Wilson Watt Puppy Clone Design - Design Review Please

[soundengine355]

Hi,

Watt Puppy Clone using:

1 x Focal TC120
1 x Scan-Speaker 18W8545
2 x Peerless PPB 831868

Cabinet Overview
http://img170.imageshack.us/img170/803/cabge6.gif

Tweeter and Midrange Crossover
http://img211.imageshack.us/img211/3308/woofervo1.gif

Woofer Crossover
http://img98.imageshack.us/img98/4876/tweetermidiy6.gif

Dimensions:
Tweeter/mid - http://img223.imageshack.us/img223/3272/cab2ro5.gif
Woofer - HxWxD - 574mm X 257mm x 420mm
-The Port is of 75mm inner diameter and about 200mm long

What you think?

Any advice on the woofer enclosure?

[Brisso57]

What do you estimate to be the cost of the drivers and the cross-over components?

cheers

Doug

[sreten]

Hi,

Using crossovers developed for particular drivers with other drivers is not a good idea.


/sreten.

[djarchow]

How did you design the crossovers. Were they designed using measurements of your drivers?

Regards,

Dennis

[sreten]

The crossovers are from here : http://www.deadwaxcafe.com/vzone/david/david.htm

/sreten.

[djarchow]

Originally posted by sreten
The crossovers are from here : http://www.deadwaxcafe.com/vzone/david/david.htm

/sreten.

Sorry Sreten,

We must have been posting at the same time. I didn't realize that these were Thorston's XOs. And just to mirror your comments, a XO is designed for specific drivers and most likely won't well with substitutions.

Regards,

Dennis

[David Gatti]

Agree with the above. Principle looks good, but it's all in the details. Also beware of an overall low impedance.

[Dr. Ram]

Originally posted by soundengine355

What you think?

Any advice on the woofer enclosure?

Hi:
There are several tradeoffs involved in enclosure and crossover design. The starting point would be the tradeoff between transient response and low frequency extension. This is what the subject of "alignments" tries to address.
Have you designed the enclosure to meet any specific alignment for your specific drivers?
As for crossovers, similar advice has already been posted. I will elaborate by saying that again there are tradeoffs. What are yours? Complexity and component count versus intermodulation distortion (the higher the order, the greater the former and the less the latter)? Flatness of passband response versus transient response (Butterworth filters have more of the former and less of the latter compared to Bessel)? Transient purity versus phase purity (LR filters have less of both compared to Bessel)

If you really want to get it right, it is good to do it scientifically. Make take more time and energy but you will get it right during design rather than end up tweaking it after construction (usually with no gain).

-Ram

[PB2]

I mentioned 10 or 15 years ago on the bass list that I was cloning the Watt/Puppy. I probably should not have used the word clone since it caused a major controversy. So let me, rephrase that and say that I was going to do an approximate copy since it would be difficult to duplicate the materials used in the enclosure and the tweeter looked to be a custom unit.

I have cloned several commercial designs with excellent results so there was no need to argue the matter.

I did not have an actual Watt/Puppy to measure but there was enough information between the Audio and several other reviews to reverse engineer the crossover with fairly high confidence. The number of components was given and the electrical transfer functions as I recall. I did most of the modelling, purchased the drivers that I could find that appeared to be from the Watt and was looking around for lower cost woofer replacements. The woofers in the Puppy were Dynaudio's at that time with excellent large signal capability.

I explained my methods to Thorsten, sent him photo copies of the reviews, and he did the copies that you see at that web site. I believe that Thorsten used all different drivers from what I suggested based on his preference and availablity.

I saw and heard the Watt/Puppy in NYC at a show and took a close look at the drivers. The tweeters looked like the Focal T120TiO2 versions but the ones that I purchased had a rubber suspension whereas the ones in the Wilson were foam, as I recall. Also the Wilson tweeter domes had a bronze color whereas the TiO2 were gray. Might have just been for cosmetics.
The Scan and Dynaudio woofers looked to be stock but it is hard to tell, obviously, without measuring them.

I never completed this project due to a lack of time and all the negative talk about them, not that I believed them. Wilson used some clever tricks to get impressive dynamics out of the Watt/Puppy. My plan was to revoice them if I found any major issues regarding their performance.

I heard years later that Spica TC-50s might have been the basis for the WATTs and you can see the similarity in the enclosure if you taper in the sides toward the top. The Spica's also use a notch filter, and the earlier WATTs were noted for the difficult input impedance as a result of the notch filter being used. I don't ever recall any claim for linear phase regarding the WATTs so I'm not sure if this is just complete speculation. Anyone?

Pete B.