The 25 watts at 10% distortion is really just a way to put a bigger number on the data sheet. Maximum continuous power before clipping will be lower, and well below 1% distortion.
Alesis owes me over a 1000 USD in warranty repair cost that I incurred when they went bankrupt back in 2001. I had to pay for warranty repairs for the repair shop said they no longer honored Alesis checks. They left me without even a reply. After 17 years I'm still pissed.
bain5872 if you filed a claim and never got paid before the bankruptcy was discharged, you’re out of luck. If you never filed a claim, you’re out of luck. Legally once the bankruptcy is discharged, all other debts are wiped out.
About 22 or so years ago I had a guy declare bankruptcy, and try to avoid notifying me. His goal was to make it look like I never responded, and thus when his BK was discharged, I'd be up a creek. I found out and did file, which is the only reason I ever got anything.
Not only business but people in general should be focused on doing the right thing even when it hurts. If everyone followed this rule there would be no need for bankruptcy courts or any other courts for that matter. Once the legal system gets involved it's a certainty, someone going lose and it's usually the sucker left holding the bag. The only winner is the court and attorneys. It grips me to know that some lawyer pocketed a thousand dollars that was owed to me. It's OK though. Alesis has lost several thousand of dollars I spent elsewhere. If it has their name on it...I don't buy buy it!
bain5872 Bankruptcy is a necessary rescue when someone is in over their head and simply cannot pay everyone back, even if they are honest and hard working. Now of cause lazy people and outright crooks are going to abuse this rescue, which is why some countries don't allow repeatedly bankrupting business owners to start new businesses for a while, while other countries have thriving credit rating companies to warn against such people.
nah they broke...turned them off for a week, came back and they have insanely low volume even though you can still hear (and see) the audio clipping from the DAC if you max the volume out but it's whisper quiet...same thing happens through usb and analog. Clipping LED works like normal not solid red like some people have
i have a pair of this studio monitor and the volume had suddenly became very soft. had to turn the volume to max to get a level 1 volume. what could be the issue and solutions?
I love the acoustic dampening foam, it's the same crap I had to clean up out of the garden yesterday from a dismantled sofa my useless waste of space brother left in there... :P
Why would there be "extra channels for stereo" in what is clearly the power supply section? Anyway, if the left speaker has no power cable, they are either sending full 4ohm speaker signal or some power + line level combination through that XLR connector. So unless they are following the traditional phantom power spec, they are probably using that socket in a completely non-standard way just for the wow! factor of using a "professional" connector, when all the actual inputs are single ended jacks or consumer digital.
Dave, is that a dual rail supply, hence 2x smoothing caps? The TDA amps are single rail, so it would be wasting half the PSU current just to power the opamps dual rail!
Are these speakers not bi-amped? They're active so the crossover is done at the pre-amp stage. Surely it'll be 25W to the woofer and 25W to the tweeter. That XLR connection to the other speaker is surely for line level rather than from the power amp; otherwise why use a differential, low noise connection. If they are 25W woofer and 25W tweeter then they're notionally 50W RMS per speaker (assuming that 25+25 is RMS), although the low frequencies will draw the vast majority of the power.
David Griffin You'll never get close to putting out continuous 25W from the tweeter, maybe up to 1/5th of the output the lower range is putting out, which is approx. 5W at the point where the lower frequencies would start to clip. The power-frequency distribution in audio is non-linear, it basically goes down as the frequency goes up. The instantaneous power however is needed to reproduce pops, clicks, syllables and other high-frequency transients.
since he commented that the crossover in these is specially set outside normal speech range for clarity in speech i am guessing it is REALLY low, meaning more of the power will go to the mid-tweeter ;) They may well have taken advatage of this to be able to use 2 identical stereo drivers, one for each side, which is cheap and would reduce crosstalk over a large stereo woofer driver and smaller stereo tweeter driver
Say it ain't so Dave. You use edge board soldering? That has to be the most unreliable connection known to man. Highly susceptible to breaking in high vibration environments. A few two way radio manufacturers have used that over the years and you can be guaranteed that within a few years the radio is going to develop intermittent faults because the edge soldered boards fail. Solder has very little durability when it comes to flexing and lead free is the worst.
