[Fantome]

Hello all!

I recently acquired a pair of Triple threat subs, and am planning my next steps in room integration with the rest of my system. Currently I am running a Minidsp flex RCA as a preamp to bi-amp a pair of Emerald Physics CS2.7 speakers, the signal is split with the woofers running off of a separate amp crossed over from the mids/highs, and the mids/highs using a separate, passive crossover to split them up running off of another amp. Currently I am running the Triple Threat's piggy backed from the woofer's amp to the high level input on the Rythmik plate amps, which is less than ideal, since I have to run the Main speaker's woofers with no lower octave cutoff so the subs can get signal, and id rather have them only do mid-bass duty.

I am torn between keeping the Minidsp flex, and making some in-line, line-level high pass filters to roll off the signal going to the main speaker's woofers, and a bypass output for the sub amps, and hopefully getting a nice even response that way, or selling the Minidsp flex and switching to a Minidsp HTX for multichannel EQ/Dirac capability, and outputting to everything separately. I like the second option better for time alignment/grouping capabilities, and being able to measure the mid-bass drivers and subs separately, but I don't know if that would be worth considering if the first option gets me 90% of the way there, since it's by far the costlier option.

I spin vinyl so i need the Minidsp HTX for its analog inputs, unless I swapped out my phono pre for a Parks Audio Waxwing or something else that outputs via optical.

Id love to get other's input on this, especially if you have done something similar in your system. 

[Glady86]

I’d try inline filters if you want a cheaper solution.That’s what I’m planning to do when I run the GR subs. I think a lot of people do it that way but most of us aren’t using DSP. But, Since you need DSP, A new mini DSP unit will be way more flexible and easy to adjust and experiment with different cut offs etc, maybe better off spending more for that.

[nlitworld]

You can still measure your speakers and time align everything with your current setup. If using REW, you'd have the left speaker use the timing reference when measuring the right speaker and vice versa. Soooo, just use the timing reference and measure the speaker with the sub off, then turn the sub on, disconnect a speaker wire real quick and run another measurement on the sub only and reconnect the speaker. If you do it that way, you'll still have the ability to time align using the phase knob on your plate amps.

As for in-line high-pass filters, that's really not a bad idea for any speaker and they're pretty easy to build. Maybe $100 in parts (little more if you go all out KLE connectors & Deudland/Miflex level caps). Your phase settings will change running those filters though (90° phase change with 1st order filters), but if you've already got the dsp for all that, couple little tweaks should be easy.

[HAL]

If you do use a DSP, aligning the subs with the mains using time delay would be better than just the phase offset.  This makes the wavefront time aligned at the listening position. 

Just simply measure the distance from the sub baffle to the main speaker front baffle and calculate the time delay from the distance using 1130ft/sec as the speed of sound in air, or TD=(Offset Distance in ft)/(1130ft/sec).  This is the delay needed for the main speakers if the subs are behind them.  If the subs are in front of the mains, delay the subs.

I do this here with my servo sub stacks behind the mains and works very well.

[Fantome]

Wow, excellent suggestions, many thanks! That's some great food for thought, and easy enough to try out using the existing DSP in my setup. I will definitely try that out, and I think I will start with the inline filter route, and hold off on upgrading the preamp unless that method doesn't give a good result. I'm guessing that it will though. 

If you do use a DSP, aligning the subs with the mains using time delay would be better than just the phase offset.  This makes the wavefront time aligned at the listening position. 

Just simply measure the distance from the sub baffle to the main speaker front baffle and calculate the time delay from the distance using 1130ft/sec as the speed of sound in air, or TD=(Offset Distance in ft)/(1130ft/sec).  This is the delay needed for the main speakers if the subs are behind them.  If the subs are in front of the mains, delay the subs.

I do this here with my servo sub stacks behind the mains and works very well.

When you say measure front baffle to front baffle distance of each speaker, do you mean the distance that it would take to bring the two baffles to parallel or the total distance apart from the center of the speaker cones?

[HAL]

The offset distance between the two speaker baffles center in the listening chair direction.  This depends on how the speakers are setup.

For the H-Frames I use the baffle inside the cabinet where the sub is mounted as the start point.  A yard stick is what I use or a tape measure.

[Danny Richie]

Ditch the MiniDSP and ask HAL about is digital crossover solution. It sounds ten times better than the MiniDSp devices.

[HAL]

Danny,
Thanks! 

[Danny Richie]

Danny,
Thanks! 

Yeah, I knew you were too modest to just come right out and say you had a better solution. Those of us that have heard what you've done know that it is one of the best all digital solutions out there.

[jakekluge]

Well, now I have to know HAL.  Would you be up to sharing your digital setup?

[HAL]

Here is a great example of Kazoom's dspNexus 2x8 system with his NX-Tremes with his servo subs.  Lots of details on how he integrated the DSP crossover design I setup for him with his system.

https://www.audiocircle.com/index.php?topic=186956.20

These are my 6x12 OB servo subs with captainhemo's cabinets I had painted hotrod black.  I have 4-HX300-12OB servo amps running the servo subs.



More info on my AC page if interested.

[BrandonB]

Here is a great example of Kazoom's dspNexus 2x8 system with his NX-Tremes with his servo subs.  Lots of details on how he integrated the DSP crossover design I setup for him with his system.

https://www.audiocircle.com/index.php?topic=186956.20

These are my 6x12 OB servo subs with captainhemo's cabinets I had painted hotrod black.  I have 4-HX300-12OB servo amps running the servo subs.



More info on my AC page if interested.

I think you can put a couple more subs on each side to reach the ceiling.  Reminds me of SNL "I need more cow bell"!  I am building triple threats with the modules just in case I want to add more cow bell later.....