Subwoofers and Crossovers.

Thanks, Mike. That was one of the articles that sent me down this path looking for an active crossover. If I hadn't read it I would be blissfully listening to RELs by now.

@khiak Those Funk Audio subs look awesome and am sure they perform well, but they are not for me. Not only are they beyond my budget but they are also really big.

@asvjerry If only it was so simple. I realize digital crossovers are really good, but I am reluctant to pass the analog output of my DAC through  an ADA process. I am starting to think I am being irrational here.

@ozzy  thanks for the information. Do you see the benefits of high-passing the mains at low volume too or just at high volume?

@yogiboy , Thanks for the information. May I ask what replaced the D110/HSU with? Just curious if there is a better solution.

@james633 , Are there any intermediate priced crossovers? I am seeing them either priced at around $200 or around $3500.

@jl35 ,  Thanks for the link. 

@james633 , Thank you, I will search the forum. I will probably use low cost high pass filter and then replace it with the JL CR-1 later.

@yogiboy I am sure, just adding the D110s will help, but one of the main reason I looking to this is to unload the bass frequencies from the mains.

@mike_in_nc , I really like the sound of Cary DMS-550 and the Luxman L-507uxii and am unwilling to insert a digital processor after the Luxman pre. Don't get me wrong, if I were to setup a new system from scratch, I will definitely get a Pre/DSP and a power amp.

I will probably introduce a DSP just for the subs though.

@artemus_5 , I did think of getting two E110s instead of two D110s + CR-1. The E110 options is much cheaper. I might be completely wrong in this, but I preferred the second option thinking that the crossover in CR-1 will be much better and I didn't want to run long line level connection to and from the subs.

Thanks for nudging me to rethink that option. 

@avanti1960 While adding the subs did you high pass your mains or did you run them full range?

I am actually very happy with my setup.. but as is the case in this hobby one always wonders if things can be improved. Hence I am looking  at adding subs/crossovers.

In my room(fairly large) the system starts to roll off below 50Hz and there is nothing left by around 30Hz. Maybe I should look at my speaker placement more critically.

@ozzy Thanks for the feedback.

@fittebd , Thanks, in fact I have been leaning towards getting Rhythmic F12SE instead of JLs along with the CR-1. I may have to add a DSP just for the subs. 

@audioman58 Thanks, it is tempting to look at SVS or ML for DSP, but I am still leaning towards Rhythmic F12s

@wokeuptobose Thanks for posting your experience with miniDSP SHD. If it is doing a great job in your expensive system, I should give up my paranoia about adding a DSP after my DAC. 

Just to clarify you are feeding the analog signal after Lampizator DAC to miniDSP to do  ADC/DAC.

I will look into miniDSP SHD.

@wokeuptobose Thanks for the clarification.  I will be sending the Luxman's pre-out to SHD and feed the SHD's outputs to Subs and Luxman for the mains. I will be getting a miniDSP SHD.

Will report on my experience once I get the SHD and subs in place.  I am still vacillating between Rythmik FM8 and JL D110.

@curiousjim thanks for suggesting SVS. As I am planning on adding miniDSP SHD, which has crossover and Dirac Live, I am looking at sub that have minimal processing.

@mijostyn Thanks for the encouraging words. Also what products are similar to miniDSP up the price ladder? not too high though.

Bought two Rythmik FM8s and a miniDSP SHD; they should be here this Friday. Deciding on the subs was easy, but the analog/digital was more difficult and I am still not 100% convinced that it is the right decision.

Will update this thread on my progress.

@m-db I am not getting the CR-1, so whatever signature the SHD leaves, it will be across the spectrum.

SHD looks very flexible and I am seeing myself setting two crossovers one at around 110/120 for general purpose and one around 170/180 for female vocals; there are four presets in SHD. This would have been almost impossible with CR-1 as a change in crossover frequency means new phase alignment.

@avanti1960 , my main aim in high passing the Spendors is to eliminate intermodulation(amp) and doppler distortion(speakers). I will also be setting one of the presets to disable the subs and run Spendors full range.  I will post my experience in this thread. 

Also, I have been reading such good things about bi-amping and adding subs with high passing the mains is another form of bi-amping.

PS. In this journey, I read your subwoofer threads in the other forum.

I had Rythmik FM8s and miniDSP SHD delivered by Saturday and have been fiddling with REW and miniDSP software until now. The subs are flanking the Spendors on the inside.

Myt steps in setting them up.

1. Level matching the subs to the mains. Initially I put them one notch above zero, but dialed them back to zero.

2. Measured subs and the mains one channel at at time at different crossovers ranging from 80 to 150. Left channel was fine all across, but the right channel was not performing well between 100 and 120. So I had to choose either 90 or 140/150 and I decided to cross them over at 150 with 24db/octave.

3. Time delaying the mains was the most time consuming step, as I had to learn the process. After several measurements and methods, the results I had was 7.5ms for the left and 7ms for right channel.  I decided to set both of them to 7.5ms

4. Finally ran Dirac Live to flatten the response curve with a little boost in the bass area.

I am going to leave it with these settings for some time.

I am noticing two immediate benefits:1. There is more bass with more texture and the drum beats have a sharper starts/stops. 2. Vocals are clearer without being effected by base notes.

I am grateful  to the forum members for all the help and guidance.

When I measured the time difference previously, I had 7.5ms for the left and 7ms for the right main/sub matching. It is probably related a little asymmetry in my room.   So I was looking for another way to calculate the time delays for the mains and I came across an article by Merlijn van Veen.

I set the main and sub with baffles in the same plane and setup my microphone directly pointed directly at them from around 5ft. I took three measurements each for the sub and the main.

First I used another method I read elsewhere to calculate the time difference using the step graph in overlays window. I calculated the average of all the nine combinations and arrived at a time delay of 6.06ms for the main.

Then I followed Merlijn's method:

1. The phase lines of the subs and mains were clustered together respectively. So that gave me confidence in my measurements.

2. The phase offset was 305 degrees at the crossover frequency of 150Hz; so they are off by 0.85 cycle.

3. Full cycle time is 6.67ms and 85% of it is 5.67ms.  This is the delay if the baffles are coplanar.

4. I positioned the speakers where I had them since before the subs came in and placed the subs 6 inches behind them. As the mains are ahead, I had to add the time for 6 inches which came out to be 0.44ms.

5. Time delay set in the miniDSP SHD is 6.11ms(5.67+0.44).

So far  the improvement is good with a cleaner mid-bass.