[biz97]

Hi,

  I'm looking to add 2 subs to my 2-channel system.  I currently have an integrated with pre-outs but no main ins.  I am looking for subs that can integrate "seamlessly" (i.e. pretty darn close) to my existing system.  I was guessing that I would run 1 RCA to each sub from my pre-outs (Left to Left input of left sub, Right input to Right input of right sub).  With two subs in a system do you calibrate each one at a time and then do fine adjustments or do you attempt to calibrate both at the same time? I am planning on placing them behind each main speaker. My mains reach down to around 47Hz according to the published specs so would I bring the sub in around 47 and work my way up to blend this best?  I was originally going to go with RELs since they have a reputation for creating almost seamless blends with many setups.  But I have been reading very good things about ACI's products too.  I was wondering if using the Force XL's could achieve similar results.  Anyone with experience integrating ACI subs in a similar setup to mine (i.e. running speakers in full range and having the sub augment the lower notes)? How successful were you?  Any other tips for working with the setup I have? Thanks!

[Lkdog]

I run a pair of older ACI Titans with my ACI Jaguars. Jags go down below 40hz in my room.
Each system and in room response is different, but generally it is believed that dual subs does a lot of good things.

Trial and error on the blending. Works great for me and with a little effort you can get great results.

[oris98]

I am using a pair of Force to complement the lower end of my Fontaine II speakers.  Without any tweaking around with crossover set at 80hz it blends in together perfectly.  I have both Force subs sit behind my speakers 2.5 feet away from the rear corners. 

[biz97]

Thanks for the feedback guys! Oris98 I was wondering if you are using filters or anything like that.  Is your cross over set to 80hz for a reason?  Another major plus is the 30 in-home period.  I can go to a lot of dealers to see a bunch of different subs but until they are in my place I won't know how they sound...

[biz97]

Also,

 Is it correct to set up each sub independantly?  I'm guessing you set one up and calibrate it and then calibrate the second one w/out turning the other one on?  Or should both be left on when calibrating?  Confused 

[Lkdog]

Also,

 Is it correct to set up each sub independantly?  I'm guessing you set one up and calibrate it and then calibrate the second one w/out turning the other one on?  Or should both be left on when calibrating?  Confused 

Good question.
I set the levels and cutoffs with both subs on as that is how I use them.
I placed them both near the main monitors about the same distance from front wall.

I do use significant bass trapping also to help with cancellations/standing waves, etc.
Each room is unique.

I am really sold on dual subs. The older Titans are a ridiculous bargain used (around $400) and perform beautifully down to 20hz territory.

[Bob Reynolds]

You might want to read Dr. Floyd Toole's paper "Getting the Bass Right" on the Harman web site.

http://www.harman.com/about_harman/technology_leadership.aspx

Click on the White Papers link.

You can download test tones from the M&K pro web site for doing level matching between the mains and subs (you'll need an SPL meter).

http://www.mkprofessional.com/wav/index.htm

[MaxCast]

Also,

 Is it correct to set up each sub independantly?  I'm guessing you set one up and calibrate it and then calibrate the second one w/out turning the other one on?  Or should both be left on when calibrating?  Confused 

I set each sub independantly.  Set the first sub -3dB.  Turn off sub1 and set the second sub -3dB.  turn them both on and see where you are at.  Adjust both up or down at this point.

What subs are you looing at?  ACI does offer filters for your mains and I think their subs have up to 36dB/octive roll off on the low pass of the subs.  I'm used a active xo set at 50 or 80 and preferred the 80.

[biz97]

Hi MaxCast,

  I purchased 2 Force XLs last Friday and con't use any filtering on my mains as I am running an integrated w/ pre-outs but no main-ins.  Look looking for bass augmentation mainly

[oris98]

No,  I don't use any filter for the main.  I tried the stuff stock approach and didn't like it.  I tried to set the xo to 60 or under and still prefer the 80hz for natural bass reproduction.

Thanks for the feedback guys! Oris98 I was wondering if you are using filters or anything like that.  Is your cross over set to 80hz for a reason?  Another major plus is the 30 in-home period.  I can go to a lot of dealers to see a bunch of different subs but until they are in my place I won't know how they sound...

[Mike Dzurko]

Good input from everyone 

I prefer to integrate both subs at the same time. The only time I might consider doing it one by one is if I had a very non-symetrical room and non-symetrical speaker placement. Otherwise, I do it just like I was doing a single.  Since your mains are spec'd to 47, that is the range I'd start in. However, besides experimenting with moving the crossover up, I'd also experiment moving it down. Depending on your mains, the room, you might have greater extension than that, and or peaks in that cutoff range. Experimentation is the key along with just making one change at a time to train yourself in what the controls do. Expect it to sound good with a little work, expect it to sound GREAT with more work and experimentation.

[biz97]

Thanks Mike!  Can't wait to put them into my system and dial everything in!

[rockadanny]

My room and speakers and sub (single Titan) are different than yours but I feel the need to chime in just the same. My speakers are rated -3db at 55Hz so I started the sub's crossover around 60Hz with a Radio Shack SPL meter and fudge charts in hand. I tried  increasing and then decreasing the crossover until I found what was perfect for me, as per my meter and ears. Surprisingly (at least to me) I ended up setting the Titan at its lowest crossover point. I did not expect to set it that low at all, but ended up with a relatively flat (within +-3db) all the way down to 20 db, where the response eventually exceeded the 6db band of +-3db from reference (-4db 25 Hz, -7db 20 Hz). Sounds perfectly integrated to me and all others who've heard my system. I am so pleased with the integration and overall effect that I plan on getting a second Titan in the near future, sooner if Mike starts offering "F"-stock models (F, being far less expensive than B, though may teeter on the ugly side, but I don't care how it looks, just how it sounds).   

Pardon me, but:  ATTENTION oris98 - you have a PM.

[NewBuyer]

...My speakers are rated -3db at 55Hz ...I ended up setting the Titan at its lowest crossover point...

Is this lowest crossover point for the Titan, 35Hz?

[rockadanny]

Yes.

[NewBuyer]

So technically would it be expected, that with those settings, you should be experiencing a some frequency sagging in the range from 35Hz to 55Hz? I'm not understanding how it could be so "off from the dial" so to speak... I guess it must be like Mike said, all about the mains/room interaction. Makes me want to revisit my own Force XL settings now!

[Mike Dzurko]

I guess it must be like Mike said, all about the mains/room interaction. Makes me want to revisit my own Force XL settings now!

Exactly right    I've heard systems where perfect integration was achieved with the crossover point as much as an octave away from where it "should" have been.  With typical full-range systems (floorstanders) the best sounding placement for image/tone, etc. is usually not the best placement for bass response. This is one of those reasons that make high-end sat-subs so flexible and desirable.

[biz97]

Awesome!  I know they will sound even better as I get them dialed in.  I have one quick question about the phase.  Since I have the subs positioned on the same wall slightly behind the speakers should the phase be set to 0 or not necessarily?  Thanks!

[Mike Dzurko]

Awesome!  I know they will sound even better as I get them dialed in.  I have one quick question about the phase.  Since I have the subs positioned on the same wall slightly behind the speakers should the phase be set to 0 or not necessarily?  Thanks!

Not necessarily is the better answer    Always fine tuning the adjustment, you never know until you do . . .