Official Sjofn HiFi "The Clue" Owners Thread

brad1138

Active Member
These fantastic, highly reviewed, little bookshelf speakers have nothing but a few very sporadic posts about them in various different online forums. I though I'd create an "official" place for owners/users to chat about them (since no one else has). And throw in my personal review.

The Clue's have a number of rave reviews over the last 6+ or so years, but still are a very unknown speaker. I had never heard of them, until I saw a pair on craigslist, and decided to pick them up last week.

They are everything the reviews say they are, the most detailed and revealing speakers I have ever owned, and I have been an audiophile for over 30 years, and an audio enthusiast for nearly all of my 50+ years... Imaging and sound stage are phenomenal.

They are a bit different in their placement requirements. Frequency response is rated at ~30 Hz to 30,000 Hz. But the low end is highly dependent on the room, and their set up in it. They are to be placed no more than 2.5 inches from the front wall, they are specifically designed to utilize the room to bring up the low end, or minimize the roll off. That may come across as a bit of a cheat, but they are designed to work that way, and it works!

My main system, consists of a pair of speakers I fell in love with in the 90's, the Mirage M3si's, driven by a Schiit Freya preamp and Mark Levinson #331 amp. I absolutely love that system, but I had never had as many spontaneous goose bumps, and chills down the spine, and even tears, as when sitting back and listening to the "The Clue's" (OK yes, it doesn't roll of the tongue particularly well...). I am still in the process of "dialing them in". The manufacture is adamant that the stand be 19-22" high. My Sanus stands where 23"... So I cut 2 inches off. I am going to have some much more substantial stands made for them, form a local welding shop.

Now with the speakers on a 12 ft wall, in a 12' x 13' x 8' bedroom, recently vacated by my kids (finally) moving out ;) I found a placement of about 16" from the outside wall, gave just the right amount (or at least best I have come up with yet) of bass. Sjofn recommend removing all bass traps, and only acoustic panels behind the speakers on the front wall. I found, with them as close to the outside walls of my room, panels on the side, worked for me (Yes, they have been borrowed from my home theater, I'll make more later).

My (recent) go to test tracks, as I have been rolling through various used speakers in this room, has been Adele 25 track #1 "Hello", Beck Sea Change track #1 and #2 The golden Age and Paper Tiger, off of CD (FLAC server actually). And Pink Floyd The Wall and Blood Sweat & Tears (ST) on vinyl.

I am not going to try to explain every nuance of every song, I am not that good of a reviewer (new to it anyway). However, the vocals (really everything) are so "unveiled" relative to any speaker I have ever had. The space around the vocals, evident with every word. The parting/movement of the lips, outside of the vocals, more clearly evident than I have ever heard.

The overall presentation is extremely smooth, not fatiguing in the least. The bass is quite good, although not quite as "overwhelmingly good" as a few other reviewers described. That could be 1 of 2 reasons, most likely due to being in a very boxy room, or I just haven't found the perfect placement for them. My money is on the former...

Included is a picture of the most current speaker location. FWIW, the room is also in need of a paint job and records on the wall, it's on my "to do" list...

I am so happy I happened across these, I think my search for speakers in this room is done :)

Again, FWIW, recent contenders, Ascend Acoustics Sierra 1s with standard tweeter, Linn Keilidh with 3 bar tweeter.

System:

ProJect Debut Carbon Esprit SB w/2m red cartridge>Schiit Mani w/Swagman Labs upgraded PS> or
FLAC server>Music Hall 25.3 DAC>

PS Audio P-200 Preamp>2 x Marantz MA-500 mono amps

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I mentioned Brian @baco99 because he has a pair of Clue's for sale that he has
gone over and detailed, they should be singing now! They are in Bartertown.
 
The guy I bought mine from used to build them in Seattle, he didn't build the pair he sold me though. He did throw in a fancy pair of "Supra Quadrax" cables, which currently go for ~$400 on eBay (I only paid $400 for spks and cables :) )

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OK, @brad1138 , here's my Sjöfn (the clue) saga in a nutshell....

