Calling all Dunlavy Gurus

I have read various posts about Dunlavys. But have any of the Dunlavy experts out there gathered the collective data on Dunlavys in one place (best mods, which replacement drivers work best, what not to change, etc)?

I have a pair of IVs and am trying to decide whether it would be worth it to mod those or whether I should consider buying some used VIs.
I would look at a pair of IVa's. I've owned both and IMO the IVa was significantly better than the IV particularly in the integration of the drivers. The overall coherence of the IVa is quite noticeable.
The IVa cost about double the IV.
I wonder how many SC-4 owners have taken a good look inside and noticed the splayed wire/clips connections to the drivers. Hard to believe, considering all the intelligence and care John Dunlavy put into his very fine product. Would one attach bare, splayed strands of speaker cable in like fashion to their speakers' terminals? Getting rid of those clips, situating the strands together and soldering to the drivers improved the overall coherence of my SC-4s.

Do you remember which version of the IVs you were comparing to? As I understand it, there were three versions using different drivers.


How hard is it to to get rid of those clips?

I honestly don't know. Purchased the original SCIV when they first came out @ $3999. Replaced these later with SCIVA @ $8000 if memory serves.

Frankly I didn't know there was a third version. I'm not saying there was no third version, I just never heard of it. I do not, in any way, consider myself an expert on these speakers.

I do know that I much preferred the IVA over the IV for reasons expressed above. IMO: When Dunlavy tweeked the original design he made major improvements.
There were 2 versions of the Dunlavy 4 speakers.
The SC-4 and SC-IVA speakers.
One of the differences between the 2 speakers is the 1VA speakers use two 10 inch Scanspeak woofers and the SC-4 speakers use two 10 inch Vifa woofers.
I can remember when the SC-IVA came out, John Dunlavy talked how hard it was to integrate the 10 inch Scanspeak woofers in the crossovers. He mentioned at one point, he thought about going back to using the Vifa woofers again in the SC-IVA speakers.
But eventually Dunlavy got the Scanspeak woofers to blend in perfectly to the mids of the SC-IVA .
Here's a good review of the Dunlavy SC-1VA speakers, where Dunlavy talks about the difference between the SC-4 and SC-IVA speakers.
According to Dunlavy, the ScanSpeak woofer has a much more powerful magnetic structure than the Vifa, and costs about four times as much. To get the best in bass performance, there's no substitute for magnetic flux, and big magnets are expensive.

The ScanSpeak woofer apparently has great low-end extension, but it also has some nasty peaks at the top of its passband. John Dunlavy says that he almost abandoned using the woofer for this reason, but kept coming back to it as the best driver for providing the bass extension and power handling he wanted. His solution to the problem consisted of several resonant circuits in the crossover, providing electrical compensation for the peaks.
Thanks Doug99, I'll check out that article. Again, my feeling is that the VIA is definitely superior to the IV. The delivery guys took the IVs (traded) when they delivered the IVAs.
I heard the difference as soon as I fired the IVAs up.
I'v heard the Dunlavy SC-IVA and the Dunlavy Aletha and no doubt Dunlavy made the best crossover.
The way the bass blended in perfectly to the mids and highs were perfect on the 2 Dunlavy speakers i heard.
Americanflag: Once inside the speaker, you will be able to
see where each clip is connected and how to remove and cut
them. After which, you will twist together strands of the
internal speaker wire and proceed with soldering to the
connectors on the drivers. Since I had never done anything
like this before, I had a friend who is an electronics
serviceman perform the entire job. Incidentally, I have the
improved, Signature version of the IVs.
The entire line of speakers, from the SC-I through the SC-VI were "Signature". That's what the "SC" stood for in the entire line.... "Signature Collection"
The only variant from this was the SC-IV versus the IVa, where the IVa was considered a different model and was actually sold side by side for a short period of time.

A couple of the other models also went through minor driver changes during their manufacturing life span but no distinctions were made.
The IVa was specifically different because it was so much more expensive than the IV and because it met Stereophile's demand of 20Hz in room response for class A "full range".
Incidentally, in response to the original post, the most comprehensive source of information on the web concerning Dunlavy speakers can be found at the link below.

It started off as a thread specifically comparing just one Dunlavy model to a pair of Legacy speakers. But it basically turned into the go to spot for a large number of Dunlavy enthusiasts.
It's very long but there is a lot of information there.
Yes, there was(is) the SC-4 and the SC-4A. However, there were two versions of the SC-4 prior to the appearance of the 4A. The first had Morel woofers and what were called composite fabric tweeters. In 1995, John Dunlavy made some changes to the original SC-4s. He replaced the Morel woofers with Vifa woofers and the composite fabric tweeters with silk dome tweeters. To accommodate the change in tweeters, he also modified some of the crossover values between them and the midrange drivers. Finally, he strengthened both the internal bracing and binding posts of the 4s.
I understand all that you have said, Opus88. But these changes were not something that John made a point of differentiating. It's not, as you implied, what made them "Signature". All of the models were always known as "Signature Collection". It would be more accurate to describe your units as being the most current version of the original. Semantics, maybe. But with all the information (and mis-information) on the web. I think It's important to make the distinction. Over time, and with endless random contribution, things can end up confusing to many.

All of the models, from the One through the Six, went through changes.
All of them had the tweeter change simply because the original, the D26, was replaced by the D27 by Vifa. The D27 had smoother response between 10k and 20k. As just one example. So it was easier to integrate. The handful of hardware changes were simply to give it a flatter response.
The SC-3 also went through a woofer change. Also from Morel to Vifa. And the SC-5 went through a upper midrange change, from a Vifa dome (D75MX) to a Vifa cone. The change in the SC-5 was purely for practical reasons as the D75MX did not stand up well to shipping conditions, let alone hard driving.
All of these changes were for practical reasons. If one were to look only at the measurement specs, the things John touted most highly, one could not likely tell which version of each speaker was being tested, so tight were his tolerances.

The IVa, on the other hand, WAS a significantly different speaker and as such received the "a" distinction. The rest of the changes, John himself argued, were not audible. Of course, most audiophiles trust their hearing far more that John did. After all he didn't believe in wire differences.

I, and a couple of my associates, have had in our possession at some point every single version of every model from the SC line with the exception of the SC-VI. I don't recall there being any internal bracing changed between the early and later versions of the SC-IV. But, it has been awhile since I looked. I'll have to check our records to confirm.

Never the less, the point here is not to call anyone out as being wrong or to argue. But the nature of the web is one of being timeless, so to speak. So for the sake of public record, I'm calling special attention to the above information.
True, ALL of the original Dunlavy models went through slight updates and changes as more preferable drivers models became available to Dunlavy. But, with the exception of the SC-IVa, these changes were not highlighted in any way by John or the company. Over the years salesmen have probably called attention to them. And I'm sure there are audiophiles who will insist that one version sounds better than another. But no special distinction was made by the designer.

Anyone interested in learning more about the Dunlavy designs should check out the link mentioned a few posts above. It has, by far, the most comprehensive information available on the web so far.
Kind thanks for the information you've provided, Pdprez. The link material is interesting reading as well.
I've spent time with the big Dunlav in a studio environment with near perfect acoustics powered by Pass labs.

The sound for a slightly truncated type speaker was nearly perfect with bass in the sub terrain, clean mids good treble though they did not have quite the vocal texture or speedy mid bass I'm used to nowadays they were quite amazing!