I have used the Dunlavy SC-V(s) with great success over the
past couple of years. The only tweaks I've used with them
are the Marigo Dots (green/white)and Orchard Bay spikes. These speakers perform better than any system I have ever heard in the 30+ years of being in this hobby. I really cannot imagine the need for extensive modification; but
I'm certainly interested in knowing more about the results
of your efforts.
Actually the following mods would work to improve any speaker. Remove all the ferrous metals in and around the crossover these include all the steel hardware, screws mounting brackets etc. Replace these with brass.Replace the steel screws holding the drivers in place again with non-magnectic type such as brass. The 10 cent resistors in any crossover should be thrown away. They should be replaced with non inductive types such as Ohmite. Better yet would be resistor bridges made up of many Vishay bulk metal film resistors, these are very expensive but the improvement will bring tears of joy to your eyes. These improvements only enhance the already great attributes of Dunlavy speakers. Speed, soundstage width and height,inner detail focus and a much lower noise floor. I know these are all passive improvements. However they make the speakers more reactive to the music. I have also settled on the Sistrum speaker platforms from Star Sound. These effectivly again add a wealth of extra detail and speed. Dan if you are much more adventurous you can seal the inside of the cabinet with a latex based product that drys like concrete. This is available from Cascade Audio Engineering. When I first did this I only did the mid-range tweeter compartment of one speaker. Again the soundstage got wider and and more detailed. Of course it took many hours to complete this procedure. The increase in performance I felt made the pain in my back go away. You do not want to use to much of the Cascade product and measure it out the same for both speakers. Many of the caps I settled on as well as the 8 and 10 gauge inductors are can be bought thru North Creek Music Systems. I am at this time having an outboard crossover and new wiring harness being assembled. Some of these ideas are out of my realm of construction ability. If you like I can talk to you about this new wire technique as well as the construction and mounting of all the components in this outboard box. Oh I forgot the solid copper binding posts from Cardas also help. I know some of these changes are scary to do or to try. Most manufacturers use only the quality of parts needed to make there products sell for a certain price point. The parts and techniques I have selected would add thousands at retail.Oh ,the madness of HI-FI. Talk to you,Tom
Have you implemented zobel circuits on the drivers? I know of 5 Dunlavy owners who have done this with great success. Also, the tweeter needs to be replaced. A Morel MDT-33 makes a great drop in replacement that is much better than the stock tweeter.
No, I did neither of those mods.I feel that if you did those type of changes you would change the time alignment.I do not have the means to measure time offset.Actually the crossover upgrades and the removal of all the steel from the around the components really show how good the Vifa drivers can be.I have been told by a designer of amps and speakers that a .47mic film and foil cap across the output of the x-over to the 2- 10inwoofers will enhance the blend from bass to mids.
Dan, please excuse my ignorance....why does the non ferrous hardware make a difference to the sound? Where can I get the brass screws and other hardware?
Secondly, I tried to open the back of the speaker but the panel was stuck firmly even though the screws were taken out. Does Dunlavy use a glue to stick the panel to the box? Please advise.
Thanks in advance.
You should be able to get brass hardware at most hardware stores. Home Depot and Sears P&H in my area have them. The crossover panel has a thin foam seal around the perimeter. You may need to pry a little bit to get it started. The botttom crossover board is in wood alignment slots, so it will need to be slid out straight (not angular). The crossovers in the SC-Vs are surprisingly heavy, this may also contribute to your seemingly "stuck firmly" crossover.
Once you have the crossover out of the enclosure, I would also suggest changing the way the the lug panel is mounted. It will allow you to use any lugs on the back of the Dunlavys. This may be difficult to describe, I'll do my best.-- When SC-Xs are delivered from factory, it is nearly impossible to put large, inflexible cables (ex.Syn Res Des Refs) on them. If the ring (spacer) that is sandwiched between the lug panel and the exterior crossover panel is moved to behind the lug panel, there is then no well that is caused by that ring (spacer). If the above description is insufficient, I believe I have some digital photos around here if anyone would like them emailed to them.
Lastly, I would also enjoy a description of how non-ferrous fastening materials effected the original sound.
Thank you, Aaron
I would just like to thank all of you for your interesting
input. I'm not sure if I'm up to the task of taking the
speakers apart, but I've learned to really appreciate the
positve efforts of trying different 'tweeks' in my system.
I am curious about what it is that you like best about
the speakers? For me it's the incredible imaging that can
be achieved at the 'sweet seat' listening position. Well
recorded music takes on a holograhic character. This position is barely two listeners wide and is the result
of allot of experimentation. In many ways I feel that my
quest for superb music reproduction has been realized
with this design.
Thanks Aaron, I will try to pry open the speakers and also try getting the brass hardware. Thanks again.
Ferrous materials around the magnetic structure (other than the pole piece} will interfere with the lines of flux.The difference I heard when I subsituted the brass machine screws was a smoother,quieter sound, less apparent hash, lower distotion,with more focus to the individual sound stage.The crossover is mounted with steel screws,and the back plate has an adhesive gasket.This assembly can be slid out of the back for inspection.Aaron, the back plate for the input terminal can be removed and a new one can be made to replace it.If you do so then you can change to the Cardas copper connectors and use any cables you want.Brass hardware can be found more easily at mom and pop hardware stores than at the big boys.Again you can buy many of the caps and resistors and inductors from North Creek Music Systems.Remember I changed the inductor wire gauge so this made the inductor much larger in size.This much, much larger size required me to mount the crossover external to the cabinet which allowed me to use any and all types of spkr. wire as well as to remove the components from the turbulence inside the cabinet.When you add up all of the minor to small to large changes that I made to these speakers over the last few years the difference I feel and to others that have witnessed them, is Huge. As time went on I became bolder and more confident in the changes I made .Some times I thought to myself "Tom don't screw up these great and expensive speskers".Remember I never changed the value of the components, only their physcial quality. I would not recomMend changing drivers.Thanks for listening ,Tom
Tom. the Zobel networks will not affect the time alignment at all. Ehider knows what he's talking about. If you Zobel the drivers, you will get much more linear results, particularly around the crossover points. The one that is probably the most critical one to do is the woofer. Line one up for the resonant frequency of the woofer and you will be amazed.
