# Best BOOM for the buck?



## RobinTheBrave (Jan 1, 2010)

I'm new to the forum and fairly new to the Home Theater market. I've been blown away by the level of technical knowledge here, and I'm hoping you guys can help me out with some subwoofer advice. 

I've pieced together a system that I'm fairly happy with, but I've become dissatisfied with the low frequency performance. We were watching Pirates of the Caribbean the other night and I could see lots of canon fire and explosions on-screen, but the little 5" woofers in my mains just didn't do it justice. I plugged in an old pair of 8" car subwoofers with a 50W RMS per channel amp. That certainly helped, but I had to max out the subwoofer level on my receiver (+10db) and crank the gains all the way up on the amp to get close to the SPL I was looking for (at which point my poor old woofers started to disintegrate :sad. I'm willing to toss about $200-250 at this problem, but I'm not sure where the money is best spent... largest woofer? highest wattage output? multiple woofers?

I realize $200 pretty much limits me to the bottom of the barrel to begin with, but hey, you've got to start somewhere. I'm willing to gloss over subtleties in sound quality. The room is not acoustically treated, and nothing else in my system is high-end (Yamaha RX-V365 receiver is the star of the show, mains are hand-me-down Pioneers, surrounds are KLHs from Goodwill). I'm looking for the cheapest way to move the most air so the LFE can be felt, instead of just "implied" by the actions on-screen ;-)

For the sake of comparison, I've arbitrarily limited my examples to Polk equipment. They seem to have a number of offerings in my price range. I'm using their CS-1 center speaker right now and have been satisfied with it. However, please offer suggestions if there are significant differences between brands.

So, the question is this... In my 20'x20' living room, what would get me the most dramatic bass?

- Two 10" powered subs (Polk PSW10, 50W RMS), one on each side of the room
- One 12" powered sub (Polk PSW505, 300W RMS)
- Two 12" car subwoofers (Polk db1240) in separate 1.5 cu ft ported enclosures (one on each side of the room), powered by separate channels of a 200W RMS per channel car amplifier (Pyle PLA2210)


I can wrangle each of these options for less than $250. I really wish I could just buy everything, take it home and try it out, then keep what works best. Based on what I've read elsewhere on the forum, I'm leaning toward the one 12" PSW505. It sounds like multiple subs have the potential to create nulls, cancellation issues, etc. Seems like a headache that's worth avoiding. But I'm also concerned that one 12" won't "fill" the room. At $99/each, the PSW10s are attractive, but I'm afraid I'd have to crank their volume to max just to hear them.

Any advice is appreciated!!


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## Moonfly (Aug 1, 2008)

Hi Robin, welcome to the shack :wave:

For a proper sub you really need to look at subs with a minimum of a 12" driver. For the budget I would also always choose one good sub over 2 slightly inferior ones.

I would lean towards the single 12" PSW 505 as well. From what I know the Pyle amps are pretty weak so would go that way, and the PSW10's use driver that are too small to be proper subs IMHO. Ive not personally heard the Polk subs, but based on experience thats what I would do for sure in your position :T


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## RobinTheBrave (Jan 1, 2010)

Thanks Moonfly!!

Now that I've got a definite direction (one powered sub, min 12"), are there any other brands/models I should consider?

I'm still working on convincing the Mrs. that we need to spend another $250 on this project. I don't want to make that challenge any harder than it already is. But if I could get something of significantly better quality for an extra $50-75, I'd be a fool not ask ;-)


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## Moonfly (Aug 1, 2008)

Its hard for me to offer you a particular brand as I'm not based in the USA, but someone will be along soon to help. In the mean time, why not do a search of the forums to see if any other options stand out. Its certainly worth investing a bit more if you can, and at your end of the budget an extra $50 could make a bit of difference.

All the best


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## marlin (Dec 2, 2009)

Hi Robin
There are a couple of websites for you to check.
1 - Creative Sound Solutions (link on this site) based in western Canada.
2 - DIYCable, who carry Exodus subwoofers, based in NW USA

Both have excellent 12" drivers, and the amps to drive them. There are also forums for both in the DIY Speakers section. You will find all sorts of proven designs.

