[Bob in St. Louis]

No Ed, I've never heard mud from the Augies. However I've never run them higher than 120Hz due to the main drivers having the ability to reach the mid double digit range.

Yea, you should get some more coffee dude. 
Maybe a Mountain Dew or two. 

Bob 

[taloyd]

4 Augies per side (8 total) and a servo sub for the lowest octave. 



Another forum member's old build, but droooooooool    50hz seems a bit high; the servo in the picture is crossed at 28hz. 

A little late in the game, but just wanted to correct the OP's above observation about the crossover settings of the servo sub: the subwoofer in the above picture is not LOW-passed at 28 Hz., it is set to have the servo correct DOWN to 28 Hz. The lowest LP setting is 40 Hz. on that sub - I know because I have one.

To digress a bit more: I'm not sure why exactly it is set to correct down to 28 - that's the highest (ie: worst) option (http://www.rythmikaudio.com/images/A300SE.jpg), it can also do 20, and 14. The latter (14 Hz.) is the best choice for sound quality - it has the best group delay curve, which is what you want for reproduction, especially in a system as nice as that.

I've said it before: the Rythmik subs are the nicest I've ever heard, and are utterly unobtrusive during use, but offer SO much ambience and detail retrieval: I was amazed at how EVERYTHING sounded better after including it in my system - even girl-and-guitar type music with seemingly no LF content. Everything was better.

With all that said, I'm about to go from boxed, ported midbass, to a 4 x 15" OB setup - and couldn't be more excited!

cheers,
-Tal

[Whitese]

Did anyone mention the Lambda Acoustics with Appolo motor now made and sold thru Acoustic Elegance (AES)?

http://www.aespeakers.com/drivers.php?driver_id=8

[Arlo]

That looks like a wonderful driver.  But that magnet looks too small to get the job done accurately. 
I want PUNCH!   

[taloyd]

That looks like a wonderful driver.  But that magnet looks too small to get the job done accurately. 
I want PUNCH!   

Actually, the magnet is that size to DECREASE the total damping of the speaker to get it in the range of where is optimal for an open-baffle (essentially unloaded) "enclosure". The speaker has a Qts of 0.7 which is IDEAL for an IB or OB situation. "Punch" has to do with EQ, and has been argued that isn't available in a velocity-source based system (open baffle,dipole, etcetera).

Also, in regards to:

Did anyone mention the Lambda Acoustics with Appolo motor now made and sold thru Acoustic Elegance (AES)?

The IB15 driver does NOT have the Apollo motor upgrade - that is expensive and only used in applications where one needs the output of two drivers in a situation where there is only room for one, and the one is power-limited. The Apollo adds a lot of heatsinking capability to the (already VERY impressive) motor of (all) the Acoustic Elegance drivers. This allows continuous high-power operation BEYOND the tolerances of the standard motor.

As distortion is proportional to cone excursion, two drivers would always be preferable if possible...

With that said, the quartet of 15" drivers I mentioned earlier is a 4-pack of IB15s from Acoustic Elegance. After doing the research, the only competitor I found for this level of quality and this application is the DPL-15 from Diycable.com. Kevin Haskins from that company is in the top echelon of customer service available. The only reason I went with the IB15 (the DPL-15 is actually superior, with slightly greater xmax, and more focus on reducing self-noise from the driver as it is actually designed for dipole use - versus the IB15 has found incidental popularity in the open-baffle crowd as it is targeted at infinite baffle applications, where it is flat to 10 Hz. when used as specified) is that AE was offering a $400 for a four-pack which makes it $160 cheaper than the DPL-15 drivers (http://www.diycable.com/main/product_info.php?products_id=684)

cheers,
-Tal Allweil

[dweekie]

A little late in the game, but just wanted to correct the OP's above observation about the crossover settings of the servo sub: the subwoofer in the above picture is not LOW-passed at 28 Hz., it is set to have the servo correct DOWN to 28 Hz. The lowest LP setting is 40 Hz. on that sub - I know because I have one.

An active crossover overcomes that 40hz limit 

[jlharden]

Well, extremely late post but I never really know where I'm going to find my old systems turn up! First off, the Rythmik DS15 was in fact crossed over below 30hz. I do not have stock crossover boards installed, but custom 20-80 hz boards. Secondly the 14, 20, and 28 hz settings are not servo correction range settings, but reflect the shape, or "q" of the eq applied to the driver. Anyway, the pictured system was good fun, but doesn't fit into the current home environment. Currently dabbling again in horns, though who knows what the future will bring!