This is an enclosure that can be played with and tested in various ways (model : DDVP-1303-WHIM).
Recommended drivers are MarkAudio CHP90 mica, CHR90, Alpair10.3, and MAOP10.
In this case, I mounted the three CHP90 at A, C, and E in the drawing and parallel wired them.
It would be interesting to mount them in positions other than A-G, or to mount a tweeter on the upper side of A and a woofer on the lower side plate.
Recommended drivers are MarkAudio CHP90 mica, CHR90, Alpair10.3, and MAOP10.
In this case, I mounted the three CHP90 at A, C, and E in the drawing and parallel wired them.
It would be interesting to mount them in positions other than A-G, or to mount a tweeter on the upper side of A and a woofer on the lower side plate.
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Hi Scott.
The impedance of CHP90 has not been measured, but the DC resistance of three units in parallel is 2.2ohm.
By the way, the impedance of the DDVP-0803 I made last time is 1.2ohm, and it sounds fine with the NuPrime STA9.
Scott's favorite Iron Maiden playback could be dangerous.
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There will be considerable comb-filtering. Comb-filtering is not "design theory", but very real thing.
Ye gods, but that's a fearsome load. 
I admit it: I'm a brontosaurus 🦕 but assuming something like a McIntosh with 2ohm output taps or a Krell isn't available, I generally work on a '3ohm absolute minimum' basis to give the amplifier an easier time. Less significant with the rise of class D amplifiers, Hypex etc. continuing the trend of clean power getting cheaper all the time of course. Just underlines the fact that I'm a dinosaur I suppose.
I admit it: I'm a brontosaurus 🦕 but assuming something like a McIntosh with 2ohm output taps or a Krell isn't available, I generally work on a '3ohm absolute minimum' basis to give the amplifier an easier time. Less significant with the rise of class D amplifiers, Hypex etc. continuing the trend of clean power getting cheaper all the time of course. Just underlines the fact that I'm a dinosaur I suppose.
True. Although in fairness this tends to apply to the majority of omni variations, including bipoles, so I suppose it depends where your priorities lie. One of my favourites on those lines, inspired by the old EPI 1000 of the '70s: https://www.markaudio.com/wp-content/uploads/2022/09/CHR90-linear-quadrupole.png -very definitely not for use too near boundaries, and very definitely not conventional hi-fi either. They do work oddly well in the context they're meant for though. No accounting for taste (raspberry ripple at this end). Four units in series-parallel to maintain the impedance load -the price apart from cost (& idiosyncrasy) being it does need a fairly 'substantial' box. 😉
Frequency and impedance were measured.
Audibly, the low end extension is excellent, and the treble is natural with no emphasis.
Vocal reproduction is unquestionable.
Although the diaphragm area is more than three times larger than that of 8", the bass extension and sense of scale are in the 8” class, while the treble has the texture of a 5" class.
Audibly, the low end extension is excellent, and the treble is natural with no emphasis.
Vocal reproduction is unquestionable.
Although the diaphragm area is more than three times larger than that of 8", the bass extension and sense of scale are in the 8” class, while the treble has the texture of a 5" class.
Yes, depends pretty much on the priorities. My friend has bipolar speakers Mirage M890i - hazy focus, but wonderful spaciousness, neutral and natural sound on top of that. I measured it with CLIO some 20 years ago - very flat frequency response, with good bass extension from two 5 1/2" woofers. Because the second woofer is mounted on the back, comb-filtering is minimal.
Side mounted woofers will have more pronounced comb-effect, but will add even more spaciousness (and smear imaging). May be fun to listen, though.
Yup, comb-filtering.
But good overall frequency trend.
Hi Sonce.
As for the comb-filter, it doesn't bother me at all in the auditory sense.
In fact, I prefer to use several of them because of the larger scale reproduction sound.
I don't think there is a big difference compared to the frequency response of single use.
Air recorded.
I don't know if it is good or bad because I rarely use rock sources for sound quality checks.
I can't get this energetic sound with MA200-M.
[Air-Recording] POWERSLAVE / IRON MAIDEN - The Four Horsemen / Metallica
[Air-Recording] Live and Let Die / Guns N' Roses - Detroit Rock City / KISS
I don't know if it is good or bad because I rarely use rock sources for sound quality checks.
