I've been gifted w/4 vifa pl18woo9 and 2 scanspeak tweeters- The eros design, I can not find? Does anyone have it, and can share w/me? have tried my best to find it, however, am blocked, or, it's gone? my email is vglaso@basicisp.net. Am trying to help a friend- (or any design using same 8 ohm woofer and a scanspeak 9300, ) crossover and box volume? anyone? thank you-
Well, the thread is 11 years old... 
I am not sure where you have looked, but the MK II Xover schematic was reposted here: Eros MKII crossover
/U.
I am not sure where you have looked, but the MK II Xover schematic was reposted here: Eros MKII crossover
/U.
The Vifa PL18WO-09-08 Woofer has a Qts of 0.34 and a Vas of 25 litres. That says a reflex box of 0.75 Cu Feet in your quaint old American units.
A series filter simply doesn't work without time alignment or some other clever tricks, which can't be applied to a 6" bass anyway. In fact the "Eros" filter was one of the awfullest things I have ever seen. No phase alignment whatsoever, it gets no "love" from me!
Below is a filter that should work very well with the two drive units. I won't consider an MTM because that is another fashionable but broken design. You can adjust the attenuator for level on the tweeter to taste. This approximates a 2.2kHz LR4 filter, with a 6kHz woofer notch suitable for the woofer's worst cone resonance, for the technically minded.
You can tune the bass reflex tube length with some sort of online calculator.
Should sound very nice. Hope it helps, and feel free to ask further questions.
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Eros MK II
I couldn't find the construction plans of the Eros MK II, they seem to have disappeared. Nevertheless I was able to do a simulation based on pictures on the net. If polarity of woofer or tweeter is reversed then the frequency response at 3 m is very flat. My only concern is the tweeter, which gets way too much low frequencies IMO.
I couldn't find the construction plans of the Eros MK II, they seem to have disappeared. Nevertheless I was able to do a simulation based on pictures on the net. If polarity of woofer or tweeter is reversed then the frequency response at 3 m is very flat. My only concern is the tweeter, which gets way too much low frequencies IMO.
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I did the sim too, Dissi. I've still got things to learn about series filters, but the "Eros" is broken on a flat baffle if only on phase. Your comments about the low crossover make sense too.
Actually there is some nice phase alignment lurking if you time align it by setting the tweeter back 2.2cm. But it's still broken on tweeter distortion from the silly low and shallow crossover.
How long do we have to endure these stupid designs?
Actually there is some nice phase alignment lurking if you time align it by setting the tweeter back 2.2cm. But it's still broken on tweeter distortion from the silly low and shallow crossover.
How long do we have to endure these stupid designs?
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How long do we have to endure these stupid designs?
Besides the tweeter issue there is nothing wrong with the Eros MK II. The speaker gets very positive reviews by most of the owners.
There's absolutely no reason to call it a "stupid design" or "one of the awfullest things I have ever seen". Steve, you really shouldn't simulate a tweeter with Fs of 550 Hz by one having Fs at 1700 Hz and then conclude on the phase response!
Well, I think somebody has to call out the rotten designs that abound. It's not enough to say "Dude, I got a series filter!" Most people must be deaf, considering some of the designs they rate as good IMO!
But what phase did you get with a different tweeter on flat baffle? I tried loads. They were all about 90 degrees out around crossover. I'm open to the science, which always wins in the end! And good phase alignment really matters to integrate drivers.
I can get a bit rude sometimes I suppose. But science is no place for feelings. The physics does what it does, regardless of your feelings.
But what phase did you get with a different tweeter on flat baffle? I tried loads. They were all about 90 degrees out around crossover. I'm open to the science, which always wins in the end! And good phase alignment really matters to integrate drivers.
I can get a bit rude sometimes I suppose. But science is no place for feelings. The physics does what it does, regardless of your feelings.
According to my simulation there's a slight phase match error of 20-30 degrees, but that's acceptable IMO. Please consider that the result is not necessarily very accurate, because the exact location of the acoustic center of a driver actually is hard to predict.
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We're turning the page now, Dissi, so it's going to be hard work to compare some slopes. Looking at your phase response, it's evident the tweeter needs to be set back another centimetre to line up better. You could offset it to the outside if you wanted too. But I think the error is nearer two centimetres. And who cares? The crossover is too low and shallow anyway.
Back to the more conventional parallel circuit for 6" woofer and tweeter. I could do even better than the below phase with a second order filter, which is just a single 4.7uF tweeter cap and the same 0.3mH coil, but that will distort more. As it is, the phase is excellent and you get more energy at crossover, which I like. This is a very nice sounding speaker based on Lynn Olson's ideas. I know, because I've built it.
