Sealed mini speaker, 3-way

[Heinrich]

There's always somebody who thinks they can come up with a better mousetrap.
Without a proper understanding of the limitations involved, your April Fool's speaker is just that.

You don't offer any arguments that I can recognize. I've noticed that from time to time. You only dismiss any respect for the arguments and explanations given before. So if you can think of something to change the above, go ahead. It is your turn. I don't consider myself to be in a poetry club.

 

[Kremmen]

I’ve got my dad’s KEF Chorale he bought in 1978 and are still in excellent condition, as I offered to help him sell them. They are best placed on low stands to get some floor gain and avoid floor bounce cancellation, but pulled away from the front wall they image terrifically and are very clean and quite linear sounding. Or they can be placed right up against the front wall if you need to position them higher up.

I temporarily replaced my Revel M16 with them and they are less refined, and lack bass in treble extension in comparison, but in isolation are great fun and look cool if you like retro.

View attachment 441079
[Star Wars balloons were for my son’s birthday]

Thanks for the post.

BTW, I'm no expert but your photo has me wondering, do you know if there is any benefit to the listener to having both speakers featuring a tweeter to the left of the midrange/woofer? I'd have thought they would be to the left and right of the midrange/woofer respectively (like my Castle Howard S2 speakers and countless other speakers). Thanks.

 

[Matt_Holland]

Thanks for the post.

BTW, I'm no expert but your photo has me wondering, do you know if there is any benefit to the listener to having both speakers featuring a tweeter to the left of the midrange/woofer? I'd have thought they would be to the left and right of the midrange/woofer respectively (like my Castle Howard S2 speakers and countless other speakers). Thanks.

I always assumed the tweeter is offset to the same side on both speakers simply to reduce manufacturing costs.
The offset itself will bring a benefit, compared to being centred on the baffle, by spreading out baffle diffraction effects. The irony is that there is still the very prominent lip around the baffle edge and the grill design has no chamfering on the cutouts.
A very quick room measurement using House Curve showed the high frequency response on the Chorales to be quite uneven (albeit with a fairly flat overall trend) compared to my Revel M16.

 

[Kremmen]

I always assumed the tweeter is offset to the same side on both speakers simply to reduce manufacturing costs.
The offset itself will bring a benefit, compared to being centred on the baffle, by spreading out baffle diffraction effects. The irony is that there is still the very prominent lip around the baffle edge and the grill design has no chamfering on the cutouts.
A very quick room measurement using House Curve showed the high frequency response on the Chorales to be quite uneven (albeit with a fairly flat overall trend) compared to my Revel M16.

Yeah, I too assumed it could be to reduce manufacturing costs (not as many jigs etc.) and hopefully there would be no detrimental effect on the sound when the speakers were combined.

I hadn't thought about offset drivers spreading out baffle diffraction effects so thanks for that info as I'd noticed that many Castle speakers in particular feature offset drivers. I'll do some research into this!

Thanks for your reply.

 

[Heinrich]

Yeah, I too assumed it could be to reduce manufacturing costs ...

The industry didn't really take off-axis reproduction into account back then. On-axis, the offset is advantageous, to not mirror left/right saves costs, side effects are neglected.

Edge effects from the enclosure are indeed a big problem if a straight-line frequency response is the goal. With my speaker, there was simply nothing that could be done because of its size. Even when placed on a shelf and packed with books, ripples of +/-2dB max remain at almost, depending on direction, randomly distributed frequencies. There are no focal points and the dispersion is very wide anyway. Subjectively, I would tend to deny a bad interference with the sound impression, it doesn't distract from the content.

 

[Matt_Holland]

Yeah, I too assumed it could be to reduce manufacturing costs (not as many jigs etc.) and hopefully there would be no detrimental effect on the sound when the speakers were combined.

I hadn't thought about offset drivers spreading out baffle diffraction effects so thanks for that info as I'd noticed that many Castle speakers in particular feature offset drivers. I'll do some research into this!

Thanks for your reply.

