Lasonic Boombox

[BoomBoxStash]

The "new" Lasonic i931BT:
Sold by Lasonic Lifestyles Inc:

LASONIC i931BTQ

(revised model)

[manufacture date: released 2022 (?)]

Lasonic Lifestyle Incorporated

3761 S. Hill Street

LA, CA 90007

213-668-6696

cs@lasoniclifestyle.com​

* Not the original Lasonic brand, fyi.

These "new" units come with a small credit-card sized remote with bubble buttons and a charging cord. This remote does work, but range is limited to a few feet. However, the internal CR-2025 battery could be old as well (?). N0 POWER CORD. The charging cord is a simple 5 VDC charger with a USB-A at one end and a barrel 5.5-mm plug at the other. This cord will NOT POWER the unit when playing. It is intended only to recharge the internal battery when NOT IN USE. NO MANUAL included. NO WEBSITE TO DOWNLOAD A MANUAL. I emailed Lasonic a month ago. NO RESPONSE. My expectations are low.

Warranty? Who knows? No paperwork inferring any warranty. No contact information. I had to surf the internet to find the above contact info, fyi.

The Weird:
No UL LISTING on the rear of the set. No such listing anywhere. I don't understand how Lasonic is skirting the law requiring this info.

Rear switch function? The original Lasonic was AC/DC. The switch allowed user choice. No AC on this unit. However, the switch has an unintended function. Switched left, it allows battery power or external battery power. Switched right, it disconnects all power. Therefore, this switch can actually function as a main on/off. Good for instances where the unit may be stored or unused for long periods of time.

Five preset tonal adjustments. One is marked "LOUDNESS". However, that it is now 'FLAT" (no tonal adjustment applied).

Menu button indicates Bass/Treble is available. Wrong! No bass/treble. Only clock (24 hour only), alarm and an "off" timer which can be used as a kind of sleep timer or sorts.

The 5-band Equalizer is wired BACKWARDS! No joke. Every unit I tried was the same. The 10 Khz band controls the bass, and vice-versa. What?????

Only 4 bands work, even though all five bands light up red. The highest band, "10 Khz" does not work at all. This was also the case on every unit I tried.

Remote Control:
Some buttons are straight forward. Others are not. The following is my best guess.

MICKTV button: refers to microphone in conjunction with karaoke tv. I don't have a wired mic to test this function. May switch mic on/off?

ECO button: may refer to echo mode when using microphone with karaoke.

MICVOL: may allow adjustment of connected mic volume?

SOUND: allows selection of the 5 different preset tonal choices.

TIME: I do not see any activity when pressing. I assume it is related to the alarm or sleep timers?

THE "5-BAND EQ" (wired backwards)
The highest band does NOT FUNCTION. I do not know why? But there seems to be a boost of anywhere from +6 dB to +9 dB, depending on whether you are listening via the main speakers and the level of volume, or with headphones.

The high band is claimed to be "10 Khz. I measured a center-frequency of 8 Khz, which is NOT ADJUSTABLE.

The next band is claimed to be 3.3 Khz (mid-high band). I measured a center of 4-5 Khz. The +/- 10 dB is accurate.

The mid-band is supposed to be 1 Khz. I measured a center of 2 Khz. The +/- 10 dB is accurate.

The upper-bass band is supposed to be 330 Hz. I measured a center of 263 Hz. The +/- 10 dB is accurate.

The bass band is supposed to be 100 Hz. I measured a center of 35 Hz !!!!!!! +/- 10 dB is accurate. VERY NICE! Much more useful than the standard useless 100 Hz mid-bass which I never liked, going all the way back to the 70's and 80's. KUDOS to Lasonic !

This model employs a Fangtec ft3128 D-class amplifier chip. NO HEAT SINK.

The internal battery measured at 12.2 VDC output. It is pretty hefty. I suspect it can deliver 3-5 AH (?).

