CurtPalme.com Home Theater Forum

[garyfritz]

I've always been a bit disappointed by the low end in my HT sound. When there are explosions &etc it goes "boom," but nothing like the kind of visceral response you get from a really good clean deep subwoofer. When I watch scenes like the White House getting nuked in Independence Day, it almost seems more like a rumbly crackling sound than a bowel-churning KABOOOM.

I originally had an Onkyo HTIB -- cheap, but it did the job and it got me started. Since then I've upgraded my fronts & center (AV123 x-mtms & x-cs Encore) and my sub (from the 10" Onkyo sub to a 12" Klipsch KSW-12). The KSW-12 might have helped a little -- the specs say it goes down to 26Hz -- but the bottom is still pretty anemic.

I've calibrated the levels on the sub & other speakers. I can crank up the sub amp but then it just gets boomy.

I've got large (4'x8'x4" OC703) bass traps in both front corners. Currently the sub is next to one of those -- see pic. (Ignore the blue sub box in the rear right corner -- that was the Onkyo sub and I've since sold it.)

I'm wondering if further improving the sub (short of something really serious like an SVS or Hsu) is likely to be a dead end? Would a better receiver help? I currently have an Onkyo HTR510. I keep thinking the receiver doesn't affect the low end that much -- it just splits out the LFE signal and the sub's amp does the rest. But...

Eventually it would be nice to get a new receiver to gain HDMI inputs and proper HDMI sound processing. But it would be nice to have some more satisfying bass too. If I'm going to put money somewhere, should it be the receiver or a much beefier sub?

Help?
Gary

[dturco]

Well Gary,

I don't know if this helps but this has been my experience, I have a Velodyne DD-15 Sub, 1250 watts.

http://www.velodyne.com/products/product.aspx?ID=4

It has a built in self equalizer with XLR mike to help smooth out responses. I set it up exactly like the manual said, 2 feet from the wall, not in a corner, and used the onboard graphs. I was not happy with the sound at all when I did it their way.

I threw the book out, put the Sub in the corner, turned off the corner mode, and it sounds sooo much better. I feel the bass and air pressure [It feels like a rush of wind up a pant leg a THX levels now] where before it sounded weak and lacked punch.

My experience, but I'd try the corner placement first. A 12" sub should move a lot off air.

[Curt Palme]

I have the same problem, but my issue is room related, not equipment related.

I've got 3 X 12" in a Tannoy cabinet, capable of 1000 watts, and I'm driving it with 300. Should be plenty of bass, but there's far more on the second floor of the house than there is in the theater room, go figure.

Over the holidays I plan on spending a day in that room, running more AC for one, as everything is run off 1 15 amp outlet(!), and I'll check phasing and will do some real time analysis, but I'm sure my problem is speaker location and lack of bass traps. I really need to do some reading about room treatment and acoustics.

Try different locations in the room for the sub.. Most subs have a phase inversion switch, try that as well. If the sub is a bandpass, that could be your issue, I've always found them to be boomy, and like direct radiating subs much better.

[Curt Palme]

I have the same problem, but my issue is room related, not equipment related.

I've got 3 X 12" in a Tannoy cabinet, capable of 1000 watts, and I'm driving it with 300. Should be plenty of bass, but there's far more on the second floor of the house than there is in the theater room, go figure.

Over the holidays I plan on spending a day in that room, running more AC for one, as everything is run off 1 15 amp outlet(!), and I'll check phasing and will do some real time analysis, but I'm sure my problem is speaker location and lack of bass traps. I really need to do some reading about room treatment and acoustics.

Try different locations in the room for the sub.. Most subs have a phase inversion switch, try that as well. If the sub is a bandpass, that could be your issue, I've always found them to be boomy, and like direct radiating subs much better.

[garyfritz]

I *think* I tried the Klipsch in the rear-right corner, where the other blue box is in that picture. I know for sure I tried the Onkyo there. (Those are the two locations where I've wired the LFE connections. Currently I drive some bass shakers from the rear location.) That's really the only corner that's available, since the other 3 corners have bass traps or a door in them.

I didn't notice the bass being any better that way. I've never experienced **ANYTHING** like the "rush of wind" effect with my sub.


Curt, bandpass vs. direct-radiating?? I don't know which the KSW-12 would be. Can you tell from the spec sheet? It's a down-firing 12" in a bass-reflex cabinet.

[dturco]

Your graph was not there when I posted last, I am going to make some assumptions here so, the door to the theater is always closed when movies are being watched, 2 that down firing drivers actually work as intended [IMO I don't think they do} so just try moving the sub closer to your screen, or try these 2 techniques.


http://www.audioholics.com/tweaks/speaker-setup-guidelines/subwoofer-placement-guidelines

http://www.audioholics.com/tweaks/speaker-setup-guidelines/crawling-for-bass-subwoofer-placement

[ecrabb]

Hey, Gary -

This HT thing is addictive, isn't it? No matter what you have, you want more... So, how much money do you want to spend? Subwoofers are a lot like sports cars. A lot of them are decent, fun cars, but to go beyond "decent", it's starts costing a lot of money... Getting really good performance costs a LOT more than just "good" performance.

Here's the deal... Your bass is anemic because your KSW-12 is anemic. I can say that because my subs are, too. The LFE is THE really weak spot in my system. I plan to do something about it - I just haven't decided exactly what.

