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Discussion Starter #1
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 :crying:
 

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Re: A question about SPL

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

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Discussion Starter #3
Re: A question about SPL

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.
 

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Re: A question about SPL

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).
 

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Discussion Starter #5
Re: A question about SPL

Problem is that the sub weighs twice as much as I do so moving it is no small feat :D 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 :)
 

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Re: A question about SPL

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.
 

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Discussion Starter #8
Re: A question about SPL

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.
 

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Re: A question about SPL

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.
 

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Re: A question about SPL

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.
 

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Elite Shackster
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Re: A question about SPL

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.
FWIW, Genelec subwoofers are one of the best ones I've measured when it comes to upper bass (>50 Hz) distortion so I'm sure it's not because of that.

http://www.hometheatershack.com/forums/subwoofer-tests/983-genelec-7070a.html

Comparing subs in different rooms is almost impossible because the acoustics of the room affect a lot on how you perceive the sound. Also remember that subwoofer alone doesn't produce all bass. Main speakers contribute A LOT to the attack and punch in music/movies.

Which main speakers you have and how is the system configured (crossovers etc.)? Have you measured the frequency response of your system with the mains, not just subwoofer? How is the Rythmik set up (damping and freq)?
 

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Discussion Starter #12 (Edited)
Re: A question about SPL

Sorry my reply took this long.

My system:

3x Tannoy Sensys 1
2x Wharfedale DFS-1
1x Rythmik DS1500 sub

All located in a 11m^2 room (not treated in any way)


The Genelec system:

2x 8050a
1x 7070a
Located in a HUGE 60m^2 room (acoustically treated) which is open to rest of the 150m^2 house

The kick-you-in-the-chest kind of bass seems to be in the low 50's. From what I know that room has a slight 1-2db bump in that area, but for some reason the system sounds compeletely flat. I mean there are no audible bumps in the freq.response like my room had before equalization. Even before equalization I couldn't get the same kind of tactile sensations as I do with the Genelec system, although I had a 9db peak right in the same zone(45-50hz). Could the lack of any kick be associated with the sub firing away from the listener?

Thanks for your support and ideas.

PS. I don't have the equipment to make accurate measurements. I do have the mic from anti-mode, but it doesn't work with my computer.
 

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Elite Shackster
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Re: A question about SPL

You say that before eq it kicked you in the chest, when there was a 9db peak at that frequency. I think it's pretty reasonable to assume that the eq took this out (as it is supposed to) and you lost the false 'chest kicking' sensation. If you want it back, just dial it back up a bit.
 

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Discussion Starter #14
Re: A question about SPL

I think you have misunderstood me. In my room I have never really had good tactile sensations. It's just that the fact, that in a room several times as large, a sub with a smaller driver and with less xmax at the same volume (SPL meter) is able to produce way more kick than I have ever felt in my room, that boggles my mind. I tried disabling the eq a few hours ago, but still I can't get the same feeling although the does produce more kick when the eq is not active. But still....
 

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Elite Shackster
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Re: A question about SPL

Unfortunately this is the nature of subwoofers and rooms. You can take the exact same subwoofer and place it in one room where it will sound great, but put it in another and you'll wonder why you bought the thing. Room response is the single greatest contributing factor to subwoofer performance. I don't think there is anything wrong with your sub at all.

If you really want to see what is going on, take your SPL meter and use it with REW to measure both rooms.
 

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Discussion Starter #16
Yeah.. I guess that's the best way to really answer this question once in for all. I think I'll have to invest in a MicAmp from VLSI to make my measurement mic work with my computer.
 
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