# A 4" midrange comparison



## npdang (Jul 29, 2005)

*Seas Lotus RM 110 magnesium cone reference 4"*

I found this driver to have the best realism and clarity of all the drivers tested due to the low loss suspension and brutally stiff straight profile magnesium cone. Smaller cones generally tend to be much stiffer than their larger counterparts as well. Combine all that together, as well as the world class excel motor with it's super low inductance and you have one very good midrange performer. However, you can see some problem areas begin to appear above 3khz and that the driver ideally should be highpassed around 300hz. It's worth mentioning that this unit had a severe forward offset that may just be a fluke.


































*Seas Lotus RM 120 reference paper cone 4"*

The latest iteration of the lotus 4" reference, it features a more optimized motor design that will also allow you to cross almost a full octave lower than the magnesium cone. Distortion in the upper octaves is very low, and you can see the driver has superb top end extension. The large rise in distortion centered at 1khz is a bit disturbing. I found it to be noticeably warmer and fuller bodied than either the nextel or the mag cone, being a very well executed coated paper cone design. Good detail resolution and low coloration.


































*Seas Nextel cone w12cy003 4"*

The latest 4" Excel driver, I find the nextel cone to be in between the mag and the paper cone lotus in terms of resolution and clarity. Not quite as husky as the paper cone, but not so cold as the magnesium. BL curve appears to be slightly improved over previous generations with a wider, flatter plateau. Feel free to cross this one over at 100-150hz. Again there is the noticeable rise in distortion at 1khz, but not nearly as bad as the lotus paper. Of all the Seas 4" drivers, this one has the best low end performance and quite good top end extension.


































*Rainbow profi paper 4"*

Pretty nice bl and cms curves, albeit xmax is fairly low similar to the Lotus mag. You'll want to keep this one crossed over at least 200hz and up. Looking at the le curve, no shorting rings are used in the motor. Distortion is worst out of this group, but that's still pretty good when you consider what you're comparing against. Paper cone doesn't appear to be as optimized as the lotus, given the ripples in the upper end response. I found it to be a decent performer, albeit with the heaviest and most muddled presentation among this group. Especially at higher output the driver began to squawk and complain noticeably as compared to the others.

































*
MB Quart QSD-210 4"*

Sorry, no distortion plot for this one. Motor seems pretty decent, albeit xmax is a bit short. Overall, I thought this driver had the worst construction in terms of feel and finish. The breakup at 4.5khz severely limits the usable bandwidth of such a small driver as well. Subjectively, I thought it was a bit polite and had decent resolution, better than the Rainbows certainly but suffered when driven hard and sounded dirty and cheap. This one was probably the worst of the group in terms of clean, effortless output.


















*Peerless 5.5" Exclusive 830882*

This driver had the best dynamic capability and low end performance, as well as Klippel results. Overall, my favorite driver out of the entire bunch. Detail and clarity just short of the Lotus mag cones and even slightly better than the nextels, it's a very dry but very clean and low coloration presentation. Turning up the volume didn't present any problems. The 4" driver I believe is even slightly better detail wise and with respect to top end extension, although dynamics and low end usability aren't as good.


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## low (Jun 2, 2005)

interesting........


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## dual700 (Mar 6, 2005)

@ RM110 BL graph!!!
Is this particular speaker from Kevin K?
If yes, maybe this one was the one repaired by some local shop, but I might be wrong, IIRC, the test seas gave me long ago had nice BL curve..


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## low (Jun 2, 2005)

dual700 said:


> @ RM110 BL graph!!!
> Is this particular speaker from Kevin K?
> If yes, maybe this one was the one repaired by some local shop, but I might be wrong, IIRC, the test seas gave me long ago had nice BL curve..


i was wondering the same thing...lol


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## dual700 (Mar 6, 2005)

Autiophile said:


> That's my RM110, brand new.


Wow, I dunno what to say...I am curious if your 2nd one measures the same..


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## kevin k. (May 5, 2005)

dual700 said:


> @ RM110 BL graph!!!
> Is this particular speaker from Kevin K?
> If yes, maybe this one was the one repaired by some local shop, but I might be wrong, IIRC, the test seas gave me long ago had nice BL curve..


As already posted, the RM110's are not mine. Btw, Mr. Eng, my mids were never worked on other than to adjust for a little tinsel slap / buzz on one of the drivers. So the cones, motors, etc. were never touched. As such, mine are available for testing, too, if desired.


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## iyamwutiam (Nov 20, 2006)

Umm - no distortion for the QSD ????
A mistake right?