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vifa and scanspeak design
-thanks for replies. (and f.w.i.w.) was amazed at any response. thanks- did some limited research, and, decided on a two way system with the vifa woofer and scanspeak tweeter. Am a complete amateur at this- w/out tools some of you people have. So, have realized nothing is perfect... Found some baffles for two way system at madisound, and , I can build the box. The cutouts are done and will work. It's the MD14-B2 product. "whatever". So, what might be best box volume, and, best crossover? It'll take me a week or so to get this put together. as an aside, interesting how series v/ parallel crossovers work. -thanks-
-thanks for replies. (and f.w.i.w.) was amazed at any response. thanks- did some limited research, and, decided on a two way system with the vifa woofer and scanspeak tweeter. Am a complete amateur at this- w/out tools some of you people have. So, have realized nothing is perfect... Found some baffles for two way system at madisound, and , I can build the box. The cutouts are done and will work. It's the MD14-B2 product. "whatever". So, what might be best box volume, and, best crossover? It'll take me a week or so to get this put together. as an aside, interesting how series v/ parallel crossovers work. -thanks-
Just reread the thread, my friend. I have covered it all. Forget about series crossovers though, they need to be time aligned.
I build speakers like this, and I know how they work. Here's probably my favourite way of building crossovers, using tagstrip and timber:
A little gallery below. With reflex, you usually just line the cabinets with rubbery stuff. http://www.diyaudio.com/forums/multi-way/223174-interesting-read-i-found-lossy-cabinet-designs-harbeth.html#post3234256
I build speakers like this, and I know how they work. Here's probably my favourite way of building crossovers, using tagstrip and timber:
An externally hosted image should be here but it was not working when we last tested it.
A little gallery below. With reflex, you usually just line the cabinets with rubbery stuff. http://www.diyaudio.com/forums/multi-way/223174-interesting-read-i-found-lossy-cabinet-designs-harbeth.html#post3234256
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What's best always is up to personal opinion. I propose a volume of 0.6 cu ft and a vent of 2" x 4.5" (ID x length), which yields a tuning frequency slightly below 50 Hz.
Cabinet damping usually is not "rubbery stuff": Cabinet-damping. But don't spend a lot of money on that, an old carpet glued on the walls does as well.
Attached my crossover proposal. Be aware that a design based on a simulation always bears the risk of not turn out as expected.
Madisound crossover components:
Inductors: Sledgehammer and 19 AWG air core
Resistors: Wirewound
Capacitors: Polypropylene (Bennic, Solen or ClarityCap PX, depending on budget)
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Frankly, Dissi, you do yourself a Dissirvice there. You should tell vglaso that your phase alignment is non-existent above 5kHz.
Let's stop pussyfooting with amateur designs, and do the real thing here:
The tweeter is set back about 3cms by the sloped baffle. The rather complex filter is here:
http://www.diyaudio.com/forums/multi-way/258017-troels-gravesen-time-aligned-3-way-published-4.html#post3971072
That's how you really do it. Give it a go, my friend. If you are serious about getting it right first time. It needs some slight adjustment for your particular drivers, but we can get to that if you are interested.
Damping and reflex issues are really not the main event.
Let's stop pussyfooting with amateur designs, and do the real thing here:
An externally hosted image should be here but it was not working when we last tested it.
The tweeter is set back about 3cms by the sloped baffle. The rather complex filter is here:
http://www.diyaudio.com/forums/multi-way/258017-troels-gravesen-time-aligned-3-way-published-4.html#post3971072
That's how you really do it. Give it a go, my friend. If you are serious about getting it right first time. It needs some slight adjustment for your particular drivers, but we can get to that if you are interested.
Damping and reflex issues are really not the main event.
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okay- Am able to create box , and make it (solid). idea of time alignment and idea of having it sloped? is beyond me. Apparently, it's necessary to make box as solid as possible. -on the inside. I propose to build a box as dissi says w/volume of .6 cu. ft. and, do the reflex thing w/vent on the back. (or should it be in front) I read a bit about all the various permutations and ways of testing- am amazed at how complex some measurements can be. Obviously, I need to make my box as... 'thrump-proof' as I can. Also- am gonna put crossover under the box... with easy access. and wire woofer and tweeter to feed each seperate. All I have to do is make box a bit taller... and feed wires in from bottom, w/silicone to fill holes once I'm done. The crossover can be changed? and, "time alignment"...? can be solved by me simply putting speakers ...slightly back.?at an angle/ My project won't look anything like some of your designs- Am simply looking for results. with existing woofer/tweeter.... thanks- It's about 90 degrees hot here where I sit, and- the heat has me in bad mood- thanks! -for response.
Hi- I built a box! (and , after much calculating, have found I failed to take into consideration (all) the bracing and so on that I did. (got carried away in making as solid as possible. Did find a few calculaters that helped, and a lot of info, but, bottom line is fact box internal volume is closer to .5 ft. sq. than it is to .6 ft. sq. internal volume. A few questions; better to seal it?, or adjust port?- And, am ready to build crossover- I see similarities in both , and look for simplicity. Understand need to attenuate the tweeter somewhat relative to woofer, and, (understand the notch filter) a further refinement) am very confused in differences in how tweeter might be attenuated to match output of woofer? any thoughts? -And, am a novice, so, that's my story, and, I'm sticking to it. - T.I.A. and hope my questions are not too simplistic.
As an aside, the various filters and differences w/em and how a response is supposed to happen makes me wonder... is the future all digitally designed ... in the future? - (with 4th order slopes (or more) betwixt drivers)(using rane products?) (are computers faster than what I can hear) Am just thinking here, but, an overlap, betwixt drivers does add something ... better than an electronic filter. any input appreciated
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