If you have more questions, just ask. The people here are super helpful


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## RobinTheBrave (Jan 1, 2010)

Thanks for the pointers!

I'm gonna spend a while shopping around tonight and see if I can come up with any other specific options. After just a quick browse, it's looking like manufactured 12" subs under $300 are pretty scarce, and under $250 are pretty much non-existent.

I hadn't really been considering a DIY sub mainly because it's cold here (Seattle, WA) and I wasn't looking for another project (just finished pulling speaker wire to make the HT install a little more permanent). But, I'm gonna spend some time looking through the DIY Sub posts and see if I can talk myself into anything. I imagine, as with most DIY projects, it's really the only way to get the most bang for your buck.


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## RobinTheBrave (Jan 1, 2010)

Man! There are some exciting designs out there in the DIY world! I'm going to be an avid lurker in the build projects database, I can tell. But, for today, I think I need more immediate graditification...

I didn't see much else in the pre-built subs that looked attractive. I found a post from '08 about subs under $300 (http://www.hometheatershack.com/forums/home-audio-subwoofers/3498-under-300-a.html), but most of them aren't available anymore. I think I'm pretty much sold on the Polk PSW505. The price is right, and it got 5 stars in the customer reviews (http://www.hometheatershack.com/ele...5_12_Inch_Powered_Subwoofer_Single_Black.html).

My wife just gave me the go-ahead, so I'm gonna order it up. I'll post a follow-up next week when it gets here...


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## drdoan (Aug 30, 2006)

Welcome Robin. Have fun. Be sure to check out our classified section. Dennis


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## lsiberian (Mar 24, 2009)

The best low cost 12" driver is the Dayton RSS315H-4 12"

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-464

For power look at an O-Audio 300 watt bash amp. 

Below are the parameter. These are proven parameters not just simulations. You will get up to 109 db at 20hz with these. That's twice as loud as a jackhammer. 

Box parameters
Vb = 4.946 cu.ft
Fb = 17.9 Hz

Vent Dimensions
Hv = 2.5 in
Wv = 9 in
Lv = 36.89 in

This would be a tremendous upgrade from the polk when the time comes


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## jpgolf14 (Dec 3, 2009)

The BIC F12 is typically considered one of the best budget subs. I have not heard one myself, but I suspect it would blow away the Polk.

$255 at amazon http://www.amazon.com/dp/B0015A8Y5M...e=asn&creative=380341&creativeASIN=B0015A8Y5M


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## Zing (Jan 5, 2009)

Robin, I think you should hold off a bit, do a little more research and, in the process, save a bit more money to increase your budget. There's a lot to consider here that hasn't been addressed. Things like sub placement, the size of your room, driver excursion, listening preferences as they relate to volume levels (SPL), etc.

You mentioned your room is 20 x 20 but what about its height? When you're dealing with subwoofers, you need to take into consideration the volume of your space (cubic feet not just square feet). If your ceiling is 8 feet high, that gives you 3200 cubic feet. If it's 9 feet high, there's 3600 and a 10 foot ceiling translates to 4000 cubic feet. Additionally, if there are opening to other rooms, that will increase the volume too. Suddenly, a particular sub that will perform well in 3200 cubic feet will not perform the same in more than 4000 cubic feet. You didn't, however, mention a couple of things that I would consider important to your quest. Have you calibrated your system? Where did you place those car audio subs you tried...in a corner or somewhere else? Were they in an enclosure? What kind of receiver (or pre/pro and amplification) are you using? How loud do you like to have the volume during movies?

It's not surprising at all that those 8 inch drivers and 50 watt amp were so taxed. 50 watts really isn't sufficient power for low frequencies, especially movie soundtrack LFEs. Frankly, I don't even know if the 150 watts from the suggested BIC sub is sufficient. Then again, that will ultimately depend on the goals you want to achieve. If you simply want to add some bottom end because you currently don't have a sub and cannot or will not spend more than $250, then likely anything will be an improvement because the 5" drivers in your mains were not designed to handle LFE cannon shots. So that too is not surprising that they didn't do it justice. But if you want a thump in your chest when a cannon is fired, considering the size of your room, I'm afraid you're going to need a bit more than $250, DIY or not.