AMPLIFIER AUTOMATIC LEVEL CONTROL BUILT-IN:
Amplifier THD is high at any level, even below 1 watt. I don't know why? Also, this chip incorporates ALC, which I abhor. I never liked ALC circuitry, going all the way back to the tape decks of the 80's. ALC never works.
So I disabled the ALC on this unit. I disconnected PIN #13 ON THE FANGTEC CHIP, per the Fangtec data sheet.
Before disconnecting, I had to push 775 mV input (AUX) to approach clipping.
After disabling ALC, I now need only 200 mV to achieve full output before clipping. Output power before/after clipping remained the same.
Before disconnecting, the sound would go in-and-out at higher volume levels or when heavy bass content was played.
After disabling ALC, sound can go into distortion, but the annoying fading in-and-out is almost completely gone. If the unit fades at all, I suspect it is due to excessive power supply demands and not the fault of the amp.

THD high either with ALC activated or not. My measurements are after disabling ALC:
POWER OUTPUT: 10.5 Watts + 10.5 Watts, into 4 ohms, 1 Khz, less than 6.5% THD. I don't know why THD is high?
POWER BANDWIDTH AT RATED OUTPUT: 20 Hz to 20 Khz, less than -3 dB. That's very good for a boombox or mini amp.

D-class amps, especially cheap ones, emit high-speed switching noise which may or may not be audible, but will show up on an oscilloscope as a type of distortion of the sine wave. I will attach pics of oscilloscope before and after adding a low-pass filter, designed to filter out that noise. The Fangtec data sheet recommends a 33 uH coil. However, I chose a 22 uH coil, which should begin filtering around 29 Khz, well above our 20 Khz audible limit. I did so to make certain all audible frequencies come through unaffected. I used a very small inexpensive toroidal-type coil, measuring less than 1/2 inch in diameter. The sine wave is now very clean (see attached pics)

S/N RATIO:
Very good. I measured 97 dB or better. That is High Fidelity level.

DAMPING FACTOR:
For the heck of it, I measured. My main audio system consists of a Yamaha receiver which boasts a DF of 120 or more, across the entire bandwidth. I am limited due to my simple test equipment. So, I measured at 50 Hz, the accepted standard bass test frequency.
My Yamaha receiver measured 124. Therefore, I deem my test to be in-the-ballpark.
The Lasonic measured 21.
There is much discussion on this spec's value. Back in the 80's and 90's, many reputable manufacturers touted their amps "feedback circuitry" and how it improved sonic performance.
According to general consensus, 50 to 100 is good. Above 100 is better. Approaching 150 is excellent. Above 150 is moot, as we cannot discern any further improvement (?).
However, some claim a value above 10 or 15 is sufficient.

I tried measuring CROSSTALK. The standard for High Fidelity is 70/50 (1 Khz/10 Khz), or more.
My Yamaha receiver is specified as 70/50. But I only measured 56/43, which is subpar.
I measured 55/36 on the Lasonic.
However, my equipment may be at fault. I do not believe I am establishing an accurate low-signal measurement when comparing high-signal to low-signal on this test. For purposes of this test, the Lasonic performed pretty close to my main audio receiver, which is good enough for me.

The SPEAKERS:
According to the retail box, the included speakers are "CEWIN VEGA". As one reviewer joked, "is this supposed to be Cerwin Vega?". Who knows? The transducers are unmarked.

The tweeter is a standard 1-1/2 inch paper cone. Paper cones are fine. To this day, an inexpensive cone tweeter can sound as natural as many much more expensive hybrid tweeter designs. The size of this tweeter is in keeping with the tweeters of the past great boomboxes.

The tweeter uses a simple 4.7 uf capacitor for a nominal crossover of about 8 Khz.

The woofer is a true 8 inch. This is the only retro boombox with woofers the size of the 80's greats, such as those found in the JVCs, the CROWNs, or the CONIONs. No crossover, which is fine for woofers, depending on their roll-off characteristics.
For anyone who works with transducers, these are obviously inexpensive low-end woofers. However, compared to woofers in one-piece retro sytled boomboxes, these woofers are excellent! It is a matter of perspective.

