Personally, I have found that all the weaknesses that are subjectively important lie in the area of the electronics - from the point where the mains power is picked up, to the connection to the driver voice coil. I have never yet swapped in another driver to 'fix' things - the game has been always sufficiently lifted by other mod's -- I have never concerned myself with FR, phase or impedance.
Of course a speaker can sound good on any sort of music, I don't believe I ever said otherwise. However, if it is easy to reproduce a piano's sound how come the majority of systems can't do it, by matching the volume of a real piano at full tilt while doing so?
Proof of performance? Like everyone, it all comes down to what one hears - I tried running the raw Behringers at full tilt, and after 10 minutes I said to my wife, OK, I won't subject you to having to listen to this any more - and went back to the normal system ...
The sound degrades well before clipping, the inadequate power supplies, etc, can't maintain clean voltage rails, and the relatively poor PSRR of the simple chip amps, and other ICs means they are defenceless in the face of the noisy mess being inflicted upon them. Sometimes, one just has to hear what it is possible when most of that is taken care of, properly ... to appreciate what a great difference it makes ....
Of course a speaker can sound good on any sort of music, I don't believe I ever said otherwise. However, if it is easy to reproduce a piano's sound how come the majority of systems can't do it, by matching the volume of a real piano at full tilt while doing so?
Proof of performance? Like everyone, it all comes down to what one hears - I tried running the raw Behringers at full tilt, and after 10 minutes I said to my wife, OK, I won't subject you to having to listen to this any more - and went back to the normal system ...
The sound degrades well before clipping, the inadequate power supplies, etc, can't maintain clean voltage rails, and the relatively poor PSRR of the simple chip amps, and other ICs means they are defenceless in the face of the noisy mess being inflicted upon them. Sometimes, one just has to hear what it is possible when most of that is taken care of, properly ... to appreciate what a great difference it makes ....
Last edited:
Just guessing on your part with no measurements then. Nope I don't accept your reasoning. How can you say the sound degrades before clipping if you aren't looking at the waveform? Running them at full tilt? Does that mean cranking the volume up to max? No one runs their amps wide open, no wonder it distorted. I've read your comments on other threads and won't bother addressing your "claims", it's waste of time honestly. It will be interesting to see what "mods" you suggest then for the Behringer but I don't think it will improve the sound one bit. Lets see then.
So you don't believe you can hear distortion from a system when listening via the speakers, that you need to look at the waveform present at the speaker terminals, or the output from a microphone in front of the speakers - does this include sound from cheap ghetto blasters, say ...?
I regularly run amps just below clipping, and sometimes intermittently into that region. On a correctly working system this will barely be noticeable ...
Sure Dan, really just think about it: Even poor NFB amplifier will have damping factor of 20, about 0.05Ohms. Zobel will have resistance comparable to DC of driver voice coil. Zobel and driver don't see each other, only the amplifier.
Your Zobel link is pathetic, this Zobel link is much better.
Hello ! has you have mentioned i think there is a possibility to add a simple and more powerful power supply for the bass section only
I do not think that the high section and filter electronics have a heavy consumption
You say that the PSRR of the chip amps is low. Have you checked in the data sheets ?
People here need parts numbers, figures, ecc. to be able to take part to the project.
The fact that you can raise quite a lot the level and still the level of distortion is not very high it is a good starting point for me.
I do not need a 110 dB-20Hz at the couch 😱
Again for drivers ... i have a dream. Aluminium drivers.
They are more and more common also in high end products.
Even in Scanspeak they offer new drivers with aluminium cones.
This must mean something
Kindest regards,
gino
P.S. i got yesterday the speakers. I have something to do in the weakend.
Thomann sells some 300 different active monitors. Active Nearfield Monitors - Thomann UK
2030A modifications that you and others have suggested will cost alltogether as much as you speakers! Perhaps you will do some cost-benefit analysis? Changing drivers means you must design a new crossover.
It is nice to have a hobby! Happy weekend!