If the speaker manufacturer is honest, the 30 watt rating is how much power it takes to destroy the speaker. If the speaker manufacturer is "typical", the 30 watt rating is a total lie. Rule of thumb is about 1 watt per inch of diameter input for undistorted sound output, the 5 inch driver in this unit is good for about 5 watts of input before it becomes "unlistenable". As far as power rating of the chip, those figures are optimistic numbers under laboratory conditions, with unbearably high distortion. In the real world expect half of the rating's output for clean sound. The power supply and heat sink could limit it further.
Tell 'em brother, too much power is never the problem, too little power destroys drivers. Yes of course with a thousand watts you could launch the driver and half the cabinet into your kitchen, however an underpowered driver will destroy the spider and it's a rap for that set of speakers and probably the power amp too; that is if anybody uses passive / power amp systems anymore. anyway, there cheap speakers and you're probably a 13 year old. mow another lawn and buy another one. next!
Always glad to see audio equipment teardowns. Thank you.
The 25 watts at 10% distortion is really just a way to put a bigger number on the data sheet. Maximum continuous power before clipping will be lower, and well below 1% distortion.
Judging by the spec sheet, the continous power with wide frequency range and low THD appears to be 10 W to 8 or 4 ohms at most.
Keep in mind they are bi-amped, so 50W available per side. But yeah, 20 a side is probably realistic
@@mycosys yeah 10% distortion means basically useless. It would sound like total crap.
30W on speakers also don't mean a thing at all.
The rubber parts are there to seal everything. Even small gaps WILL be noticeable (like little farts).
I see no link but I remember the video! Great content Dave thank you!
2:43 - Haha, I like how the manufacturer of the transformer is called "TOP CHEERS"
Alesis owes me over a 1000 USD in warranty repair cost that I incurred when they went bankrupt back in 2001. I had to pay for warranty repairs for the repair shop said they no longer honored Alesis checks. They left me without even a reply. After 17 years I'm still pissed.
bain5872 if you filed a claim and never got paid before the bankruptcy was discharged, you’re out of luck. If you never filed a claim, you’re out of luck. Legally once the bankruptcy is discharged, all other debts are wiped out.
I had assumed as much 17 years ago. However, thanks for letting me know.
About 22 or so years ago I had a guy declare bankruptcy, and try to avoid notifying me. His goal was to make it look like I never responded, and thus when his BK was discharged, I'd be up a creek. I found out and did file, which is the only reason I ever got anything.
Not only business but people in general should be focused on doing the right thing even when it hurts. If everyone followed this rule there would be no need for bankruptcy courts or any other courts for that matter. Once the legal system gets involved it's a certainty, someone going lose and it's usually the sucker left holding the bag. The only winner is the court and attorneys. It grips me to know that some lawyer pocketed a thousand dollars that was owed to me. It's OK though. Alesis has lost several thousand of dollars I spent elsewhere. If it has their name on it...I don't buy buy it!
bain5872 Bankruptcy is a necessary rescue when someone is in over their head and simply cannot pay everyone back, even if they are honest and hard working. Now of cause lazy people and outright crooks are going to abuse this rescue, which is why some countries don't allow repeatedly bankrupting business owners to start new businesses for a while, while other countries have thriving credit rating companies to warn against such people.
Bought these back in 2012 for $200...still going strong after blasting so much music thru these lol
nah they broke...turned them off for a week, came back and they have insanely low volume even though you can still hear (and see) the audio clipping from the DAC if you max the volume out but it's whisper quiet...same thing happens through usb and analog. Clipping LED works like normal not solid red like some people have
i have a pair of this studio monitor and the volume had suddenly became very soft. had to turn the volume to max to get a level 1 volume. what could be the issue and solutions?
I love the acoustic dampening foam, it's the same crap I had to clean up out of the garden yesterday from a dismantled sofa my useless waste of space brother left in there... :P
Why would there be "extra channels for stereo" in what is clearly the power supply section?