These woofers feature a heavy paper cone. A decent magnet of about 8-10 ounces. A 1 inch voice coil. And a wide foam-rolled cone suspension which allows decent movement (X-MAX probably around 1.5 to 2.5 mm, I imagine)

I measured the woofer"s free-air resonance (Fs) to be 53 Hz, which is very good. Typical 8 inch woofers will have a Fs in the 40's to 50's Hz range, with some extending lower.

speaker impedance is measured at 4 ohms.

 

[BoomBoxStash]

Addendum to my above post:

OTHER ATTRIBUTES OR NOTES ABOUT THE LASONIC I931:

Internally, the woofers are secluded in separate left and right sub-enclosures, which are sealed. I personally prefer sealed or acoustic suspension designs, as they tend to be less boomy. Downfalls of ported designs also include noise which exits the ports, which is totally avoided in a sealed enclosure.

The handle is sturdy and locks into several positions, which is nice. It does not fall and bang into the unit every time the unit is set down.

Heavy padded rubber feet serve to protect fine furniture and reduce vibrations between the boombox and the surface on which it sits.

The included FM TUNER is supposed to feature RBDS, according to the retail box. I am doubtful of this. I did not see any station with digital content displayed and no way to turn on or off such a feature.

The tuner is analog, not digital. That is fine. Just making a point. For those disliking a digital display on a retro boombox, allow me to point out that AIWA introduced the CS-880U in the early-mid 80's. It featured both a digital display and a sealed enclosure of its speakers, which incorporated a pair of 5 inch woofers, 1 inch cone tweeters and a 6 inch passive radiator. The CS-880U was ahead of its time and to this day, is one of the sought after collector boomboxes of the 80's. It was a very high-end one-piece portable audio in all respects.

AM radio is included. This is a nice touch. In the old days, boomboxes not only featured AM and FM, but also shortwave bands.

Build quality is typical. The knobs and switches of the old great boomboxes were better, but the enclosure itself is about average.

I am powering and charging mine with a 12 VDC 5A brick-style power supply I happened to have on-hand. So far, I see nothing detrimental. Even after a few hours use, the battery did not get warm. No warm or hot wiring. The original Lasonic i931BTQ did state a power consumption of 60 Watts maximum in the manual and the UL Listing on the unit stated 58 Watts. Since the power supply I am currently using has about a 60 Watt power consumption, I am going to see how it works out.

I apologize for splitting up my post. I guess I was verbose.

I hope this detailed review helps.

 

[Superduper]

Hmm. Lasonic lifestyle website shows way more hello kitty stuff and t-shirts than boomboxes.

Question: you showed oscilloscope patterns, presumably of the output. Aren't these amps BTL topology and did you use differential probes to acquire that waveform?

 

[Reli]

This model was first introduced in 2008, but with an iPod dock instead of Bluetooth.

You're right about ALC on the Line In circuit, it's garbage on most boomboxes, for example the Hitachi TRK-3D80

 

[Superduper]

This model was first introduced in 2008, but with an iPod dock instead of Bluetooth.

You're right about ALC on the Line In circuit, it's garbage on most boomboxes, for example the Hitachi TRK-3D80

Oh, I thought this was a new model? Or is it just an old one? The website seems to be selling them, presumably new?

And why would a line in circuit need ALC, isn't that typically for recording levels only, and just curious where does the 3D80 say anything about ALC?

On the Lasonic, apparently the chinese shoehorned a chinese chip in there for ALC on the playback circuit? That's just weird, perhaps in an effort to try to make the amp compatible with all sorts of input types and signal levels. But this is a new era and the 3D80 is much more closer to the classic era and I doubt there's ALC in any circuit except maybe for record level.

 

[Transistorized]

I'm not sure where my model falls into all of this. It's the style with the iPod but no Bluetooth. i931x. I think I got this new around 2010

 

[goodman]

BoomBoxStash thanks for the detailed review.
From the pictures I saw, the only new things are the changed remote control,
the addition of the rechargeable battery and the removal of the internal transformer.
I don't see an indicator or diode, showing charging. There is no change in appearance and functions.

Compared in price/features to the Aiwa retro boombox LINK it is at a similar price, but with much fewer functions.
Years ago I had the AC powered model (pic from internet) but I didn't like its functionality and sold it.

