Thank you for this.
So in reality it is impossible to make a (3 way)loudspeaker with using only natural rolloffs of the drivers? It would be enormous load for the amplifier?
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Well I did not say it has a crossover,dont put words in my mouth please.
I have the feeling that pretty haughty people write here?
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Hi Sape, yes that is correct.
The simplest design is a mid-bass driver (170mm) with a choke for the upper roll-off (2.5 - 3kHz) and a tweeter with a cap to block the low frequency getting through to it. This design would have very little bass extension, but with a good box design and a sub-woofer it makes the easiest way to do it.
All the best, Kevin
The simplest design is a mid-bass driver (170mm) with a choke for the upper roll-off (2.5 - 3kHz) and a tweeter with a cap to block the low frequency getting through to it. This design would have very little bass extension, but with a good box design and a sub-woofer it makes the easiest way to do it.
All the best, Kevin
You can actually measure it quite easily with a homemade test CD of a frequency sweep from 20 to 20kHz (use Audacity and make it a slow sweep over say a couple of minutes)
Feed the speaker/s from a source of 6 volts RMS via a 600 ohm series resistor. The RMS voltage as measured across the speaker terminals then equates to the impedance. So 60 millivolts would be 6 ohm, 40 millivolts 4 ohm and so on.
(Method above credited to Doug Self)
But it takes time.
Most of what I posted, I have posted before.
Next time I will give a summary. After that it be even shorter.
Then I get criticised for being "terse".
My patience in posting help reaches a limit when I answer the same questions/errors every week/month/year/decade.
If only Members would look for the information.
It's all there !
And after all that help, we get a thank you worded like this
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Well Thank You once more.
I will most certainly offer a good scotch dram when I visit there.
I ' d say : for power consideration, the tweeter should be filtered 2nd order, as the woofer generally survive the peaks ( at least those with more than 1" voice coil )
And : bass extension isn't consequent to that; if inter-frequency-modulation is considered and also other things ( "cooperation" with the tweeter ) such SQ, then yes...the blanket, ya know.
Hi Tony,
I was lucky enough to be pairing a ScanSpeak with a SEAS P17RCY, and they were a perfect match with the very most basic of crossover. Unfortunately with most speakers one does need a 2nd order filter. I just had such a good sounding small speaker back then, and not a very big listening room/lounge.
Kevin
I was lucky enough to be pairing a ScanSpeak with a SEAS P17RCY, and they were a perfect match with the very most basic of crossover. Unfortunately with most speakers one does need a 2nd order filter. I just had such a good sounding small speaker back then, and not a very big listening room/lounge.
Kevin
I would like to think that you do so because your clear, helpful and patient input, like that of some others, is greatly appreciated by so many who (like myself) have so much to learn - do please continue.
I do hope not, that would be so selfish and sad.
I am aware that there are posters who clearly have a great deal to offer but whose wealth of knowledge perhaps renders them unable patiently to explain things in simple terms and who get impatient with those who do not have the same level of knowledge but who wish to learn - perhaps they should become (or are) school teachers
No names, no pack drill.
Not impossible, but a really bad idea.
That's not the main problem. For example, one could use three 16 Ohm drivers for a total load of about 5 Ohms, which most (if not all) amps would be quite happy to drive.
The main trouble is that high frequency drivers don't handle low frequency input well. Playing bass through a tweeter would likely cause over-excursion of the dome (or cone) and thus bad distortion. The power handling of tweeters is also quite low, so there would be a good chance that they'd burn out. The low power handling isn't normally a problem because only a small fraction of the total power is in the treble.
I wonder why speaker manufacturers don't follow the apparently entirely sensible approach taken by Kiriakos? Perhaps they don't have access to the sophisticated and expensive equipment he must have used - or simply wouldn't understand how to use it? ...
Recently I had to replace foam surrounds in my PHILIPS speakers so become useful and operate again.
My other alternatives were: a) to replace four speakers drives with a new. b) Recycling this pair with it cabinets and heading for a new pair at 600 EUR.
Because of this reason for a first time in my life I searched hard to find as much documentation was available about every bit of this pair of speakers.
What I discovered was that PHILIPS at 90s was had under full control their speakers design, starting from cabinet’s size and suggested speaker stands if the cabinets were short.
Or about speaker drives characteristics which were followed by perfectly matched crossover networks, which they was also having perfectly matched capacitors, which they were also designed for sound application and in their specifications’ there is data of ESR testing in all the acoustical range.
Those days there is no more manufactures which has total control from start to finish regarding loudspeakers design.
Therefore there is a greater degree of uncertainty when a consumer gets parts from different sources which never have any very detailed specifications data.
Now in the world of electrical measurements’ it is supposed that the user has to accept the average measured value from the range of Min/ Max/ Average.
According to my measurements’ the average impedance in these specific speakers is somewhere at 7 Ohm which is considered as good enough.
There are many speakers with the woofer connected directly to the woofer, my Dyna A25s for example.
Here is an example of a 3-way speaker design, using parallel crossover.
SEAS TJL3W
There are plots of impedance measurements of the individual drivers near the beginning, and the overall system impedance toward the end.
The first thing to notice is that the individual drivers are not simply resistive devices. They may be categorized as "8 ohm", or "6 ohm", or whatever. Combining them with caps, coils, and resistors in the crossover circuit creates an even more complex system impedance.
Obviously, the system impedance is frequency dependent, and a result of the combined effect of everything in the circuit. Even without a crossover, the combined effect will still be frequency dependent.
Well we can do the scary complex word as tremendously simple by using the dissipation factor instead of the word complex impedance.
But naturally if you do not own any specialized measurements instrument, all the words sounds as scary.
Because they remind you that you need to pay 200 - 300$ for a Test and Measurement equipment.
A UMIK-1 costs $75 + shipping and comes with a cal file. The latter is what is important. To make an impedence jig costs <$20, depending on what you have on hand. The software is free. So not such a big expense to do it properly.
Many around here have miniDSP's, they work very good, are extremely flexible and relatively inexpensive. As others have mentioned LR4 isn't the fix for all, but doesnt matter as you can change to other types on the fly without additional parts. I have 2, 2x4's running 4way active.
Many around here have miniDSP's, they work very good, are extremely flexible and relatively inexpensive. As others have mentioned LR4 isn't the fix for all, but doesnt matter as you can change to other types on the fly without additional parts. I have 2, 2x4's running 4way active.
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