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## dual700 (Mar 6, 2005)

kevin k. said:


> As already posted, the RM110's are not mine. Btw, Mr. Eng, my mids were never worked on other than to adjust for a little tinsel slap / buzz on one of the drivers. So the cones, motors, etc. were never touched. As such, mine are available for testing, too, if desired.


My bad, Mr. K  
Guess I owe you lunch again..


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## kevin k. (May 5, 2005)

^^^ Nah, my turn to buy next time...  

And, thanks to Nguyen for doing the comparison and posting the test results...


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## npdang (Jul 29, 2005)

I think it's funny how with the 7" Nextels, they are so amazing but as you go down in size to the 4" it seems as if the motor isn't as highly optimized. While the opposite is true of the Exclusives... the 7" isn't as good but as you go down in the line to the 4" it gets almost perfect.


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## bdubs767 (Apr 4, 2006)

npdang said:


> I think it's funny how with the 7" Nextels, they are so amazing but as you go down in size to the 4" it seems as if the motor isn't as highly optimized. While the opposite is true of the Exclusives... the 7" isn't as good but as you go down in the line to the 4" it gets almost perfect.



doesnt the rev follow the same pattern as the Seas?


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## Pseudonym (Apr 17, 2006)

hey npdang, if u want to add the morel wr4's to this little list, send me a pm and we'll see about shipping one of mine out.


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## Guest (Jun 4, 2007)

the measurements largely speak for themselves, of course ... but i find the construction quality of the MB Quart QSD's to be outstanding  easily the equal of any Seas driver i've held.


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## FoxPro5 (Feb 14, 2006)

npdang said:


> *Seas Lotus RM 110 magnesium cone reference 4"*
> I found this driver to have the best realism and clarity of all the drivers tested due to the low loss suspension and brutally stiff straight profile magnesium cone. Smaller cones generally tend to be much stiffer than their larger counterparts as well. Combine all that together, as well as the world class excel motor with it's super low inductance and you have one very good midrange performer. However, you can see some problem areas begin to appear above 3khz and that the driver ideally should be highpassed around 300hz. It's worth mentioning that this unit had a severe forward offset that may just be a fluke.


Based on your tests, what would be the optimal slope for both the LP and HP on the Lotus??


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## pianist (Mar 10, 2006)

i've long ago decided that i wanted to run the exclusive 4's in my future 3 way setup, but i know that they are

1. out of order everywhere
2. in high demand

has madisound or tymphany sent out any word of them delivering any new drivers?


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## npdang (Jul 29, 2005)

B-Squad said:


> Based on your tests, what would be the optimal slope for both the LP and HP on the Lotus??


Ideally 300hz to 3khz. Although I think you could go higher and lower depending on how loud you listen and your tolerance for non-linear distortion.


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## FoxPro5 (Feb 14, 2006)

npdang said:


> Ideally 300hz to 3khz. Although I think you could go higher and lower depending on how loud you listen and your tolerance for non-linear distortion.


Ok, how about the slope though? 

My thinking is that I'll hear that distortion based on the rolloff into those frequencies. Just trying to bridge my graph reading skills with my tuning skills.


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## GlasSman (Nov 14, 2006)

iyamwutiam said:


> Umm - no distortion for the QSD ????
> A mistake right?


No. He just doesn't have the plots. I'm sure the driver has distortion. And probably more than the others.


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## truejoker (Apr 1, 2007)

what would be the perfect match to the seas lotus 7" driver and the neo twiter in your opinion ? the seas or the firless exclusive?
thanks very match


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## azngotskills (Feb 24, 2006)

truejoker said:


> what would be the perfect match to the seas lotus 7" driver and the neo twiter in your opinion ? the seas or the firless exclusive?
> thanks very match


With that combo, i dont think that a dedicated midrange in needed


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## truejoker (Apr 1, 2007)

azngotskills said:


> With that combo, i dont think that a dedicated midrange in needed


from the reviews that ndpang gave on them there is a hole in the range that the two do best . i don't remember the actual points .
and i mean the mag version not the nextel


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## m115919h (Jun 12, 2008)

Great write up.


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## bruther (Sep 22, 2009)

npdang said:


> *Rainbow profi paper 4"*
> 
> Pretty nice bl and cms curves, albeit xmax is fairly low similar to the Lotus mag. You'll want to keep this one crossed over at least 200hz and up. Looking at the le curve, no shorting rings are used in the motor. Distortion is worst out of this group, but that's still pretty good when you consider what you're comparing against. Paper cone doesn't appear to be as optimized as the lotus, given the ripples in the upper end response. I found it to be a decent performer, albeit with the heaviest and most muddled presentation among this group. Especially at higher output the driver began to squawk and complain noticeably as compared to the others.


Can someone help me read what these chart mean??


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