Hivi 3.1A DIY Speaker With Sehlin Mod Review

[beagleman]

I think I'm going to put another set of these together stock and send them to GR research and have him build a crossover for them. He seems to get a lot of praise for his work. I think these are worth it.

Not even sure why I am replying to this comment, but what you are proposing surely can not hurt at all, but do you feel almost like you are cheating on Scott S.??

 

[AllenW]

Not even sure why I am replying to this comment, but what you are proposing surely can not hurt at all, but do you feel almost like you are cheating on Scott S.??

I don't think so. I really like what he did with these and I'm sure he could have made it as good as anyone if he had started from scratch but I feel like I'm imposing on him by asking him to do that. I can go this route and pay for it. I just think these speakers can be epic. I want to see what's possible.

 

[AllenW]

Not even sure why I am replying to this comment, but what you are proposing surely can not hurt at all, but do you feel almost like you are cheating on Scott S.??

I mean he was doing this to keep it budget. I'm just hyped on these speakers and want the best version possible.

 

[beagleman]

I mean he was doing this to keep it budget. I'm just hyped on these speakers and want the best version possible.

It is fine, I was semi kidding to be honest. Your motivation makes more sense to me now.

Hope they turn out to your liking!
A very impressive speaker for sure.

 

[Piranesi]

There now exists the Swan/HiVi M300 Mk. II, a very interesting proposition for the price.
It's conceptually similar to the 3.1s, as a three-way speaker with a planar tweeter, 2-inch midrange and 6.5-inch woofer.

The difference is that it benefits from built-in discrete amplification, DSP, and streaming capabilities. And all of that for about ~800usd sounds like a screaming good deal.

For what it's worth, Zeos from ZReviews (predictably) loved them. It would be interesting to get a pair to Amir for measurement. I'm planning to purchase a set myself at some point- either these M300 Mk. IIs or their bigger brother M500s with an 8-inch woofer instead.

 

[Mudjock]

I've been silent on the "tubbiness" issue, as I am not sure whether a crossover mod is the best way to fix it. Often one is stuck with whatever the bass alignment is, unless one wants to change that via a different cabinet volume, port size, or damping material inside the cabinet.

In practice, one can sometimes change the perception by adjusting the level of the higher frequencies to balance the sound out. In this case, the adjustment I suggested and AllenW implemented did address some of the high frequency emphasis, but Amir's measurements (which I believe to be more accurate than mine at lower frequencies) also showed a bit of a dip in the 200-400 Hz lower midrange region, which might allow the area immediately below to be emphasized. That could be helped by changing L4 from 1.5 mH to 1.2 mH and increasing C5 from 68 uF to something around 100 uF.

 

[beagleman]

I've been silent on the "tubbiness" issue, as I am not sure whether a crossover mod is the best way to fix it. Often one is stuck with whatever the bass alignment is, unless one wants to change that via a different cabinet volume, port size, or damping material inside the cabinet.

In practice, one can sometimes change the perception by adjusting the level of the higher frequencies to balance the sound out. In this case, the adjustment I suggested and AllenW implemented did address some of the high frequency emphasis, but Amir's measurements (which I believe to be more accurate than mine at lower frequencies) also showed a bit of a dip in the 200-400 Hz lower midrange region, which might allow the area immediately below to be emphasized. That could be helped by changing L4 from 1.5 mH to 1.2 mH and increasing C5 from 68 uF to something around 100 uF.

With that woofer (assuming L6-4R) looks like the cabinet size is ideal as is. I assume they "tuned" the box to right around 50Hz. With my quick calculations it should be very flat to to, and a bit below box tuning.
And it looks like your measured impedance "dip" is right around 50 Hz.
I was just curious if more deep bass could be found, but looks like box if anything is a bit on the large size already, and pretty much close to ideal.

assuming woofer is Fs 50, Qts .4 and Vas of 14.69 l.

 

[larry8]

The mod to the tweeter circuit is just component swaps, too. The only difference is that all 4 components are swapped.
R1 goes from 1.5 ohms to 5.6 ohms
C1 goes from 3.3 uF to 1.5 uF
L1 goes from 0.1 mH to 0.15 mH
C2 goes from 6.8 uF to 2 uF

Hi,

Planning to build this amazing speaker, just a question on the perfectionist mod.

