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Where do I do my crossovers?

beefkabob

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#1
I have the SHD Studio, which has a variety of crossover DSP capability, including a crossover for a sub.
Then I have the JBL 708P which can do all sorts of DSP fun, including a crossover for a sub.
Then I have the SVS PB16 which can do its own DSP crossover and such.

Right now, I have the recommended SVS settings on the speakers and sub. It sounds good, but maybe not fully integrated.

Will I be able to do a better job with the minidsp software while disabling the crossovers in the speakers and sub? Or do JBL and SVS have their own awesome mojo? I see that the miniDSP software has more options for crossover curves.
 

Soniclife

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#2
Glib answer, whichever one measures the best.

Sensible answer, whichever gives you most control, that you know how to use, are not overwhelmed by options, or frustrated by the interface.

I'm guessing the mini DSP is the only one that offers full control over the delays, which might lead to the technically best solution.

I think you are going to have to experiment, and probably drive yourself a bit nuts in the process.
 

jhaider

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#3
Yes, I think you will be able to do better using internal capabilities of the SHD Studio guided by measurements. Also, disabling all the bass management in the 708Ps and sub(s?) will make future glitches easier to handle if something goes sideways later, because all of your bass management is handled from a single control panel and the whole scheme can be saved to/restored from a single file. Also, with the processing outputs at line level (from DACs) you could more easily verify the target curves with measurements if desired.

As for where to start, there are three threshold questions:
1) How many subs?
2) How loudly do you listen?
3) What quirks in the measured response in the intended listening area could make blending subs into mains harder?

How many subs is important because often the idea is to have the maximum number of sources playing in the modal region. If you have two or more subs there is more freedom in the crossover. My experience is single subs often require fairly low crossovers (i.e. 40-50Hz) for tolerable performance, but a 4 sub system can really jell with mains with crossovers well over the 80Hz default. Based on Audioholics' SVS PB16 measurements I would suggest a lowpass ceiling of 100Hz, and depending on your answer to the next threshold question I think 50Hz is a good lowpass floor. Assuming you use Dirac, I recommend filtering both speakers. Your 708s can run full range with the subs folded in, but I think that violates some assumptions Dirac makes.

How loudly you listen is important because you want to make life easier for your mains. Here, as long as your listening distance isn't an acre away from the speakers, you have broad latitude: 708 has a largish and long throw woofer.

Response quirks matter because equipment and listeners are both better off when you work with the room rather than fighting it.
 

beefkabob

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#4
As for where to start, there are three threshold questions:
1) How many subs?
2) How loudly do you listen?
3) What quirks in the measured response in the intended listening area could make blending subs into mains harder?
1 sub.
I haven't measured SPL. At 10 feet to the listening position (sides of the not quite equilateral triangle, with 8 feet between speakers), I usually have the volume between -10 and -20. The sub is -20 when I want extra bass, but really should be around -30 to -34. Perhaps I should sell it and get two smaller subs, but I like how it shakes the room. Buying another one of these monsters will piss the wife off, and the sub is already running far below its top volume range and still shaking everything. Anyway, in that -10 to -20 range, the speakers seem perfectly happy. At -0, I don't get clipped sound, but I do get a sense of the speakers feeling strained, like the highs and lows seem closer together. Even -10 is really loud, so no need to go higher.
I don't know the quirks of the listening area. I know there are tons of reflective surfaces, from a hardwood floor to a tile-covered fireplace and a large window behind the listening position. Currently the sub is a little off center, though it could be moved.
 

beefkabob

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#5
I switched to the SHD Studio for crossover and adjustment. I was lazy so only used one speaker location, a quick and dirty Dirac tune. There's a few bass dropouts, but OMFG does this sound better. I could never manually get the sub to match the speakers. Dirac cleaned that up nicely. I'd been wondering if I wasted money on the SHD and should have gone with a streamer and AES adapter. No such thoughts now. Dirac is the real deal, y'all.
 

Dj7675

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#6
I switched to the SHD Studio for crossover and adjustment. I was lazy so only used one speaker location, a quick and dirty Dirac tune. There's a few bass dropouts, but OMFG does this sound better. I could never manually get the sub to match the speakers. Dirac cleaned that up nicely. I'd been wondering if I wasted money on the SHD and should have gone with a streamer and AES adapter. No such thoughts now. Dirac is the real deal, y'all.
What do you mean by dropouts? I have an SHD Studio with 708Ps in our living room (no sub) and in the other system have an SHD with some vintage JBL 250ti / JBL B460 sub. I was used to receivers before using the SHD’s so it took a little bit to get used to the setup, but I too would definitely run your crossover through the SHD. Tons of options regarding crossovers, slopes etc to experiment with and measure to see which sounds better.
 

beefkabob

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#7
Small, sharp dips in frequency response. Room modes? They're all in the low frequency range.
 

jhaider

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#8
I don't know the quirks of the listening area.
Step 1 to sub integration is "measure the response at the listening area to discover the quirks." :)

Since you ran Dirac, if you want to post 'before' measurements I'm happy to take a look.

In the absence of those, since you're using one sub and speaking practically 708P is not SPL limited until the very deep bass, I would start by looking for the natural rolloff of your 708Ps at your listening position, maybe add a slight highpass filter (like a 1st order) in Studio SHD to the existing rolloff to for greater headroom, and lowpass the sub where the 708Ps start rolling off. Match the slope by eyes.
 

beefkabob

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#10
The sub is at different power levels because I played around and had the sub higher and allowed Dirac to lower the sub. Not sure what level to put the sub at, actually. Smoothing is at 1/48.

Big rolloff at the high frequencies...
This is only one run each from about my forehead at the listening position. Not averaged. Umik is facing the point between the speakers.
 

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TLEDDY

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#12
DSP vs. Parametric equalizer with Subwoofer adjustable out

Can I use my calibrated microphone into Mac software and adjust the FR manually as opposed to an automatic DSP between my preamp out and the amplifiers? Planning on using a balanced connection between them.
 
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