Help with Dunlavy SC-IV signature

Hello to all. I friend recently gave me a pair of SC-IV as they were too big for his room and he did not like their sound. The speakers sounded very bright to me but I attributed that to the cheap surround sound receiver he was using. I expected them to sound way better on my gear. No such luck. I tried them with a Moon P5 and Ayre v3 and they made my ears bleed, same with aMusical Fidelity M6PRX and Pre. I finally put then on a Nakamichi CA7 and PA7 with the tone controls all the way back and they started to sound way better. My current speakers are Martin Logan Expression 13A and Von Schweikert VR4 Get III. I added a Behringer DEQ2496 and turned the mids and highs down 7db and now they sounded very good. I have had Vanderstein 5A, Magnepan 3.7i and Utopias among others and I have never encountered something this bad. It's as if an equalizer was turned all the way up in the mids and highs. I removed one of the crossovers and to the eye they look ok I would have to remove them and measure everything to know for sure. Has anyone run into this before ? should I rebuild the crossover to see if it will improve ? What other measurements should I take ? Thanks in advance for your assistance.


Wonder if someone changed out some drivers resulting in a large imbalance between upper and lower frequencies.  you can look for signs that screw holes have moved.


That does seem strange. In all the years since they came out, I've never heard anyone describe them as bright or unbalanced.

I’ve never heard anyone describe them as bright or unbalanced.

Especially unbalanced unless somebody messed up before.

Check that tweeters are the originals and nothing is changed on the crossovers.

Searching on internet and Agon you can find useful info about their crossovers and how they should look.

Tone controls all the way back is not a good sign.

Your have experienced ears. 

The recording engineer who nudged me into this hobby had modified Duntech Sovereign's and me with little practical experience. He passed and years later I heard that general presentation again at a small shop with Dunlavy IV's. It wasn't about the scale of the big Sovereign's, I was told the time and phase is what I was glomming onto. Vandersteen's and Avalons get this.

IMO these are well worth investigating. Sounds like monkeys under the hood or aged out components. I know nothing but this might be a good place to get some direction. Good luck with it.

I am going to disassemble them and check drivers and connections. ultimately I will then look to do something about the crossover. thank you for the responses.

@cerberus79 This is hard to believe, but I trust you have done your home work. Dunlavy speakers are anything but bright. May I ask you what kind of source material you used to find out these speakers sounded "bright"? Also, these are very efficient speakers with sensitivity of 92 dB. Have you tried this with a tube amp?

Before you try to work on the crossover or any other parts, I would try to see if the problem remains with a tube amp. They have first order crossovers and drivers are designed to handle "leakage." If the drivers are changed, that may explain this problem. Also try moving the speakers to short-wall if these are currently placed  along the long-wall. 

I used both Qobutz and CD sources. I played Jazz, Blues and Rock. The results were the same regardless of music or pre and amp. I have not tried tubes. My tube amp is a Cary 300SEI F1 and it only puts out 13 watts per channel.

Dunlavys are 92db but were always better driven with good powerful solid state.

Requirement 100w in 4ohms min. Their resistance varies from 3-7,5ohms.

Needs too many tubes if going for good volume. 


@petg60 I agree with you about running these with a good SS amp due to impedance dropping to around 3 Ohms. All of my auditions with these speakers were done with SS amps. I think "problem" is with the speaker, not his electronics up stream.

I have visited Dunlavy Labs here in Colorado Springs many years ago. They are no longer in business and John Dunlavy has passed away. May he Rest in Peace! His speakers are used as references for mastering among many other applications. I finally settled with Thiel speakers and I could have easily accepted Dunlavy speakers too. Both use first-order x-overs and true to the source material. 

May not be a bad idea to contact Duntech and find out if they have any suggestions.

It appears from my research that these speakers do not have a common crossover. The crossovers were voiced to the pair, with that in mind I am going to remove but not disassemble the crossover and make a schematic of it. I am also going to get some speaker analysis software and measure their output. It was suggested to me that a simple resistor change in the Mid and Tweeter section might solve the issue.

I had a pair of Dunlavy SC 4 years ago driven with the original pass 350, didn’t do much for me so I got a pair of Papsworth Audio P200,s . 200 watts a channel that woke them up. 
I disagree Dunlavy best with high power ss, high power tubes yes. 

Did you ever find out what the issue was? I have 4 pairs of Dunlavys: SC-III, SC-IV and 2 pairs of SC-V, none of them are bright or unbalanced. I'd say they're the most neutral and balanced speakers I've ever heard. 

