Need help with Sub question...

I've been getting the itch to either upgrading my current sub, Dynamo (previous model), to either a JL Audio F112 or one of the larger ML subs, Depth/descent depending on price. The other thought is to add a second matching Dynamo. I really love the tight bass and musicality of the Dynamo and wanted to hear what your thoughts were on this. Does having 2 subs make that much of a difference and if you have 2 do you have to have matching subs or does having say 1 dynamo and 1 abyss not make much sense?


Here is my current system.

http://www.martinloganowners.com/forum/showthread.php?t=7613

Yeah, no matter what you've got, that itch keeps coming back, doesn't it?

I too have a Dynamo -- my only ML speaker at present, actually. I like it fine for any music that doesn't contain cannon fire or very deep organ pedals. It can be overwhelmed by LFE in action movies -- my references are the opening scene of Attack of the Clones and the cannon shots in Master and Commander -- and the level has to be turned down way too far to stop it from bottoming. So If you intend to play a lot of stuff like that, I don't think just adding a second Dynamo is the answer; I'd look for something heftier. Hope that helps.

Multiple subs (sometimes unmatched is the new thing).

Earl Geddes has been posting on several forums and his web-page about multiple matched or unmatched sub-woofers.
http://www.gedlee.com/

Toole and Sean Olive sometimes write about multiple subs in the book, web-page and blogs.

If you add a second larger sub, you might try using a much lower cross-over frequency on the 2nd sub.

2 dynamo subs

Hi. I have M/L Aerius i's and have added 2 dynamos in a small 11'x11' room. Because the room is small, they work well if you keep the level down and I have them crossed over at 35hz. You have to play with the phase, but I use the phase at 90 degrees and I think they blend well. They do have a problem keeping up with the panels sometimes, depending on the music, but generally add a warmth and kick that isnt there without them. I run them off the pre-amp out RCA jacks to one sub and then run a second wire to the 2nd sub. -Bob.

The trick for adjusting phase between the mains and the sub(subs) is:

Reverse the polarity to the mains or the sub (whichever is easier).
Play a test tone of the crossover frequency.
Adjust the phase for the least sound (null) at the normal listener position.
The return the speaker polarity to normal.

It's a lot easier to hear a null than to hear a peak.

Since my knowledge with speaker setup is not advanced

Can you explain it in Lehman's term on how to properly align the phase? Also, does anyone know if there is a big difference between the Dynamo and say the Abyss? I wouldn't mind moving up with a larger driver for the bigger low-end but not at the expense of quick, tight bass that the small 10'in driver might provide. Just curious, is the Dynamo basically the same driver for the Spire's or Summit X's, if so would it make sense to stay with the dynamo is i decide to add either of those down the road to keep everything a close match?

Based on these factors in order of preferences 1-being highest
Priorities:
1) Quick tight bass
2) musical
3) tight deep low-end for movies or music
4) Cost
5) Smaller the better or easy to position

Options currently considering: Open to others
a) 2nd Dynamo
b) upgrade to Abyss, maybe add 2nd if needed
c) upgrade to JL Audio F112 or F110
d) upgrade to Depth i


Thanks again.

Hello,
Really and truly, the ESL Series (Grotto, Depth, and Descent) are in another league than the Dynamo and Abyss. Especially so with the Tri Driver array in the Depth and Descent.

The Descent was a huge undertaking for Martin Logan that is the culmination of 5 Years of R&D to make a Subwoofer that has the speed of their Electrostatic Speakers. After multiple Designs, ML decided on a Sealed, Servo Controlled, 3 Woofer or in ML Speak "Tri Linear Driver Array" configuration.

The magic was in placing the 3 Woofers 120 Degrees apart or in ML Speak, Balanced Force Driver Arrangement.
Here is the description: "Conventional subwoofer enclosures vibrate in reaction to driver activity, creating a secondary and highly colored sound source. In extreme cases, the cabinet may even dance on the floor. The typical expedient of adding mass can make the problem less obvious, but it doesn't really make it go away. Resonant bass smear is inevitable unless cabinet vibration is drastically attenuated. MartinLogan's BalancedForce design places multiple identical drivers in exact opposition to one another, so that their forces on the cabinet almost perfectly cancel.

Employing a novel application of the BalancedForce principle pioneered in the original Descent, Descent i locates the three drivers of its TriLinear™ array precisely 120 degrees apart on the cabinet. Their reaction force vectors exactly balance at the center point for near-total cancellation, reducing spurious cabinet radiation by as much as 25 dB (a power factor of more than 300:1)."

The Depth employs all of the same technologies, but uses 8" Woofers instead of 10" and uses a less powerful Amplifier in a 30% smaller enclosure.

The original Decent used a single 400 watt Amplifier while the "i" revision upgraded to three 250 watt Amplifiers. With the Depth, Amplification went from 300 watts to 350 watts.

The Grotto is an excellent Subwoofer as well, but only uses 1 of the 10" Woofers from the Descent with a 300 watt Amplifier. However, the Grotto is Servo Controlled which the Dynamo and Abyss are not. Moreover, the Grotto has a more heavily braced enclosure weighing 51 pounds while the 12" Abyss weighs 39 pounds and the 10" Dynamo weighs 28.5 pounds.

Or to put it another way, while the Grotto and Dynamo use the same size Woofer, the Grotto almost weighs twice as much due to the aforementioned stouter enclosure and heavier Magnet in the Woofer.

Though not all agree with me, the "i" revision to the ESL Series was not huge with the exception of the Descent i which almost has twice the power.

With the Depth and Grotto, the "i" revision was mostly cosmetic changes with slightly more powerful Amplifiers. In addition, the Descent i and Depth i have "Triple Servo Correction System" while the originals had "Advanced Servo Control" I am not sure what the real difference is.

I do know that when I called Martin Logan about adding a Depth i for use with my original Depth, they said it would not pose any problems whatsoever. Again with the Depth, the Amplifier went from 300 to 350 watts. I am not sure if a Descent and Descent i in the same room would work as well due to the much higher power in the Descent i.

The Dynamo and Abyss are excellent Subwoofers. I also really like that they are Sealed Enclosures and offer the choice of front firing or down firing. It is just the ESL Series are truly special.
Cheers,
JJ

fvbruin said:

c) upgrade to JL Audio F112 or F110

Thanks again.

Click to expand...

I'm running a JL F112 in my 2 channel system with my Vista's; it integrates well with ML and is a very accurate sub, IMHO.