Help with Wilson puppy clone crossover

[andyrlb]

Hi guys ,
So I intend to redesign the watt clones ( kind of !! ) that I have and I want to build the puppies for them .
I have the designs and drawings of a similar design but the 8” drivers they’ve used are no longer available ( Peerless 217 WR 33 ) and the crossover is I presume designed with these in mind so how do I get around that ?

I’m no electronics engineer btw .

The Crossover is as simple as it gets. The highpass feeding the David "satellite" is a simple 1st order Unit. Note that the output to the Satellite is inverted in Phase. However, depending upon the room and listening conditions it may be neccesary to connect the David "satellite" in phase in order to avoid room resonances. Feel free to experiment.

The Lowpass feeding the Woofers uses an Impedance Compensation. If the Dynaudio 21W-54 Woofers are employed, this Compensation is un-neccesary and should be omitted. It might be desirable to connect a high power resistor of 15 Ohm Value (> 50W) across the Woofers to slightly attenuate the woofers as well as reducing the Impedance swing at low frequencies.

Again, building methodes and part quality are to the higest standards. The Wire to the woofers was left as conventional stranded wire, the wires to the crossover as well as those to the connectors feeding the David Satellite Speakers are made from the same DIY-Litzwire that was used in the Satellite. The short Interconnection between Woofer and Satellite also uses this wire

 

[dave]

Did you read my ultimate speaker build thread, it's a bit back in the DIY somewhere. They are particularly lovely, even if I say so myself, I am listening to them now, sigh. Immersive like a warm bath....
It feels as if you are in a similar predicament as I was when I started. I ended up effectively with a passive 2 way, as do you? And bass. Trying to get the bass to cooperate, a pain. I have ended up with a Beringer dcx just to control the upper and lower bass. I found doing what ever filtering was required to get a kind of text book crossover filters measured in the near field. The filtering is wild, but the results are excellent. Took them to Stoke, and needed only very slight tweaking to make them work in a quite different room. Good luck.

 

[andyrlb]

Did you read my ultimate speaker build thread, it's a bit back in the DIY somewhere. They are particularly lovely, even if I say so myself, I am listening to them now, sigh. Immersive like a warm bath....
It feels as if you are in a similar predicament as I was when I started. I ended up effectively with a passive 2 way, as do you? And bass. Trying to get the bass to cooperate, a pain. I have ended up with a Beringer dcx just to control the upper and lower bass. I found doing what ever filtering was required to get a kind of text book crossover filters measured in the near field. The filtering is wild, but the results are excellent. Took them to Stoke, and needed only very slight tweaking to make them work in a quite different room. Good luck.

Hi Dave , I will hun down your thread , ideally I want to find the ideal cabinet design, drivers ( woofers ) and crossover and then commit to the build .

 

[dave]

Hi Dave , I will hun down your thread , ideally I want to find the ideal cabinet design, drivers ( woofers ) and crossover and then commit to the build .

If only it was that easy (my opinion). Have you tried diyaudio? There are some (a lot) good people on there, especially if you catch their interest. Can be a bit trial by fire, if you are new as they try and sus out where you are, but worth it.

 

[andyrlb]

If only it was that easy (my opinion). Have you tried diyaudio? There are some (a lot) good people on there, especially if you catch their interest. Can be a bit trial by fire, if you are new as they try and sus out where you are, but worth it.

Yes that’s where I started, I was sent the design by a member on there . Like you said some good people , some not so good too I’ve found in the past .

 

[JANDL100]

... Trying to get the bass to cooperate, a pain. I have ended up with a Beringer dcx just to control the upper and lower bass.

I've a Behringer Ultrapatch Pro just lying around. I can't even remember what it does or why I bought it.
But check out the spec, and if it's if any use to you @andyrlb you can have it.

This is a bit of a random post, isn't it. 😏

 

[JANDL100]

... Took them to Stoke, and needed only very slight tweaking to make them work in a quite different room.

... and give one of the best sounds at the show IMHO. 👌

 

[andyrlb]

I've a Behringer Ultrapatch Pro just lying around. I can't even remember what it does or why I bought it.
But check out the spec, and if it's if any use to you @andyrlb you can have it.

This is a bit of a random post, isn't it. 😏

That is such a kind offer Jerry , I’ve read up briefly about it and can’t see myself using something like that . Really appreciate the offer though. Top man

 

[Lawrence001]

Does anyone here have concerns with the circuit diagram? I posted on AoS about the + being connected to both sides of the bass drivers and a short circuit across the amp at higher frequencies via the capacitors in parallel but I'm no expert. I think it's missing an inductor at the top + before the caps.

 

[bobovox]

There’s a short circuit with the +ve terminal connected directly to the -ve terminal (middle of diagram on the left hand side).

 

[Lawrence001]

There’s a short circuit with the +ve terminal connected directly to the -ve terminal (middle of diagram on the left hand side).

I assumed they were both supposed to be positive as it would be so obvious.

 

[bobovox]

I assumed they were both supposed to be positive as it would be so obvious.

