Thanks. I'll try to convince my friend to contribute what he's done for his SC III's. I know he found some exotic military caps and ribbon tweeters.
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A great effort on your part, but it is all electrical. I had the SC-IV's and also made some mechanical modifications that I thought helped improve the the speaker dramatically. Change the bases to one's made by Sound Anchor in Florida. These are spiked and steady the speaker. On your new Eichman speaker terminals, be sure to solder them in. One major improvement that I made was to solder the wires directly to each driver. You should consider this when changing your wire. And last but not least is to install on the back of each speaker Tekna Sonic C-10's (4) & C-5 (1) vibration absorbers. Now the box will truly disappear.
Did you replace the internal wiring? What gauges did you use?
I removed the bases many many years ago. My speakers have no base and are supported with three Aurios Pro's with Black Diamond Racing pucks against the speaker and Tungsten balls between the Aurios/BDR pucks. This isolation technique is posted on my virtual system isolation page. With the Aurios, the vibration issue is completely gone. I also use one 1/2" Walker disk and one 1" walker disk on the top of the cabinet.
At any rate, you are very correct that the stock bases MUST be removed and replaced with something better.
Thanks for your comments,
JD well written and composed. Here are some of the additional mods I performed on my Dunlavys several years ago. All brass non ferrous hardware used thru out not steel of any sort. Paint internal surface with V=Bloc from Cascade Audio . V-Bloc is not a damping agent but a water based sealer that fills the pores of the wood, dries like concrete not rubber. V-bloc vibrational transfer agent made the biggest difference of all the mods I did to my SC4's and was also the most labor intensive. Mods were all applied in single stages ..replacement of inductors resistors and all caps. Crossover was outboard hard mounted on 1/4in. 2024 aircraft aluminum plate and then placed on Sistrum Sp1 coupling platform. Wiring harness consisted of 10 identical lengths of Sonoran Plateau speaker cable soldered directly to each speakers individual terminal.Speaker itself set atop Sistrum 101 coupling platform. Sounded speactacular, as big as they were they were gone, nothing but a wall of sound side to side and floor to ceiling..There is no reason why any speaker would not perform better with any of the mods JD described. The pain in the butt part is also the cool part. Perform each mod individually this adds to your learning curve and memory bank of knowledge as the mod progresses. Be patient all these parts need to breakin as individual components and then meld together as a group. Jd you offered much and you succeeded. Tom
hi guys .. first i must send a pray to heaven to Mr.Dunlavy for things he did for our ears.
after reading this thread some ideas to share appear in my head.
sc 4 is time (phase) coherent design so every changes in 3-d geometry must change time domain arrival of acoustic pressure .changing of bass units must by considered according to membrane geometry and i think its much better give a try to better existing woofers(decribed by mr.Dunlavy like a technologicaly not on top in cca 1996)..so try this.. increse BL figure by adding aditional magnet ring to existing magnet( from burned-out car woof bass unit.be maximally carefull with handling and attaching them to place.immediate increase of force is dangerous to your fingers and ring will be dammaged too )..increase will add "live" to bottom end and lift-up deepest octave.it brings a increase in sensitivity too,which is not needed.. attenuation of this phenomena of adding extra ring I use to "abuse" to cone damping with special coating (4-5 layers LTS 50 from VISATON solution 1:1 or 1.5 with water painted on old turntable in concentic circles continually from edge to center with paint brush.DO NOT FORCE DRYING WITH HEAT GUN,LEAVE NATURALY DRY OUT IN ROOM APROXIMATELLY 30 MINUTES )resulting in smoother midrange and better look . try this with midrange with 3 layers too..
next idea is to replace MOX resistors with Caddock mps resistors on alu cooler (take original insulation washers too)from old computer switching supply.. it will result in highest possible tranparency without residual harsh(caused by thermally generated noise in transients in carbon layer)..
next tip is internal wiring replacement with ultimate Cardas wire in proper size bought like OEM for internal speaker wiring in meterware.contact Cardas distributor near you.try teamwork with order.this decision to use Cardas wire lift your previously invested money somewhere you can hardly imagine.. i using Cardas in my top construction with Duelund caps and Mundorf supreme and matching of sound characters is magic(allow burn-in for month)..
try remake your existing printed board to point-to point wiring .. next increase of air and sharper bodies of instruments is on the way..
Thank you for your excellent thoughts. Given the language translation, you did a great job getting your ideas across, and gave very good descriptions of sonic expectations. The time phase is an issue, but the premium tweeter I replaced the existing tweeter with is physically exactly the same size. The only difference physically was where they have the wire connectors. This was why I needed to modify the cabinet by adding a small notch to allow for this.
I have given a great deal of thought to using C-37 violin shellac for the mid-range which should give a large improvement and then I can avoid the problems of substituting a premium mid-range driver.
Your magnet thoughts are very interesting, I will give that one some thought. I agree that the next two biggest improvements will be in internal wiring and an external point to point crossover.
At any rate, it's fun to see us trying to improve these wonderful speakers rather than trying to find a replacement. Given how good they are, and how those who like the sound of Dunlavy will need to spend a lot of money to match the quality of these speakers, modifying them seems to make a lot of sense.
