Cornwall IV and subwoofers

I have played with subs a lot over the years. 3 different rooms and 4 sets of speakers with the same subs. 

I have found two methods work for any speaker.


#1 use a high-pass filter and crossover where the bass driver of the mains drops down -6db before the port pics up, if ported. This has by far been the best sound for me regardless of speaker I used. It was right around 60hz every-time (55-65). This method lowers the distortion of the mains, let’s them play louder, and greatly reduces port noise. 


#2 using just a low pass and come in where the speakers drop off -6db in your room (including the port). Just do a quick measurement sweep and it will probably be around 35hz (my guess basses on measuring a number of room/systems). This works fine but you will need the phase right too. This method just adds bass but does nothing for the mains to make them “better”. 



The 6db point is important If you use method number 2. If do it at 0 db or the -3db point you will get a hump in the bass where the two phases come together. Using method #1 you can crossover where ever you want. But too high and the subs sound like…well subs to me. The -6db point of the bass driver is a real nice place to start. 

Hello,
Is there a budget for the two subs. On the low end I would suggest the REL T7-9i or X. Starting with the I series they went front firing and passive down. If you have a higher budget I would go JL Audio F series. Like two F110. If you want a whole mother level add the JL Audio CR1 crossover. This you can use with any speakers or subs. You have to be running separates to use the crossover. Plus it has a bypass for home theater. The last option would be the KEF KF92 sub. This is a dual side firing sub that goes down to 11hz. For $2k it’s a good value. Plus they have a wireless kit so placement is easy. If you are in the Chicagoland area this store lets you demo stuff in your home on your system. https://holmaudio.com/
It doesn’t matter how far down your front speakers go. My speakers go down to 25 hz at -3db. Everyone should have two subs. 

Lot’s of good info here. Thanks to all. My budget will flex for whatever gives best sound and integration, and will also fit in my restricted lateral space. Unfortunately, a pair of anything is not really possible, given space constraints, so I’m thinking about just a single sub at this point. If I set it to around 40hz, I doubt it will be directional. I listen almost exclusively to jazz via vinyl and don’t really need to plumb the deepest depths.

I’ve been experimenting with a 15-year old Von Schweikert VRS/1 that I’ve had parked in another system. It’s sealed, 10-in, down-firing, and won’t cross over below 50hz, so it is certainly suboptimal for the Cornwalls, though it is just right for the Merlin TSM that it’s normally used with. Still, I can readily hear the advantages of a sub with the CWs: soundstage opens up, ambience increases, music is more visceral and floats on its foundation. I’m connecting at this point via low pass, and 50hz doesn’t quite mesh to my ears, giving a bit of a hump. Volume is set just to intimate the bottom frequencies, not push them at me.

After reading around, I think I’m leaning toward a Rythmik F12 or F15. They are compact enough, especially the 12, and offer myriad adjustments. Servos get a bad rap among some audiophiles but this version of the tech gets a lot of positive comments for "speed" and musicality.

Has anyone compared Rythmik to some of the other big players like Rel, JL, Hsu, SVS? Curious how it stacks up.

Bill

Bill,

I don't think I'd high pass the CW as was mentioned above. Their bass quality down into the mid  to upper 30s is too good to mess with. I'd just roll the sub in and let it do it's thing way down low.

Oz, I'm with you. That's my feeling as well.