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Sony Sub Tweaks (1 Viewer)

Joined
Sep 28, 2000
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23
I know it's been discussed before, but since the search function never seems to work...
Does anyone have the links to the past threads regarding the Sony SAW-M40 tweaks.
If not, any interest in reigniting this useful discussion since there seems to be a lot of SA users.
 

Matt Wallace

Second Unit
Joined
Feb 20, 1999
Messages
400
Just got one myself. Wouldn't mind rehashing that awesome thread that was going about a month or so ago
wink.gif

Matt
------------------
"And I say I'm dead, and I move"....
 

Barry_B_B

Second Unit
Joined
May 14, 2001
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453
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Barry
Don't recall the links, but implemented a couple of the tweaks this past weekend.
1. Polyfil. Looked for the bags but wound up buying a sacrificial pillow at K-Mart for $3.50. Took the woofer out (be careful not to strip holes), lined top, sides back and bottom except port area. About 1 pound was recommended from what I remember.
2. Uncouple. The sub has no feet, and mine is on a carpet covered concrete floor. Placed it on a cement garden block, 1' square about 3" thick.
3. Increase weight/reduce resonace. Covered top of sub with old mouse pads to protect it, placed a second cement block on top. Didn't weigh them, but compared to my weight set they're about 15-25 lbs.
Results? The blocks are ugly, but can be covered. Want to play with location and recalibrate again. Much better with music now, better distinction between notes. Could swear it plays lower, but may just be wishfull thinking
laugh.gif
Sounded great on movies U-571, The Matrix lobby scene and Predator jungle battle. Will hold me 'till the upgrade next year.
 
Joined
Sep 28, 2000
Messages
23
Since I haven't seen too many responses, I will post some info. I have found on other sites. I don't take credit for any of this...I am just cutting and pasting:
I have had several people e-mail me for more information on the modifications I have made on my sub, so I am writing this for all to see.
1. For those who have not yet looked inside the sub, the Sony uses a LONG rear firing port to augment the lower octaves of the bass response (this has the effect of making the driver act like it's in a bigger cabinet). This port is located near the bottom of the cabinet, and extends to within 2-3" of the front of the cabinet. The energy from the rearward motion of the driver needs to reach this port somewhat in tact to be effective. Using a polyfill type insulator will absorb a good deal of this energy, and that's why I suggest using a foam type. It will help to reduce cabinet resonance, but still allow the air to flow to the port. I found some at partsexpress.com (no, I don't work for them)called Vertek XTC. 1 roll of ADF-8 cut properly just fits in the interior of the cabinet, using a staple gun to secure it to the side walls.
2. The goal with using spiked feet is to eliminate cabinet motion as a result of driver excursion. Idealy, the only part of your speaker that should contribute to making sound is the drivers. If you place a large box with a smooth flat bottom on a carpet, the result is a sliding cabinet as the drivers (woofers) move back & forth. Spiking the cabinet will help to couple the cabinet to the solid floor under the carpet. This will tighten up the bass & improve the imaging of your main speakers (If your mains are on stands, spike the stands!) Placing a heavy object on top of the speaker can also help, but may not be astetically pleasing.
I got the spiked feet from partsexpress.com the 1/2" size worked well. You'll need a 1/2" drill bit & a 10mm allen wrench. Drill the holes about 1 1/2" from the corners, use the wrench to drive in the base, and screw in the spikes. Adjust the height so the cabinet is just off the floor.
3. EXPERIMENT WITH LOCATION! This sub is very picky about where it is placed in the room. I tried the traditional setup in the corner near the rear wall, and got nothing but one-note boom (maybe that's what the EAR was experiencing.
By moving the sub out of the corner, and out about 8" from the rear wall, I was rewarded with smooth bass. Remember, with such a long port, it needs room to "breath". Also, experiment with the phase switch to match the response with the rest of your speakers.This will also help to eliminate the "boom" factor. All sound generated is in waves. The lower the frequency, the longer the wave. Does your sub sound different when you sit with your head near the opposite wall? You may be experiencing a problem with standing waves. That's why it is critical to experiment with position to create the best response, and that's true of ANY subwoofer.
AND ANOTHER:
1. Go to partsexpress.com.
2. In the upper left corner where it gives you the box to type in a part number, enter 299-114. This is an Ultimate 12" shielded driver.
3. Read the description (it's actually a POLY cone, not paper as they have listed)
4. BUY IT! For $25 US dollars, it's a steal! And just for the hell of it, tell'em I sent you.
And now for the bad news. It's not an exact fit! It's just a little too big. So, I used a Dremel tool with a rotory drum sanding bit to make the opening bigger. A file with a curved edge will also do nicely. Not much needs to be shaved away, and then it will fit. Also, use the screws they send you, as the have more gripping power (yes, you'll need to make new screw holes as well).
And now the good news - you'll be rewarded with louder, cleaner, DEEPER, more articulated bass, and less "boom box" sound. Yes, I hate to admit it, but "The ears" was right, even just a driver can make a huge difference in sound quality. Oh well, he's still a self serving show off, and I would love to see the expression on his face when he discovers that Canadian Bacon is really just ham.
Anyway, what cemented it for me was chapter 4 on Independence Day ID4. It shows a sattalite moving across the screen, and running into the large alien ship. With the old driver, there was an annoying tympani type boom-boom-boom as it got to the center of the picture. After putting in the new driver, it's all but gone.
Also, listening to track two of Bjork's Post album ("Hyper Ballad") the driver goes much deeper and cleaner than before. On Soul Coughing's first album, Ruby Vroom, The bass line is much cleaner and articulated.
All in all, it was a cheap way to improve the sound of this unit. At $25, I would think any owner of the sub could afford the upgrade. This & some time invested in making the hole bigger will pay off big time.
 

Barry_B_B

Second Unit
Joined
May 14, 2001
Messages
453
Real Name
Barry
Quote:
"Using a polyfill type insulator will absorb a good deal of this energy, and that's why I suggest using a foam type. It will help to reduce cabinet resonance, but still allow the air to flow to the port."
So I killed the pillow for nothing? Oh, the guilt
eek.gif

Will give the foam a try, as last night I was playing with the sub again, needed to boost the gain a smidge to get the "whump" back. Really like what this did with music!
Like the idea of an upgraded driver, but had always thought they needed to be in an enclosure specifically designed for the particular driver?
 
Joined
Sep 28, 2000
Messages
23
I have hardwoods, would installing rubber feet on my sub help?
Also, would placing plants, or something like that on top make much of a difference?
 

Saurav

Senior HTF Member
Joined
Feb 15, 2001
Messages
2,174
Also, would placing plants, or something like that on top make much of a difference?
If someone decided to water it, it probably would
wink.gif
Seriously, I had a wooden/particle-board shelf under my sub, and then I put one granite slab under and one on top of the sub, and it did seem to tighten up the sound a bit. This is purely subjective though. The theory behind putting a weight on top of the sub is that it stiffens the cabinet a little, thus reducing unwanted vibrations. It costs just a couple of bucks to try it, which for me places this firmly in the "nothing to lose" category of tweaks. It also makes you look geeky and audio-expert'y to your guests, and that's pretty good for a couple of bucks too :)
 

Barry_B_B

Second Unit
Joined
May 14, 2001
Messages
453
Real Name
Barry
Did some more listening with music and tv last night, IMO there is a real improvement. Will also be doing the "plant mod" for looks!
laugh.gif
 

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