In some posts such as this one:

https://imgur.com/a/GvjB52R

I see that modded component list has:
1x Rezistor of 5.6 ohms
2x Rezistor of 2 ohms
1x Capacitor of 1.5 uF
1x Capacitor of 5.6 uF
1x Capacitor of 2.2 uF

So 2 questions
Why the difference of of 2.2 uF capacitor (shouldn't be a 2.0 uF one ?)
In your list above you don't mention anything on the 2 ohms rezistor

 

[Mudjock]

I used 2 uF for one of the capacitors in the tweeter circuit. Some have used 2.2 uF. My sim shows a negligible difference and I haven't heard any negative reports.

There are actually 2 ohm resistors used in the perfectionist mod, but they are in the woofer and midrange circuits. The post of mine that you quoted describes the tweeter circuit.

I hope that helps.

 

[01svtL]

It looks like these scored about the same as the GR Research XLS Encore with subs. Am I reading that correctly? I want to do a floor stander, and was considering using the front baffle of the HiVi 3.1 and building into the PE Denovo 1.16 knockdown cabinet cabinet, or going with GR's X-SLS encore floor standing kit. I will be crossing to an HSU sub, but want to cross around 50-60hz, so need my mains to have some punch. I listen to rock/metal - any advice?

 

[larry8]

I used 2 uF for one of the capacitors in the tweeter circuit. Some have used 2.2 uF. My sim shows a negligible difference and I haven't heard any negative reports.

There are actually 2 ohm resistors used in the perfectionist mod, but they are in the woofer and midrange circuits. The post of mine that you quoted describes the tweeter circuit.

I hope that helps.

Thanks @Mudjock it's my first time venturing into the DIY, hence apologize if asking any stupid questions I'll try to use 2 uF then, as I think this is what the circuit diagram shows as well.

One more if I may, it's around the damping material. I think the kit comes with something included (foam), but it doesn't seem to be traditional material. While reading some comments and forums, some are suggesting that the foam is not intended to be used for filling the cabinet, but rather for packaging. While some say this foam can be used inside the cabinet. What would be your suggestion?

 

[drfous]

The Swan videos show the cuts and measurements for the included foam.

 

[GGroch]

As of Sept 25 all of the Swans/HiVi products on Amazon U.S. are no longer available. Swans US website has also been down for several weeks. The SWANSKITS.com with assembly videos is still up, that is maintained by Frank Hale.

Hopefully this just marks a just a change in distribution and they will be back soon rather than an exit from the U.S. market.

 

[sychan]

In practice, one can sometimes change the perception by adjusting the level of the higher frequencies to balance the sound out. In this case, the adjustment I suggested and AllenW implemented did address some of the high frequency emphasis, but Amir's measurements (which I believe to be more accurate than mine at lower frequencies) also showed a bit of a dip in the 200-400 Hz lower midrange region, which might allow the area immediately below to be emphasized. That could be helped by changing L4 from 1.5 mH to 1.2 mH and increasing C5 from 68 uF to something around 100 uF.

Hi Scott,
I just managed to get my hands on a HiVi 3.1a kit today, and I'm trying to figure out what your the final crossover suggestions are. I think I found the crossover that AllenW built from page 4 of the thread. Apparently with this crossover, eventually the brightness settled down to reasonable levels after some break-in (though that may be a contentious idea). You suggested that the remaining bass criticisms might be addressed by changing L4 and C5. Is this drawing a reasonable summary of the final state of the crossover?

Do you think the last 2 changes are worthwhile, since it seemed to be kind of off the cuff, unlike the updated crossover on page 4 which you had modelled?

Thanks!
Steve

 

[Mudjock]

Hi Steve, I did model the L4 and C5 changes, which you depict correctly, before I suggested them. Below is a comparison of the two (green curve is Mod6). It shows a small change, but one that should help fill in the dip shown in Amir's on-axis measurement in the 200-400 Hz area.

The difference between Mod5 and Mod4 (the "perfectionist mod" in red) is quite a bit larger.

So I would definitely recommend trying Mod5 if the perfectionist mod is too forward or too bright in your room/system. I think Mod6 goes a little further in the right direction, but I'm not sure how audible it will be.

 

[sychan]

Hi Steve, I did model the L4 and C5 changes, which you depict correctly, before I suggested them. Below is a comparison of the two (green curve is Mod6). It shows a small change, but one that should help fill in the dip shown in Amir's on-axis measurement in the 200-400 Hz area.

