A Question About SPL

[DragonArt]

Hi,


I'm just wondering, why aren't I getting the same punch-you-in-the-chest kind of bass out of my subwoofer as what I get out of a Genelec 7070A? The 7070A has a 12" cone and 12,5mm of Xmax. My sub has a 15" cone and 15mm of Xmax. Could it be the room? The sub is now in a 10m^2 room, so it is a total overkill, but still the sub seems to become colse to bottoming on some of the movie scenes. Or then I'm just imagining. If I look at the cone, and it seems to move almost as much as the Genelec's cone does in a room that is several times as large as mine at volume levels where the genelec can easily be felt across the (big)room. I'm satisfied with the sub in every aspect except it's SPL ability (believe it or not!). So, any ideas what's happening here? FR at the listening position doesn't have any dips in the 50-100hz zone. The sub is now firing into a corner full of stuff, don't know if it affects the subs performance. I know comparing two diffrent subs in two diffrent rooms is very difficult, if not impossible but still....

Thanks for your patience, I just never seem to have enough bass

[tonyvdb]

Two questions, where do you have the sub located in the room (what kind or room) and what are the dimensions of the room?

[DragonArt]

The sub is in the front left corner of the room, about 3ft towards the listening position and is firing into the corner. Room dimensions are 14,7ft lenght, 9,8ft width, 8,2ft height. The room is a typical all concrete bedroom in an apartment building. The sub is EQ'd flat with Anti-Mode 8033.

[tonyvdb]

In a bedroom you have one bad thing going for you and that is the bed as it acts as a huge bass trap and absorbs alot of the punch that the sub puts out. Have you tried placing the sub in different locations? By placing the sub at your listening position and then crawling around the outside of the room you can find the best placement for the sub (where you hear "feel" the best response from the sub that is where you place it).

[DragonArt]

Problem is that the sub weighs twice as much as I do so moving it is no small feat Also, the sub has a ton of stuff on top of it, so I probably just leave it where it is now(I know, I'm lazy..). Thanks for your help anyways

[tonyvdb]

No problem. Are all the walls and ceiling also cement? This can also be a cause of your issues as there is very little movement and lots of reflection and this can cause nulls in the frequency response due to interaction with the reflected sound canceling its self out.

[Mike P.]

I would suggest moving the Genelec 7070A sub to where the Rythmik Audio DS1500 is so you can compare the output of the two in the same room. This would determine if this is a room interaction problem or not.

[DragonArt]

Yes, all the walls, floor and ceiling is concrete. Listening by ear, there aren't any nulls in the FR (sweep). I don't own the 7070A, so I really can't compare the two in the same room. Also, moving a 150lbs sub to third floor of an apartment building by hand is a job I want to avoid But I'll see if I have the time to test the sub in my living room.

[Bill Fitzmaurice]

DragonArt wrote:

The sub is EQ'd flat with Anti-Mode 8033.

Don't assume that flat is always best, or that maximum impact comes from the lowest octave. Measure the Genelec in action to see what it's doing that you like so well.

[thxgoon]

I agree with Bill and Mike. The room is almost always suspect in subwoofer issues. Download a copy of REW and take some sweeps, both at the listening level and at the sub. Also try disengaging the Andi-Mode and see if it helps.

For what it's worth, kick you in the chest bass is generally mid to upper bass frequencies. Subwoofers with high levels of distortion will output this upper level bass when it is not present in the input signal. A switch to a lower distortion sub results in a perceived loss of impact.