Whatever you do, don't get hung up on driver size alone. It's not a hard and fast rule that 12-inch drivers are superior to 10 inch drivers. There are so many other variables that come into play it's not funny. The design of the enclosure, power of the amp, excursion of the driver (Xmax) and location of the sub in your room will come together and form what you hear and feel. For example, I would much rather have a good quality, well-designed 10 inch sub with, say, 25mm Xmax and a 300w amp, located in a corner than any garden variety POS 12 inch with 9mm Xmax and a 150w amp.

As I said, don't rush this and don't throw away your hard-earned $250 on something that isn't sufficient for your needs. Research, ask, learn, save and then buy (used if necessary). I promise you, you'll be much happier in the end.


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## jpgolf14 (Dec 3, 2009)

Hey Robin,

I just noticed you are located in Seattle. I am in Everett. I have a Yamaha YST-SW215 http://www.amazon.com/Yamaha-YST-SW215-8-Powered-Subwoofer/dp/B0000W59F4 that I am not currently using. It sure isn't anything special but if you want you can pick it up and try it out for a few weeks. That would at least give you an idea of what a bottom of the barrel "home" sub can do. While you're there you can also demo my current sub, which is a 12" sealed Image Dynamics sub out of my car that I hardly ever drive. Certainly not designed for HT use, but its honestly a huge step up from the Yamaha. Explosions hit much better. 

I am also just starting a DIY ported 15" AV-15H that will be the permenant sub for my home theatre. So you could check out that project too.

Let me know if there is anything I can do to help.

BTW I think a really nice budget DIY sub would be the ported 12" Dayton Titanic sub and the Bash 300 amp. That would be a little over $300 from parts express. Add $20 for a sheet of mdf and call it a day. That would destroy any $300 commercial sub that I'm aware of. I'd be happy to help with any of the DIY aspects, altough I'm no expert either.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-404
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-750

John


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## RobinTheBrave (Jan 1, 2010)

Aaagh!!! I think I jumped the gun a little... The Polk is on its way already :doh:

I know patience is a virtue, and I'm usually methodical to a fault in my decision making. But I'm finding it sooo hard to bridle my enthusiasm in this case!! I've had a taste what a difference a sound system can make. Now I want it all to come together *yesterday* so I can start enjoying more movies! LOL 

No worries, though. I've got 30 days to return it if I decide it was the wrong choice. I can tell this is something I'm going to be tweaking for years to come. So even if I keep the Polk, all this great advice won't go to waste. It'll just be fueling the next round of upgrades :spend: Besides, you've got to start somewhere! You appreciate the Corvette that much more after you've been driving a Geo for a while 

Thanks Zing! A lot to think about there. If there's one thing I'm quickly learning, it's that I've got a lot more to learn!  I definitely *want* the thump in the chest, but for now I'll take whatever improvement I can get. I'm spending x-mas + b-day money right now. I don't expect I'll be able to grow the sub budget any time soon, or at least not at a pace I'm willing to wait for.

The living room is 20x20x8, open to the kitchen (12x15x8) on one side. I haven't calibrated the system. I sat in the "sweet spot" on the couch and used a sound level meter (C weighted, rapid sampling) and the receiver's Speaker Level controls (Yamaha RX-V365) to verify that I was getting roughly the same SPL out of each speaker when playing the test tone. That's about it though. I have an Avia dvd that I used to calibration the video a few years back. I vaguely remember it having a section for audio calibration too. Should I use some sort of a dvd wizard like Avia, or is there a better process?

The 8" subs were in separate off-the-shelf ported carpet boxes, 1.5 cu ft each, I have no idea what the port was tuned to. They were on the floor (low pile carpet) directly in front of the TV, about 6' from the couch.

Thanks for the offer, John! I'm actually in Sedro Woolley, WA (up closer toward Bellingham). I just round down to Seattle because it's easier  Once the weather clears up I'll have to pick your brain for advice on a DIY build. I can't take two steps in my garage without tripping over something right now, so an indoor wood-working project is off the table. The engineer in me is sold on the idea of a DIY sub. I need to learn a lot more before I could make any decent design choices or fully appreciate the outcome, though.