Also, about the ferrous metals, if you separate the chokes and coils wider apart, they will have less interplay between them. The fields interact more when they are closer together. If you can get them a six inches to a foot apart, then do it.
It is critical when soldering to not get cold joints. They will filter the high frequencies out.
Thanks for the kudos. As you point out, the Zobels on Dunlavys are a definite mod to implement.
I know of 3 Dunlavy SC-IVa owners and one Althena owner who have implemented Zobels, and all are extremely pleased with the results. The sound is much cleaner and more musical. This mod does not have a downside. It is a true "win-win" circuit implementation.
Ferrous material in and around a circuit board can attract RFI.This is why one should use brass hardware which does not act as an antenna and also is less resonant
than the steel screws and mounting plates found in Dunlavy as well as other speakers.When I made hese upgrades in materials there an apparent improvement in clarity as cleaner upper mids and highs.
Ehider, where can I get these zobel networks or at least do some research on them? Thanks
Also, many thanks to Theaudiotweak for the update on mods on DAL loudspeakers!
Tell me your Dunlavy speaker, and I can give you the values for each driver. These networks go directly across the driver's speaker terminals. This is a 5 minute mod per driver (once they are removed, which you can soncially evaluate for yourself by doing only one speaker and comparing to the other.
In terms of doing research, you'll find more mis-information than good information on zobels. Where most people get confused is that a cululitive crosssover zobel circuits are much different than individualized zobel circuits wired across each and every speaker driver. Individualized zobel circuits are implemented to correct the phase angle shift that occurs at the speaker driver due to the inherent inductance within a speaker's voice coil. Once this phase angle is reduced by using this zobel circuit, the interaction between that driver and the amplifier is improved, which in turn improves detail and control (soncially).
The circuit that I am describing is a true "win-win" implementation, with no sonic or electrical downsides. It amazes me that more speaker manufacturers don't use these circuits. When you hear a pair of Dunlavys or Pipedreams improved (by their owners who implement these circuits) you start to wonder what else the speaker designer missed! In my experience there are MANY "Class A" rated speakers that can be improved upon with tweaks such as this.
I agree wholeheartedly with Ehider.
I won't even dare doing the cross-over mods or addding zobel (?)networks to my speakers(V's), But I could change all speaker fasteners to brass. Will the gain be significant?
I do agree that these speakers are great just the way they are. And I do sense unanimous agreement in above posts that the suggestions made speakers perform even better (hard for me to imagine), but risk of screw-up while performing the mods are great, perticulary if your are not hands-on with solder gun and stuff.
Say any of you who has done mods successfully in LA area?
hello I also would like to know if somebody in the LA area performs these modifications?
The Kentucky Derby is here in Louisville the first Saturday in May. Pack up your selves and your speakers and we will have a speaker modification party in the infield on Derby Day.Just being silly!! Anybody out there in the Ky. and Ind. area I could probably help you, or refer you to someone in one of those two states who could do these type of mods.....Tom
Any updates to this thread?
I have pair of Dunlavy SC-VI that I would like to upgrade the binding poles (with top Furutech), crossover capacitors and resistors, and perhaps bi-amp with an Krell KBX crossover.
Does anyone have the crossover schematics of the SC-VI or at least the low pass and high pass frequencies?
I have a pair of Dunlavy SC-VI, and I am considering upgrading the binding posts, resistors, capacitors. Probably with Duelund cast copper or silver components and Furutech top binding posts.
Perhaps also bi-amp them using an active crossover like the Krell KBX and a second pair of Krell FPB 750mcx.
Does anyone have the SC-VI crossover schematics and/or high-pass and low-pass filter frequencies?
Hey - I just decided to raise my Dunlavy SC-IV/a by adding the supplied bases, but have lost the original bolts. Does anyone know the size/metric/US, etc?
Im going crazy going back and forth to the hardware store.
I tried to lift up my sc 4s and help you out on the screw size ,but they are too heavy for a one man job. I would get 8 of every screw size thats close and return the rest.. i think mine were about 3 inches long, but is been many years since i moved them. Good luck and the bases with probably help tighten up the low end.
This is an ancient thread but seemed like, perhaps the best way to contact you short of trying through Star Sound Technologies...
Looking to potentially recap/refresh my Dunlavy SC-IVs and had a question or two.
Ancient???? Is the OP still living??
This is Tom speaking..send me an email thru Audiogon..and a phone number if you wish.
I replaced all the sand resistors with Mills and capacitors on my SC4,s years ago and your correct they ,made a huge improvement. I did the same with my Dynaudio S25,s , replaced the sand resistor with Mills, caps with Murdoff MPK and VCap CUTF bypassed with VCap TFTF on the tweeters and WOW you will get all you say u well theaudiotweek. The Dynamics's S25,s are just stunning now.
Those of you who are wondering on the bypassing of the CUTF with the TFTF is because the CUTF is smoother more magical then the detailed TFTF, The CUTF our only avail in smaller Values so I used a 0.01 CUTF bypass with a 1.5 TFTF, this will give you the SQ qualities of the CUTF rather then the TFTF.
I hope this make sinse.
By the way North Creek Music was sold and is no longer in business, Its a shame George was a great help to us DIY,s and built a crossover for me as well.