[takayama69]

Hi

If size, price of drivers and complexity of the XO don´t bother... check out the Classic at HumbleHomemadeHifi's. Here you can find a 28 liter 2-way with dayton RS 225 crossed at 1400 hz.

But one puzzling speaker is Krell Resolution 3. Seas magnesium 8 and the XT 25 krossed with a third order filter at some point > 2 KHz in a small box (baffle is 2" to subtract from volume.. )
Anyone made a clone or just a dissection of the XO ??

 

[JRace]

Yes but only because my real interest is about the used slopes and Fx on such 2-way...Otherwise thanks for your input

Then I guess a 8" with no crossover mated to a tweet with a simple 6dB @ 300Hz isn't what your looking for!

 

[CharlieLaub]

It's possible to do a good 2-way with an 8" woofer. The limiting factor is that the off axis response of many 8" woofers starts to drop around 1.2k Hz or so. Of course this depends on the design and material of the cone, the profile/shape, etc. But there are good examples in the DIY world of how to pull this off, for instance Mark K's RS225/RS28A:
Dayton Reference RS225
I've developed a variety of active crossover boards and I have a few 8" drivers that are candidates for a 2-way, so I am hoping to explore this type of speaker a little more in the near future.

Of course you can go "larger" with the tweeter and cross over lower. There are a couple of small (e.g. 2") inverted dome full range drivers from Tang Band that could be crossed over about as low as you desire (e.g. 800 Hz) to create a 2-way. For instance the W2-800SL.

Once you go larger with the woofer, the off axis response starts to be a real problem, unless the woofer has a special design that provides smooth off axis response. For instance, the Seas A26RE4 stand out. But most 10" drivers will just not be suitable.

-Charlie

 

[RockLeeEV]

Once you get to even a 6.5" woofer I think it starts to get tough to mate to a 1" tweeter.

By the time you get to 8" woofers IMO you should really consider waveguides.

How about pairing the upcoming Exodus Anarchy 8" woofer with the upcoming Seos-10 Eliptical waveguide. I don`t really know what drivers work in that SEOS 10 but i`m sure you can find an excellent match to the Anarchy.

The Linkwitz Orion does pair the Seas W22 with the Seas millenium, with a low (1.4khz) 4th order crossover point.

 

[jerome69]

Then I guess a 8" with no crossover mated to a tweet with a simple 6dB @ 300Hz isn't what your looking for!

No I don't think so, although we have this kind of specimen

A 8"+1" is a classical design, no problem to find many DIY projects
Vifa C20WH
Monacor SP200X +
TQWT-
High Efficiency Speakers
Rôle du RLC - Enceintes
etc.

But with bigger woofers, it is more tricky. You can mate a 1" with a 10" or a 12" @1.5kHz or 1.1kHz no problem. I made it but as explained it is not ideal.
With a waveguide it is better for the tweeter which is very stressed.
But I still think, a 1" should not work under 2kHz.

 

[crazyhub]

Thanks for the replies guys but I have to precise a few things; I have already the drivers at home and I'm waiting on the enclosures builded by a carpenter; the drivers are:
http://www.scan-speak.dk/datasheet/pdf/d3004-660000.pdf
8NMB420 - High Output MB Neodymium Driver
A previous thread didn't give a lot of replies...:
http://www.diyaudio.com/forums/multi-way/114123-xo-scan-speak-6600-a.html

So the only and real purpose of this present thread is to give me an idea of what Fx and slope does give an acceptable listening result in term of directivity issues by browesring what others did already do. I guess I know all the technical constraints (mech x-max/power behavior), what I don't know is where to place the bar...In short, should I go as low as 1.5k or even 1.2k (tricky!)...or 2k is really suffisant?

 

[jerome69]

http://www.eighteensound.com/staticContent/applications/kits/18Sound_kit8.pdf

 

[wolf_teeth]

I've done one so far...

...and am in line for the second right now.

"MAX" (I don't have the writeup completed, but the build thread is viable over on PETT):
MAX pictures by wolf_teeth_speaker - Photobucket

"Destinations" TMPP towers:
Destinations pictures by wolf_teeth_speaker - Photobucket

The Destinations are currently a work in progress, and I'm working on the cabs right now. I hope to have them at MWAF in a month...

Later,
Wolf

 

[crazyhub]

To jerome69: Fx of this 18sound kit is astonishingly high for a horn tweeter...but also prooves that this 8" (close to mine) should not make a wrong job up to 2kHz...Thanks for the link I did know of!

To Wolf: It seems you aren't afraid to cut your tweeters very low...How low and with what filter order would you dare cutting an undamped (read without series R or Lpad) SS 6600 for a hifi use? I thought 1.4kHz third order or so...

 

[wolf_teeth]

To Wolf: It seems you aren't afraid to cut your tweeters very low...How low and with what filter order would you dare cutting an undamped (read without series R or Lpad) SS 6600 for a hifi use? I thought 1.4kHz third order or so...

I only do it when necessary, and if the tweeter is able to do so. If it could've gone higher, I would've. It's the Vifa DX25, and it's using a 5th order electrical plus a conjugate notch on it's Fs. There is a series 2.5 ohm resistor, but most of the attenuation and adjustments are in the DCR of the coil-shunts, and there is a damping circuit for the top-end. This is effectively 7th order acoustic, and 8th order net for the entire xover.

So- It's xover'd about 1.5kHz, 8th order acoustic.

Later,
Wolf

 

[Nanook]

not 8", but how about 10"?

how about making a modern "copy" of the A25? Have a look at World Designs kits. If soured from NA dealers, then about USD$280 for the drivers (if you can find them). Choose your enclosure style. Make an updated or impoved crossover as per World Designs. Easy to drive, quite deep (and very well controlled) bass. Very enjoyable to listen to. Or find a pair of original A25 speakers and revamp them starting with the enclosure. I happen to know where you can get some (dirt cheap!).

 

[paulspencer]

One of the main issues is whether the tweeter can cross low enough to make it work.

Another way to go about it is with a compression driver and waveguide. With a 90 degree waveguide you are looking at a starting point of about 1.8k, that could work quite well.

 

[Francec]

My two way used a Peerless 8" 830869 crossed at 2.kHz and performed well with a passive crossover BUT a lot better with an active.

Frank

 

[kevinlin1013]

I knew a commercial speaker example: Wilson Audio's duette.

Scan Speak 1" Dome tweeter and Scan Speak 8" woofer. (I guess)

 

[Mr. dB]

There have even been 12" 2-ways that worked a whole lot better than they should've:

Spendor SA3:

I guess the slot-loading is an attempt to deal with dispersion at the top end of the 12" woofer's range. The tweeter is a 1 1/4" Audax.

BBC LS5/8 is similar:

An externally hosted image should be here but it was not working when we last tested it.

Harbeth makes several 8" 2-way systems, with crossovers as high as 4KHz.

 

[Charles Darwin]

Most manufacturers of studio monitors have one or more 8"+1" in their program.

Quested has 4, KRK 3, Genelec 2 and one 10"+1" for example. They are all active.