DIY Subwoofer Risers

[Drew664]

Alright, thanks for the advice. I think I'm going to go higher, so at least 12" and most likely I'll hit the 21" mark to hit the '25 rule' (guideline).

I wonder what putting it on a TV tray would do ....Test run tomorrow morning as not to wake the neighbors tonight.

[Big Daddy]

Originally Posted by crazyBLUE

There are A few in there that would work . I am curious By having them so high would it cover the room more evenly & what do you think the affect would be if all four subs where on the front ~ 2 on the floor near center & 2 mounted up on wall spread farther apart !

That is something in our heads. As far as subs are concerned, ceiling or floor are the same. Waves do not discriminate and go in ever direction interacting with the boundaries. Visualize your room upside-down with you sitting on the ceiling.

[Drew664]

I tested raising my sub off the ground this morning. I demoed the Iron Hide flip from Transformers with the gain turned half way on the sub. A 7' ceiling means 21" is the ideal placement for a sub

Test #1 -
I left the sub sit on the ground. Result is like always, usually it didn't sound clean enough. It rumbled a bit too long.

Test #2 -
Used a TV tray to elevate my sub 26" from the floor. Result wasn't that great except things vibrated in my room that didn't before. Didn't seem to fix my problem.

Test #3 -
Put the sub on a set of old speakers which raised them 17". I actually felt that the bass didn't rumble quite as much.

Test #4 -
Put the sub on a smaller set of old speakers which raised them only 11". I couldn't tell any difference from test #3.

Conclusion -
I'm going to leave my sub on the smaller set of speakers for now and continue to research and play around with different heights. I think my bigger problem is placement, but currently that's limited to the sub cord. Eventually I will get a longer one (probably 15') so I can have greater freedom in placing it in a sonically better spot. An upgrade wouldn't hurt either, but not while I'm in an apartment.

[Big Daddy]

CrazyBlue,

Have you made a final decision about the location of the subs? Did you visualize your room upside-down?

[crazyBLUE]

Originally Posted by Big Daddy

CrazyBlue,

Have you made a final decision about the location of the subs? Did you visualize your room upside-down?

WOW ~ you you really want to see me do this don't you BD I think I have come close to A square within the room ! tomorrow my monoprice order will be delivered with A ton of RG6U RCA's & some other things ! I will put Tape on the walls were I think they should go & take pics for you to see / options & opinions from you !
Fair enough

[liquidice]

that poor, poor condo....

[Big Daddy]

Originally Posted by crazyBLUE

WOW ~ you you really want to see me do this don't you BD I think I have come close to A square within the room ! tomorrow my monoprice order will be delivered with A ton of RG6U RCA's & some other things ! I will put Tape on the walls were I think they should go & take pics for you to see / options & opinions from you !
Fair enough

This will be the new look of your room. You wil be sitting on the ceiling.

CrazyBlue.jpg

[Grevlin]

Ha!

Wait- I think I need to back track a few posts...

Edit: found it.

[crazyBLUE]

Originally Posted by Big Daddy

This will be the new look of your room. You wil be sitting on the ceiling.

Attachment 6622

You have to give me A minute here !!

You had that all readyfor me didn't you


As I've said before you always make my day !!!

[crazyBLUE]

Ok Big Daddy !!! I almost forgot to take pics because I was busy hiding the PINK wire!!!

The only way to have A square is to have it off center to the display almost 2 feet ( front door ~ bedroom door ) The tape is 20 inches from the ceiling & the 125 is 16 1/2 inches tall w/feet !
Sorry they are A little dark !

[Big Daddy]

Originally Posted by crazyBLUE

Ok Big Daddy !!! I almost forgot to take pics because I was busy hiding the PINK wire!!!

The only way to have A square is to have it off center to the display almost 2 feet ( front door ~ bedroom door ) The tape is 20 inches from the ceiling & the 125 is 16 1/2 inches tall w/feet !

Perfect square is the best and easiest to deal with. However, if they are in a perfect square, it is still ok. Mine are not in a perfect square, but they still sound fantastic. I play test tones through the subs and walk around the room with my SPL meter. The variation in sound level is less than 4-5dB. Usually, next to the walls, the subs are the loudest.

The key is calibration. Make sure you calibrate each one separately by turning off the other three and measuring the sound level from your listening position with an SPL meter. You should adjust the level of each with the knobs on their back. After each one is calibrated, don't touch the knobs anymore. You should run the receiver's calibration program and tweak the level of all the speakers with an SPL meter.

To get the best results, you need a subwoofer equalizer like the Velodyne SMS equalizer/analyzer. See the sticky thread on the Velodyne in the Subwoofers section.

[crazyBLUE]

Originally Posted by Big Daddy

Perfect square is the best and easiest to deal with. However, if they are in a perfect square, it is still ok. Mine are not in a perfect square, but they still sound fantastic. I play test tones through the subs and walk around the room with my SPL meter. The variation in sound level is less than 4-5dB. Usually, next to the walls, the subs are the loudest.

