Dynamics, brute force and resolution with tiny feet.

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If I remember correctly Zaph was pretty disparaging regarding Morel drivers and others using a similar design and has the measurements to back it up.

Yep, here are his comments about the MW166:
"Comments: The response is smooth enough to work with, but this driver is plagued by highish tall order distortion through the midrange. It has a huge voice coil (3") but a tiny spider supporting it. I don't recommend this driver as it's non-linear distortion of all types is pretty obvious with most music. Tested October 2005."
 
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I prefer first order x-overs in speakers for domestic use, imo they sound better and i belive in having as little as possible in the signal chain.

The Oy speakers have this x-over today:

oyfilter-2.jpg
 
I did wonder about the crossover. I know what the simple coil and capacitor one sounds like. In fact it's rather coloured even if lively. Lynn Olson and Jeff Bagby comment they found such a setup unsatisfactory in their D'Appolito designs.

I'd think something better would be 1mH coil, 10uF and 3 ohm in series shunted across the bass. 3.3-4uF series and 0.4mH shunt on the treble. Plus 2 ohm/10 ohm wirewound attenuator on the tweeter. That would give the tweeter an easier time of it and lose some cone breakup. Good start point for adjustment by ear.

But it's up to you.
 
This is all VERY interesting, Ingvar! You'll just have to ignore sreten's usual negativity.

Hi,

There is nothing negative in my opinions. I'm all for enthusiasm and all
against misrepresentation of facts or alleged "experience" versus calling
referring to driver tests as "hearsay", when clearly descriptions of a
persons "experience" is as near to real "hearsay" as it actually gets.

I don't know whats VERY interesting about it, given the paucity of details.

Its a very expensive MTM, built by someone who freely admits that he
has no real experience of building such speakers, so no real perspective.

Given that you could build this for a hell of a lot less :

My RS180 MTM Design

In pretty much the same cabinets, or a different box choice, with near
identical sensitivity, bass extension and SPL capability, the obvious
question is do the far the more expensive drivers deliver the goods ?

I don't think so, nothing negative about that, and the above designs
crossover is currently far more advanced than the conjecture here.

rgds, sreten.
 
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Hi,

There is nothing negative in my opinions. I'm all for enthusiasm and all
against misrepresentation of facts or alleged "experience" versus calling
referring to driver tests as "hearsay", when clearly descriptions of a
persons "experience" is as near to real "hearsay" as it actually gets.

I don't know whats VERY interesting about it, given the paucity of details.

Its a very expensive MTM, built by someone who freely admits that he
has no real experience of building such speakers, so no real perspective.

Given that you could build this for a hell of a lot less :

My RS180 MTM Design

In pretty much the same cabinets, or a different box choice, with near
identical sensitivity, bass extension and SPL capability, the obvious
question is do the far the more expensive drivers deliver the goods ?

I don't think so, nothing negative about that, and the above designs
crossover is currently far more advanced than the conjecture here.

rgds, sreten.

But they don't seem to go very low, so they would need a pair of subwoofers?
 
I prefer first order x-overs in speakers for domestic use, imo they sound better and i belive in having as little as possible in the signal chain.

The Oy speakers have this x-over today:

oyfilter-2.jpg

I fail to see how a standard 2nd order xover has any more in the signal chain than a 1st order one.
As far as I see it the extra components are parallel to the drivers and as such not strictly in the signal chain.

Either way I never liked too much acoustical overlap between drivers and very much prefer 24dB active to any passive xover.
But that's just me…
 
I fail to see how a standard 2nd order xover has any more in the signal chain than a 1st order one.
As far as I see it the extra components are parallel to the drivers and as such not strictly in the signal chain.
Contrary to popular belief, all components in a circuit are in the signal chain.
Parallel or series no matter, all are in the signal path, especially since sound is AC.

Later,
Wolf
 
Like tuxedocivic indicated, there is a problem which looks like a polarity issue, but it may run a little deeper. Why don't you post the xover schematics so that we can have a look at it? As a general remark, 3Khz is way too high for a combination with 6 1/4" midbass unit. One of the good things of the Morel tweeters is that you can xover really low. 1.75Khz with steep filterslopes might be better.

Another thing is that a bit more damping material might flatten the FR. These drivers can certainly do better than the +/-7.5 dB shown in your measurements.
 
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Did I miss them or were there no distortion measurements in that thread?

There weren't, zaph had them on his site, I had only done T/S measurements at that stage. I've tried to find my Holm measurements with sine sweeps of my final crossover but seem to have overwritten them :( not particularly happy about that! The point was that zaph's measurements of at least the MW144 didn't seem to be representative of how they are normally, so his comments about how bad they are should be taken with a grain of salt.

I've attached a measurement of the MW144's running full range in their enclosure, but I don't recall the measurement conditions (and they could have been compromised). It looks pretty horrid, and gave me a lot of grief working out a suitable crossover but I was happy with the final result.

The final (without distortion shown) measurements of the completed speaker are in this post --> http://www.diyaudio.com/forums/multi-way/68301-my-morel-mtm-project-4.html#post2776367

Tony.
 

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Tony,
the reason I was looking for distortion measurements were Zaphs comments on the 144 and this:
"Comments: This Hi-Vi poly cone driver has a 3" voice coil with an inset magnet similar to Morel and Dynaudio woofers. The difference is that the Hi-Vi has a superior motor and outperforms them in the harmonic distortion department. If I were going to use this style of inset magnet woofer, I would choose the Hi-Vi over Morel or Dynaudio."

regarding the Hi-Vi D6.8 and his comments on the 144. I didn't get as far as comparing listed T/S to measured T/S or FR after that.
 
Correct- the CAW638 is like the MW166/MW168 with a cast frame.

The MW144 is the classic woofer where the CAW538 would be the evolved unit.

Not the same.
Wolf

Okay, so the drivers are different yet you seem to say that because the MW144 has high distorsion means that CAW638 also has high distorsion. Are there any measurements of the CAW638 available? I thought they played pretty clear at Ingvar's place, much clearer than my CSS EL70eN would do at the same SPL ;)
 
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sorry didn't mean to derail things. The reason I posted the link to the mw144 is because although it is smaller (5" vs 6.5" ) it uses the same motor as the MW166 which is the predecessor I believe of the CAW638.

The point was that even if zaph has said that the drivers are crap, that the measurements that he had were not necessarily representative of the drivers in general.

Since the CAW series are quite a bit different (mostly in the basket I think) then any comparisons to the previous drivers may be a bit pointless anyway :) My original post was just to say, yes I have used morel drivers too and really like them!

Tony.
 
I haven't seen measurements of this particular driver but it would be nice to find out.

It just seems that the inset magnet motor design may be inherently prone to high distortion the same way underhung motor designs are inherently low distortion but also low efficiency. Higher distortion may well be the price one has to pay for the higher power capabilities (via larger diameter voice coils) of inset magnet designs.
There is a price to pay for everything and if one would get high power handling for free surely everybody would use the inset magnet design.
 
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