Like epos es did.
Obviously you can't do it with tweeters because you'll fry them, but does anyone do this and like the sound?
One of my favourite speakers over the years have been the old British epos speakers, es range. These were infamous for never using crossovers at all. Apart from a capacitor on the tweeter which acted as a high pass and stopped low frequencies destroying it. Of course the cabinets become a tuning mechanism and drivers have to be sourced or spec'd to roll off appropriately, possibly, but they were a very successful speaker here in the UK. And obviously component matching was another factor, lots of naim users liked them, because they were designed on naim amplification.
I have to say owning hundreds of speakers over the years epos were always one of my favourite and they did have a sound which others I thought couldn't quite match in certain areas. I know their designer Robin Marshall was a bit of an advocate against crossovers at the time.
But anyway anyone have similar feelings about no crossovers or using drive units in such a fashion with good results?
A crossover of whatever form is allways another thing to send a signal through after all. It influences the sound.
Obviously you can't do it with tweeters because you'll fry them, but does anyone do this and like the sound?
One of my favourite speakers over the years have been the old British epos speakers, es range. These were infamous for never using crossovers at all. Apart from a capacitor on the tweeter which acted as a high pass and stopped low frequencies destroying it. Of course the cabinets become a tuning mechanism and drivers have to be sourced or spec'd to roll off appropriately, possibly, but they were a very successful speaker here in the UK. And obviously component matching was another factor, lots of naim users liked them, because they were designed on naim amplification.
I have to say owning hundreds of speakers over the years epos were always one of my favourite and they did have a sound which others I thought couldn't quite match in certain areas. I know their designer Robin Marshall was a bit of an advocate against crossovers at the time.
But anyway anyone have similar feelings about no crossovers or using drive units in such a fashion with good results?
A crossover of whatever form is allways another thing to send a signal through after all. It influences the sound.
Lots of boxes with a simple cap XO.
The system i am currently using has FR running wide open with helper woofers hi-passed with a cap as a PLLXO.
In this box, why is there such large driver spacing?
dave
The system i am currently using has FR running wide open with helper woofers hi-passed with a cap as a PLLXO.
In this box, why is there such large driver spacing?
dave
Seas A26 Devore Style Build
Post #51 has the (unfinished) relook at the A26, including some XO stuff.
dave
There was a budget 6,5” Vifa back in the day which had such a smooth roll off that no xo was needed. Unfortunately I threw it away 10 years ago which I now regret. Don’t remember the model and since Vifa is swallowed by Perless/Scan Speak/Tymphani conglomerate I no longer managed to keep track of all the series. It had a very tiny soft dust cap. Membrane of polypropylene I think. I used it in a few different designs, one bookshelf and one floor stander both worked very well with a Seas 1” tweeter and a cap only. Very effective. I want to find it again and see what else it can do for instance in a 2,5 way.
westsounds,
perhaps you aren't aware of that drive unit itself acts as a filter so the philosophy against crossovers is contradictory in itself. Manufacturers can pretend they believe this approach to be better than the other because it is cheaper to produce so and there is a niche for it. Customers are "sowieso" uneducated most of the time. And there is a new owner now.
perhaps you aren't aware of that drive unit itself acts as a filter so the philosophy against crossovers is contradictory in itself. Manufacturers can pretend they believe this approach to be better than the other because it is cheaper to produce so and there is a niche for it. Customers are "sowieso" uneducated most of the time. And there is a new owner now.
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Also my 25 year old Tannoy profiles does not have a filter on the bass. Sounds great. Also polypropylene.
And yes the Seas A25/A26 is a winner for 50 years already.
And yes the Seas A25/A26 is a winner for 50 years already.
Ah ok, its nothing novel epos were doing then by running their drivers without any crossovers and feeding their drivers full range.
Nice designs never come across those before they look good.
Not exactly sure why they spaced them like this. I'm pretty sure they were separate chambers the lower units tuned more for the bass and the upper, mid/bass, even though there were no crossovers. They were triwired as well, so each driver could benefit from its own amplifier, 3x naim NAP250s, these were designed on NAP250s if I'm not wrong, I know the slightly earlier es11s and 14s were for sure. At least with three separate supplies I suppose you could if you really wanted to balance the drive units sound with different gains on each amplifier. Although I never thought they were unbalanced ever even with one amp. They did need a lot of space though for relatively small and compact speakers, positioning was more critical with these speakers than most. Twin rear ported, one on the lower chamber and one on the upper.
I hate it when that happens 🙁
Knew about the new owners, they're still going and they never strayed far from the original es philosophy although they did try a few different ways of making their epos speakers, with soft dome tweeters and crossovers. I remember talking to Mike Creek at length about the tweeters and he argued so much about the virtues of soft domes, a couple of years later most epos had metal domes again 🙂 what the original series were known for having. But IMHO the old es series were always the best epos ever sounded.
Nice designs never come across those before they look good.
Not exactly sure why they spaced them like this. I'm pretty sure they were separate chambers the lower units tuned more for the bass and the upper, mid/bass, even though there were no crossovers. They were triwired as well, so each driver could benefit from its own amplifier, 3x naim NAP250s, these were designed on NAP250s if I'm not wrong, I know the slightly earlier es11s and 14s were for sure. At least with three separate supplies I suppose you could if you really wanted to balance the drive units sound with different gains on each amplifier. Although I never thought they were unbalanced ever even with one amp. They did need a lot of space though for relatively small and compact speakers, positioning was more critical with these speakers than most. Twin rear ported, one on the lower chamber and one on the upper.