 

[Reli]

Oh, I thought this was a new model? Or is it just an old one? The website seems to be selling them, presumably new?

And why would a line in circuit need ALC, isn't that typically for recording levels only, and just curious where does the 3D80 say anything about ALC?

On the Lasonic, apparently the chinese shoehorned a chinese chip in there for ALC on the playback circuit? That's just weird, perhaps in an effort to try to make the amp compatible with all sorts of input types and signal levels. But this is a new era and the 3D80 is much more closer to the classic era and I doubt there's ALC in any circuit except maybe for record level.

On the 3D80 as soon as you play Line In it sounds normal for about 2 seconds, but then the volume drops noticeably. And unlike the other audio sources, you can't make the meters peak no matter what kind of device is connected to it.

 

[Superduper]

On the 3D80 as soon as you play Line In it sounds normal for about 2 seconds, but then the volume drops noticeably. And unlike the other audio sources, you can't make the meters peak no matter what kind of device is connected to it.

I took a look at the 3D80 schematic. All source modes go directly to a function selector, and then passed off to a 4558c opamp (line amp). This includes radio/tape/etc. From the line amp, the signal is basically passed off to the equalizer circuit before going to the power amp. If there is attenuation, it could be your music source. Maybe it doesn't like the impedance of the aux input of the boombox. There is no ALC involved in the 3D80 playback circuit. I think it's either, once again your audio source, or your hitachi has an internal issue if that delayed attenuation can be confirmed.

 

[BoomBoxStash]

This model was first introduced in 2008, but with an iPod dock instead of Bluetooth.

You're right about ALC on the Line In circuit, it's garbage on most boomboxes, for example the Hitachi TRK-3D80

The 2008 model to which you refer was made by the real Lasonic. This model I bought is only Lasonic by name. The quality is not there.

 

[BoomBoxStash]

The 2008 model to which you refer was made by the real Lasonic. This model I bought is only Lasonic by name. The quality is not there.

Yeah. I despise ALC. Uselss. Never works as claimed.

 

[BoomBoxStash]

Hmm. Lasonic lifestyle website shows way more hello kitty stuff and t-shirts than boomboxes.

Question: you showed oscilloscope patterns, presumably of the output. Aren't these amps BTL topology and did you use differential probes to acquire that waveform?

The BTL doesn't matter, to my knowledge. I used 8 ohm dummies and measured 2-channels driven to arrive at a more realistic measurement. What you need to avoid is using a common ground with BTLs.
By adding a 32uH coil in series with each dummy load, I eliminated any noise generated by D-class amps and also provide a more accurate output measurement, as the added coil changes the dummy load from resistance to impedance, more closely mirroring an actual driver.

 

[BoomBoxStash]

The BTL doesn't matter, to my knowledge. I used 8 ohm dummies and measured 2-channels driven to arrive at a more realistic measurement. What you need to avoid is using a common ground with BTLs.
By adding a 32uH coil in series with each dummy load, I eliminated any noise generated by D-class amps and also provide a more accurate output measurement, as the added coil changes the dummy load from resistance to impedance, more closely mirroring an actual driver.

Sorry. I used 4 ohm dummies. I was thinking about something else. My bad

 

[BoomBoxStash]

Addendum to my above post:

OTHER ATTRIBUTES OR NOTES ABOUT THE LASONIC I931:

Internally, the woofers are secluded in separate left and right sub-enclosures, which are sealed. I personally prefer sealed or acoustic suspension designs, as they tend to be less boomy. Downfalls of ported designs also include noise which exits the ports, which is totally avoided in a sealed enclosure.

The handle is sturdy and locks into several positions, which is nice. It does not fall and bang into the unit every time the unit is set down.

Heavy padded rubber feet serve to protect fine furniture and reduce vibrations between the boombox and the surface on which it sits.

The included FM TUNER is supposed to feature RBDS, according to the retail box. I am doubtful of this. I did not see any station with digital content displayed and no way to turn on or off such a feature.