When I was a teenager and lived at home (mid 1990s) I would often pull the chorales right out into the room well away from the front wall and any side walls. They were on low stands which no doubt helped keep the lower mid and upper bass full. Anyway, in this position they imaged like crazy. The whole soundstage started around a foot behind the speakers and depending on the recording, some instruments were placed 3-5 feet back.
My dad, whilst into hifi, had no idea that you could create such an effect from well positioned speakers.

 

[Heinrich]

When I was a teenager and lived at home (mid 1990s) I would often pull the chorales right out into the room well away from the front wall and any side walls. They were on low stands which no doubt helped keep the lower mid and upper bass full. Anyway, in this position they imaged like crazy. The whole soundstage started around a foot behind the speakers and depending on the recording, some instruments were placed 3-5 feet back.
My dad, whilst into hifi, had no idea that you could create such an effect from well positioned speakers.

I had a pair of Canton GLE100 a few years back. Despite all modern instrumentation and EQ I couldn't get it to sound right. It drove me into desperation. The 60/70s were not that romantic as one wants to believe today ;-) Many times people were just happy that something comes out and there is plenty of bass and treble, which they missed from their kitchen radio.

 

[Joe BKNY]

The 60/70s were not that romantic as one wants to believe today ;-) Many times people were just happy that something comes out and there is plenty of bass and treble, which they missed from their kitchen radio.

! Truth! Those years may appear to younger hipsters like a happy universe of vinyl surrounded byMidCenturyMod danish furniture. But deeply antagonistic social divides, and the ongoing death of thousands of young soldiers and civilians in a hopeless war (among other things) were playing out to the sounds of acoustic suspension loudspeakers from AR and KLH. Speaking of, the arrival in our kitchen of a KLH Model 21 transistor compact tabletop radio able to play in what sounded to our young ears like hi-fidelity the new phenomenon of free form FM radio felt like a revolution.

 

[Heinrich]

! Truth! Those years may appear to younger hipsters like a happy universe of vinyl surrounded byMidCenturyMod danish furniture. But deeply antagonistic social divides, and the ongoing death of thousands of young soldiers and civilians in a hopeless war (among other things) were playing out to the sounds of acoustic suspension loudspeakers from AR and KLH. Speaking of, the arrival in our kitchen of a KLH Model 21 transistor compact tabletop radio able to play in what sounded to our young ears like hi-fidelity the new phenomenon of free form FM radio felt like a revolution.

Yeah, stereo (stereo) was just magical, from vinyl. All those bits and pieces, the many things to consider, a clean record surface to begin with. I started with a tube radio, steampunk already, then in the age of 12 began to dismantle that 600 volt gear … and the next reiterated for the first six lives of me.

Now, this little speaker in focus here, is meant to be end game. Of course it does not pay for all the thought and craftsmanship needed to build it. I‘m particularly disappointed by the left overs of edge diffraction despite the packed bookshelf they sit in. A little bigger and half of amp could have been spared etc.

The question, actually, was if I could squeeze it so much, and the three-way approach would still save it. El cheapo drivers, but no sloppy choice, simple x/over with a smidge of brains, 9mm poplar plywood, go figure! Pressing it very hard, still true, the dedicated midrange saves it.

I‘ve got a proof of concept. I‘ve got s/o to give it to (for free). You come and ask if it would compare to a Purify two-way. Sure, the Purify two-way is necessaryly quite narrow, the little one is necessarily quite wide in dispersion.

Would a 5“ P/ driver attached to the given cabinet, maybe with drones/reflexed go as low as 20Hz (30 to be fair) with that spl? What happens to the mids? Still looking for a sponsor to invest 20 times the cost, for the sake of (scientific) argument …

 

[Heinrich]

Mount into a shelf of some books:

Measurements in position

In room, in contrast to the standard with microphone pointed at speaker axis 30° instead of towards ceiling; 30Hz suckout due to room dimensions, level not to scale (was ~76dB)

 

[Heinrich]

Mount into a shelf of some books:

The second opinion of the future user is fairly positive, despite the missing lowest octave 20..40Hz. It wasn’t reasonable to fight the room.
The AV receiver used now struggles hard. It is class A/B analog and the specific power demand loads it where it is the most lossy (half power at 25watt) It runs hot. My own class D amps just shrugged shoulders.