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## jpgolf14 (Dec 3, 2009)

I know what you mean Robin, I'd call that Seattle as well.

Good luck with the Polk. Let us know how it sounds.

The engineer in me is convincing me to go DIY.


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## RobinTheBrave (Jan 1, 2010)

That BIC F12 looks pretty nice. It's hard to judge these things on paper, though. Spec-wise they look pretty similar... Has anyone heard both? Obviously it's more of a hassle to trade up now, but I'm not ruling it out.


Polk PSW505
-------------------------------------- 
Design: Front-firing 
Frequency Response: 23Hz - 160Hz 
-3dB Frequency Response: 28Hz - 125Hz 
Sensitivity: ??
Drivers: 12" Diameter, High excursion polymer composite cone 
Magnetic Shielding: YES 
Gold-Plated Terminals:??
Power: 460 watts Dynamic Peak, 300 watts Continuous Average 
Impedance: 8 ohms 
Dimensions: 16.13" x 15.13" x 18.19" 
Weight: 43 Pounds Each


BIC F12
--------------------------------------
Design: Front-firing 
Frequency Response: 25Hz - 200Hz 
Sensitivity: 90dB 
Drivers: 12" injection molded long-throw woofer
Magnetic Shielding: YES 
Gold-Plated Terminals:YES 
Power: 475 watts Dynamic Peak, 150 watts RMS continuous 
Impedance: 8 ohms 
Dimensions: 17"H x 14 3/4"W x 17 1/4"D 
Weight: 42 Pounds Each


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## RobinTheBrave (Jan 1, 2010)

LOL  Polk gets "chuckle points" at least... Pulled up the PSW505 manual on their website. This is from the "trouble-shooting" section...

Q: “Why does my system hum?”
A: “Because it doesn't know the words.”


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## RobinTheBrave (Jan 1, 2010)

The Polk arrived yesterday! It's no chest-thumper, but as Zing pointed out, with my budget and room that was never really an option. It does have a very respectable rumble, though  

I was disappointed at first... I plugged it in, popped Pirates back in and watched the "Port Royal raid" scene. Immediately I noticed some "distortion". I thought, "What a POS! The sub amp vol is barely at half and it's already popping and crackling!" Well... after about 30 seconds of investigation I realized the sub wasn't crackling, it was rattling the hanging pictures on the other side of the room!! (hee, hee  ) So, yeah... plenty of power there, I think.

I need to play around with placement and receiver config a little more. I watched about 45 mins of movie last night, and it seemed a little "boomy". I think I probably just need to turn it down a bit. The sub volume is a little over half-way, and the swfr level on the receive is at +2dB.

For $249 and free shipping, I couldn't be happier!! I gives me LFE punch I was looking for. And best of all, after 4 weeks of tripping over wires etc, I can finally stitch up all the home theater stuff and have my living room back!!

Thanks to all for the help and advice!!


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## Zing (Jan 5, 2009)

RobinTheBrave said:


> *I think *I probably just need to turn it down a bit. The sub volume is a little over half-way, and the swfr* level on the receive is at +2dB.*
> 
> For $249 and free shipping, *I couldn't be happier*!!


For about $40 more, you could be a lot happier. Buy yourself a Radio Shack analog SPL meter and calibrate your system and you won't have to "think" about turning anything up or down. You'll know, precisely. Your ears will get you close, but not precise. And precise, in this case, is what you want. If you're not going to calibrate properly, then at least heed the following - besides it's free. 

I would encourage you to take that +2dB trim level setting and decrease it to about -2dB (maybe even -3dB) then use the gain knob on your sub to get the output back up to a satisfactory level and leave it there. By doing this, you accomplish two things. First, having your trim level above 0dB really should be avoided if at all possible. Granted, +2 is a lot better than +6 but +2 is still above 0. Having it set at anything above 0 starts to alter the predefined gain structure and increases the possibility of noise and distortion. Perhaps all that distortion you heard wasn't just the pictures. A very good rule of thumb to remember is: It's always better to turn it down than it is to turn it up. By design, your AVR can sound its absolute best with those trim levels at 0dB. The second best sound can be had by having them somewhere in the negative range. And the absolute worst sound can come from having them in the positive range.

