Dunlavy Audio Labs Archive - From the mind of a "Legend"!
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Beerad
New Member
I had a couple hundred hours on the Jantzen superior z caps. And prob over 1000 hrs on the alumen z caps. I did try the cast silver bypass cap up until recently. They sounded great in most aspects but added a dryness to the sound the took away something that I liked with the tinned copper, fast forward till yesterday and I replaced the tweeter cap again, but this time to z-cap ODAM. Very early so far but really like what I’m hearing so far. Better than the Alumn out of the box in my system. Also got around to rewiring with the Duelund tinned copper a month or two ago. A lot of people on the forums have talked about this as an upgrade. The wire I pulled out was very badly oxidized and very green. It was a pain in the butt but has made a substantial improvement. After seeing how the old wires look, I imagine any new wire would bring sonic benifits.
SimplySound
Kent Engineering & Fondry
I've never had the gumption to mess with my SC-IV's, but your posts are giving me some thought Beerad. May probe your knowledge at some point, so thanks for your insights!
That said I did an ARC sweep of my room a month back and found that my HRCC Center Speaker had no treble. Turned out the tweeter had been replaced with a stock Vifa D27TG-35-06 at some point in it's history (unbeknownst to me) and it was blown. So I replaced it with a ScanSpeak Discovery D2606/9220. Sounds awesome!
So, I guess to those who are afraid to tinker with what John had so maticulously built, there could be some improvements made, no doubt!
That said I did an ARC sweep of my room a month back and found that my HRCC Center Speaker had no treble. Turned out the tweeter had been replaced with a stock Vifa D27TG-35-06 at some point in it's history (unbeknownst to me) and it was blown. So I replaced it with a ScanSpeak Discovery D2606/9220. Sounds awesome!
So, I guess to those who are afraid to tinker with what John had so maticulously built, there could be some improvements made, no doubt!
Beerad
New Member
Hit me up, would be glad to share any part of my experience. Have done some mods that have shown little or no improvement and some that have brought about meaningful changes.
Brent71
Well-Known Member
Not a clue. I pulled 6 drivers out of my first pair of SC-V and none of them had numbers written on them like that. It could be something as simple as how they were cataloged into their computer records, or it could be something else entirely. I'd be curious to know.
SimplySound
Kent Engineering & Fondry
Well 'Untitled New Member'... maybe you'll become a subscriber? 
He doesn't know how accurate we can be in the dark! Hope this helps!
He doesn't know how accurate we can be in the dark! Hope this helps!
SimplySound
Kent Engineering & Fondry
And in the process of helping out 'New Member', I stumbled on this interesting article from Audio Perfectionist Journal.
In this Journal we’ll examine some speaker systems which are demonstrably accurate, according to all the accepted objective standards.
These speakers have flat frequency response within narrow limits so they don’t emphasize some frequencies while de-emphasizing others. These speakers are time- and phase-correct so they won’t reproduce some harmonic overtones out-of-phase with the fundamental tones, smearing transient sounds over time
He goes into depth on Dunlavy, Thiel & Vandersteen. Pretty cool reading for a winter afternoon!
SimplySound
Kent Engineering & Fondry
OK Folks, this information is probably pertinant enough that I thought we should preserve not only a provided link, but also a PDF of the text itself. It is a LONG read, but valuable for referencing what some have done maintaining and improving these 'legendary' speakers now approaching 30 years old.
@Beerad, the experience with my HRCC has convinced me that I'm going to mothball my SC-IV tweeters and replace them with the ScanSpeak Discovery D2606/9220. Then I will probably follow some of this advice. Have you seen this posting on Audiogon and what are your thoughts having gone through the upgrade? I saw you used Duelund wire for connecting things together.
This is the source for Duelund Components...
@Beerad, the experience with my HRCC has convinced me that I'm going to mothball my SC-IV tweeters and replace them with the ScanSpeak Discovery D2606/9220. Then I will probably follow some of this advice. Have you seen this posting on Audiogon and what are your thoughts having gone through the upgrade? I saw you used Duelund wire for connecting things together.
Review: Dunlavy Audio Labs Dunlavy IVa crossover modification
Dunlavy crossover modifications starring Duelund Coherent AudioThis is the source for Duelund Components...
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pwayland
New Member
Hello all, It has been a few years since I visited this forum and appreciate the great information! Since then, I sold my SC-IVA to a recording studio in Nebraska however I have remained true to the DAL. Currently have 2 pairs SM-1, an SC-S2, an SC-S1, (both passive) and Duntech Black Knights. My first pair of SM-1 were purchased from a DAL Engineer named Greg in CO Springs. He worked as an engineer at DAL and included with the sale were two replacement tweeters of the same matched batch! The second pair of SM-1's I bought from Carl Mueller, who found his way to acquiring the remaining inventory after the factory closed. Both subs I bought from the daughter of a fan who had passed. Both with blown plate amps. I am writing and seeking for DAL knowledge, because I recently acquired a pair of Cantatas in CO Springs from CL. These are not like any I have seen and think they could be SC-III.A prototypes. The difference from Cantatas are as follows: 1. The front baffle is recessed allowing the rectangular grill to sit flush. 2. All drivers are Morel CAT308 tweeter, MW166 mids MW1076 woofers. The plate serial numbers are 197a and b. I have seen earlier and later Cantata serial numbers but these numbers are on the higher end. The X-Overs use SM-1 PCBs and they have DAL branded wire as well as typical solen fast caps etc. One woofer has 1994 date stamp. They sound wonderful and to my ears have extended HF as compared to my SM-1's. One woofer has an open circuit voice coil.... looks like Morel MW1075 is essentially the same and available... Would love to hear any comments or info anyone might have! 