It looks a bit like it started off with the top half of the diagram, with a +ve and -ve, which would be sensible enough but the second set of terminals got added along with the two caps. Difficult to know really.

 

[andyrlb]

Here what I downloaded with that schematic..


The Crossover is as simple as it gets. The highpass feeding the David "satellite" is a simple 1st order Unit. Note that the output to the Satellite is inverted in Phase. However, depending upon the room and listening conditions it may be neccesary to connect the David "satellite" in phase in order to avoid room resonances. Feel free to experiment.

The Lowpass feeding the Woofers uses an Impedance Compensation. If the Dynaudio 21W-54 Woofers are employed, this Compensation is un-neccesary and should be omitted. It might be desirable to connect a high power resistor of 15 Ohm Value (> 50W) across the Woofers to slightly attenuate the woofers as well as reducing the Impedance swing at low frequencies.

Again, building methodes and part quality are to the higest standards. The Wire to the woofers was left as conventional stranded wire, the wires to the crossover as well as those to the connectors feeding the David Satellite Speakers are made from the same DIY-Litzwire that was used in the Satellite. The short Interconnection between Woofer and Satellite also uses this wire.

 

[andyrlb]

So I have these …..


I intend to build a dual woofer cabinet ( puppies ) for these to sit upon .
And yes I will be completely changing the finish at least.

 

[bobovox]

I think I've got it - the Watt is wired across the lower set of terminals, hence the description of it being wired out of phase. A bit more labelling on the diagram have saved some head-scratching.

OK, based on the description in the text, I'm going to assume that the top half of the diagram is intended as the low pass crossover for the two Peerless units. The Zobel network is the 100uF cap and 2.7Ohm resistor across the terminals of the woofers. This flattens the rising impedance of the woofers with frequency, such that they may be considered as a resistive load. Ideally you would have a means of measuring the impedance of the frequency range of the drivers (eg a Dayton DATS) so that you can deduce the voice coil DC resistance and its inductance but without that you are stuck with using the datasheet values.

Generally, simple calculators don't work in practice, Zobel networks are one exception that do work, provided the DC resistance and inductance used are sufficiently accurate. You can calculate the replacement values for the Zobel here:

https://diyaudioprojects.com/Technical/Speaker-Zobel/

If you use the values for a single drive unit, double the capacitance and halve the resistor value as you have two drive units in parallel.

As I wrote above, I assume that the two capacitors are intended to provide the high pass filter for the Watt but it is not labelled clearly on the schematic. The value of the large inductor depends on the crossover frequency and the impedance of the Zobel-ed woofer pair. Do you know what the intended cross-over frequency is? I'm guessing the target crossover is about 150Hz?

Alternatively, as was suggested above, active crossovers have a lot of advantages in the bass region - you don't have to worry about the impedance, you can adjust the crossover frequency and attenuation of main speaker or bass unit at zero additional expense (ideally taking measurements with a microphone) the and you might even get the opportunity for room correction thrown in. Get a high power class D amp module to drive the bass unit and you are sorted.

 

[bobovox]

BTW also, are the replacement bass units about the same sensitivity as the ones for which the crossover was designed?

 

[andyrlb]

BTW also, are the replacement bass units about the same sensitivity as the ones for which the crossover was designed?

That was the original reason for my question
The drivers for that xover are no longer available so I need advice on which replacement drivers would be suitable and then how would I change the xover for said drivers ?
Or am I out of my league maybe

Here is a link to what I was sent , I also need to figure out the details of the xover in the watts .

http://web.archive.org/web/20090307015108/http://www.deadwaxcafe.com/vzone/david/david.htm

 

[dave]

Thanks, that link is helpful. re the original development. I would consider building the sub enclosure, but making the front panel where the drivers mount to be removable, so if some drivers don't work out it is not too painful to try some others. You could get lucky and land on some alternative drivers that just work.
It would be interesting to do some reverse engineering with a box calculator, if you know the driver parameters for the Dynaudio and the Peerless and the box and port dimensions, finding an alternative driver that gives a similar response, by dropping the parameters into the sim and comparing the responses. Not more than 1/2 a dB of relative lumpyness, depending on how good the original attempt was.

 

[andyrlb]

Thanks, that link is helpful. re the original development. I would consider building the sub enclosure, but making the front panel where the drivers mount to be removable, so if some drivers don't work out it is not too painful to try some others. You could get lucky and land on some alternative drivers that just work.
It would be interesting to do some reverse engineering with a box calculator, if you know the driver parameters for the Dynaudio and the Peerless and the box and port dimensions, finding an alternative driver that gives a similar response, by dropping the parameters into the sim and comparing the responses. Not more than 1/2 a dB of relative lumpyness, depending on how good the original attempt was.

I plan to make several baffles that I can change out to find the best solution/design. I think that the actual woofer cabinet will do the job well . Funny thing is I actually think I have 4 8” drivers in the loft but can’t remember for the life of me what they are ( no markings)
What would I need to look for in a driver to get close to the ones mentioned?

 

[andyrlb]

Something like these ?
They come with box calculations too .

https://www.falconacoustics.co.uk/d...nits/peerless-830667-subwoofer-sls-range.html