when does bass get to be overkill?

[scottr0]

i was wondering what constitutes too much bass in home theatre........i am planning on 9 - 12inch subs in my living room .... is that too much .... it will equal out to about 2200 watts of power on 9 subs ... oh by the way my room is 16x22

[Cal Weldon]

Originally posted by scottr0
i was wondering what constitutes too much bass

When you suddenly have to go to the bathroom.

[GRollins]

Wimp!
I've got twelve 12" drivers. (First generation Dayton Titanics.)
Seriously...and I've said this before...beware, if the driver doesn't have a true frequency response graph available, don't buy it. DO NOT accept a T-S simulation plot as a substitute. Ever. The simulations are far, far from the mark. You will not get the deep bass you anticipate if you buy a Shiva/Titanic/et. al. based on T-S simulations. They're 12-15dB down at 30Hz and falling fast.
Take it from one who knows.
Should you buy a driver of this class, you will have to use active EQ to get anything like flat response. This will take a lot of R&D, amp power, money, and time that you might prefer to use in other ways.
I am always sadly amused by those who buy drivers of this nature, then swoon over the soi disant deep bass. Harrumph! Lots of 80Hz does not a subwoofer make! Shows how few people know how to listen.
Don't say you weren't warned.

Grey

[MikeW]

What do you have diving those subs?

[tbraver]

Originally posted by Cal Weldon


When you suddenly have to go to the bathroom.

Brown Note

[jonz]

I think you'e right....I just converted my 2 tempests sonos to an IB configuration....and I am scratching my head ..why I didn't do it sooner instead wasted all that time and effort building boxes....IMHO I think for the deepest bass ever you cannot beat an IB....I am planning to add 2 more for a total of 4...I already got a BFD EQ...and a Crest CPX 2600 amp..even tough IB's don't need too much power...Already my present IB...which is in a line array...is trying to destroy the wall their mounted on.....

[GM]

Greets!

You don't reach the point of diminishing returns until a flea powered (~1 W) amp can drive the system to reference level (115 dB/listening position below 80 Hz). It is assumed that below 20 Hz there will be room gain, so the subs can be less efficient below this point based on it.

Since real explosions, rocket launches, etc., can be above 150 dB, with cannon fire, howitzers, etc., rarefying the air at >194 dB, it's up to you to determine how much your room/home's construction and whoever's watching the movie can handle. FWIW, I busted mine up pretty good with just sustained 16 Hz pipe organ notes at ~live levels in the 120-125 dB range before I even got the chance to set up a HT to see what they could do WFO on special effects, but then it's a stick built post WWII G.I. tract house (aka 'cracker box' around here).

Regardless, if your budget allows for this many subs, then by all means use them if for no other reason than their greater efficiency nets you lower distortion via more dynamic headroom to EQ it flat with less/no electronic boosting.

GM

[GRollins]

Mike,
I usually use one of my Threshold S-500s or an old Hafler 500. I've got plans on the board to give each driver a dedicated amplifier, complete with servo feedback loop, but other projects (Lovoltech circuits, for one thing) keep sneaking in ahead so I haven't gotten that done yet.
Note that active EQ is a killer for amps, demanding prodigious amounts of power in the lower octaves. Mine goes to 16Hz before it tapers off, which is really playing dirty pool. My Hafler, which is the "Pro" version, keeps triggering its protection circuit on serious organ passages. Poor thing.
Class D amps would seem to be a natural for this, but I have yet to hear one that wasn't lean on the low end. I suspect this could be cured with a decent design and a robust enough power supply, but I'd have to build such a beast from the ground up, as none of the commercial units have sufficient power supply for a table radio, much less 500-1000W.
(I could get diverted into a story about playing bass through a Crest amp once upon a time, but will resist the temptation.)
Incidentally, for those who don't believe me when I say the Titanics/Shivas/Tempests/etc. are less than they're advertised to be...go ahead, buy one. If you know how to hear, you'll know you've been swindled the first time you listen. Otherwise, measure it. If you accept ahead of time that you're going to have to use EQ to get decent response, you won't be so bad off. I had to learn the hard way.

Grey

[RobWells]

3 Tempests in ~600L sealed, no EQ. Room 20' x 10'

[micb]

GRollins do you run sealed and have a very large room?