Coming from JBLs (yep, that ones) of similar size the clarity was praised, lack of dull muddied harshness, it has smooth fluidity, happy dynamics, natural separation of notes, convincing spatial imagination even off axis, and not most of all, but still an easy going bass which is just there with detailed distinction, not as a fun blocking stop sign. In short, it pretty much works for whom it‘s for. Fun fact, first not interested in hifi stereo topics at all, now she wants more. If we only knew before.

 

[Audionaut]

I think the next one up in the range was a three-way? Can't recall the name of them now.

KEF Cantata
T52
B110B
B139

Loved them. Very good Speakers at that Time.

 

[Mart68]

KEF Cantata
T52
B110B
B139

Loved them. Very good Speakers at that Time.

That was the one. Never had a listen to them but they look like speakers I'd like:

https://pearl-hifi.com/06_Lit_Archive/02_PEARL_Arch/Vol_16/Sec_53/KEF_Topics/Vol-3_No-2_The%20Calinda%20and%20Cantata%20Loudspeakers.pdf

 

[Heinrich]

That was the one. Never had a listen to them but they look like speakers I'd like:

https://pearl-hifi.com/06_Lit_Archive/02_PEARL_Arch/Vol_16/Sec_53/KEF_Topics/Vol-3_No-2_The%20Calinda%20and%20Cantata%20Loudspeakers.pdf

Hi guys, I'm not that strict on many topics in my life, let alone others'. But here I was asked to change the thread's title from "LS3/5 revisited" to something not KEF LSx/y related, as mentioning the (in?)famous LS3/5 was seen as klick baiting, or irritating at least.

Now you discuss not, with any word, that one, but KEF's history in general, w/o connection to the decidedly limited mini speaker's features. Look, my little ones show nearly the same bass resonance frequency, with similar Qts, but a very differend approach to rendering the mids. Paper cones, dedicated midrange up to only 2kHz, in contrast to plastic cone covering the mids also up to nearly 4kHz. And so on.

I would love to see substantial criticism, in actuality. But there was none so far. Would you mind to find some issues with my more modern design? It is complicated, needing DSP for instance. Low outcome, due to size, for much input in tech and money. What do you think?

 

[Mart68]

Hi guys, I'm not that strict on many topics in my life, let alone others'. But here I was asked to change the thread's title from "LS3/5 revisited" to something not KEF LSx/y related, as mentioning the (in?)famous LS3/5 was seen as klick baiting, or irritating at least.

Now you discuss not, with any word, that one, but KEF's history in general, w/o connection to the decidedly limited mini speaker's features. Look, my little ones show nearly the same bass resonance frequency, with similar Qts, but a very differend approach to rendering the mids. Paper cones, dedicated midrange up to only 2kHz, in contrast to plastic cone covering the mids also up to nearly 4kHz. And so on.

I would love to see substantial criticism, in actuality. But there was none so far. Would you mind to find some issues with my more modern design? It is complicated, needing DSP for instance. Low outcome, due to size, for much input in tech and money. What do you think?

Apologies but you did bring up the Calinda so that set us off down memory lane...

I don't agree with your hypothesis that making a small speaker a three way solves bass extension issues. Obviously a three-way is better all else being equal. But you can't cheat physics/Hoffman's iron law. You seem to have in room extension down to 40Hz flat which is impressive in itself even of it does require DSP. But to my mind there's no point in going so small, the speaker could be three to four times the volume for the same application, wouldn't that make life easier?

 

[Heinrich]

Apologies but you did bring up the Calinda so that set us off down memory lane...

I don't agree with your hypothesis that making a small speaker a three way solves bass extension issues. Obviously a three-way is better all else being equal. But you can't cheat physics/Hoffman's iron law. You seem to have in room extension down to 40Hz flat which is impressive in itself even of it does require DSP. But to my mind there's no point in going so small, the speaker could be three to four times the volume for the same application, wouldn't that make life easier?

