Watkins woofers- what's so special about them?

[KraftwrkTrbo]

I think due to the complexity of the Watkins design, I am better off just using the existing passive crossover, just provide a dedicated (hi amp) amplifier. So just bi amping for now. Need to modify the crossover accordingly. Then see how itN sounds, and if it warrants a further look into multiamping the low/mid, mid dome and EMITs.

 

[KraftwrkTrbo]

Any comment/suggestions why Infinity chose the VERY narrow band (just 1.5 octave) from 200-600 for the midbass? And the LOW (for a 1.5" DOME) starting point of 600?

 

[VanArn]

The impedance of the Watkin's speaker in the resonance region is unknown, however the centre frequency of the network can be found using f=1/2Pi x root(L x C).

 

[Bodhi1]

I know one thing, my Renaissance 90's ate my 100w Classe Cap-2100 integrated for lunch. The Rens were way underpowered. The next amps I bought would have been a perfect match - Boulder 1060 and modded/re-tubed Ayon CD-5s as linestage. But alas, I ended up selling the Rens within a few months and ugprading to Martin Coltrane Alto's

 

[Speakernutz]

I have 2 sets of WSC-1As made by Mr Watkins on my Yammy & wouldn't have anything else. One set was racooned about 10 yrs ago, I bought the 2nd set reconditioned from Mr Watkins. He & his son, Bill, are really nice guys, "Hard-to-get-away from" types when you go & see them...

Racooned???

 

[sregor]

Racooned???

As in "racoon those woogers".
Phrase has been floating around AK for nearly 20 years and probably came from a poorly worded ad and is a mispeak of "recone those woofers"

 

[Magfinity]

With today's technology I'd argue Watkins woofers are definitely outdated. Even back then I preferred servo controlled woofers over watkins offerings hands down.

That being said , it's well known that bill Watkins and Arnie nudell not always saw eye to eye. The rs4.5 was example of that , bill said in a old forum post that they got recalled due to killing amps.

He adjusted the woofers and asked nudell to adjust the crossovers as well. He refused , and they sent them out the door as is. Bill said something along the lines "I was contracted by nudell so ultimately his choice " but was outspoken enough to be discontent with that decision.

So far the Watkins I've heard rs series and definitely the Renaissance 90 and 80 (owned them, and were NOT HARD to drive at all so that's weird to read that above ) I feel they have this mystical lore around them perpetuated by fans.

In reality I've heard img woofers do just as good especially servo controlled (irs beta and the irs v) are definitely different league speakers. But still , didn't miss any Watkins

 

[MarkRSIIIa]

With today's technology I'd argue Watkins woofers are definitely outdated. Even back then I preferred servo controlled woofers over watkins offerings hands down.

That being said , it's well known that bill Watkins and Arnie nudell not always saw eye to eye. The rs4.5 was example of that , bill said in a old forum post that they got recalled due to killing amps.

He adjusted the woofers and asked nudell to adjust the crossovers as well. He refused , and they sent them out the door as is. Bill said something along the lines "I was contracted by nudell so ultimately his choice " but was outspoken enough to be discontent with that decision.

So far the Watkins I've heard rs series and definitely the Renaissance 90 and 80 (owned them, and were NOT HARD to drive at all so that's weird to read that above ) I feel they have this mystical lore around them perpetuated by fans.

In reality I've heard img woofers do just as good especially servo controlled (irs beta and the irs v) are definitely different league speakers. But still , didn't miss any Watkins

The funny thing, today's amps could handle anything Watkins could come up with, easy.

 

[Magfinity]

The funny thing, today's amps could handle anything Watkins could come up with, easy.

The woofers weren't really the issue, it was how nudell implemented them in his speakers.

Look at the kappa 9,img coned system that dips to 0.8ohm didn't even have a Watkins . The rs4.5 was plagued with impedance issue (even allegedly pulled under McIntosh) and had to be revised.

Infinity in terms of crossover design and complexity, and very dubious choices (using passive networks in a way to push more low end out of them)

Created more issues than the Watkins woofers themselves.

I also don't agree entirely with your assessment, there are plenty of amps today that won't take kindly to 2ohm and lower dips unless you spend big. And I'd argue with if your amps do it? I measured 8-10 amp pulls from a K9 on my amps. That IS NEVER good FOR any amp you're taxing them for no reason.

That's always been an infinity thing especially in their bigger models with Watkins and especially the k8 and K9 speakers. You had to spend significant coin for a current monster. That's not changed unless you want a class d on it.

Done that too (2.4kw at 4 ohm) and that went well, it was nowhere near my ati bricks tho in sound quality. Just the power supplies weight 100lbs I use two of them for my ht and hifi needs.

I got rid of my kappa 9 and rs1b I totally prefer the Cary Christie kappas over nudells. They were easier to drive and had way better drivers and design overall from its older brother the kappa series I (still own a kappa 8) my main system is the kappa 8.2.

