ACI Maestro... - Page 2

Brian Bunge · 08-24-2004, 09:19 PM

Craig,

Of all your reviews, this one is the one that interests me the most. The first subs I built used the drivers in ACI's Titan and Force subs back when they were still available to the DIY'er. So I'm intimately familiar with the quality of the drivers that ACI uses in their products. I can only assume that the 15" driver in the Maestro follows in their footsteps. Over time I too have grown rather fond of low Q, sealed designs.

Mike, as always thanks for the great products. I know the Maestro will be just as big a hit as the Titan and Force have become.

Edward J M · 08-25-2004, 07:40 AM

Thanks Mike:

Would it be safe to say that the Q = 0.6 only applies to the theater input, where F3 is 35 Hz?

If so (and considering the estimated internal volume of the enclosure) it would seem the theater input uses little or no EQ?

Does the application of EQ (at the speaker inputs) to achieve an F3 of 19 Hz (anechoic) alter the total Q of the system?

If so, is the transient behavior (impulse response) of the Maestro different for the theater input vs. the speaker input?

Can the equalized speaker level inputs be used for HT applications (for greater extension) if the user keeps the overall volume within the clean/safe limits of the Maestro? Or would this be considered a misapplication of the intended use of the product?

Thanks,

Ed

Mike Dzurko · 08-25-2004, 09:32 AM

Brian:
Good to see, er hear from you again. I hope all is well w/you and you family. Thank you for the kind comments. I think it’s safe to say the Maestro is already a bigger hit than the Titan or Force. At least it’s pretty BIG when we’re building and packing them

All the best to you and RAD.

Ed:

Actually everything is really designed around what we feel are the “normal” inputs; the left and or right. Whether used at line level (the sub out from a Processor), or with the speaker level adapters, (a two channel system without preamp outputs), these are the inputs that we feel measure and sound the best. The theater input is in some ways a hold over. It is useful in those rare situations where someone wants it REALLY loud and is willing to give up some sound quality. Rap, Industrial type music, etc. comes to mind.

I’d say the vast majority of users use the left or right inputs on all our sub models. That’s the way I use it too.

Robert_Gaither · 08-25-2004, 12:15 PM

Quote:

True and funny at the same time. Are you ambidextrous Craig?

Rumor has it that he is ... he has the ability to drink beer from either hand...

Craig Chase · 08-26-2004, 12:11 PM

Robert... Not only drink a beer with each hand, but smoke a cigar while doing so...

This review will be a lot of fun... Our main theater room is 5700^3 feet. It will be interesting to discover how the Maestro handles a room that size.

Edward J M · 08-26-2004, 12:44 PM

Quote:

Actually everything is really designed around what we feel are the "normal" inputs; the left and or right. Whether used at line level (the sub out from a Processor), or with the speaker level adapters, (a two channel system without preamp outputs), these are the inputs that we feel measure and sound the best. The theater input is in some ways a hold over.

Thanks, Mike.

Ironically, I would imagine "purists" might find the Theater input (if it is truly unequalized) more attractive, as it should preserve Q = 0.6 and a true 2nd order alignment, with the lower group delay and optimal transient behavior the low Q sealed subwoofer is known for. Of course the downside would be an F3 of 35 Hz, but strictly for popular music applications, that would seem deep enough. What are your thoughts?

Craig, the B4+ in the 20 Hz tune would probably match up best with the Maestro (using the speaker inputs) in terms of anechoic extension.

Craig Chase · 08-26-2004, 12:55 PM

Ed ... it is in 20 Hz mode now... This is easy enough...

steve nn · 08-26-2004, 05:44 PM

>>>It will be interesting to discover how the Maestro handles a room that size.<<<

Most definitely. Thats a good size room Craig, as you know.

Craig Chase · 08-26-2004, 06:25 PM

Steve... It is amazing how the room shrinks when my kids bring friends in to watch a movie....

And yes... It will be fun to see if a single Maestro can deliver all the home theater and music bass desired on a larger room. Tests like Titan AE, LOTR:ROTK and other great bass movies will most definitely be used...

Mike Dzurko · 08-27-2004, 08:31 AM

Ironically, I would imagine "purists" might find the Theater input (if it is truly unequalized) more attractive, as it should preserve Q = 0.6 and a true 2nd order alignment, with the lower group delay and optimal transient behavior the low Q sealed subwoofer is known for. Of course the downside would be an F3 of 35 Hz, but strictly for popular music applications, that would seem deep enough. What are your thoughts?

Ed:

Very assute, and you'd be dead on except the Q> .6 with F3 at 19 sounds even better for a purist than Q > .6, F3 35.

Craig Chase · 08-27-2004, 08:47 AM

Mike... Would you like to tell us why it sounds better? Or would you have to kill us? ...

It IS pretty common that the effect of "eq"ing a sealed design causes some phase delays similar to a ported design.... You have not experienced any such problems with the Maestro ?

Mike Dzurko · 08-27-2004, 09:26 AM

Craig:

All else being equal, a lower F3 will sound better because the group delay is lower in frequency and less audible. I don¡¦t want to have to kill anybody

but the technology is proprietary, and we don¡¦t own it. It has been around for many years and is a property of the U.S. OEM company that we purchase the amplifiers from. We¡¦ve used it in the Titan for over 12 years and the Force for over four years. The way I understand it, in terms of Q, the driver thinks the cabinet is approx. twice as large as it really is. Measurements confirm this and show the more gradual roll-off of the left and right inputs vs. the Theater input. The following close mic chart is of a Titan sub, (don¡¦t have the Maestro file here but they look very similar with the Maestro showing a bit more below 20):