The tuner is analog, not digital. That is fine. Just making a point. For those disliking a digital display on a retro boombox, allow me to point out that AIWA introduced the CS-880U in the early-mid 80's. It featured both a digital display and a sealed enclosure of its speakers, which incorporated a pair of 5 inch woofers, 1 inch cone tweeters and a 6 inch passive radiator. The CS-880U was ahead of its time and to this day, is one of the sought after collector boomboxes of the 80's. It was a very high-end one-piece portable audio in all respects.

AM radio is included. This is a nice touch. In the old days, boomboxes not only featured AM and FM, but also shortwave bands.

Build quality is typical. The knobs and switches of the old great boomboxes were better, but the enclosure itself is about average.

I am powering and charging mine with a 12 VDC 5A brick-style power supply I happened to have on-hand. So far, I see nothing detrimental. Even after a few hours use, the battery did not get warm. No warm or hot wiring. The original Lasonic i931BTQ did state a power consumption of 60 Watts maximum in the manual and the UL Listing on the unit stated 58 Watts. Since the power supply I am currently using has about a 60 Watt power consumption, I am going to see how it works out.

I apologize for splitting up my post. I guess I was verbose.

I hope this detailed review helps.

As additional addendum. No longer using a 12 VDC power supply. The charging cord which this Lasonic provides is a simple USB-A to a 5.5mm plug which only delivers 5 VDC. I am assuming there must be a transformer or other component in the charging board which boosts thw 5 VDC to the proper charging voltage. From everything I've read, if I continue to use a 12 VDC power supply with this unit, I could fry the charging board, damage the lithium battery or even fry the main board.
Just an fyi to anyone interested.

 

[BoomBoxStash]

Hmm. Lasonic lifestyle website shows way more hello kitty stuff and t-shirts than boomboxes.

Question: you showed oscilloscope patterns, presumably of the output. Aren't these amps BTL topology and did you use differential probes to acquire that waveform?

Hahahaha, yes, I saw that as well.
After about a month, NO response to my email. Very disappointing.

 

[BoomBoxStash]

Addendum to my above post:

OTHER ATTRIBUTES OR NOTES ABOUT THE LASONIC I931:

Internally, the woofers are secluded in separate left and right sub-enclosures, which are sealed. I personally prefer sealed or acoustic suspension designs, as they tend to be less boomy. Downfalls of ported designs also include noise which exits the ports, which is totally avoided in a sealed enclosure.

The handle is sturdy and locks into several positions, which is nice. It does not fall and bang into the unit every time the unit is set down.

Heavy padded rubber feet serve to protect fine furniture and reduce vibrations between the boombox and the surface on which it sits.

The included FM TUNER is supposed to feature RBDS, according to the retail box. I am doubtful of this. I did not see any station with digital content displayed and no way to turn on or off such a feature.

The tuner is analog, not digital. That is fine. Just making a point. For those disliking a digital display on a retro boombox, allow me to point out that AIWA introduced the CS-880U in the early-mid 80's. It featured both a digital display and a sealed enclosure of its speakers, which incorporated a pair of 5 inch woofers, 1 inch cone tweeters and a 6 inch passive radiator. The CS-880U was ahead of its time and to this day, is one of the sought after collector boomboxes of the 80's. It was a very high-end one-piece portable audio in all respects.

AM radio is included. This is a nice touch. In the old days, boomboxes not only featured AM and FM, but also shortwave bands.

Build quality is typical. The knobs and switches of the old great boomboxes were better, but the enclosure itself is about average.

I am powering and charging mine with a 12 VDC 5A brick-style power supply I happened to have on-hand. So far, I see nothing detrimental. Even after a few hours use, the battery did not get warm. No warm or hot wiring. The original Lasonic i931BTQ did state a power consumption of 60 Watts maximum in the manual and the UL Listing on the unit stated 58 Watts. Since the power supply I am currently using has about a 60 Watt power consumption, I am going to see how it works out.

I apologize for splitting up my post. I guess I was verbose.

I hope this detailed review helps.

UPDATE TO MY REVIEW:

Eh, I cannot recommend anyone buying this thing. So much is wrong, misrepresented or working incorrectly, if working at all. A crying shame. This unit has some potential.
No warranty which I can find.
No response from Lasonic Lifestyles Inc.
Some front fscing buttons already began acting up (not working) after only a few days use. Very Very disappointing.
Definitely not the old Lasonic.