I hate it when that happens 🙁
Knew about the new owners, they're still going and they never strayed far from the original es philosophy although they did try a few different ways of making their epos speakers, with soft dome tweeters and crossovers. I remember talking to Mike Creek at length about the tweeters and he argued so much about the virtues of soft domes, a couple of years later most epos had metal domes again 🙂 what the original series were known for having. But IMHO the old es series were always the best epos ever sounded.
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I have a pair of Mordaunt-Short MS100 speakers from the late 80s.
The mid/bass driver runs 'full range' and relies on its natural roll-off, initially 6dB/octave above 5000Hz, to blend in with the tweeter.
Any attempt I've made to low pass filter that driver simply sucks the life out of the reproduction!
The mid/bass driver runs 'full range' and relies on its natural roll-off, initially 6dB/octave above 5000Hz, to blend in with the tweeter.
Any attempt I've made to low pass filter that driver simply sucks the life out of the reproduction!
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I can understand that. And MS were the sister company to epos, they were very similar.
There are so many woofers and tweeters in this world, that I do not have time to try them all!
Nevertheless I can spot a goodie. 😀
What about a 6" paper Vifa PL18WO?
Vifa PL18WO-09-08 Premium Line 6.5″ Woofer – AmpsLab
Rather pricey these days at about £100.
Vifa PL18WO-09-08 Woofer
And this horn-loaded Morel CAT 378 tweeter:
MOREL CAT 378 Soft Dome Horn Tweeter – AmpsLab
Again, not cheap. About £50.
Since Michael Chua is a personal buddy of mine, I can't give you the circuit. But he will email it to you. Excellent work IMO. Essentially a coil on the bass and a cap on the tweeter. But a bit of extra cleverness too:
Finch (Morel CAT378 + Vifa PL18W0-09-08) – AmpsLab
Nevertheless I can spot a goodie. 😀
What about a 6" paper Vifa PL18WO?
Vifa PL18WO-09-08 Premium Line 6.5″ Woofer – AmpsLab
Rather pricey these days at about £100.
Vifa PL18WO-09-08 Woofer
And this horn-loaded Morel CAT 378 tweeter:
MOREL CAT 378 Soft Dome Horn Tweeter – AmpsLab
Again, not cheap. About £50.
Since Michael Chua is a personal buddy of mine, I can't give you the circuit. But he will email it to you. Excellent work IMO. Essentially a coil on the bass and a cap on the tweeter. But a bit of extra cleverness too:
Finch (Morel CAT378 + Vifa PL18W0-09-08) – AmpsLab
Wasn't it the P17 or something like that? It was a really popular driver in the 90s.
Exactly. This is a very common trait on inexpensive 2 way speakers. Design a poly woofer with a relatively smooth top end with an inexpensive motor design that doesn't have any shorting rings or other doohickies that lower the inductance. The result is a driver with about 1mh of inductance that creates a fairly decent top end roll off. Slap a cheap tweeter in there with an inline cap, and sell it for a hundred bucks, or use marketing spin to mark it up to $1k. The trade off is that usually you still get some high frequency breakup from the woofer that's less than ideal, and usually the crossover ends up high enough that you're well above the range where the woofer starts beaming.
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The Audax tweeter was high passed at 5,000Hz using a second order filter, but these particular units were actually designed to handle a first order filter as large as 4.7uF.
However, the Audax tweeters eventually stopped tweeting and I 'upgraded' them.
Heresy alert! I run the replacement tweeters via a 2.2uF cap in sympathy with the MS100's minimalist vibe!
I encountered a similar, airy minimilism when renovating my friend's Bose 301 Series 2 speakers.
P.S. I think Jim has just summed up the design philosophy of the MS100. It doesn't have a poly woofer, but it does have a real wood veneered cabinet which helped justify its price! 😉
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The woofer you are trying to remember is the Classic 6" polycone Vifa P17-WJ-00-08:
Vifa 2-Way Loudspeaker System
Didn't need much doing to it.
Vifa 2-Way Loudspeaker System
Didn't need much doing to it.
Yes, I get this, and what the other member said about the speaker itself being a filter. But surely the less filters the better even if the speakers are filters themselves. And epos speakers were well respected here in the UK, amongst many of the most discerning audiophiles and magazines. They were and still are sort after, they were not even promoted as having minimalist crossovers as a feature.
like everything else, it's a compromise. I think loudspeakers are where compromises are still the most prevalent, because they're the only part of your signal chain that's still got a mechanical element. Less filters may improve upon some aspects that are considered desirable, but in turn will negatively impact others. Allowing 2 speakers to have a wide overlap in frequencies introduces a whole host of potential problems, especially when their phase alignment isn't perfect. Vertical off axis response usually suffers. Imaging can suffer because you've got 2 separate point sources playing the same thing. Overall sound quality can suffer because woofer breakup nodes aren't well controlled. Baffle step compensation becomes difficult to implement, so these simpler designs often have a weak midbass output, which colors the sound. I generally find these compromises to be too much for whatever perceived benefit that you can get from minimal filtering, but other folks see it differently.
The MS100s were certainly promoted for their minimalism.
A "pseudo-active drive principle" is how MS described the directly coupled mid/bass driver.
Vifa P17WJ yes that’s the one. I think I had the 4 ohm version. Anyway great driver. Seems like Scan Speak took over its production looks available still. But to that price I don’t know. The power handling wasn’t very great.
ScanSpeak Classic P17WJ00 6.5" Woofer
Look at the 4 ohm curve
ScanSpeak Classic P17WJ00 6.5" Woofer
Look at the 4 ohm curve
An externally hosted image should be here but it was not working when we last tested it.
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I notice the top and bottom speaker drivers look slightly different, with the top having slightly smaller dustcap. Maybe the top is for mid and bass, bottom for bass only. It would create a baffle step like freq response, a 2.5 way I think that's how it is called.
Oon