 

[rs1b]

To better understand how and why you get low impedance numbers on models like the RS 4.5 you need to understand how the Watkins woofer and circuit works. It is a simple tuned circuit where the large value cap and coil resonate at a specified frequency . I will use the RS 2.5 for example . One Watkins woofer . In free air it should resonate around 20HZ and the 4 ohm coil will have an impedance of around 39 ohms in free air, at that point and the 2 ohm coil is around 10 ohms in free air. In the box the 4 ohm coil and 2 ohm coil will resonate around 40HZ and will have an impedance of around 26 ohms in the box for the 4 ohm coil and 4-6 for the 2 ohm coil. The cap and coil are designed to resonate at 40hz and since they are inline with the 2 ohm coil as they resonate it is basically a straight pass through to the woofer, and since the current flow would find it easier to go through the impedance of 2 ohm coil and that is what it does. The issue with the 4.5 is that they put the 2 x 4 ohm woofer in series which is amp friendly but the 2 ohm coil is put in parallel taking it down to just around 2 ohms or a little below like 1.8 ohms . They do add a bass cut switch to add some resistance into that circuit and I suggest always using it. The math for a tunes circuit is easily calculated. A tuned circuit by the bay doesn’t just start a one frequency , it will begin resonating well above and well below the actual point where the impedance is at its very lowest. The story that Arnie added mass thus causing the issue by having the resonance being off would only have created a slight issue on the 4.5's and I have never seen any drivers where mass was added on the poly cones . This I believe applied to the Quantum Line source QLSI The issue is that the two 2 ohms coils should never have been put in parallel. This can be fixed easily by putting those in series. Yes it will reduce a little of the ultra low end but only a very little. If you are a die hard and want it as it was made . No problem. Just get a good amp. I have the Aragon 4004MK2 and it doesn’t even break a sweat.
For the purpose of this reply it is referring to the RS 4.5's . These use a 20MH coil with a 2000 MF cap. This combo will resonate at 25HZ. The QLSI uses a 20MH coil and a 1400MFcap. This resonates at 30HZ . The RS 2.5 uses a 20MH coil and a 700MF cap and resonates at 42HZ

 

[Magfinity]

To better understand how and why you get low impedance numbers on models like the RS 4.5 you need to understand how the Watkins woofer and circuit works. It is a simple tuned circuit where the large value cap and coil resonate at a specified frequency . I will use the RS 2.5 for example . One Watkins woofer . In free air it should resonate around 20HZ and the 4 ohm coil will have an impedance of around 39 ohms in free air, at that point and the 2 ohm coil is around 10 ohms in free air. In the box the 4 ohm coil and 2 ohm coil will resonate around 40HZ and will have an impedance of around 26 ohms in the box for the 4 ohm coil and 4-6 for the 2 ohm coil. The cap and coil are designed to resonate at 40hz and since they are inline with the 2 ohm coil as they resonate it is basically a straight pass through to the woofer, and since the current flow would find it easier to go through the impedance of 2 ohm coil and that is what it does. The issue with the 4.5 is that they put the 2 x 4 ohm woofer in series which is amp friendly but the 2 ohm coil is put in parallel taking it down to just around 2 ohms or a little below like 1.8 ohms . They do add a bass cut switch to add some resistance into that circuit and I suggest always using it. The math for a tunes circuit is easily calculated. A tuned circuit by the bay doesn’t just start a one frequency , it will begin resonating well above and well below the actual point where the impedance is at its very lowest. The story that Arnie added mass thus causing the issue by having the resonance being off would only have created a slight issue on the 4.5's and I have never seen any drivers where mass was added on the poly cones . This I believe applied to the Quantum Line source QLSI The issue is that the two 2 ohms coils should never have been put in parallel. This can be fixed easily by putting those in series. Yes it will reduce a little of the ultra low end but only a very little. If you are a die hard and want it as it was made . No problem. Just get a good amp. I have the Aragon 4004MK2 and it doesn’t even break a sweat.
For the purpose of this reply it is referring to the RS 4.5's . These use a 20MH coil with a 2000 MF cap. This combo will resonate at 25HZ. The QLSI uses a 20MH coil and a 1400MFcap. This resonates at 30HZ . The RS 2.5 uses a 20MH coil and a 700MF cap and resonates at 42HZ

Actually Watkins himself spoke about that , they got recalled, bill himself did modifications to the woofer. And urged nudell to also handle the crossovers adapting them go the new parameters. As they kept blowing amps ) allegedly).

I remember reading that bill said something along the lines "we were contract bounded, so ultimately nudell did his own thing "

He refused to do so...it's a speaker I don't even wish to own . I find them butt ugly and knowing the harsh demand they have. Like the kappa 9's just to get some bloated low end out of them..no thanks.

