SVS SUB BETTER WITH LOW PASS FILTER OFF

The only heresy I know is trying to do this all without measurements first.  I mean, it's dogma, but I find getting this right by ear alone is so random. 

Bloom and bloat IMHO had more to do with room modes, where a little EQ can go a long long way.

Glad you found a setting that works for you.

If you play just your subs you will probably hear male vocals in your subs this way. If it sounds fine… no big deal. The slope at your amps 80hz might not blend well with your mains. Maybe try a different slope if possible. If the slope is 12db for example it is out of phase and you would need to make the sub 180 degrees or change the leads on the speakers. Could just be nulls and room nodes 

Super good tip! My mains are Klipsch Lascala (II) so the bass is weak. The amazing thing is that the music sounds so much more "organic" (if you can imagine what I mean by that). Cohesive may be an even more unhelpful word but whatever...I like it better. My room too is unique in that I live in a yurt which fails to provide any reflective hard surfaces. (All fabric) So the normal rules don't apply.. I'm afraid I'm on my own on this one. But...it sounds amazing...just sayin'

I’m not 100% sure but it sounds like you might have been double ganging the filtering. You say your subwoofer output from your preamp or amp is 80 dbs, I think you might have meant 80Hz. If so, in most cases you would NOT need the low pass filter set at all on the SVS subwoofer itself then. The correct thing to do in this case is to either bypass it entirely (which you have found sounds better) or to turn the setting on the subwoofer as high as it would go, say 250 Hz or whatever, such that the slope of the crossover in the sub doesn’t interact with whatever slope is used by your preamp when it does its low pass at 80Hz. Anyway, that is what my old Klipsch subwoofer manual says to do. In other words, you’d only engage the sub’s crossover and low pass filtering if you were sending it a FULL range signal from your preamp. So, I’m just guessing here, but what you were hearing before might have been the crossover slopes of the preamp or amp subwoofer output interacting with the slope of the crossover in the sub. Removing the one from the sub filled in that "hole" you were describing, so it now blends better with your main left and right speakers.

Yes, of course 80 hz was my intention, and as usual for me its the most obvious stuff I miss. Glad I randomly discovered my mistake. Sure is much better. Now to put more Nano goop on my contacts! Any obvious advice on this sub I might have missed as well?

One things for sure… I need to see pictures of the yurt hifi room!

I would think your room would be almost 100% null free other than ground bounce. the La scala having very poor bass extension I am sure aids in the higher “crossover” point. 
 

I find my personal subs always lack a bit of detail compared to my mains above 100hz. I also find the sound stage with deep voices can get a little strange when using high crossovers. With that being said I will say a lot of subs play very clean all the way up to 200hz.  

I have the Arendal subwoofer and set the bypass at 10hz -15 hz above the floor of my main floorstander speakers that go down to 35hz. I read somewhere that 10hz above the low was a good place to start. I too switch the low pass 12hz filter off, as that works for me too. Saying that I use very little db gain, about 2.5db to get a very smooth integration. I agree doing it by ear even though I can do it through an app strung in my listening position is not as good as having some form of room correction, but in my case the room, is the room, is the room!

Glad you found the settings that work for you in your unique room.  Agree we need to see pictures your room sounds cool.  I have a pair of SVS SB1000 Pros.  My 2 preamp sub outs are also fixed with no adjustments available so like you I have the crossovers setting on the SVS app for each sub set to “off”.  It sounds great.  The one thing I will adjust is the sub volume as needed on the app depending on the music I’m listening to.  If the bass starts to overwhelm I’ll turn it down a few dbs or occasionally up.  Usually have them set to -12 db. As instructed in the SVS manual. 

The most vexing and confounding problem I know of is how different speakers measure once in a real room, and how different each room is.  I'd go mad if I tried setting up a subwoofer by specs alone.  Some may argue that I "went mad" instead, but potato potatoe.

Also, hot tip:  If adding a sub to ported mains try sealing the main speakers.  That often leads to easier integration and less distortion.

Curious:  Does the 80Hz subwoofer setting on your amp also have a high pass on the mains; ie cutting off the bass to your LaScala’s below 80Hz?

What @erik_squires said is pretty much dead on:

I'll be setting up a new system in a second location soon so keen on hearing about others' sub integration.  In regards to plugging ports in ported speakers as @erik_squires suggested, while this lowers the f3, doesn't it also lessen the effective roll-off slope at the low end?  Wouldn't a steeper one be easier to transition to a sub like the SVS with selectable slopes?  Also along these  lines, what role does the hack of adding straws in the ports make?  I thought this was supposed to de-tune the port's dominant tuning frequency while still allowing for the same mid woofer performance that the XO was designed for.  

Since most subs interact with mains like stand mounts around 80hz, and the "phase correction" on subs really operates as a time delay based on 80 hz, a setting around 90 deg should help mitigate causing a notch or a bloom.  All else being equal.  Room etc.  

Soon as I read the OP, I realized he has both crossovers engaged, preamp and subs, disabling one of them will produce the best performance. I have dual SVS SB2000 and was using a Halo HINT which has bass management system including high and low filters. 
I never used those as I sent my mains a full signal then set crossover on the HINT at 50Hz, the subs have to be set to LFE so they get a full signal from the HINT. If you wanna use the crossover on the subs then make sure the filters on the preamp are set to LFE or off if you can. 
Now I have a JC2BP which has no bass management system so the subs get a full signal from the Main outs, so now I set the crossover on the subs to 50Hz. 

doesn’t it also lessen the effective roll-off slope at the low end?

Yes, but by that time it’s all pretty low in level. The point is not that this should always be done but to try it and listen for yourself. In some cases this can even help with room related bass bloat. I’ve had one A’goner say that plugging 1 of the two speakers finally dialed in the bass for him.

This is a safe, reversible experiment. 

(To Josepad) So I will try and turn off bass bypass on my integrated so full signal is sent to my mains again and set "Low Pass Filter" on SVS Pro2000 at "ON". Then set SVS "Low Pass Filter" to 35 hz or so. Sound right?

Moonwatcher was correct. 

@allears4u Yes u can try that. Subs are all about experimenting, but for sure you only want to use one crossover, either the sub or the integrated. I never hi pass or low pass my mains, just did not like the performance. Set the crossover around 10-20 Hz above how low your mains are rated, then adjust from there. 
with the SVS subs you also get a variable phase adjustment which is also critical for integrating with your main woofers. 
Have fun!