SimplySound
Kent Engineering & Fondry
I believe you could be right PWay... the SC-III.A's on Page 4 of this thread show a rounded top corner. Yours doesn't have that so they could be a proto-type.
I spy a Pass Labs X150 or X3/X5 in your rig. I run an X3 and love the sound!
pwayland
New Member
Yes indeed, X150.5 biased to XA30 Iq. with ZenMod Labs Iron Pre (balanced) which I built. I just love the Pass Labs DAL sound!
With Black Knights
Brent71
Well-Known Member
They must be prototypes, or something built with leftover parts, because I've never seen a DAL speaker with Morel drivers, except for the early SC-IVs that had Morel woofers. Those were changed about a year into production to Vifa woofers.
edit: From what I remember, the Morel MW 1076 is the same driver used in the early SC-IVs.
edit: From what I remember, the Morel MW 1076 is the same driver used in the early SC-IVs.
pwayland
New Member
Yeah, weird right? The other oddity is square corners. Leads me to believe prototype. We know Morels were on the shelf. Only thing I can say is they have every attribute of DAL. Flat response, although the high end is faster and extended. I've heard it said JD had Cantatas in his house. A stretch for sure, but could these be those? I possibly pissed off Carl M. after my last purchase, but I'm sure he might know...
Beerad
New Member
Yes, I used Jadem6 experience as a guide for my upgrade with good results.
Yes I used jadem6 experience to help me navigate the crossover portion of my upgrade. He was very thorough in his process and descriptions. I have no experience with the scanspeak tweeter and how it will incorporate with the crossover. The seas crescendo which many have used is what I have opted for. I have tried different values of resistors in the main path due to the difference in sensitivity of the seas compared to the original. I settled using the same value that was in my original crossover. Sounded the best and most natural.
I did rewire with the duelund tinned copper wire in cotton. Used 12 guage for bass 16 for mids and 20 for the tweeters . Happy with results. Did have 16 guage on the tweeters originally but got better detail and air with the 20 guage. The process was time consuming and frustrating but worth it. I was unable to use original holes that wires went through. So I cut original wire close to the holes and left in place to keep the box sealed in those locations. Upon completion of drilling new holes inside and running new wire I siliconed all new wires in new hole locations. Can’t say I noticed a difference upon sealing new holes since I had the open until I was settled on wire diameter. Hope this helps. I do not get to this thread enough. If I haven’t responded in a timely manner or you wish to have a direct conversation feel free to email me directly at brad@gharring.com.
SimplySound
Kent Engineering & Fondry
Yeah, those are beautiful and I'm sure sound just as nice! Great setup there! Look like they have just the right amount of separation and rear wall clearence!
I wish I had the room to get a little more separation for my SC-IV's, but we have what we have! And that goes back to some comments that I've made in other threads that your room dictates your sound in many cases, even though there is always room to make minor tweeks.
Bodhi1
Super Member
Yes the Sovereigns are sizeable. They're the same height as the Infinity IRS-V's. My friend built a dedicated Den in his backyard for that system, hence everything was optimised for those speakers. Their transparency isn´t quite up to the level of the best modern speakers, but that can be substantially improved with a high end x-over upgrade incl: better internal wiring + some nice WBT Nextgen binding posts. That was a grainy photo and didn't really do the speakers justice. I've seen higher res photos and those sepakers were in beautiful condition. The buyer got a good deal.Yeah, those are beautiful and I'm sure sound just as nice! Great setup there! Look like they have just the right amount of separation and rear wall clearence!
I wish I had the room to get a little more separation for my SC-IV's, but we have what we have! And that goes back to some comments that I've made in other threads that your room dictates your sound in many cases, even though there is always room to make minor tweeks.
My current Magico S5 Mk2 speakers are about the biggest speakers I could fit in my apartment. Though i've learned that speakers like Magico's are over-engineered and unecessarily expensive, and that better value can be found elsewhere. My next speakers (Qualio IQ's) will have a smaller form factor, yet they will have significantly better sound staging, imaging, off-axis performance and naturalness. The only area where my Magico's would have an advantage is in the bass which is a compromise I can live with. My next speakers will also be much more affordable, which will allow me to specifiy a high end x-over upgrade & invest in a better amp, cables and new racks. And the Qualio's won't dominate the room like my current speakers, so happy days.
But I digress, the SC-IV's are good performers and are good value, but still large speakers at 6ft h x 34" d, so they'd need room to breath as you noted. Re: your comment about speaker-room coupling, I agree. When I bought my S5 Mk2's, I bought them because obviously I liked their sound, but also because the S5's coupled optimally to my room. Then I built the rest of my system around the speakers which is consistent with my approach to system-building. Based on all the feedback I've gotten from Qualio's Designer, Grzegorz Rulka, the IQ's should blend into current living/dining room without causing room issues. The speakers are rear-ported, however they come with acoustic foam bungs for the rear ports if required, so I wouldn't need to add room treatments if I have any bass issues, which is good given my limited options to bring the speakers out in the room.
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