It's also terrific having an international discussion. I love Audiogon for that.
HI JD6 :-)
C-37 is another good idea,but i never tried it on cone.i have a touch with it only throught website rewiew.shellac is acoustically very friendly material but very expensive in terms of hand made coating. i am using it as wood finish with significant improvement to velvet(vacuum tube-like) and definition(focus in image,air,being "there") of the Sound.
next i want to describe,is yout tweeter replacing . size (basket dimensions) is not the most important.. matching of the parameters is general task. resonance frequency ,impedance curve and sensitivity plays a game.original tweeter was made to Dunlavy specs by OEM department of Vifa.finding a match is like a win in lottery.so you miss a life chance to win money :-))) .. more questions?.contact me via mail,please.
After reading everything above it has become apparent that nobody on this thread has much technical knowledge. I'm not trying to rain on the parade here, but there are some serious issues with the approach taken by JD. Robert hints at the problem above, but doesn't quiet make it clear. Trying to "mod" your speakers by replacing the original tweeter with a more costly unit would be the same as trying to upgrade your Dodge Neon by jamming a Formula 1 engine under the hood - it just doesn't work like that. The reason the Dunlavy speakers sound good is because they're properly designed using proper testing equipment, years of experience, and a whole lot of trial and error. By replacing the tweeter with one that "looks physically the same" you've gone and ruined the entire design process. Did you check to make sure the TS parameters were identical? Does the efficiency match? Is the frequency response, resonance, and impedance identical? If the answer to any of the above is no, then you have to re-design the entire crossover to accomodate the new tweeter. Upgrading a few capacitors is not a re-design. A tweeter isn't like a capacitor. If you replace a cap with one of equal value and voltage rating, you don't alter the fundamental design. The tweeter on the other hand, is an electro-mechanical device, and unless it exactly matches the other unit, you're changing the fundamental design of the speaker so much that there's no way to tell what you'll end up with. If you're going to head down that road then you may as well start from scratch and design a proper speaker with top quality parts and top quality crossover components using proper technique and measurement equipment. Trust me, it'll be cheaper than spending $3000 on a pair of finished speakers, and then rebuilding them with another $2000 worth of "modding" parts.
Stick to simple cap / resistor / inductor upgrades, and whatever cabinet tricks you feel like. Leave the woofer, tweeter and midrange the way they are. Speaker design is not a trivial task, nor is it black magic. You don't just mix and match various expensive parts of arbitrary value to make a good speaker. Almost all tweeters look very similar, but trust me, they aren't the same.
Anyhow, the rest of your work looks pretty good, and congrats on the crossover upgrades, hopefully those caps sound as good as they look!
Owen not everyone who responded to this Dunlavy thread or other posts about these same speakers changed out any of the five drivers. Most all posters including myself made changes in crossover quality, wire and cabinet coupling only. Much of this has been written,posted and added here over a five year time span. Tom
Do you think I'm a complete idiot? Step back and read, YES SIR, THE SPECS DO INDEED MATCH IDENTICALLY!!!
Why the h&^$ would I post anything about the tweeter if not for teaching. I posted my experience so people could learn that despite an exact match in specifications, the sonic qualities are different. Yes, the Dunlavy speaker is built to an exact specification, many tests and ...
...TO A PRICE POINT. If there was not budget constraints (keeping the Dunlavy IV below the V) then I'm sure John would have considered better quality parts. That was never John's goal with his speakers. He strives to make a speaker at an affordable price point that would compete with more costly speakers. He succeeded many times over, but that is not to say the quality of the components are not suspect.
Of course the tweeter was a bold change. I'm not stupid! The tweeter also made a significant difference in clarity, grain and openness. It also appears (to the ear) as having a increased treble energy.) I reported this as a fact, that to my ear, so that others might learn. I thought I was quite clear about the risks involved with this modification, as well as all the others.
If the purpose of writing a post was to be perfect, than I could never write a word for I am very far from perfect. If the purpose of writing is to share experiences (as the novice you so eloquently pointed out, NOT) then I believe I did a great job, and you need to calm down. Perhaps a bit less coffee...
It certainly was nice hearing from you.
Following you footsteps I changed the tweeters of my Dunlavy SC-VI to top Seas Crescendo and it was a great upgrade, very similar specifications, sound much better.
I also vastly upgraded the crossover with Duelund.
My other components keep getting changed, but not the speakers, which sound amazing.
My congrats for the excellent work that you have done. I bougt in 1997 the Dunlavy SC-IV and I still have them. I like this speakers but sometimes I would like smoother highs. Could you kindly tell us which is exactly the model of Seas Crescendo tweeter that you have installed? Many thanks in advance. Carlo
JD, Thanks for sharing you experience! Lots of good info.
I am curious about the inductor values you posted of 4.42 mH and .082 mH. Were these the Duelund Engineers tested values ? and were they the final values used? also could you share the measured DCR values? A schematic I found on another forum indicated inductor values as follows: 0.16mH-0.16 Ohm, 8.2mH- 0.8 Ohm. Pretty different. I will measure the DCR values on mine when I remove, however I don't have the equipment to precisely measure inductance. If anyone else has any data in SC-IVA crossover inductors it would be most appreciated.