To have really good, "visceral", bowel-churning LFE, you need two things: Low frequency extension and LOTS of power. A couple of the really good subs that would epitomize what you're talking about would be something like the Elemental Designs A7s-650 or an SVS Ultra. Those subs are capable of usable in-room frequency response to below 15hz and at over 100dB. That's visceral, gut-rattling bass. It takes a huge, heavy, well-built driver with lots of excursion (or two) and massive amp power (750-1000 watts) to accomplish that... Unfortunately, it also takes $1500-2000 to buy that driver and amplifier.

Now, for comparison... Your KSW-12 is spec'ed down to 26hz, but probably doesn't offer much usable below 30hz, and has a 105W amp. My M&K's are in pretty much the same category... I have two of them for more SPL and lower distortion - but adding multiple subs doesn't do anything for low-frequency response, which is what makes LFE "guttural". To use the car metaphor again, there's simply no way to go 175mph with 250hp. Physics are against you. Same with a small sub and small amplifier - it won't do "bowel-churning".

Now, assuming you don't want to spend $2000 (I don't either), you'll probably have to look at a Parts Express kit or go whole-hog DIY. If you go that route, you can get performance not far off the big dogs for a LOT less money. DIY subs are a deep subject - there are tons of options in lots of price ranges. I'm happy to go into it, as are others here, I'm sure.

To answer your question about your AVR... No, unless something is misconfigured, you shouldn't need to replace it to improve your bass. Your right that it's basically mixing the low-pass from your mains with the LFE and sending it to the sub.

SC

[garyfritz]

That first article mentions concrete walls/floors causing boominess, which is definiately a problem in my HT. The blue walls in my diagram are concrete, as is the floor; however the walls have wallboard mounted on 4" studs, with insulation behind them, so hopefully that mitigates that problem.

I haven't done the "put the sub in your chair" test yet but I should.

I've never quite understood the "put the sub in the corner for max output" advice. I don't need to *maximize* the sub output -- the sub amp is currently set at 3 out of 10. I could move it somewhere else and compensate with more volume. Instead of just making it louder, I want to increase the pantleg-blowing bass without the boominess. Maybe the "sub in the chair" test would help me find a better location for that.

[dturco]

Yep, I don't get the corner thing either, it goes against everything I read, but, it sounds great this way for me, and feels good too.

[garyfritz]

[dturco]

If I was going to build it myself I wouldn't do all the hard bits, I'd buy a kit.
http://www.parts-express.com/wizards/searchResults.cfm?srchExt=CAT&srchCat=536

[garyfritz]

That *would* be simple -- sounds like you just put 'em together. Wonder if they're any good? They've got a 250W 15" for $285, and a 1000W 15" for $750. I gotta think 250W would be enough for my small room! Surely 1000W would be massive overkill?

There are some used subs on CL in driving distance -- mostly Velodyne, some others:
Velodyne DLS-4000R, 12", $450
Velodyne VA12bVX10 12" AND 15"??, $250
M&K MX-150THX dual 12", $600
Velodyne FSR-15, $550

...but I'm wondering if a better sub would help, or if I have room problems that a better sub wouldn't overcome? Even with my corner traps &etc?

[dturco]

More Power never hurts bass.

Oh, and IMO 300W minimum for any sub any size room,you can always turn it down, but you can never make up for lack of raw power.



I would still put your sub in your chair first.

[greg_mitch]

Please consider these if you want to go DIY. They may be a bit more expensive but the wood is already pre-cut!

http://www.edesignaudio.com/index.php?cPath=2_136

Many well proven designs.

I have a few 15" MFW from AV123 and they definitely stepped my bass up a notch but I still haven't tracked down the best place for them. I would prefer a single larger sub I think as opposed to two just for placement issues. Someday I will get REW working with my external sound card and get some measurements.

IMO you will not see any noticeable improvements unless you spend at least $500 or more internet direct or $800 or more brick and mortar.

Also, consider used as you can get a whole lot more for the money.

[garyfritz]

That edesignaudio site is not real clear on what they're selling...

You like the MFW-15, eh? They claim response below 18Hz +/- 4dB, but it's only 350W. I know AV123 is having troubles but I like my x-mtm's and x-cs. And they're only an hour away so I don't have to add shipping. They have an open-box diamond-black MFW-15 for $580, hmmm...

[dturco]

Gary,

Aren't MFW's only like $600 NIB? Where's the discount for open-box?


Velodyne NIB http://www.vanns.com/shop/servlet/item/features/549375157/velodyne-dls-5000r

[garyfritz]

Hm. You're right, they ARE selling them for $599 NIB. I read the price wrong. Guess it's only a $20 discount for open-box, sheesh. Other speakers get a much better discount -- e.g. the x-omni is 45% off in B-stock! Why not the MFW-15? I'd jump on one in a second for $350...

[greg_mitch]

Personally I wouldn't buy new from AV123 new until MLS reconciles the raffles he stole from.

I would and did buy an MFW used. I was able to get both of mine for $900 shipped off the used market.

Satin black and Diamond Moho.

The edesignaudio setup provides you everything you need unassembled. All you need to do is assemble it with nails and glue and then either paint or veneer it. Pretty great option.

[ecrabb]

I'm seriously considering this, Greg:
http://www.edesignaudio.com/product_info.php?cPath=2_136&products_id=849

It looks pretty similar to the A7s-650, so it should be flat down to ~17hz, and down 3db at 15hz. In-room, they saw the A7s-650 is good to almost 10hz. Wow.

Between throwing my old M&K's on craigslist, and selling the set of really nice new-in-box MB Quart drivers I have on the shelf, I shouldn't have to dip into the kitty so much, and after a weekend or two in the garage, I'd have all the bass I've been wanting so much.

What do you think?

SC

[greg_mitch]

[dturco]

That should blow your pant legs up