I can't get this energetic sound with MA200-M.
[Air-Recording] POWERSLAVE / IRON MAIDEN - The Four Horsemen / Metallica
[Air-Recording] Live and Let Die / Guns N' Roses - Detroit Rock City / KISS
Hmm 🤔!
A really different way to get great sound…
Coming from Martin Logan Panels, that seems like an ok Load!! 🤣🤣!
I guess using 6 drivers increases the $$ ¥¥ a bit… then we have to compare the sound to 8 inch drivers that are a bit more expensive… probably you have already done that???
A really different way to get great sound…
Coming from Martin Logan Panels, that seems like an ok Load!! 🤣🤣!
I guess using 6 drivers increases the $$ ¥¥ a bit… then we have to compare the sound to 8 inch drivers that are a bit more expensive… probably you have already done that???
Six drivers are more expensive, but can reproduce equivalent bass in a smaller capacity box than the box for 8”.
The treble has the advantages of a small diameter.
CHP90 mica is a good driver.
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No. Physics laws tells us box volume will be the same for identical efficiency and low-frequency cutoff.
Yes.
Hi Sonce, thanks for your comment.
I don't think theory and reality will be the same.
I am testing for a better way.
Common mistakes about reality and ("unproven") scientific theories. 🙂
In science, law give us numerical answers (outcome), theory give us answers why and what is happening. Both are proved in reality.
Physics laws numerically perfectly describe loudspeakers behavior (in all loudspeaker variants - small and large) and that is practically proven in reality by measurements.
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Drivers C and E are connected in series.
I don't understand the theory, so I play 1-ohm and 2-ohm speakers without concern, but the connection this time is 4.6Ω so anyone can do it safely.
There seems to be no big difference in frequency response between the 3-parallel.
The side sound pressure has been reduced, so the sense of spaciousness has decreased, but there does not seem to be a big difference in bandwidth balance and quality.
[Air-Recording] CHP90 mica(series and parallel) - Better Be Home Soon - Andrea Zonn
[Air-Recording] POWERSLAVE/IRON MAIDEN - The Four Horsemen/Metallica - CHP90 mica(series & parallel)
I don't understand the theory, so I play 1-ohm and 2-ohm speakers without concern, but the connection this time is 4.6Ω so anyone can do it safely.
There seems to be no big difference in frequency response between the 3-parallel.
The side sound pressure has been reduced, so the sense of spaciousness has decreased, but there does not seem to be a big difference in bandwidth balance and quality.
[Air-Recording] CHP90 mica(series and parallel) - Better Be Home Soon - Andrea Zonn
[Air-Recording] POWERSLAVE/IRON MAIDEN - The Four Horsemen/Metallica - CHP90 mica(series & parallel)
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What is the purpose of using cheap units but make them a 1 or 2 Ohm load and then have the need for an amplifier that can let nails glow?
It should be a concern to have a realistic impedance of 4…8 Ohm for use with relatively normal amplifiers otherwise you may loose right what you gained left.
The decolonisation of electronics seems to be going steady but IMHO some old fashioned obsolete basic electrical theory would not hurt.
It should be a concern to have a realistic impedance of 4…8 Ohm for use with relatively normal amplifiers otherwise you may loose right what you gained left.
The decolonisation of electronics seems to be going steady but IMHO some old fashioned obsolete basic electrical theory would not hurt.
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Maybe to use 4 units per box (2 x serial) parallel (2 x serial)
in the same level all
1pc@front
2pc@side-right
1pc@side-left or 1pc@back?
.
Maybe some experiments with port area, has to be bigger for multiple drivers?
Because of increased Sd area which is factor in design...
.
(I have same type cabinet 16 ohms drivers but 2 cabinets in parallel, one on top on other.
So You can use also 2 drivers per cabinet and 2 cabs per channel one in rwvwrsw on the top of other.
To get the 8 ohms...)
in the same level all
1pc@front
2pc@side-right
1pc@side-left or 1pc@back?
.
Maybe some experiments with port area, has to be bigger for multiple drivers?
Because of increased Sd area which is factor in design...
.
(I have same type cabinet 16 ohms drivers but 2 cabinets in parallel, one on top on other.
So You can use also 2 drivers per cabinet and 2 cabs per channel one in rwvwrsw on the top of other.
To get the 8 ohms...)