Kestrel 2 crossover question

[AllCaster]

Looking to make a Kestrel 2 copy. The drivers are the Peerless HDS 182 6-1/2" and Vifa XT25TG30 1" dual concentric dome tweeter. I think the XO point is between 3,000 to 5,000Hz. Does anyone have an idea on the values for the XO, for a first order design? It may (or may not) need a Zobel for the woofer or an L-pad on the tweeter. This is my first DIY for speakers. The cabinet should be far more complicated than the XO. Thanks.

[nate]

Pat, uses first order simple crossovers, no l-pad or zobel networks. In this speaker, as well as other current models, he uses a minimum of components. I've heard this speaker and it is pretty good in some areas.
Nate

[AllCaster]

Thanks Nate,
I know the Swift has one cap, one inductor, and one resistor. For the Kestrel 2, if anyone has experience or modeling of the Peerless and Vifa drivers, values for the two or three components would be appeciated. Thanks again

[EngelholmAudio]

Originally posted by AllCaster
Looking to make a Kestrel 2 copy. The drivers are the Peerless HDS 182 6-1/2" and Vifa XT25TG30 1" dual concentric dome tweeter. I think the XO point is between 3,000 to 5,000Hz. Does anyone have an idea on the values for the XO, for a first order design? It may (or may not) need a Zobel for the woofer or an L-pad on the tweeter. This is my first DIY for speakers. The cabinet should be far more complicated than the XO. Thanks.

At sucha high XO (well over 3k) the Peerless unit has turned into a beaming soundsource. You will most likley have a shift in sound caracteristic in the cross over area (from non beaming to beaming to non beaming tweeter).

I'd try a bit lower XO freq.

[LaMa]

The tweeter is a real PITA to make a 1st order XO, I've made some simulations with my measurements of it, and if you want 1st order slopes 6.8 uF will suffice (starts rolling of at ~5 kHz, 3 dB down at ~3 kHz). In combination with a series resistor of 3.3-4.7 ohm you can attenuate the tweet a bit, although I recommend to use a shunt resistor aswell. Then I can shape the response a bit more.

Thus: 1cap 1R gives on tweet: 6.8uF and series R of 3.3-4.7 ohm


Or:
1cap 2R (a proper Lpad): gives 5.6uF and series R of 6.8 ohm and a shunt R of about 15 ohm.

Because I'm using measurements of the tweeter on another baffle YMMV and I can't gurantee optimum performance.

The woofer you mentioned I've never used, but because it's a polyprop which behaves well I would experiment with 1.5 mH - 2.2 mH series coil.

Good luck and don't forget that distance advice is very difficult for this kind of questions.

[LaMa]

Originally posted by EngelholmAudio
At sucha high XO (well over 3k) the Peerless unit has turned into a beaming soundsource. You will most likley have a shift in sound caracteristic in the cross over area (from non beaming to beaming to non beaming tweeter).

I'd try a bit lower XO freq.

You are right about that, but then the tweeter isn't cooperating anymore. I would suggest atleast a 2nd order electrical XO at 2-2.5 kHz in that case the midbass isn't beaming that much and the tweeter can handle it easily, but then again it wouldn't be a "Kestrel" (by the way what is a Kestrel speaker???)

[AllCaster]

meadowlarkaudio.com
The design philosophy is slanted baffle with first order, minimal parts XO, and transmission line. The Kestrel 2 is a very different design from the original.
The original Kestrel with Vifa drivers crossed at 4.7kHz.
The slightly larger (7") Shearwater crosses at 2.7kHz, using the SS 18W8545 carbon fiber woofer and SS D2905/9500. The 2.7kHz is just before the 30 off axis begins to drop off. The 2.7kHz is also at 4xFs of the tweeter.
For the Peerless 182, that would be 4 to 4.5kHz. For the Vifa XT25TG30 1" dual concentric dome tweeter, 4xFs is about 2kHZ. The XO is probably at least 3 kHz.
6moons.com has a review of the Kestrel 2, including a discussion of TLs with the designer, and a cross section of the speaker. Soldering is easy once I have values, the cabinets will be the tough part.
Looking for a hifi DIY father and son project; woodworking, refinishing, soldering, and listening to the music.
Thanks

[dtaylo3]

In general, that Vifa tweeter does not really like low order crossovers.

See sheldon stokes website and his making of a vifa P13 and Vifa Radiator mini monitor.

Note his comments on the tweeter.

Also, the Kestrek 2 may not be using off the shelf Vifas.

IMHO, 1st order crossovers are highly overrated.

[5th element]

Okedoke heres what I know about this speaker from my hifinews review. There is a measured response of the tweeter, woofer and combined.

There is a large area of overlap from about 1500 to 5000hz between these two drivers.

The f3 on the tweeter looks to be about 3.5khz and the woofers is about 2.5khz.

To be honest with you the review they got was a mixed bad, certain things were like and certain things we not. The good bits were basically what the woofers good at and thats bass and rhythm, I can tell you the HDS series are good at this, infact they are excellent for the size of the cone.

They also say that they image well, but they have a slightly recessed sound which mutes detail and the trebble is rolled off in the top octave which gives a slightly dull sound.

Id personally use steeper slopes with these drivers, especially with that tweeter.

They also say in the review that since they had started using this tweeter with 1st order they have not had a single device die. However the XT can handle lots of power and has a low fs, which would indicate that it can handle power, and it can, what it cant do is sound good with a low XO and high SPL.

[AllCaster]

Thanks to all,
The Peerless HDS seem to be the way to go for the woofer. However the tweeter can certainly be changed.
From the PE site:
MOREL MDT-40 1-1/8" COMPACT DOME TWEETER
SCAN SPEAK D2905/9300 1" TEXTILE DOME TWEETER
VIFA D27TG-35 1" SILK DOME TWEETER
VIFA DX25TG-05-04 1" FABRIC DOME TWEETER with shunt
Open to all tweeter suggestions, $80 is about the max per tweeter.
Joseph