The key is calibration. Make sure you calibrate each one separately by turning off the other three and measuring the sound level from your listening position with an SPL meter. You should adjust the level of each with the knobs on their back. After each one is calibrated, don't touch the knobs anymore. You should run the receiver's calibration program and tweak the level of all the speakers with an SPL meter.

To get the best results, you need a subwoofer equalizer like the Velodyne SMS equalizer/analyzer. See the sticky thread on the Velodyne in the Subwoofers section.

Thanks Big Daddy ! My crazy head is getting closer to just doing this ! I WILL BE THE CRAZIEST ONE OF ALL TIME ON Blu-ray.com !!!

[potee]

I just built a riser per BD's instructions. I didn't put foam on the out side of the legs like the pics on page 1 of this thread. Do I need to do that? Also BD said to cover with carpet after putting foam on. The pics don't show it and I can't figure out how unless I make it a box.
Thanks potee

[liquidice]

you actually want to put foam underneath the riser to help decouple it. You don't really need to cover up the foam if you don't want too.

[potee]

I did put the foam between the legs. I just didn't do it on the outsides.like BD showed in page 1. The riser and the 2x4 legs are all carpeted.
potee

[liquidice]

sounds like it's good to go. Can you post pics?

[Fors*]

I just built my second sub riser, except this one is for my cylinder SVS sub. I used a round cutting board as the platform under the sub. The build is explained in my gallery. It is the second gallery listed. Thanks Big Daddy for your patronage, as your stickys have helped tremendously. It took me less than 1 hour from start to finish to build this riser.

[DBlackGT]

Hi I got a question for all you audio experts since I am not. And to understand and get a visual of my problem you will have to take a look at my ht gallery.

The issue im having is im hearing little to no bass from where I sit on my couch, however if I walk to the opposite corner by the counter behind my dinner table the bass is out of this world! I have tried moving my sub over and closer to me, I have also tried making it front firing instead of down firing but nothing.

So my question is would one of these sub risers work for me? or stuffing it with padding or such make a difference? I'm really in need of some help cause my downstairs neighbors are hearing the bass and so are the people sitting at my dinner table but not anyone who sits on the couch. Any help would be greatly appreciated. Thanks.

Also if I need to give you more details about my setup just ask, thanks a lot.

[Big Daddy]

Originally Posted by DBlackGT

Hi I got a question for all you audio experts since I am not. And to understand and get a visual of my problem you will have to take a look at my ht gallery.

The issue im having is im hearing little to no bass from where I sit on my couch, however if I walk to the opposite corner by the counter behind my dinner table the bass is out of this world! I have tried moving my sub over and closer to me, I have also tried making it front firing instead of down firing but nothing.

So my question is would one of these sub risers work for me? or stuffing it with padding or such make a difference? I'm really in need of some help cause my downstairs neighbors are hearing the bass and so are the people sitting at my dinner table but not anyone who sits on the couch. Any help would be greatly appreciated. Thanks.

Also if I need to give you more details about my setup just ask, thanks a lot.

A riser will definitely help. However, you have to remember that the bass frequencies have long wavelengths and they interact with the room boundaries and create standing waves. As a result of these standing waves, you will have hot and cold spots across the room. If you put your subwoofer in a cold spot, you hear no bass. If you put your subwoofer in a hot spot, the bass will be too loud and tiring. For the same reason, if your seat is in a cold spot, you hear no bass and if your seat is in a hot spot, the bass will be too loud.

Normally, a subwoofer works best when it is placed in a corner or is against the wall. For the same reason, when you put your seat in a corner or against the wall, the bass will be too heavy and tiring.

The middle of the room is the worst place for placing a sub or for putting your sofa.

With one subwoofer, you should experiment with its location to find the best bass response. If you are lucky and patient, you may be able to find this location. However, you will get good bass only for a single listening position. As soon as you move slightly to the right or to the left, the bass may disappear.

If you add another subwoofer, you will be able to get more even and smoother bass across the room for almost all listening positions. Experiments at the National Research Council of Canada and Harmon International have demonstrated that the ideal number is 4 subwoofers.

Possible Solutions:

1. Put it on a riser.
2. Use the crawl technique to find the best location for the subwoofer so that you get good bass in your main sitting area.
   • Move your subwoofer to where you normally sit.
   • Put it on a chair or stool.
   • Play a CD with heavy bass sound or play the test tones through the subwoofer.
   • Walk (crawl) across the room (preferably with an SPL meter) and listen to or measure the bass sound. Mark the locations where you hear the loudest bass.
   • Move your subwoofer to one of those locations and be happy with one sub.
3. Buy a second subwoofer and be happier.
4. Buy 3 additional subwoofers and be the happiest.

To better understand the above, read A Guide to Subwoofers (Part II): Standing Waves & Room Modes.

[liquidice]

Ah yes, one of my favorite galleries because of room aesthetics! I really think you need to do the 'subwoofer crawl'. Maybe you've heard of this technique, but if not, watch this short video here. Raising the sub will help with DB, or volume, and also the overall 'tightness' of your bass, but not what your explaining. Basically, you've just got your sub setup in the wrong spot, and if you find the ideal spot, then you can start playing around with the riser and stuffing it. Let me know what you think.