Anyway, if the left speaker has no power cable, they are either sending full 4ohm speaker signal or some power + line level combination through that XLR connector. So unless they are following the traditional phantom power spec, they are probably using that socket in a completely non-standard way just for the wow! factor of using a "professional" connector, when all the actual inputs are single ended jacks or consumer digital.
what camera are you using for this video?
Dave, is that a dual rail supply, hence 2x smoothing caps? The TDA amps are single rail, so it would be wasting half the PSU current just to power the opamps dual rail!
Simon Ashton The control opamp for the faulty LED (main channel video) was running on dual rail ±15V supply.
Are these speakers not bi-amped? They're active so the crossover is done at the pre-amp stage. Surely it'll be 25W to the woofer and 25W to the tweeter. That XLR connection to the other speaker is surely for line level rather than from the power amp; otherwise why use a differential, low noise connection. If they are 25W woofer and 25W tweeter then they're notionally 50W RMS per speaker (assuming that 25+25 is RMS), although the low frequencies will draw the vast majority of the power.
I use these monitors. The technical spec say 30W RMS per channel. The XLR out connects directly to the other speaker from the power amp.
David Griffin You'll never get close to putting out continuous 25W from the tweeter, maybe up to 1/5th of the output the lower range is putting out, which is approx. 5W at the point where the lower frequencies would start to clip. The power-frequency distribution in audio is non-linear, it basically goes down as the frequency goes up. The instantaneous power however is needed to reproduce pops, clicks, syllables and other high-frequency transients.
I believe I alluded to that in my last sentence; thanks for reminding me though.
since he commented that the crossover in these is specially set outside normal speech range for clarity in speech i am guessing it is REALLY low, meaning more of the power will go to the mid-tweeter ;)
They may well have taken advatage of this to be able to use 2 identical stereo drivers, one for each side, which is cheap and would reduce crosstalk over a large stereo woofer driver and smaller stereo tweeter driver
Say it ain't so Dave. You use edge board soldering? That has to be the most unreliable connection known to man. Highly susceptible to breaking in high vibration environments. A few two way radio manufacturers have used that over the years and you can be guaranteed that within a few years the radio is going to develop intermittent faults because the edge soldered boards fail. Solder has very little durability when it comes to flexing and lead free is the worst.
Tangobaldy is legend
Stunning.
Could you make a video on Bill Of Materials? I'm working on one right now and it's more than a little confusing (I'm an apprentice by the way) thanks!
Bunnie did a blog post on that www.bunniestudios.com/blog/?p=2776
its possible that TDA7265 on the woofer is bridged.
not unless theres a second there to drive the other speaker
I thought this was dankpods for a sec
If its 32w mpo then it's max rated power should be 16w rms
REC Caps, SRYSLY??
PS Caps and transformer- Junk
"Music Output Power", THD 10%. The amount of bullshit in amplifier specs seldom fails to amuse.
THD of 10% seems really horrible.
The jrc are cheap and good
If the speaker manufacturer is honest, the 30 watt rating is how much power it takes to destroy the speaker.
If the speaker manufacturer is "typical", the 30 watt rating is a total lie.
Rule of thumb is about 1 watt per inch of diameter input for undistorted sound output, the 5 inch driver in this unit is good for about 5 watts of input before it becomes "unlistenable".
As far as power rating of the chip, those figures are optimistic numbers under laboratory conditions, with unbearably high distortion. In the real world expect half of the rating's output for clean sound.
The power supply and heat sink could limit it further.
you might want to catch up on the last 30 years of driver engineering. Oh and those amps are 25+25W nominal - 15W+15W @ 0.02% THD
Tell 'em brother, too much power is never the problem, too little power destroys drivers. Yes of course with a thousand watts you could launch the driver and half the cabinet into your kitchen, however an underpowered driver will destroy the spider and it's a rap for that set of speakers and probably the power amp too; that is if anybody uses passive / power amp systems anymore. anyway, there cheap speakers and you're probably a 13 year old. mow another lawn and buy another one. next!
*HyGROscopic
Yes, I know, but my brain has other ideas
EEVblog2 I'm just givin ya the business for some fun. ☺