 

[rs1b]

Actually Watkins himself spoke about that , they got recalled, bill himself did modifications to the woofer. And urged nudell to also handle the crossovers adapting them go the new parameters. As they kept blowing amps ) allegedly).

I remember reading that bill said something along the lines "we were contract bounded, so ultimately nudell did his own thing "

He refused to do so...it's a speaker I don't even wish to own . I find them butt ugly and knowing the harsh demand they have. Like the kappa 9's just to get some bloated low end out of them..no thanks.

You know its funny how stories come about. In the Quantum series of speakers Bill Watkins of course supplied the woofers. But if you look at the woofers that were used in the QLS1,Q2,Q3,Q4,Q5. They all used the exact same woofer # 902-1180 . Now consider the different box sizes . From the huge QLS1 to the much much smaller Q5's and everything in between all the same woofer. Since the woofer had an FS of about 20HZ it would resonate in a different place in each box due to size difference. If you look at the schematics for each you can see how Infinity just adjusted the cap and coil so that it would resonate to match the tuned frequency of the given box. The only one that it didn't work on was the QLS1 The box way far to big for that woofer and was very easy to over drive it. The tuned frequency of the box did not match the tuned frequency of the cap and coil which was about 25HZ. Even at that we sold a few of them and never heard of an amp blowing up. The 4.5's were a tougher load as discussed in the previous post but again almost all amps sold in those days could handle that load. Again we never had a customer complain about that. I have to wonder for those who complained what were they driving them with? If you were buying 4.5's in the day you were buying an appropriate amp. We sold them with Sansui BA-3000 or BA-5000 . Haflers, Phase Linear,Bryston, BGW, Ampzilla,Threshold. All drove with no problems. As to the 2.5's the RS2B RS1B all were not super difficult loads for a real amp. You can see for yourself the crossovers and parts used as below.

Infinity Quantum Serie

 

[kwape]

hey folks,

have a set of quantum 3's with watkins woofers which pertain to the rs2.5 and rs4.5 models. if anyone knows the correct part number watkins woofer for the quantum 3 speakers please let me know. might be sourcing a set if i can find them.

or perhaps i have the wrong information, the post above mine is to the contrary lol. maybe these are correct?

attached pics of the watkins woofers in my quantum 3

 

[rs1b]

hey folks,

have a set of quantum 3's with watkins woofers which pertain to the rs2.5 and rs4.5 models. if anyone knows the correct part number watkins woofer for the quantum 3 speakers please let me know. might be sourcing a set if i can find them.

or perhaps i have the wrong information, the post above mine is to the contrary lol. maybe these are correct?

attached pics of the watkins woofers in my quantum 3

If you are asking will they work in your application. The answer is yes. Are they the correct original woofers . No. If they were they would have black paper cones not Poly. If you had the original the difference you may notice a slightly better very low frequency response , The new ones have more powerful magnets and you will notice an improvement in mid bass and overall more efficient. They were designed for the 2.5's and the 4.5's which use much smaller boxes than the Quantum series.

 

[Jim Pearce]

If you are asking will they work in your application. The answer is yes. Are they the correct original woofers . No. If they were they would have black paper cones not Poly. If you had the original the difference you may notice a slightly better very low frequency response , The new ones have more powerful magnets and you will notice an improvement in mid bass and overall more efficient. They were designed for the 2.5's and the 4.5's which use much smaller boxes than the Quantum series.

Correct and I have some.

 

[Jim Pearce]

I bought a pair of Reference Standard 1.5's with Watkins 12" dual voice-coil woofers on ebay a few months ago. One of the woofers was damaged, maybe in shipping. (Hopefully the seller didn't sell it to me that way. I didn't have any way to test them when I received them because my receiver was out for repairs.) I live close enough to Watkins Stereo to be able to get them to repair and restore them. Mr. Watkins (son) found a used WA-120 in his inventory and replaced the damaged-beyond-repair woofer with the used one, so as to keep the system as original as possible, also less expensive than using new replacement woofers. He also spent some extra time expoxying the woofers to prevent damage if they are accidentally dropped. He gave (as in no extra charge) me a few extra fuses for the speakers, and he also made up a set of very nice speaker cables at no extra cost to me. (Can't guarantee that he will do that for you.) I think he felt sorry for me because the woofer was damaged when I received it. I picked them up a few days ago. He hooked them up to his in-store system before I left. The bass was just astounding. I could feel the vibrations in my feet. I listened to a jazz trio, and the cymbals were very nice. If the recording quality is good, the woofers render an upright bass very nicely. One hears a pitch, and not just a low thump, from the upright bass. I brought them home, hooked them up to my Yamaha R-2000 receiver, and put on "Heavy Weather" by Weather Report. Lots of low-frequency synthesizer stuff, which the 1.5's handled very nicely. I'm no speaker expert, but I am a bass player, and I like what I hear from the Infinity RS 1.5 with Watkins dual voice-coil woofers very much.

There is one hell of an interesting white paper on these.