But who need vertical dispersion so much? I remember when I was young and rented a room on a second floor. I made an MTTM. I could feel the even power response and that it sounded nice. But I didn't really want it. But the story is about my neighbours. Many of them mentioned how good it was (and they have heard a lot of my other speakers for comparison). And they listened from down at first floor level across the house. So may be vertical dispersion at work
The 8" plus tweeter has been done to death in a sense. The really simple crossover versions like Acoustic Research AR4 and AR6 are familiar enough. They relied on heavy bass cones with impressive natural rolloff and crossed around 1.5 to 2kHz to a cone tweeter with a L-pad.
I thought the old SEAS Njord kit was interesting. Probably the natural successor to the paper CA21REX is the H1288-08 CA22RNX. The 25TFFC could probably be replaced by any similar modern SEAS soft dome. H0881-06 27TFFC
I'd suspect it sounds a bit rough and ready, but interesting simple crossover of Dynaco A25 similarity. And not a million miles away from that Monitor Audio MA-800 driver layout by the look of it.
snup, your posts more resemble tweets, IMO. Just sayin'.
An externally hosted image should be here but it was not working when we last tested it.
I thought the old SEAS Njord kit was interesting. Probably the natural successor to the paper CA21REX is the H1288-08 CA22RNX. The 25TFFC could probably be replaced by any similar modern SEAS soft dome. H0881-06 27TFFC
I'd suspect it sounds a bit rough and ready, but interesting simple crossover of Dynaco A25 similarity. And not a million miles away from that Monitor Audio MA-800 driver layout by the look of it.
snup, your posts more resemble tweets, IMO. Just sayin'.
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my posts has nothing to do with tweeting.
If tweets resemble my posts, I was here first. So antisocialmedia : up yours.
I have never been a facebook accountholder or any other pathetic "social"interactive webmisuser. I TAKE OFFENCE BY YOUR STATEMENT, SYSTEM7.
just because I don't post pictures and confusing scientific papers, dug out of long forgotten filecabinets, doesn't mean that I am tweeting for your displeasure or trying to put down your contributions.
I will try to be at least that gentlemanlike.
While you ponder this wrath,
look at the sa210
If tweets resemble my posts, I was here first. So antisocialmedia : up yours.
I have never been a facebook accountholder or any other pathetic "social"interactive webmisuser. I TAKE OFFENCE BY YOUR STATEMENT, SYSTEM7.
just because I don't post pictures and confusing scientific papers, dug out of long forgotten filecabinets, doesn't mean that I am tweeting for your displeasure or trying to put down your contributions.
I will try to be at least that gentlemanlike.
While you ponder this wrath,
look at the sa210
snup, anyone who ventures into Lynn Olson's heavyweight "Beyond The Ariel" thread with insensitive remarks about the Challenger Space Shuttle Disaster risks having his head ripped off. Just sayin'. Again.
8" polycone underhung reflex bass plus metal tweeter this time. The Epos M12.2. These sort of speakers relied on a polycone with a well behaved response unfiltered. The bafflestep is built into the driver inductance a bit like the SEAS A26. It can be done. Then you cross to a metal dome with a small resistance for level and maybe 3.3uF filtering.
It surely has some lively detail. Whether it goes loud or totally smooth is more debateable. My current opinion is that these sort of speakers are JUST MADE for a simple series filter. Which really ought to sound better. Sadly I couldn't convince an owner to have a bash at improvement. But greatly lovely drivers anyway.
8" polycone underhung reflex bass plus metal tweeter this time. The Epos M12.2. These sort of speakers relied on a polycone with a well behaved response unfiltered. The bafflestep is built into the driver inductance a bit like the SEAS A26. It can be done. Then you cross to a metal dome with a small resistance for level and maybe 3.3uF filtering.
It surely has some lively detail. Whether it goes loud or totally smooth is more debateable. My current opinion is that these sort of speakers are JUST MADE for a simple series filter. Which really ought to sound better. Sadly I couldn't convince an owner to have a bash at improvement. But greatly lovely drivers anyway.
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Snup, if the ceiling reflection is a problem it would depend on the angle and the delay. Absorbing a ceiling reflection might be better than trying to avoid it with a trick baffle, as this can affect a wider section of sound and at an earlier delay.