2030A modifications that you and others have suggested will cost alltogether as much as you speakers! Perhaps you will do some cost-benefit analysis? Changing drivers means you must design a new crossover.
It is nice to have a hobby! Happy weekend!
What you get in datasheets in miniscule in key areas, like PSRR - but it's a starting point. The chip amps are in fact quite 'powerful' ones, comparatively speaking - the more good juice you feed them, the better they will perform ... 🙂.
Remember, these were the best units I heard on the day, comparing them to other brands that were up to 5 times more expensive ... so when I say they distort, it was relatively benign relative to the others. That blues track I mentioned ealier to Dan, they were able to pump that out with the overload light constantly flickering - but you weren't able to perceive any stress from the units.
Give them a good thrash, with high energy music, with lots of treble - if brand new the tweeter and associated circuitry will need to bed in. Personally, I wouldn't even start to think of what I thought of them until they've been hammered for 4 or 5 hours at close to clipping volumes.
Probably the greatest benefit of 'better' drivers is that one shouldn't have to condition the drive units to the same degree ...
Send them back - they're faulty.
The ones I heard (and are currently set up back home) stay clean, even when nudging the Limit LED.
It was one of those "its not that loud" moments, until I tried to speak...
Chris
PS - I'd say they benefit from a sub: a ported 8-10" driver hitting 30Hz would complete them.
Last edited:
A quick datapoint on PSRR in LM3886 - its 50dB @ 20kHz, from -ve rail referred to the input. Subtract the closed loop gain (26dB minimum for stability) and you get 24dB PSRR. So 100mV on the neg supply becomes 6mV on the output.
Put this another way - if your error budget is the noise floor of 16bit (dithered) @ -93dB then you'll want to keep the noise induced from the supply on the output below 0.5mV. Meaning keeping the 20kHz ripple below 9mV.
Last edited:
Except, the units use TDA7293s. The datasheet is pretty hopeless, unless someone has one with more info.
Again, the distortion I'm talking of is relative to what I know is obtainable - compared to most amplifier units in audio shops they perform very well, as is.
Again, the distortion I'm talking of is relative to what I know is obtainable - compared to most amplifier units in audio shops they perform very well, as is.
Subjectively you find weakness in electronics. You simply do not know. Results are all subjective. You simply do not know.
Drivers are weakest link in all audio systems. Swapping drivers leads to at very least tweaking levels; likely changing crossover point. Any driver related filters will likely need to be changed.
Hacking new out of box product voids any warranty.
Modding only one is pointless. Modding two is total loss of reference; unless a second pair is also used for comparison.
Speakers stand up well to many critics regardless of cost.
I did a quick and dirty PSRR measurement of the TDA7293 - same ballpark as the LM3886. Since they both seem to be single pole compensated, the OL unity gain freq more or less defines it (there, the PSRR is 0dB). It has the capability though of having its small signal rails powered separately from the output. Tricky to arrange (the die substrate goes to the small signal -ve rail, not the power one as one might initially assume) but do-able. I've never seen a commercial implementation that has tried this.
Following on from my earlier error budget analysis, I reckon the supply impedance needs to be <5mohm at 20kHz. Anyone achieved this at the pins of their chosen chipamp?
Thanks for doing that, Richard.
Yes, I've wondered whether anyone has tried separating the rail feeds for this family of semi's - and how much benefit accrued.
It was some time ago, but my National chip effort used LM338s plus heavy paralleling of low ESR caps at the pins - should have been in the ball park of that <5mohm at 20kHz figure.
Yes, I've wondered whether anyone has tried separating the rail feeds for this family of semi's - and how much benefit accrued.
It was some time ago, but my National chip effort used LM338s plus heavy paralleling of low ESR caps at the pins - should have been in the ball park of that <5mohm at 20kHz figure.
Hi,
My problem is hijacking of a thread to spout your own opinion
as though it is fact, when it is not, and generally just talking
inaccurate pseudo-technical garbage about a subject you
do not understand thoroughly, if at all in any real sense.