Fig 1 - Sjöfn HiFi (the clue) Speakers
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I picked these speakers up to test them because of the reviews. I had to hear what was going on and understand what they were doing to get bass response that low from a 5" driver. The design is also strikingly similar to my own "Cleghan" speaker, which also has a funny name, uses a 5.25" driver, has a funny port, and is about the same overall size.

Fig 2 - Cleghan Compact Monitor & Custom Bandpass Powered Subwoofer
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Before I got the speakers, of course, I read all about the nuances of placement. I plugged them into my system on stands that were set to be the exact right height. I sat down for a listen, and... Sadness ensued. The speakers had some bass, which is remarkable for a compact speaker like this. But the high end was almost completely missing. Dull, lifeless. In disbelief, I tried them on a different system. Same result. I swapped amps. Same result. Eventually, I decided to take the speakers apart to see if there was something wrong. Turns out, there's a LOT wrong. But I will get to that in a minute.

For the record, the cabinets are made from Parts Express pre-built kits, with custom cut front faces to match the physical needs of The Clue's drivers. The cabinets are very well-built. The crossovers are mounted to the underside of the front baffle, with components glued directly to the MDF and everything is direct soldered. Crude, but effective and easy to access since the front face comes off easily with four machine screws. The 5.25” Scanspeak woofer is incredibly stout with excellent performance. The Peerless/Tymphany 3/4" dome tweeter is glued to a custom-cut waveguide, which is then glued to the baffle from the front. The tweeter is a good "budget" component, but not really in the same category as the woofer. The port is double-flared and about 10" long. The enclosure is STUFFED to the gills with foam egg crate, which acoustically makes the diminutive box "bigger" to the woofer, contributing to the low design frequency and the overall bass response. The crossover looks to be a fairly simple 2nd order 2-way at about 3,000 Hz with a Zobel network thrown in for impedance correction at certain frequencies. A thermistor was used in series with the tweeter as overload protection.

Fig 3 - (the clue) Crossover/Motorboard
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Fig 4 - (the clue) Woofer
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And this brings me to this particular (the clue)’s many issues...

Still in disbelief at how badly they sounded, I took some measurements. Lo! And behold! The high frequencies were dropping off precipitously at around 6,000 Hz. This could not be right. So, I opened up the speakers and connected just the tweeter with a very simple 1st order filter to see if the tweeters were gone. This test resulted in the tweeters coming to life in a way I hadn't heard before. That's when I did some investigative work. I noticed that some of the crossover components didn't look right to me. I sent an email to Lars at Sjöfn HiFi and explained the issue. He connected me to Jim Croft who sent me the crossover schematic. And there was the issue. The crossovers were wired incorrectly from the production line!

Fig 5 - (the clue) Frequency Curve - REW Measurement from 1 meter. Note the tremendous drop off starting around 6kHz.
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If you look at the crossover/motorboard, above, you'll notice a large coil attached to the tweeter as part of the slope integration part of the circuit. You'll also noticed three resistors labeled 1.5 ohm, 1.5 ohm, and 1 ohm. After comparing to the schematic, it turns out that one of those resistors is completely the wrong value. One of the 1.5 ohm resistors was meant to be 16 ohm! This makes a huge difference due to the placement of that resistor in the circuit. At 1.5 ohm, it's essentially creating a shortened signal path for the signal to "dump" from positive to negative without going through the tweeter at the output that's expected. So this explains why the tweeter had minimal output.

You'll also notice that the tweeter coil and the woofer coil are swapped. The woofer should have a larger 0.64mH coil for it's choke. Using the smaller coil essentially raises the crossover point of the woofer.

The solution was 1) Swap the woofer and tweeter coils so they are in their correct spots in the circuit, and 2) replace the arrant 1.5 ohm resistor with a 16 ohm resistor (I went with a 15 ohm, but given the +/-2% tolerances on resistors, this was close enough. They actually measured 15.35 anyway.). The result was incredibly flat response from 30 Hz to 20kHz, with just under 2% THD, even at the lowest bass frequencies. This is quite remarkable and part of the reason why these speakers had such stellar reviews.