If I understand correctly, the MTM should have a flat (or continuous sloping) directivity index. Not a bad thing either way.
If I understand correctly, the MTM should have a flat (or continuous sloping) directivity index. Not a bad thing either way.
Another take on the 8" woofer + cone tweeter theme
Hi all,
inspired by this thread, I have decided to have a go at modelling and actually building a 2-way 'monitor' of this type for a friend, as follows:
I'll keep you all posted as I actually start assembling this in the Summer months...
Cheers,
Marco
Hi all,
inspired by this thread, I have decided to have a go at modelling and actually building a 2-way 'monitor' of this type for a friend, as follows:
- 8" Woofer: Mivoc WM-8 (92 dB/2.83V/1m, high Qms)
- cone tweeter: Monacor HT-22 (91 dB/2.83V/1m)
- box: 24L bass-reflex tuned to 50 Hz
- crossover: 2nd order electrical, phase matched (see simulation below)
I'll keep you all posted as I actually start assembling this in the Summer months...
Cheers,
Marco
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marco-gea, that's a terrific project and really readable post! Doesn't look easy to me. Rough old woofer cone breakup there and a 2kHz crossover that is unknown territory for me with an HT-22 tweeter. Back in the LEAK Sandwich 300 day, they used to wire two tweeters in series for the power handling, below. But, I'm gripped already!
There's some terrific 5" woofers been made. Like Lynn Olson's favourite Polycone Vifa P13WH, now sadly obsolete. Paper cone and woven polycone well behaved 8" and 10" are still easy to find too. SEAS still make more than you can shake a stick at!
It's 6" bass that is the hard one to make a two-way out of IMO. Time alignment is awkward, and rolloff is shallow and they seem to need huge and awkward bafflestep to get the rolloff flat. So today's classic and, I hope, inspiring speaker is the Heybrook HB2:
Now from what I know, these polite Audax polycones weren't the last word in high Qms at 1.5, but they certainly roll off a bit faster than the 6" paper cones that made Troels Gravesen admit his Sliced Paper Scanspeak 6" 18W8531G00 did not win a cigar: SP95. I thought the polycone Vifa P17WJ looks easier, and it's still around. The tweeter is a non-ferrofluid Audax soft dome that seems to benefit from a bit of Fs and 6kHz bass notching from the weird shunt LCR from bass to tweeter.
The SP95 is a third order butterworth, like the Heybrook. And a very nice one, IMO. It works in either polarity. Where they diverge, is in the cone material. Which are you going for? Well, like with the paper Peerless Nomex 830875 used in so many speakers, you just look at the polycone 830874 and say, THAT looks easier! My simulation gives you a rough idea what is going on in the SP95. Terrible impedance, BTW!
There's some terrific 5" woofers been made. Like Lynn Olson's favourite Polycone Vifa P13WH, now sadly obsolete. Paper cone and woven polycone well behaved 8" and 10" are still easy to find too. SEAS still make more than you can shake a stick at!
It's 6" bass that is the hard one to make a two-way out of IMO. Time alignment is awkward, and rolloff is shallow and they seem to need huge and awkward bafflestep to get the rolloff flat. So today's classic and, I hope, inspiring speaker is the Heybrook HB2:
Now from what I know, these polite Audax polycones weren't the last word in high Qms at 1.5, but they certainly roll off a bit faster than the 6" paper cones that made Troels Gravesen admit his Sliced Paper Scanspeak 6" 18W8531G00 did not win a cigar: SP95. I thought the polycone Vifa P17WJ looks easier, and it's still around. The tweeter is a non-ferrofluid Audax soft dome that seems to benefit from a bit of Fs and 6kHz bass notching from the weird shunt LCR from bass to tweeter.
The SP95 is a third order butterworth, like the Heybrook. And a very nice one, IMO. It works in either polarity. Where they diverge, is in the cone material. Which are you going for? Well, like with the paper Peerless Nomex 830875 used in so many speakers, you just look at the polycone 830874 and say, THAT looks easier! My simulation gives you a rough idea what is going on in the SP95. Terrible impedance, BTW!