Yes I am / was an EEE and don't insult my intelligence.
rgds, sreten.
Last edited:
Still i have a question
Why all these doubts on the crossover ?
Is it not active ? i mean placed before the power amps ?
The bass driver has to cope with freqs up to 2kHz
the tweeter from 2k up
I hope that differencies in the new tweeter sensitivity could be cure with the on board attenuators .... i hope.
If not a good quality resistor should do the trick.
Am i missing something ?
Regards,
gino
P.S. however not only Behringer use chip amps ...
Why all these doubts on the crossover ?
Is it not active ? i mean placed before the power amps ?
The bass driver has to cope with freqs up to 2kHz
the tweeter from 2k up
I hope that differencies in the new tweeter sensitivity could be cure with the on board attenuators .... i hope.
If not a good quality resistor should do the trick.
Am i missing something ?
Regards,
gino
P.S. however not only Behringer use chip amps ...
Last edited:
Hi,
Why do you think new tweeters are a good idea ?
Response is good
The roll-off of any new tweeter will need to closely match
the roll-off of the current tweeter if the active crossover
has been properly designed for the target acoustic function.
It will also need to match the waveguide and have a similar
response trend, (above is tested not in the waveguide).
Distortion is good
No issues except for the ultrasonic break up stuff
rgds, sreten.
Why do you think new tweeters are a good idea ?
Response is good
The roll-off of any new tweeter will need to closely match
the roll-off of the current tweeter if the active crossover
has been properly designed for the target acoustic function.
It will also need to match the waveguide and have a similar
response trend, (above is tested not in the waveguide).
Distortion is good
No issues except for the ultrasonic break up stuff
rgds, sreten.
Last edited:
Hello !
thank you sincerely for the graph that it is very promising
Now i am at work but in the weekend i will open them and try to identify the parts 😱
My dream would be to get the TS parameters of the woofer
That would be very useful i guess
Thanks and regards,
gino
thank you sincerely for the graph that it is very promising
Now i am at work but in the weekend i will open them and try to identify the parts 😱
My dream would be to get the TS parameters of the woofer
That would be very useful i guess
Thanks and regards,
gino
Last edited:
Now you are the one putting words into my mouth. Sure you can hear distortion by just listening but to find out what type of distortion it would help tremendously to have equipment to look at the waveform as it would help tremendously to have the proper equipment and software to help modify an existing speaker system. If you think by just listening that you can improve an active speaker then why bother looking at a data sheet in the first place? I mean those data sheets were provided by the manufacturer that MEASURED the product instead of listening🙄
Why run amps so hard? If you are running into clipping then you need a more powerful amp. You want to improve the sound by replacing parts that barely if at all will change the sound yet you accept the "barely noticeable" distortions of a clipping amp? I find your reasoning on what to replace and the absence of any measurements to be folly and to suggest to the OP to do what you suggest just wasting his time and money.
It sound to me a too refined approach for a cheap speaker.
Anyway any bad sound will be quite apparent
it is only a feeling but i like greatly waveguide ,,, very very much
Again i do not think that the differences could be heard
I have these D28 in a Dynaudio of which i like only the tweeters and the box
So it will be the donor ...
I love the clean sound of the D28 ,,, and it should be also quite distortion free i guess
http://www.gattiweb.com/images/dynaudio/d28-2_data.pdf
i opened the bigger 2031 and did not like the woofer aspect
For me the woofer quality is much more critical of the tweeter quality
The woofer has the tough job
When i look at the price for good 7" woofers i faint
The Madisound Speaker Store
almost 1000 USD/each 😱
Very very high ,,,
So i think that also the quality will be extremely different because if not this expensive parts would be without market
But i intend to modify just one and with the balance control on the preamp, a nice one, go from left to right and listen for differences.
I should do this with a mono signal i think ...
So that i can always get back
Thanks and regards,
gino
Last edited:
- Status
- Not open for further replies.