The second thing this accomplishes is, in the event you'd like a little more bottom end for a particular recording, you can adjust the sub trim level on your AVR. You won't need to crawl on the floor and/or behind something to adjust the gain knob on the sub. You can simply do it via remote control on your AVR. Plus, an added bonus is that you'll know beyond a shadow of a doubt where you started, how far you went and where you need to go to put it back. It would only be a poor attempt at guessing when using the gain knob on the sub.


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## RobinTheBrave (Jan 1, 2010)

Thanks Zing! I actually have an SPL meter (Radio Shack brand too!). Am I shooting for equal levels out of ALL the speakers? When I have the sub at the same SPL as the others it "sounds" too quiet to me (on the test tone). Should I use a different weighting when measuring the sub? I generally use C.

Obviously, using my ear to set the speaker levels didn't produce the optimum results, so I'm open to trusting the SPL meter


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## Zing (Jan 5, 2009)

RobinTheBrave said:


> Am I shooting for equal levels out of ALL the speakers? When I have the sub at the same SPL as the others it "sounds" too quiet to me (on the test tone). Should I use a different weighting when measuring the sub? I generally use C.


I am more than a little surprised to read that you find it too quiet. Typically, the sub should be set a little lower than the other speakers due to the RS SPL meter's inability to accurately measure lower and lower frequencies. There's even a compensation chart to show the inadequacies and the actual SPLs at given frequencies. Case in point - my 5 speakers read 73dB on my SPL meter but for the sub, it reads 68. Even still, sometimes I think it's too loud. Anyway, since I don't know your equipment, configuration, layout and placement, any comments are nothing more than conjecture and speculation.

Regardless, yes, you are shooting for equal output from all 5 speakers at your listening position, with the meter's weighting set to "C" and its response set to "slow" and its range dial set to 70dB. *Be very sure that, in your AVR's speaker setup/configuration menu, your speakers are set to small and the subwoofer is set to on or yes*. If you have the ability to specify a crossover frequency, a good starting point would be somewhere between 80-100Hz. Depending on your speakers, that frequency might need to be changed but that range isn't excessive one way or the other to begin with.

If you need more output from your sub, there are two things you can do. First, corner placement. It yields the greatest output but at the cost of possibly being boomy and a less-than-smooth response. Second, you could try placing it in close proximity to your listening position, perhaps behind or next to your seating. You'll likely have to increase its level but having it closer to you will ensure the sound waves are the strongest/loudest. Keep in mind, as you experiment with placement, you'll need to recalibrate it each time.

Something else to consider is the common suggestion of placing your subwoofer at the listening position (even to the point of placing on your seat cushion) and then crawling all around the room on the floor trying to determine where it sounds best. When you find that spot, that's where the sub should and, in theory, sound that good when you're seated.

*EDIT* Something just ocurred to me. Does your subwoofer have a phase adjustment? If it does, and it's not set correctly, that could very easily result in a weak output.


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## RobinTheBrave (Jan 1, 2010)

Hmmm... I'll have to have my wife sit in on the next level check that I do. Make sure that I'm not just missing the lower portion of my hearing range  I'm pretty sure that's not it, though. My wife has the bass in her car turned up to the point that it's uncomfortably loud to me, and she thinks it's perfect. Plus, I think my hearing check a few years back was within normal limits at all frequencies. Honestly, I think I just need to spend some time developing my "aural palate", so to speak. It takes a while to tune into the subtleties of fillet mignon when you've been eating McDonald's for years. The knee-jerk reaction may be to cover the steak in ketchup (ie, crank the sub) to get back to a familiar taste, when in reality "less is more".

The sub is placed close to the wall, about 2' from a corner. It sounds like that could account for some of the boomy-ness. I'll play with the placement to see if there's another spot I like better.

The speakers are all set to sml in the AVR. The labels on the back of the speakers (mains and surrounds) say they'll do 80Hz-20kHz. I left the AVR crossover at its default of 80Hz, with the understanding that the speakers may not perform as advertised and that I may need to tweak it once I get savvy with REW and can actually plot their output.