Thanks! But ask the 'customer' No, she first saw even that small ones as an insult to her aesthetics. Then it became clear that an obviously handmade 'object', in that peculiar artsy lingo, has more appeal than the industrial, plastic JBLs she has. When it came to performance there was a little bit of a shock. I told her, on top of that, the size would limit it by far to begin with. Why I didn't tell before (I did), and there would have been a bit more space left and so forth.

The little ones realize a lot of what was deeemed unachievable before. Clarity foremost, dynamics, bass extension was well known to her from my own home, but was mentally connected to more than 10 fold the size and taking care of many details, amplification, equalizer etc. Something that won't be acceptable for good reason in a regular household.

Next purchase: a set of more powerful amps. Mabe subs will follow as to mitigate the room acoustics. I personally would say, it won't be necessary once the enthusiasm settles, and the real, more humble demand is acknowledged.

In regard to tech, by what could I prove, that the three-way makes it? I've given the measurements on an alternative two-way, see post #49. Intermodulation is about 20dB lower, and I think it contributes, besides the wide and even radiation pattern, to 'clarity'. Or vice versa, to keep clarity doesn't need to limit bass.

 

[Mart68]

Thanks! But ask the 'customer' No, she first saw even that small ones as an insult to her aesthetics. Then it became clear that an obviously handmade 'object', in that peculiar artsy lingo, has more appeal than the industrial, plastic JBLs she has. When it came to performance there was a little bit of a shock. I told her, on top of that, the size would limit it by far to begin with. Why I didn't tell before (I did), and there would have been a bit more space left and so forth.

The little ones realize a lot of what was deeemed unachievable before. Clarity foremost, dynamics, bass extension was well known to her from my own home, but was mentally connected to more than 10 fold the size and taking care of many details, amplification, equalizer etc. Something that won't be acceptable for good reason in a regular household.

Next purchase: a set of more powerful amps. Mabe subs will follow as to mitigate the room acoustics. I personally would say, it won't be necessary once the enthusiasm settles, and the real, more humble demand is acknowledged.

In regard to tech, by what could I prove, that the three-way makes it? I've given the measurements on an alternative two-way, see post #49. Intermodulation is about 20dB lower, and I think it contributes, besides the wide and even radiation pattern, to 'clarity'. Or vice versa, to keep clarity doesn't need to limit bass.

What were the JBL? Control One? I have some of those, well judged balance for a miniature but clarity isn't their strong suit.

Appreciate the IMD is a lower with the 3 way, agree that increases clarity. I have always wondered at the popularity of small two-ways. But there's the market - small, and ideally, cheap. The customer, as you say, is always right.

 

[Heinrich]

What were the JBL? Control One?

Can't tell in detail, as is not in the interest of the current owner. But it was a tier up, still mass market, though ;-)

That issue(s) with the two-way paradigm was my personal interest to accept the task. The speakers were for free, but now decision and purchase is made to upgrade the amping at comparatively high cost. I didn't expect that kind of a confirmation of success.

O/k it ain't that discriminative, as quite a few fellows do so for their LS3/5s also Still wondering what it comes to once the excitement has settled, getting back to real, daily routine.

 

[jamescarter1982]

The superiority of a 3-way designs can be shown with multitone distortion measurements and also with smoother direcitivity measurements, although second can be compensated with the use of a appropriate tweeter waveguides. With good drivers like some Purifi things can get hard though if the 3-way competitor drivers are not of a high engineering level.


Hundreds of compact 3-ways in the 70s from almost all German loudspeaker brands and not only, for example original and new Wharfedale Super Denton

View attachment 441003

to the Neumann KH310 and its predecessors

View attachment 441008

I have several such in my small vintage loudspeaker collection, for example from 1979 with also a 7" woofer

View attachment 441007

what is this speaker from 1979 please ? is it a braun ?

 

[thewas]

what is this speaker from 1979 please ? is it a braun ?

Yes, a Braun SM 1002.