View attachment 167036

Thanks for posting the FR differences for the 2 mods, I really appreciate how thoughtful you are in following up!
Yeah, just eyeballing the delta between mod5 and mod6, it looks a good deal less than 1db, probably totally a wash in any room you'd actually put the speakers. That's super useful to be aware of, thanks again.

 

[ayane]

I just bought a kit to build these speakers, and I'm looking forward to putting them together and using them. I'll be pairing them with a Loxjie A30 for now, and perhaps a PSB PB-1000 down the line. It's my first foray into high fidelity speakers (Edit: into building and owning my own HiFi, not experience), and I honestly would've never been down this route if it weren't for ASR to give a starting point. I think this is the best that $500 can buy today.

I think the "tubby" bass will need some re-tuning of the acoustics to improve; that'll be challenging but worth it since the woofer is rated to work well down to 50 Hz. I'm going to design my own crossover circuit for these to then get a flatter response from ~50 Hz and up. The response from mods 5 & 6 (Thank you @Mudjock !) are a good starting point. I also want to take advantage of the bi-wiring posts so that I can bi-amp them down the line, although that may be overkill for a budget bookshelf speaker, depending on how much power they can handle...

 

[tktran303]

Hmmm.

“First foray into high fidelity speakers” and “I’m going to design my own crossover circuit” is going to be difficult.

You will go further if you build them as designed and use some room EQ to tune the bass to your liking.

Otherwise you may go around in circles.

Nothing wrong with that of course, as long as you’re willing to play the long game…

 

[ayane]

Hmmm.

“First foray into high fidelity speakers” and “I’m going to design my own crossover circuit” is going to be difficult.

You will go further if you build them as designed and use some room EQ to tune the bass to your liking.

Otherwise you may go around in circles.

Nothing wrong with that of course, as long as you’re willing to play the long game…

To be clear, it'll be my foray into owning a hi-fi system. I have plenty of experience with audio acoustic, electronics, and DSP engineering; I just haven't ever had the time or patience to have and set up my own, and I'd rather begin with something cheap (but still competent). Even so, I hardly think implementing just the crossover mod would be difficult for a beginner. I do agree that the room correction deserves its due diligence always, and that's a separate ongoing project

My end goal is to flatten the the on-axis response with as much bass extension as possible so that they sound as best as they can, sans-EQ. The reason I'll be re-doing the cross-over is because I plan on modding the acoustics of this speaker to achieve this goal, and that'll completely mess up the response that the crossover was intended for. I think the woofer can perform better than it is within the stock arrangement. I think it's a reasonable goal to get this woofer to extend flatly to 50 Hz reliably by tweaking the port alignment or cabinet arrangement. Of course, all of that will completely change the measurements.

If I can get the bass to extend just a tad bit lower while preserving the midrange and tweeter output and distortion, I think that's a much more solid starting point. The stock response has too much energy in the mids (kind of a "cuppy" sound to me that's most apparent in the 303's in acid house music) and clearly overemphasized highs (it's most evident to me when listening to the high frequency effects in "Sonic After-6290 Mix" or Christina Aguilera's "Genie in a Bottle") compared to hearing it on the Genelec 8341As. Amir called the HiVis "bright" in the review, but I'd go so far as to say that they're kind of "glassy" or "shouty" after hearing the un-modded version in a reference room.

What I had in mind is to flip the rear panel to have the port on the bottom with a tube extending it up to the top, and stuffing some additional damping to mask the tube from the midrange and tweeter (and perhaps absorb some of the tweeter/mid reflections and port leakage that may be causing the up-tilted stock response in the first place). I might also 3d print a different port entirely depending on how much patience I have...

 

[Mudjock]

I'm not sure if it was clear, but what Amir reviewed was "Mod 4", which some still found a little bright. The crossover from the stock kit is a lot brighter. "Shouty and glassy would be consistent with my recollection. My pair started their life out that way.

If you are interested in doing your own design, I would applaud that. I am sure others will be interested in what you come up with. My recommendation would be to set yourself up so that you can revert to Mod 4 to Mod 6 in case the improvement efforts don't go according to plan. It's also worth noting that an advantage of the bass alignment HiVi chose is that power handling is very good. Trying to extend the bass response will negatively impact that somewhat.