Manger MSW and Eton 11-581/50 HEX Plans

[phase_accurate]

yes, this driver sounds very good......! those flimsy 6 - 8" midbass units hasn't got a chance.....and its price is fair too...

Agreed, this Eton driver is a very fine one.

Just as a remark: My flimsy 8" Audiotechnology driver has more than 30% higher Vd (linear), 50 % larger voice-coil diameter and less ringing and coloration at it's upper end, than this Eton.
And the price is not that much higher.

But I don't doubt that you will succeed with your project either.
As far as the crossover-frequency goes: I doubt that they cross over as high as 300 Hz on this one:

http://www.newtronics.de/html/produkte/mega.htm#


Regards

Charles

[navin]

i have not seen the Eton specs so cant comment on it. i did use teh 7" kevlar eton in the late 80s and it was a nice driver but that was a long time ago.

from what i rememeber i was told that one of the criteria (for choosing a mate for the Manger) was a high Bl/Mms ratio something in the order of 0.3-0.4 T/g. the other criteria was something called "musicality". this is subjective.

Also given that Manger proposes the ZeroBox (not having energy stored inside the box) I would expect it to mate better with a a good 8 or 10" in a TL. The 109 is not a TL but the Qts of the 8" is 0.5-0.6.

There are other options one could consider.....aperiodic, Short wel damped TL, TQWT, etc.. but the idea is to ensure that the rear wave is fully absorbed or dissapated very fast.

As far as we are discussing high Bl/Mms ratios I am wondering when SmCo and NDfeB magnets become the norm. these magnets will allow us to build the magnetic circuit into a "phase plug", free up the area directly behind the cone allowing the cone to breathe better, and improve the Bl; killing multiple birds with one stone

[angel]

Originally posted by phase_accurate
Have you actually done any measurements or listening tests to compare different crossover frequencies ?

No. I unfortunately lack the funds to acquire Manger drivers right now. When this problem has been sorted out, I'll see what I can do, but don't hold your breath. :/

While imagination tells me that you are basically right, you should also keep in mind that the MSW has an x-max of +- 3.5 mm and that it is almost a fullrange driver.

Regardless of this, distortion is directly related to driver travel. Travel is related to power, especially low frequency power. A driver that produces e.g. 2% THD at 90dB, will produce 1% THD at 87dB.. Simple math.

KYW also pointed this out in connection with the thread on 15" woofers; the JBL 2226 (121dB: 1% H2, 1% H3) should produce 10ppm H2 and 10ppm H3 at 90dB, which is likely less than what most high-end amplifiers will add.

If you relieve it from low-frequency content you increase woofer problems like IMD and resonances (specially with drivers using very stiff cone material) in exchange.

The resonances of a stiff cone driver, such as the Seas Excel series, are easily controlled. Especially when using active drive, where one can realize steep filters and notches at little cost.

As to IMD, I have not seen the specs for the 8" Seas Excel, but I imagine there might be some reason why Sigfried Linkwitz chose to use it as midrange in his Orion. IIRC, ScottRHinson made a post regarding the low IMD of the Excel series.

[phase_accurate]

Regardless of this, distortion is directly related to driver travel. Travel is related to power, especially low frequency power. A driver that produces e.g. 2% THD at 90dB, will produce 1% THD at 87dB.. Simple math.

Partially agreed (it seem that THD is more or less proportional to the input VOLTAG and not power) but you will add IMD and midrange colorations from the woofer instead. The MSW isn't a midrange driver - it is a fullrange driver. I have heard a system that was using an MSW as a fullrange and it sounded excellent. It was used as a nearfield monitor for recording and didn't have to go very loud though.

KYW also pointed this out in connection with the thread on 15" woofers; the JBL 2226 (121dB: 1% H2, 1% H3) should produce 10ppm H2 and 10ppm H3 at 90dB, which is likely less than what most high-end amplifiers will add.

AFAIR the 1 % figures are for SPLs around 110 dB and not in the 120ies but I would have to look at the spec-sheet once again.

Regards

Charles

[angel]

Originally posted by phase_accurate
Partially agreed (it seem that THD is more or less proportional to the input VOLTAG and not power) but you will add IMD and midrange colorations from the woofer instead.

If the THD is proportional to the voltage, then it should be even lower, due to the high sensitivity of the JBL2226. Can't quite recall the efficiency of the Seas Excel 8", though.

As to colorations, I think you will find that the Seas Excel series is one of the least colored speakers around, provided they've got real hardware driving them, and have a decent crossover (taking into account the notch filter at 3-5kHz)...

AFAIR the 1 % figures are for SPLs around 110 dB and not in the 120ies but I would have to look at the spec-sheet once again.

My bad. The measurement is at about 110dB, yes. Above that, compression starts to become an issue, amongst other things, climbing to some 3dB at full 600W input.

But it is not really relevant, as I was suggesting the Excel, which can't handle nearly that much. However, it can handle more than the Manger, and the use of two drivers will buy headroom anyway.

If you're going to buy the MSW, giving the Excel a go, with an active crossover, isn't a very significant expense. Just have a fullrange switch on the active XO, so that you can turn the Excel on/off according to preference. Just tune the enclosure for the MSW so that it is suited to operate by itself.

[tbla]

angel, it seems to me that you like the seas units - and i'm shure that these are very fine and at least on par with all the other "high end" units......BUT, if one wants "cone area" the seas, scan speak and vifa and others just don't fit the bill......!
nothing beats a 15" (besides 2 x 15".... )

[angel]

tbla,

I mentioned the JBL 2226 (15") earlier in this thread, and its sibling 2241 (18") would fit the bill even better. They'd probably perform pretty well, too.

My recommendation of the Excel was based on aesthetics and simplicity of construction.

The MSW is about 8" in size, and a similarly sized woofer would complement its appearance nicely, and would make cabinet construction simpler in some cases...

The Excel just happens to appear to be the best option in that size range.

Of course, if baffle size is of no concern.. by all means, go for larger drivers, as long as their characteristics match those of the MSW (at least frequency response for the first few octaves, and acoustic phase at the crossover frequency)...

[phase_accurate]

One reason (atually the MAIN reason) for unsing an MSW is it's temporal behaviour. You wouldn't want to mess that one up with a 15" (ANY 8" will be better in this respect). You'd rather use (a) 15" as (an) additional sub(s). I have two 2226 in stock, and I once started a closed box for an ELF speaker, using one of these. I will try it together with the MSW two way speakers some day.

Despite of what I've said above I will also try the MSWs on an open baffle together with the 2226es just for curiosity. I have already heard the MSWs full-range on an "open baffle" (actually an unfinished box) and the first impression was good.

Regards

Charles