 

[BoomBoxStash]

Oh, I thought this was a new model? Or is it just an old one? The website seems to be selling them, presumably new?

And why would a line in circuit need ALC, isn't that typically for recording levels only, and just curious where does the 3D80 say anything about ALC?

On the Lasonic, apparently the chinese shoehorned a chinese chip in there for ALC on the playback circuit? That's just weird, perhaps in an effort to try to make the amp compatible with all sorts of input types and signal levels. But this is a new era and the 3D80 is much more closer to the classic era and I doubt there's ALC in any circuit except maybe for record level.

All the websites are confusing, if not outright deliberately misleading consumers. This includes big name vendors such as Amazon Prime and walmart.com and many others. Multiple pictures being posted, of which many are pics of old models which were actually made by the original Lasonic brand.
From my experience and many reviews I've read, if you buy a "new" Lasonic i931, you will most likely receive a model NOT resembling the pictures included on the vendor's website.

As for the ALC. The fangtec chip features a built-in ALC to regulate amp output. For instance, if playing loudly or reproducing music with heavy bass, the ALC kicks in and causes dropouts in sound as a manner of reducing the chance of the amp going into clipping.

On top of that, there is a separate level control built-in, which monitors demand on the power supply and will also cause dropouts in playback if the demand on the built-in battery is too high.

I'm not a fan. Not that I like clipping by any means. But, constant dropouts are very irritating. I do not like ALC, period.

 

[BoomBoxStash]

Oh, I thought this was a new model? Or is it just an old one? The website seems to be selling them, presumably new?

And why would a line in circuit need ALC, isn't that typically for recording levels only, and just curious where does the 3D80 say anything about ALC?

On the Lasonic, apparently the chinese shoehorned a chinese chip in there for ALC on the playback circuit? That's just weird, perhaps in an effort to try to make the amp compatible with all sorts of input types and signal levels. But this is a new era and the 3D80 is much more closer to the classic era and I doubt there's ALC in any circuit except maybe for record level.

This is supposed to be a "new" Lasonic model, but NO LONGER made by the original Lasonic brand.
However, I ordered 3 of these "new" units recently. NOT ONE WAS NEW!

Retail boxes arrived unsealed.
All 3 units were defective.
2 of the 3 units had all the plastic film torn off the fronts of these "new" units.
THE GRAPHIC EQUALIZER ON EVERY UNIT I RECEIVED WAS WIRED BACKWARDS!
This is not a joke.
And, to add insult to injury, only 4 of the 5 equalizer bands worked on all 3 units.
Not one unit came with a manual.
None of them came with any warranty info.
Only one of the three included all accessories (charging cord and remote), and that particular unit would not power on, even after attempting to charge the unit for hours.
I honestly do not understand how these "new" Lasonic i931's are even allowed to be sold to the public in such fashion?1

 

[BoomBoxStash]

I'm not sure where my model falls into all of this. It's the style with the iPod but no Bluetooth. i931x. I think I got this new around 2010

View attachment 61249

I am not sure. But, yours is an authentic Lasonic. Not the junk out now. I think they emerged around 2008. But do not quote me. I remember a version from the original Lasonic brand which included bluetooth which I bought on-line in 2015. I did not like that one either.

 

[BoomBoxStash]

Hmm. Lasonic lifestyle website shows way more hello kitty stuff and t-shirts than boomboxes.

Question: you showed oscilloscope patterns, presumably of the output. Aren't these amps BTL topology and did you use differential probes to acquire that waveform?

Hahahaha, yes, I also saw the Hello Kitty merchandise. I am wondering if this company even cares about the product being sold with the Lasonic brand?

BTL should not require any special measuring, other than do not use a common ground.

I included an in-series 33uH coil to clean up the sine waves and also to result in more realistic measurements. By adding the coil, inductance is introduced into the circuit, which in turn causes the amp to 'see' the dummy 4-ohm load as impedance rather than resistance, which more accurately mirrors what an amp sees when powering a driver (speaker).