Certainly Richard it would be my pleasure.
This is going to be long.
Well...when I first started messing around with this stuff. It was more about home theater than two channel.
So I've had the garden variety of subwoofers. The first being a 15 inch Cerwin Vega passive in a huge ported enclosure! This thing stood 3 feet high and 3 feet deep. What a monster! I would get complaints from neighbors across the hall and one floor up. They said I was knocking their pictures of the wall ! Oh what fun!
This was during my apartment dwelling days.
From there I believe it was the DCM SW 250..this is a dual 12 inch monster. The bass could actualy give me a headache! One thing I discoverd about dual enclosured subs and subs that used a passive radiator. They all have a slow roll off.At least the ones I've heard. The bass just drags along. These aren't the subs for an 2 channel audiophile.
This is how the True Sunfire subs are .They will shake your brain stem loose but have no further use too me. The Paradigm Sizmeic is the same way..unearthing bass but slow. Also the Deftec super cubes fall in with this group. All of these are made to be unobtrusive in size but lack finesse.
I've had the circuit city and best buy brands..like JBL(absolute crapola),Kenwood with a servo(not bad), Infinity and Velodyne Mass market versions(50 hz bass hump kings) all were ported designs. None were designed to give you an quick accurate bass. More bloated with a 50 hz bass hump. Most consumers don't know any better. They love that 50 hz hump. The average consumer also doesn't realize, your not supposed to be able to locate a sub in the room with your hearing.
If you can localize it ,it needs to be adjusted or tossed!
On to one of my favorite HT subs. The SVS CS plus 16-46 tube with the 12 inch Aluminum driver. this thing looks like a water heater seating in the corner. I have measured this sub down to 13 hz! For a ported design the bass was extremely fast and heart stopping.
I tried different professional amplifiers on it like the Mackie and Peavey. I settled on the Peavey 900 watts into 4 ohms. The amplifier was installed in a closest in the hall way. I had the the wires running through a wall and then over to the sub. This is when I had my Mcintosh/Meridian front end with Deftec speakers all around for HT.
I had a buddy come over to watch Saving Private Ryan. By the end of this movie ..him and I both could hardly walk.
These subs when paired with the right amplifier. Have that kind of bass that feels like somones punching you in the stomach!
On to the ULD Velodyne 15. This sub has a servo and comes with an amplifier. It is a sealed design. We're talking subiterrean tight clean bass with this baby! The sealed design allows the bass to roll off fast in your room. I don't think I could use one for music though. It's can be over whelming. It also doesn't have that mid bass snap. These subs seem more designed for HT as well. They might be a good foundation with an already fullrange multi driver speaker though.
The deftech TL 15 incher is basically the same as the ULD 15 too my ears.
Floor rattling bass not really intended for music. It does have a fairly fast roll off since it is sealed.The Paradigm Reference 15 incher falls right in with Deftecs and Velodynes. It's more of a movie sub built for impact(I have a friend that's a dealer so I get to play with some of this stuff). I've also done some professional installations with another good friend.
I like the snap of the 12 inch drivers. For a single driver speaker I wouldn't go any larger than a 12 inch sealed sub. Depending on the room size a 10 incher would be even better IMHO. Probably the best way to adjust and integrate two subs into your system... is to use a SPL meter. Play solid tones with just your main speakers on. Find a reference..let's say 70 db. Disconnect your speakers. Turn only one subwoofer on. Play the same white noise tones. Try to get it as close to 70 db with the volume adjustment on the subwoofer. Do the other subwoofer the same way.
Now plug everything back up except leave one sub off.Have someone to adjust the crossovers slowly while you listen to familar music. Do this with each subwoofer. When your done every thing should be seamless.
Stay away from ported subwoofers for music. They will only cost you frustration!
I've been playing with some placements. I took my Omega 8's off their stands and placed them on my subs. Now they are 9 feet apart and nearly 10 feet from me. I have them towed in to cross infront of my face.
The drivers centers are exactly 36 inches off the floor. It sounds damn good!
My sound stage is only shorter when I stand up in front of them. Other than that ..it's like having 40 inch tall fullrange floorstanders in the room.