Both the sub and the AVR have phase adjustments. When I set the sub up, I experimented with its phase adjustment switch and couldn't really tell a difference between the two settings. I figured if I was getting a cancellation due to the phase of the sub, it must be small enough that I'd need a plot to find it.

I just realized that when I've been doing my level adjustments, I've been doing them with the AVR at -20dB, since that's about where we watch movies (-24 to -18dB). I noticed in another thread that someone said to do the level check at reference volume. Your mention of the setting SPL meter dial to 70dB seems to concur with that. I hadn't thought about it before, but is it important that I have the AVR at 0db when I do the checks?


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## mademperor (Jan 5, 2010)

Zing said:


> *EDIT* Something just ocurred to me. Does your subwoofer have a phase adjustment? If it does, and it's not set correctly, that could very easily result in a weak output.



Take a look at my thread here, I did extensive testing with a Polk Audio PSW110 and the phase control had a big impact on SPL.

Phase at 0* increased SPL by quite a bit....

Freq - No Sub//Sub-Frt Sm // Lg ## Sm//Lg
--------------------- Phase 180 ## Phase 0
028hz - w/o 79 with sub 67 // 67 ## 68 // 68
031hz - w/o 77 with sub 71 // 71 ## 74 // 74
036hz - w/o 78 with sub 75 // 75 ## 77 // 77
040hz - w/o 77 with sub 75 // 75 ## 79 // 79
050hz - w/o 80 with sub 80 // 80 ## 84 // 84
063hz - w/o 82 with sub 81 // 80 ## 86 // 86
071hz - w/o 91 with sub 79 // 79 ## 87 // 87
080hz - w/o 82 with sub 82 // 82 ## 94 // 94
089hz - w/o 82 with sub 78 // 78 ## 87 // 87
100hz - w/o 73 with sub 68 // 68 ## 80 // 80
111hz - w/o 67 with sub 72 // 72 ## 67 // 67
125hz - w/o 79 with sub 76 // 76 ## 79 // 79


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## Zing (Jan 5, 2009)

RobinTheBrave said:


> I just realized that when I've been doing my level adjustments, I've been doing them with the AVR at -20dB, since that's about where we watch movies (-24 to -18dB). I noticed in another thread that someone said to do the level check at reference volume. Your mention of the setting SPL meter dial to 70dB seems to concur with that. I hadn't thought about it before, *but is it important that I have the AVR at 0db when I do the checks*?


Not really. When you run the internal test tones on most AVRs, their default process is to output the tone at 0dB. However, if you adjust the volume control during this process, all bets are off as this would cancel the default and begin to output the tone at the newly-adjusted level. So I suppose to be safe, you could turn the volume up to 0dB but if you're careful not to touch it, it won't matter.


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## RobinTheBrave (Jan 1, 2010)

Boy howdy, turning the sub down help a LOT! No more distracting "boomy" sound, but still nice solid bass when the soundtrack called for it. I just finished watching District 9, and it sounded perfect. Nicely balanced.

I redid the speaker levels. My Yamaha rx-v365 definitely plays the test tone at whatever the main volume is set at. I have the default volume set to -29 dB when the AVR comes on. If I go into the Speaker Level setup at that point, the test tone doesn't even register on my SPL meter. If I exit out of the menus, turn the volume up to -20 dB, then go back in and start the speaker level setup again, I get readings of 55-60 dB on the meter. When I turn it up to 0db, I get meter readings in the 70's, as expected.

I did a test, balancing the levels with the volume at -20dB, then checking them at 0dB. I found that it didn't affect the balance (as one would hope it wouldn't). If the levels we equal at -20db, they were still equal with the volume at 0dB. However, I did find that changing the volume dramatically changed my perception of the sub level. With the test tone volume at 0dB it was immediately obvious that I had the sub WAY to high. I backed the sub level down to 0 on the AVR, and took about 1/8 of a turn off the volume knob on the sub (just a little below half now).

Thanks again for the help, Zing! I've got a movie marathon planned this weekend to celebrate :bigsmile:


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