Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Mark "Bass Pig" Weiss]

As I am about to drop a major amount of money on a quantity of these drivers, I am very interested in UNBIASED reports on their performance, particularly reliability.
There's a thread here that talks about glue failures on Aura-Seismic drivers. I'm trying to determine if CGN is a completely different driver (even though it looks suspiciously like the Aura-Seismic driver) and if it is free from this problem.

I have gone through a number of different drivers over the years and the ones with Kapton voice coil formers that used a cyanoacrylate adhesive for 'fast cure' manufacturing production line volume output were failing frequently.

I really do hope that the CGN drivers are built to withstand the punishment of thousands of watts and being driven to their full Xlim frequently without failure because I like the fact that they have a 2" linear excursion and over 3" before damage levels. These can move some serious air.

At present, we have some 'bulletproof' E-V EVX180Bs employed, and they take the punishment without complaint. In fact, they are the first speakers we've used that we didn't destroy during our break in testing. But in my quest for not settling for second best, and always striving toward deeper bass in smaller boxes, the CGN-1808 seems to be a good step in the direction of this goal. Why settle for 2" of excursion when you can have 3+".    

So what are your impressions of this driver? Is it as good as claimed? Is it robust, or does it fall apart with heavy demand?
This is an expensive driver, and as such, I want to be sure that we're not going to fall into the trap of reconing these every week. Any input based on actual FIRST-HAND experience with these drivers will be appreciated.

Thanks!

[Mark "Bass Pig" Weiss]

Nobody? Is everyone on holiday this week? Or no CGN-1808 owners here? Or is it some dark, deep conspiracy to silence the comments about this product?  

[Tim Padrick]

I doubt that there are many users that have them in anything other than BassMaxx boxes.  I'm sure that they would give you an honest assesment of their reliability in those boxes.

I had a pair of Aura 1808s in reflex cabinets.  They finally pooped out, but they were pretty old, were driven pretty hard, and the cabinets were tuned much higher than they should have been.

Also look into the Bassmaxx Merlin driver and http://www.worxaudio.com/product_desc_true.php?id=56

[Mark "Bass Pig" Weiss]

Thanks for the WorxAudio link. The TL1801SS looks like a contender. I have a pricing and engineering spec inquiry into them.

There was a thread somewhere on here that had a pretty negative view of Aura Seismic drivers, but I understand those are no longer being made, or have been redesigned.

[Antone Atmarama Bajor]

      As far as I can tell from all of the cabinet/driver modeling I've been doing.  

    In a conventional direct radiator cab the Seismic/Aura/CGN are incredibly efficient Mid Bass Woofers.  But They are not very good Sub woofers.  Horn Loading may change that.  But an optimal Reflex box for one of those things is  2.368 cu ft. with a really large long port making it a total volume of 7.568 cu ft.

    -3dB is at 66Hz.

    It does look like it would be a real nice candidate for an ELF sealed Box Bass System though.

    Maybe almost as good as the Adire Tumult 18 as a sealed subwoofer.

    In a 2.368 cu ft Heavy stuff box with a Qtc of .47 one could achieve 110dB at 20Hz with the BrandX-1808.

    By the Way how much do those things cost.  I can't find any pricing anywheres.

Antone-

[Antone Atmarama Bajor]

     The Merlin looks like it is ~ the same driver as the 1808 but they offer no specs.

Antone-

[Mark "Bass Pig" Weiss]

CGN has this T-S info on their web site:

Extended Bass Shelf/ BW, Vab = 9.94 cu. ft. , Fb = 27.4 Hz , F(-3) = 28.84 Hz, Peak 0 dB


Are you saying that with larger boxes the efficiency of these drivers falls off rapidly as compared with a different driver you had in mind?

One would thing that with a large enough box size and a driver with a large Xmax and strong electrical damping that it should be possible to achieve very low frequency output at high SPLs, since SPLs are directly replated to displacement. Now assuming we have a linear displacment of 2" p-p, and that the unit is in a box large enough and with a vent long enough for an F3 of 15Hz, the box should produce a high output in that range. I can expect some loss of efficiency in the 50-120Hz range, but really my interest is to produce the 10-25Hz range, so very large boxes and long vent paths.

It appears that there are two very similar units: CGN-1808 and Aurasound NRT18-8. The latter has a slightly higher BL factor and Vas.
The third option you mentioned seems like a significantly different unit. It weighs some 20lbs more than the Aura or CGN driver and has an aluminum cone. But they list no technical information on this driver on their web site.
(Why is it speaker manufacturers have such poorly-implemented web sites? The download dropdown link is non-operational. I wonder if that was meant to be a link to the spec sheet?)

Can I contact you off-list about your other question?

[Antone Atmarama Bajor]

With port you'll need a little over 11.29cu'  Cab.

    I'm not sure what kind of extension you want but I'm sure you could use 4 lab 12 drivers in ~ the same volume cab and get the same performance below 40Hz.  You can see from these charts that the Seismic is most powerful in the MidBass.



    I'll post you some charts of an optimized 4 X Lab 12 cab.
As opposed to an optimized "High Fidelity" Seismic.

Antone-

[Antone Atmarama Bajor]

Here are three charts.

Orange the LF extension Seismic  one Big box!
Yellow Optimal "High Fidelity" Seismic Cab
Blue Optimal "High Fidelity" 4 X Lab 12 Cab




    The great thing about the Lab is its 149$ a driver retail.
I don't know how much the Neo Drivers cost but PM me I'm curious.

    If its LF extension you need the Labs will deliver, and you can split a 4 X 12 cab into 2 2 X 12 Cabs for ease of movement.
If you need the 10dB of extra Mid Bass Headroom than the Seismic is clearly the winner.

    I have my BS-212's I built using lab 12's They do pretty good for LF extension.  I mounted the drivers in a differential configuration they have extremely low harmonic distortion to and down bellow cutoff.  Not much more than 1.08% at 20Hz with 100Watts @ 10Meters.  They do a good job of making buildings rattle (The Rattling is more apparent than the fundamental pitch).  There is more about them posted in this thread.  I'm thinking the Neo's will have a lot more harmonic distortion in its Extended Range.  

    You may find that extension that low isn't as useful depending on your application.

Antone-

[Mark "Bass Pig" Weiss]

Thanks for plotting the response vs amplitude curves.
It might be helpful if I mention that the design will employ two 18" drivers per box, not one.
Currently getting about 139dB @ 1M from dual EVX180Bs in one such cabinet design, over the 40-125Hz range, with 230V p-p signal swing at the input terminals. I would expect 6dB more output from the CGN drivers, due to doubled excursion capability, and a lot more than 6dB of undistorted output, as the Xmax is about three times that of the 180B.
This is rapidly turning into a 'money is no object' project. We've even looked at the MTX JackHammer drivers, just for laughs.  
However, we wish to keep the cabinets under 40 cu ft, and it appears that this will be an achievable goal. (An earlier design from the 1980s employed four Altec 3182 drivers in a 96 cu ft box which proved impossible to move through a doorway. While it moved a lot of air at 16Hz, the drivers proved to be too fragile and soon failed due to voice coil former scrape on pole pieces.)
The dual EVX180Bs in pairs of 16 and 20 cu ft boxes have the 35-125Hz range nicely covered. The goal of adding the CGN drivers is to achieve overall system flatness to 16Hz without electrical EQ.