Technics SB-F1 Review (Vintage Speaker)

[restorer-john]

I have owned a few pairs, and while not the greatest sound, it is "Good enough" to enjoy and very durable and just simply amazing in some hard to describe way.

Exactly. Used with brackets on the back parcel shelves of cars, under the eaves and around the pool for background music. In the basement/den/spare room for extended music and awesome in kids' college rooms. They even did a passive minimus 7 subwoofer which we have someplace in a box...

A five year, unconditional warranty, bullet proof cabinet and cheap spare parts made for a legendary mini/micro speaker.

I just wish I had some photos of the 24ct gold plated million speaker Minimus 7s they awarded to all regions in celebration of the sales.

I miss Tandy/Radio Shack from those days. They were actually at the zenith of innovation, from computers, to mobile phones and even audio. It was fun while it lasted.

 

[KxDx]

I worked at the Shack from summer 1989 until Early 1991, first job out of high school.

They went downhill quick in the 1990’s. The first time I went into a store and saw “RCA” branding on some of their audio and A/V gear I knew the writing was on the wall.

Everyone is right about the Minimus 7’s. They would go on sale half price every year around Black Friday and flew off the shelves. My store in Wash DC would build a 5 foot tall pyramid of M7 boxes and I wish we had taken a time lapse video of the stack shrinking.

 

[tktran303]

Preference Rating
SCORE: 1.2
SCORE w/ sub: 5.0

Sensitivity: 86.0dB (300Hz-3kHz ; spec: 86dB)
Frequency response: +/- 14dB 80Hz-20kHz

Very interesting they this scores only 1.2 despite reasonably good directivity.

Is the bass extension more important than the directivity?
What else is dragging down the score?

 

[MZKM]

Very interesting they this scores only 1.2 despite reasonably good directivity.

Is the bass extension more important than the directivity?
What else is dragging down the score?

Look at the last image which shows the 4 score components. The SM_PIR (r^2 of the PIR/EIR curve) is basically 0, that is because that graph is very flat in the treble and not sloping downwards too much, most caused by the response at 8kHz retaining its energy off-axis for some reason.

 

[Dennis Murphy]

I'd like to see the Optimus PRO LX5 measured some day with the unusual Linaeum tweeters. Could send mine in if I ever get around to refoaming them.

Here's the very similar LX550--I think the woofer was a little different, but it had the same Linaeum tweeters. The tweeter's radiation pattern results in a null on axis, but this largely fills in off axis. It would be interesting to see how the Klippel would put all of this together into a room response. You can see the on-axis and 30 degree off-axis here: http://murphyblaster.com/content.php?f=rslx_m.html

 

[krabapple]

Archimago took a stab at measuring the Minimus 7 here

 

[enricoclaudio]

I would like to see how a Magico A1 bookshelf behave regarding resonances as it has aluminum enclosure as well.

 

[Dennis Murphy]

Archimago took a stab at measuring the Minimus 7 here

That was a pretty good "stab." Does anyone know which measurement software Archimago is using?

 

[tktran303]

Hi Dennis,

That’s REW, short for, Room EQ Wizard.

It’s Donateware.

 

[thewas]

That was a pretty good "stab." Does anyone know which measurement software Archimago is using?

Here he describes his measuring method, software seems to be REW.

Musings/Measurements: quasi-Spinorama "qSpin" & the KEF LS50 bookshelf loudspeaker...

A blog for audiophiles about more objective topics. Measurements of audio gear. Reasonable, realistic, no snakeoil assessment of sound, and equipment.

archimago.blogspot.com

 

[Cougar]

Had a pair of these that were given to me. never cared for the sound of them. Like another poster said, maybe good for a bench speaker in the garage.

Now the Technics Linear Phase series SB-7000a was really nice! I had a pair for a while and sold them. I wish I had them back.

 

[Persik]

I had these paired with the cassette deck and turntable in 90s
Subjectively, I really liked the sound and they delivered sufficient power in my room, good times...

 

[Rottmannash]

Very cool to see these measured and to see them have relatively high performance. These small "mini hi-fi" speakers and complementary "mini component" audio stacks were quite popular for a while in the 80's and 90's and some big Japanese names (like Technics, Sony, Aiwa, Toshiba/Aurex, JVC Victor, etc) put out some genuinely fantastic equipment in tabletop form-factors. The Toshiba/Aurex Micro System 15, for example, is such a prime example of miniaturization and precision engineering:
View attachment 199529

On the speaker end, I think the "standard" that most of us in the US was familiar with was the Radio Shack Minimus series and it's derivatives:
View attachment 199530


I'd like to see the Optimus PRO LX5 measured some day with the unusual Linaeum tweeters. Could send mine in if I ever get around to refoaming them.

I have a pair fo the RS Minimus speakers. Pulled them out a year or so ago when fiddling with outdoor speakers and was underwhelmed. Back in the closet they went.

 

[Dennis Murphy]

Here he describes his measuring method, software seems to be REW.

Musings/Measurements: quasi-Spinorama "qSpin" & the KEF LS50 bookshelf loudspeaker...

A blog for audiophiles about more objective topics. Measurements of audio gear. Reasonable, realistic, no snakeoil assessment of sound, and equipment.

archimago.blogspot.com

Thanks very much for the link and info. I had a feeling it was REW, but was hoping it was a new program that had timing probes in line with the speaker that would determinie driver offsets and locations, like the late and much lamented Praxis. REW looks like it's great for measuring the final product, but not quite what's needed for design work.