Perhaps there are some audiophiles not as great as they assume they are…




I have had a bunch of great speakers in the last 10 years including Vandersteen 5, 5a, Utopias, Electras, Magnepan 3.7i, Ariel 10t, Von Schweikert VR4 GenIII, B&W 802 D2, Tyler, Martin Logan Summit X, Martin Logan Expressions 13a, Reference 3a and more. The Dunlavy speakers were terrible. As it turns out the person that purchased them from me informed me that changes had been made to the crossovers. I suspected that but it was difficult to confirm because Dunlavy speakers of the same model can have different crossovers as they are voiced individually. The new owner has much experience in this area and was able to correct the issue. The speakers now sound very good.

Yep, what you described was atypical of the many many Dunlavy speakers i have heard and sold. My comment wasn’t aimed at you. Best to you on your musical journey 


@cerberus79,  good that you got to the bottom of the problem, even after no longer owning the speakers.

I enjoyed a pair of Duntech Princess speakers for 19 years and would like to clarify a few points here.

John Dunlavy began his speaker business, Duntech, in Texas before moving it to Australia.  That company continues in business under other ownership.

His Duntech models were high quality in design, components, and build.  John believed in time and phase coherency and based his designs on that.  But my Princesses were rated at 90 dB which may have misguided some.  The manual recommended at least 200 wpc "for musical enjoyment" and I found that to be true.   The best match I found was with VTL 300 monos, and later Parasound JC-1 mono amps.

At one point John returned to the US to begin building a new Duntech model.  My assumption was his concern over the high shipping costs from OZ because of size and weight, so a model built in the US could be more competitive.  However it was not a sales success and John separated from Duntech to begin another company, Dunlavy Audio Labs (DAL), located in Colorado Springs.  There he designed and began building a new line of speakers, based upon their sibling Duntech models.  These were the SC series mentioned here by others.  The DAL speakers became highly successful for both home and studio applications.  So I'm not surprised that your buyer found inappropriate crossover modifications to be the culprit for the poor performance.  John's engineering prowess led to the crossover designs which were critical to the sonic success all of his models. 

When John's health began failing he sold DAL, but the continuation of the brand was not successful and the company closed after about a year.  For those with adequate space and appropriate components I believe both Duntech and DAL models can provide great musical satisfaction, when found used in good condition.


@cerberus79 Somebody messing with the crossovers would explain a lot of things. John and team measured every single raw driver and entered all the measurements into a computer, computer-selected a set of matched drivers to build a pair of speakers, then tweaked every crossover in real-time to get the measurements he wanted, that were within a certain tolerance of his reference. Every single completed speaker, even within a matched pair, has slightly different values for the crossover components.

The reason I have two pairs of SC-V is because the first pair I bought showed up with dead tweeters and mids. The seller claimed they were fine when he put them into storage a year earlier, but didn't test them before he built a crate and shipped them to me from East Bridgewater, MA to Cedar Rapids, IA. He refunded me money to cover the cost of replacement drivers from Madisound, but obviously they weren't matched like they were from DAL. They sounded great when I got them going again, even better than my SC-IVs, but it always bothered me that they weren't matched like when they left the factory. I never did figure out the cause of the dead drivers; they all measured open, but didn't smell like voice coils were burnt. 

Another pair of SC-Vs showed up on eBay about 1-1/2 years later for a really good price, I figured if I didn't buy them I'd kick myself for years to come, and talked myself into buying them. I rented a cargo van from Enterprise and made the drive from Cedar Rapids to Irvington, NY to pick them up from mastering engineer Joe DiGiorgi. I'm extremely happy with them, and they'll be the last pair of speakers I ever need. Surprisingly, despite the replacement drivers in the 1st pair, both pairs sound very close, the main difference being slightly better imaging on the 2nd pair. JD changed from dome mids to cone mids during production, somewhere around serial number 150 from what I've found by looking at every available pic of SC-Vs I can find on the internet, and I suspect that has more to do with the slightly improved imaging than the replacement drivers. My first pair are 117-A/B, second pair are 198-A/B. 


Duntech/DAL crossovers -  The crossover board on my Duntech Princess was accessed by a removable panel on the back of the cabinet.  Once opened the board could be slid out since mounted on drawer rollers.

A friend of mine with design background was curious to see that crossover so I opened it up for him.  He exclaimed, "All it needs is a transformer and it would be as complex as an amplifier."  I don't have an electronics background but that board was stuffed with parts and looked complex to me!