Folks. Hi.
Just wanted some recommendations for a 3-way sealed box, will likely be roughly 40 L volume. I am looking for a bit of a unicorn;
5-6"
> 90db efficiency
Flat from 200Hz - 6kHz
8 Ohm
decent power handling
Something like a new version of the now discontinued Seas M15CH001
Thoughts?
Just wanted some recommendations for a 3-way sealed box, will likely be roughly 40 L volume. I am looking for a bit of a unicorn;
5-6"
> 90db efficiency
Flat from 200Hz - 6kHz
8 Ohm
decent power handling
Something like a new version of the now discontinued Seas M15CH001
Thoughts?
First thought is that's a bad idea (5-6" up to 6k)
Second thought is this:
www.audioexcite.com >> AudioTechnology 15H521206SDKM
Second thought is this:
www.audioexcite.com >> AudioTechnology 15H521206SDKM
Have you looked at the PHL range? E17-1060? They have alot of variety.
Beyma 6MCF200ND also looks very nice, I'm curious to try it...
Beyma 6MCF200ND also looks very nice, I'm curious to try it...
Flat on an infinite baffle? Or flat on a small width baffle? (..and if so: what size baffle width?)
I'm also assuming it's "flat on-axis" as well. Though remember what the response will be like off-axis depending on your tweeter and its high-pass relative to the pressure loss of the mid. driver off-axis at higher freq.s..
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The free-air response.
We aren't planning on crossing it over @ 200hz, more likely 500, but we'd rather have it as flat as possible to an octave below in free air. Same at the top end, likely crossing over at 3-4k but just want to be careful.
It will be a fairly wide-baffle stand-mount 3-way. Ideally something that can be easy to drive.
We aren't planning on crossing it over @ 200hz, more likely 500, but we'd rather have it as flat as possible to an octave below in free air. Same at the top end, likely crossing over at 3-4k but just want to be careful.
It will be a fairly wide-baffle stand-mount 3-way. Ideally something that can be easy to drive.
Actually..........
[200*6000]^0.5 = ~1095 Hz mean
~13543/pi/~1095 = ~3.94" dia. piston, so ~5.5" frame size.
At a 500 Hz XO point, it's even more HF biased at a ~2.49" dia. piston and whatever frame size this dictates; I've no clue as this is compression driver 'territory' for me. 😉
GM
A good plan and since proportional octave wise, driver size remains the same. 😉
GM
I don't think you understand what you are asking for. 😱
Almost no driver is going to have a free-air response (no baffle) at a meter or more that is anything close to flat, and certainly not over such a wide bandwidth.
If you just want to replicate (..or a bit more "flat") the Seas driver (AS IT WAS MEASURED), then there are a few options.
At the higher-end is:
SCAN SPEAK 12MU/4731T00 (Mid-range 4", 4 Ohm, 150 Wmax)
At the lower-end is:
MONACOR MSH-116/4 (Mid-range 4", 4 Ohm, 120 Wmax)
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How critical is it that you get 90 dB / 1 W sensitivity from the driver? Especially since you want it 8 ohm impedance?
Also, ScottG is right, you want a directivity match with two drivers (or driver groups) crossing with each other, and a 5", let alone a 6", is not going to be matching up with a tweeter at 5-6 kHz.
You are specifying a number of parameters, most of which unfortunately don't impact performance. If we have more info about the rest of the system, or what type of acoustic performance you want to achieve, there'll be fewer blanks to fill in.
Also, ScottG is right, you want a directivity match with two drivers (or driver groups) crossing with each other, and a 5", let alone a 6", is not going to be matching up with a tweeter at 5-6 kHz.
You are specifying a number of parameters, most of which unfortunately don't impact performance. If we have more info about the rest of the system, or what type of acoustic performance you want to achieve, there'll be fewer blanks to fill in.
Everyone's talking like a 6" 8ohm driver with >90dB@1w sensitivity is difficult.
Here's one: Eighteen Sound - Professional loudspeakers
Here's a dedicated mid that's closer to 100dB@1w: Eighteen Sound - Professional loudspeakers
There's also the 6ND430 which has more Xmax for LF reproduction, at the expense of sensitivity. Excellent driver, though.
Chris
Here's one: Eighteen Sound - Professional loudspeakers
Here's a dedicated mid that's closer to 100dB@1w: Eighteen Sound - Professional loudspeakers
There's also the 6ND430 which has more Xmax for LF reproduction, at the expense of sensitivity. Excellent driver, though.