Fig 6 - (the clue) Frequency Curve - REW Measurement from 1 meter. Crossover Fixed.
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But, that wasn't everything wrong with these speakers! The terminals were not installed all the way into the cabinets. This caused the internal wires to nearly touch inside the cabinet. I noticed a few times one of my amps going into protect mode, and now I know why! These speakers almost blew an amp! I removed the terminals, cleaned them, and installed them completely in the cabinet so they wouldn't rotate.

Fig 7 - (the clue) Rear Terminals - Installed Incorrectly
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Fig 8 - (the clue) Rear Terminals - Internal showing wires almost crossed.
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Fig 9 - (the clue) Rear Terminals - Installed Correctly
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But Wait! There's more! One of the bass ports was severed inside the cabinet. I had to repair this too.

Fig 10 - (the clue) Rear Terminals - Broken Bass Port
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In summary, (the clue) speakers are very special speakers. I fully appreciate and respect anyone (like me) who has decided to take a design, build something from their garage, and try to go mainstream with it. I also fully respect and appreciate all of the mistakes that can occur along the way as we entrepreneurs get excited and try to do things too fast. I don't know who assembled these speakers for Lars, franky it doesn't matter, but I would highly suggest anyone with (the clue) open up their set and take a look inside. It's possible you may have some anomalies in there that need rectifying. Once these issues are fixed, the rewards are exceptional sound in every way.
 
That is scary... sounds like yours were made by someone on their last day as an FU... I had read about the Parts Express connection.

Mine sound great, but now I am curious, so I will probably pop them open.
 
I also borrowed a pair years ago to compare to the Guru's and poped one open, mine
did not have those issues and I wanted to mention that point to point wiring is very
reliable as long as the wires are twisted so that there is a strong mechanical
joint before soldering. It looks like a few there were just tack soldered.

I thought the Guru's sounded better in level matched comparisons.

Wish I'd taken a picture of the Clue crossover.
 
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I also borrowed a pair years ago to compare to the Guru's and poped one open, mine
did not have those issues and I wanted to mention that point to point wiring is very
reliable as long as the wires are twisted so that there is a strong mechanical
joint before soldering. It looks like a few there were just tack soldered.

I thought the Guru's sounded better in level matched comparisons. Wish I'd taken
a picture of the crossover.


True - I am by no means implying that they are all like this, but they are so easy to come apart, might as well check.
 
True - I am by no means implying that they are all like this, but they are so easy to come apart, might as well check.

I was just giving another point of reference, your post was excellent and
people _should_ check their speakers.
That break in the splice of the port tubes is really bad, as I've said before aluminum
duct tape works great to splice them like that.

You mentioned a poly fuse, the Guru's also have it on the tweeters.
 
Well, I went ahead and pulled mine apart, and everything looks good. Although, that seems like an awful lot of very dense foam padding for a ported speaker... Basically, just about every inch inside is filled with it, just enough room for the woofer magnet and the port tube...

Does that seem right?

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Well, I went ahead and pulled mine apart, and everything looks good. Although, that seems like an awful lot of very dense foam padding for a ported speaker... Basically, just about every inch inside is filled with it, just enough room for the woofer magnet and the port tube...

Does that seem right?

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Yes, packed in very tight. All of those holes essentially add surface area, which "tricks" the woofer into thinking it's in a bigger box than it is. Not usually seen in ported boxes, you sometimes. It's a unique case. Show a pic of you crossover if you can. I'm curious.
 
I am still working on optimum placement, and acoustic panel integration. I have side acoustic panels, which does tighten up the imaging/clarity, but I have discovered it really robs the speakers of overall energy and impact. When I removed the side panels, the enjoyment I felt when I first hooked them up came back. I am going to build some side diffusers, which should retain the energy, and help with imaging. The imagining w/o anything on the sidewalls, is very good, with side panels, it is excellent. But overall, removing the side panels is the better option for me.

The room is 12' x 13' x 8', with speakers on 12' wall, and panels behind them. Speakers are currently about 2' in from side walls.
 
you look to be in good shape! since you have them open, wrap some duct tape around those ports where they connect
 
Also, a handy little trick to find 22.5 degree angle toe in. Take a piece of paper and fold from 1 corner twice. :) (90 ->45 ->22.5)

The Clue speakers are supposed to be exactly 22.5 degrees toed in.

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