Upgrading sub to get a live feel.

Tim,

Thanks for your assumptions, but they are completely wrong.  It is rather ironic that you attack my position and claim that high quality music reproduction is not my goal, while you time and time again say that the quality of subs matters little, only the quantity.  Keep in mind your frame of reference is that your bass is the best you have heard.  That doesn't mean that there aren't much better sounding subwoofers, just that you haven't experienced them.  It is akin to someone saying that a quarter pounder at McDonalds is the best burger out there and the only way to do one, when the only burgers they have ever had are from Sonic and Burger King.  McDonalds may the best that person has had, but it doesn't mean they are the best.  

For the record, I don't have a home theater system and never have.  I did hook my TV up my stereo this year after we rearranged the room and the TV ended up between the speakers (someone gave us a 75" TV).  Since I don't want movies, I think I have listened to the TV through the stereo twice, the $179 Yamaha Soundbar from Costco is what I use, as it gives great dialog clarity without blasting the sound level.  

I do have a lot of experience with subwoofers and their integration.  More than 30 years ago, I started building subwoofer enclosures for cars because the ones that I heard were all boomy and crap sounding.  At that point, all calculations had to be run by hand using the Thiel Small parameters and a calculator.  

The great thing about cars is they have a fixed cabin gain below about 50 hz with NO standing wave issues and a fast decay time.  With good drivers and a properly designed enclosure (or infinite baffle) you can get amazing, accurate, low distortion bass in a car.  With cabin gain, a well designed sealed enclosure will roll off at the same rate as the gain, with perfectly flat response to below 20hz.  I am not talking about the 160db SPL competition bass (which is achieved with narrowly tuned vented enclosures in the 60-70hz range), I am talking the ability to hit 115db cleanly down to 20hz.  The current system in an old BMW I have does exactly this (HSU 12" driver in a 1.25ft sealed enclosure, QTC .65, mains will do about 105db).  

There is something magical that happens when you have that free dynamic headroom.  Most home subs suffer from dynamic compression and distortion when turned up.  It starts in the 90db range below 30hz for nearly all subs, until you start getting into the big boys.  For example, even the Velodyne DD18+, considered a huge, accurate sub, cannot hit more than 110db at 30hz, 105 at 20hz.  Same for a Rythmik F18. 

When all you have ever heard are subs that are running into dynamic compression and distortion (which is the case with almost all home subs when pushed to even 100db), they sound great, until you hear a setup that doesn't.   When you hear the setup that doesn't you experience this effortless, fast, tight, bass that seems to come from blackness.  It also has a dramatic effect on the sound of the mains, making them sound much cleaner.

At the end of the day, it is not about hitting huge SPL levels, it is about getting the best sound, which requires using subs that can stay clean and not run into dynamic compression.  4 10" subs can't do this in a reasonably sized room.  It is why my progression of home subs has taken me from Velodyne F series, through ULD's, to HGS, and finally Rythmik.  At each step, it has seemed to be amazing (and better than anything I ever heard at a dealer), but the next step revealed more.  

Finally, you can rag on those guys at the AVS forums, but unlike many, they spend a lot of time correlating objective data with subjective sound to get improvements.    

Sure, swarms are nice, but not everyone can afford or has the space for them.

The Swarm is not expensive as subwoofers go, and if space is an issue, the Swarm is often an excellent solution, as the actual boxes are small and easy to place since they are specifically intended to operate in the room boundaries, i.e. against the wall.

Another aspect about them is they are only meant to go up to 80Hz. At and below this frequency, bass is omnidirectional (its *harmonics* above 80Hz that impart location information to bass instruments). Part of this is that it simply takes a while for the ear to detect bass at these frequencies- by the time its done so, the bass waveform has traveled a distance longer than most people's rooms!

**So especially if space is at a premium** the Swarm is an excellent option. We are seeing a lot of our older customers going into smaller rooms and otherwise downsized living situations- this is an excellent means of not having to sacrifice musical enjoyment just because the listening room got smaller.

@mcreyn, wow really good post. I'm actually restoring my '84 911 and was thinking of adding a car stereo system, but always wondered if I could ever get something that would sound close to what I get in my home system. I have to admit I am a bit of a dinosaur when it comes to car audio, but you have now sparked my interest to research this further.

On the home front my room is somewhat small, 20' x 12', and I have used a version of the swarm for the last few years that was inspired by some work Roger Modjeski at Music Reference was doing and the way in which he designed and ran his ESL speakers. I don't play loud, under 80 dB, no home theater, and most of the music I listen to doesn't have anything that extends below 30 Hz. I'm now upgrading the woofers to 10" housed in sealed boxes, and thanks to mijostyn who has posted on a few of these threads I have rearranged my swarm to be what he refers to as a line source bass array. We both use Acoustant speakers (his 2+2, mine Model 2) so his experience was helpful. In addition to my panels, I use a Beveridge RM3 crossover with 4th order 24 dB slopes for high and low pass, and biamp. I've been really pleased with the results so far and I'm looking forward to hearing what the upgrade brings.

Your experience though has me thinking about some other options for the future. In some ways perhaps active subs might be more beneficial for my next listening room. Rythmik is on my radar, but would be curious to know more about your setup and some pointers about using multiple active subs.

clio09,

For car stuff, I find simple is great. Check out CDT, Hertz, and Diamond Audio for components. For subs, Image Dynamics work well. For a car the size of a 911, an 8" will just cut it, a 10" if you can fit it. You can use speakerboxlite for free on an IOS device to model drivers in enclosures. Sealed works best in a car unless you are looking for max SPL.

Regarding your setup. Given your listening levels, you are not likely to be running into compression or high distortion levels. I will caution you with using sealed subs in a home environment, you will likely need to eq to compensate for roll off in excess of room gain. BTW, loved those Acoustats, remember hearing them driven with a Hafler front end (XL-600). Now I am giving away my age.

Sealed Rythmiks are an experience. The only way I can describe them is slightly dry, very clean, and great impact. In my office, I use their base L12 with a paper driver, which is slightly tighter and cleaner sounding than the HGS-12 it replaced.  In my main system, I used an F15HP, which is significantly tighter and cleaner sounding than the two HGS-12s it replaced, and crushes them in output).   Don’t tell Noble, but I am only using one right now in my main setup (after using two subs for a couple of decades). There is a second on the horizon, but my listening room has little in the way of standing wave issues at my listening position. This is driven in part by its large irregular shape (21 feet long, 13 feet wide for part, 19 feet in part, a ceiling that goes from 9 feet to 18 feet, and two large openings to other rooms). As a result, I have one dominate mode in the 40hz range that is easily addressed with a single band parametric eq. Two will provide a more even response, but some additional headroom (which is needed, as a certain wife has bottomed the Rythmik when in control of the volume, music, drinks and dancing).

As far as setup, lots of trial and error with REW and moving the sub (subs before) around and playing with phasing, cross-over, and PEQ. I have tried a Mini DSP after the crossover and did not like the results (but it could be I am not savvy enough with the setup). When I say trial and error, I probably ran 200 sweeps before I got everything dialed in. REW is a gift compared to doing it with a CD with tones, an SPL meter and graph paper or a spreadsheet. Well worth the cost of the UMIK ($100) and the learning curve.

https://www.roomeqwizard.com

Two RELS