Chris
From a thread on another forum, the homage/inspiration/idea behind the speaker is the Yamaha NS1000 from the 70s which had a beryllium dome 3.5" midrange operating from 500-6k Hz (I think), 12" woofer in a modest sized sealed cabinet. I think this is where the 8 ohms, 90 dB efficiency and high crossover frequency are coming from.
I am not sure if the intention is to cross very high on a flat baffle but if so a large diameter midrange will not be suitable. Unless it is a strongly damped soft resonant cone like the SEAS which are rare these days. How close would this be to the small hard dome of the NS1000 in performance?
Not sure about the flat for an octave either side of the passband. It may be a want rather than a requirement with smooth being acceptable but then again it may not. Assuming sufficient SPL for a monitor physics works against the combination of small, high-efficiency and flat for 3 octaves. The midrange in the NS1000 was flat(ish) for about half that according to the measurements on Troels website. The 4" Scan-Speak you suggested has the wide passband but too low an efficiency which is an issue due to a passive crossover.
It looks like an interesting project but the specification of what is to be preserved, what may be surrendered, and what may be gained from a few decades of evolution seems to still be work in progress.
-my first problem was specifying what's basically a no-baffle dipole midrange that's flat. When someone says free-air under a test condition it's almost always just a driver on a bench measured in the extreme near-field - which won't have the same result measured at 1 meter.
OK then, so a Yamaha NS1000.
At a width of almost 15" and an off-set midrange you can achieve a fairly linear response down to about 900 Hz where you'll start having diffractive gain of a bit over 3db with that "bump" centered on just under 500 Hz (where it's a bit over 3db). At about 220 Hz the pressure should be nearly the same as the average (over 900 Hz).
-basically a "flat" driver is never flat on-baffle.
When I've got time I'll look into drivers that are more efficient and that might work better.
OK then, so a Yamaha NS1000.
At a width of almost 15" and an off-set midrange you can achieve a fairly linear response down to about 900 Hz where you'll start having diffractive gain of a bit over 3db with that "bump" centered on just under 500 Hz (where it's a bit over 3db). At about 220 Hz the pressure should be nearly the same as the average (over 900 Hz).
-basically a "flat" driver is never flat on-baffle.
When I've got time I'll look into drivers that are more efficient and that might work better.
I couldn't find anything that worked.. I wanted the little 4" aerogel mid from Audax to work, but its upper freq. response has more ripple and is boosted, plus it doesn't have a "dip" in response below 900 Hz.
The 4fe32 was about the closest, but it's got that problem much higher in freq., isn't that efficient, and will still have treble loss a bit above 2 kHz off-axis that is significant.
The 4fe32 was about the closest, but it's got that problem much higher in freq., isn't that efficient, and will still have treble loss a bit above 2 kHz off-axis that is significant.
AE TD6M ticks most (all?) of the boxes, but I still don't think this is exactly what he needs.
Uncorrected there would be a large dip centered around 1.3 kHz for the TD6M.
It of course has a lot of pressure loss of axis: about 13 db 45 degrees off-axis at 6 kHz (..and strangely it's worse at 30 degrees at 6 kHz).
I just think (..like most "I want this" posts) that the requirements are unrealistic.
Jon's evaluation (MD60N-6?) driver might work for this if the requirements are "reined in" and applied in a more beneficial fashion (ie. something more similar to the Yamaha design):
Driver Evaluations for a new project - Page 10
..it's too bad Dayton Audio's production on the 2" dome mid has gone to crap (also as noted in that linked page); it *might* have been suitable with the right design restraints.
It of course has a lot of pressure loss of axis: about 13 db 45 degrees off-axis at 6 kHz (..and strangely it's worse at 30 degrees at 6 kHz).
I just think (..like most "I want this" posts) that the requirements are unrealistic.
Jon's evaluation (MD60N-6?) driver might work for this if the requirements are "reined in" and applied in a more beneficial fashion (ie. something more similar to the Yamaha design):
Driver Evaluations for a new project - Page 10
..it's too bad Dayton Audio's production on the 2" dome mid has gone to crap (also as noted in that linked page); it *might* have been suitable with the right design restraints.
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I think the driver evaluated by Jon is the Morel EM1308:
Morel EM 1308 2-1/8" Dome Midrange
At least, that is what appears when I hover over the lines on the graphs.
Morel EM 1308 2-1/8" Dome Midrange
At least, that is what appears when I hover over the lines on the graphs.