 

[lewdish]

I'd love to see more vintage stuff get measured! While I strongly doubt they can hold a candle to modern speakers that are designed properly, its still cool to see when they're good they stay good~ Honestly for collectors I think its nice to say that they were actually built well for their time, and if you have them then keep em! Wouldnt put a ton of money into the vintage gear, but its nice to say that you have them.

 

[beagleman]

I'd love to see more vintage stuff get measured! While I strongly doubt they can hold a candle to modern speakers that are designed properly, its still cool to see when they're good they stay good~ Honestly for collectors I think its nice to say that they were actually built well for their time, and if you have them then keep em! Wouldnt put a ton of money into the vintage gear, but its nice to say that you have them.

I would think that "Decent" vintage stuff can compare to new stuff. But the actual design philosophy is somewhat different.
One has to compare apples to apples though.

Most stuff now, is Sat/bookshelf with Subs.
Back in the day, a lot more towards "Full range" large all in one speakers. Bookshelf from back then (in general) were made more to a price point, and for a different usage really.

Many modern speakers go for a particular sound, that often is "Hot" on the Treble, and does not try to do much deep bass.
It is the so called "More resolving" sound, that is usually just boosted treble that at first appears more detailed and clear.

I do agree vintage is probably not "As good" overall, but still they have many positives.

Again, it depends on what Era of vintage we are talking about. 50s-early 70s, is distinctly different than mid 70s-late 80s stuff for sure.
I feel that speakers kind of were mostly at the best they could be by the 90s.

Since then it is just small refinements and so on.

 

[SegaCD]

I have a pair fo the RS Minimus speakers. Pulled them out a year or so ago when fiddling with outdoor speakers and was underwhelmed. Back in the closet they went.

Not surprised. They were widely available & a good deal in the day, but are vastly overshadowed by more modern speaker designs! Not too many non-boutique speakers from the 70s-80s that didn't sound like an AM radio.

 

[Xyrium]

This is awesome. I miss the old hey days of affordable but great Technics stuff. These look like I'd have to drop in a high shelf, but nice indeed. Even directivity was pretty good....just shows that you really don't have to reinvent the wheel.

 

[hyfynut]

This is a review and detailed measurements of the Technics SB-F1 mini vintage bookshelf speaker. It is on kind loan from a member:
View attachment 199516
SB-F1 was produced in Japan around 1978. It has a stout, diecast aluminum frame. I understand it was quite expensive for its time despite its diminutive size. I got a kick out of the circuit breaker in the back. Had forgotten about these back in the day:

View attachment 199517

Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than an anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.

Measurements are compliant with latest speaker research into what can predict the speaker preference and is standardized in CEA/CTA-2034 ANSI specifications. Likewise listening tests are performed per research that shows mono listening is much more revealing of differences between speakers than stereo or multichannel.

Reference axis was the center of the tweeter (aligned by eye). Measurement room was at 15 degrees C.

Technics SB-F1 Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker is and how it can be used in a room. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:
View attachment 199518

I don't know why but I expected a very poor frequency response but that was not the case. Response is quite flat and would be at home with many small speakers (and better than many). It does have a tilt up toward the higher frequencies though. And there are a lot of jagged peaks indicating resonances.

Early window is similar to on-axis:
View attachment 199519
Predicted in-room response as a result is decent:

View attachment 199520

Power handling was surprisingly good at 86 dBSPL but understandably, falls apart at 96:

View attachment 199521

View attachment 199522

Horizontal directivity and beamwidth is good:

View attachment 199523


View attachment 199524

Vertically it is messy like a lot of 2-way speakers are. Make sure you are at or slightly above tweeter axis when listening:
View attachment 199525

Impedance is around 5 ohm which is good for this day and age:
View attachment 199526

Sorry, forgot to run the CSD/Waterfall test.

Technics SB-F1 Speaker Listening Tests
First impression with female vocals was very positive. Sound was clean with just a hint of brightness. Switching to tracks with more bass though degraded performance fair bit. At very low volumes, it was still very good. But turn up the volume and there is a nasty resonance that is quite audible. Turn it up more and the sound gets very muddy with distorted bass. You could argue this is to be expected but I could not get past the resonance.

FYI I could clearly hear the resonance in the frequency response sweep during testing at 96 dBSPL.

Conclusions
I am impressed with level of engineering that went into the design of SB-F1. If it didn't have that nasty resonance, it would be highly competitive even today. But with it and the limited power capability, I can't see a good reason to recommend it.

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Wow talk about a time warp. My dad bought a pair of these when I was 11 from the Base Exchange on Lakenheath Air Force base in England.

 

[Pattern]

Very cool to see these measured and to see them have relatively high performance. These small "mini hi-fi" speakers and complementary "mini component" audio stacks were quite popular for a while in the 80's and 90's and some big Japanese names (like Technics, Sony, Aiwa, Toshiba/Aurex, JVC Victor, etc) put out some genuinely fantastic equipment in tabletop form-factors. The Toshiba/Aurex Micro System 15, for example, is such a prime example of miniaturization and precision engineering:
View attachment 199529

On the speaker end, I think the "standard" that most of us in the US was familiar with was the Radio Shack Minimus series and it's derivatives:
View attachment 199530


I'd like to see the Optimus PRO LX5 measured some day with the unusual Linaeum tweeters. Could send mine in if I ever get around to refoaming them.

I run a pair of Minimus on my desktop, impressive for their size in both sound and physical weight, you could kill somebody with these things.