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Discussion Starter #1
Hey, decided to start a new topic for this question as it got a bit lost in other stuff previously.... I did search but mainly found years-old stuff of differing thoughts.


I've currently got one Dayton 1200 sub as part of a home theater setup... I'm planning to add a second Dayton sub... as the space is large I was thinking of adding a Dayton 1500 rather than a second 1200.

(receiver is a Denon 900W with Audessy if it matters, it's 7.2 but both outputs are the same signal)

Is that going to be fine, or is there a major reason I should instead get rid of the 12 for 2 15s? (or even just skip the 15 and buy a second 12 instead?).

Any input greatly appreciated... thanks.
 

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Hey, decided to start a new topic for this question as it got a bit lost in other stuff previously.... I did search but mainly found years-old stuff of differing thoughts.


I've currently got one Dayton 1200 sub as part of a home theater setup... I'm planning to add a second Dayton sub... as the space is large I was thinking of adding a Dayton 1500 rather than a second 1200.

(receiver is a Denon 900W with Audessy if it matters, it's 7.2 but both outputs are the same signal)

Is that going to be fine, or is there a major reason I should instead get rid of the 12 for 2 15s? (or even just skip the 15 and buy a second 12 instead?).

Any input greatly appreciated... thanks.
Generally same subs would be ideal but the big issue seems to be mixing ported vs sealed and or different brands as frequencies can cancel each other. You should be decent with 2 daytons for now then upgrade when you can.
 

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The big issue is over driving the small sub. The subs should be level matched in the setup and the small sub can be placed closer to the MLP which will help prevent over driving it. Floyd Toole wrote several papers on using different size subs.
 

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Discussion Starter #4
The big issue is over driving the small sub. The subs should be level matched in the setup and the small sub can be placed closer to the MLP which will help prevent over driving it. Floyd Toole and several papers on using different size subs.
well, the specs on the two are pretty similar... the 1200 is a 130W amp and listed frequency response is 25-140 Hz... the 1500 is a 150W amp and listed 23-140 Hz....

Selling the 12 for a small loss and getting 2 15s is an option, but bumps my cost by almost 1/3rd ($175 vs $275, figuring I can sell the 12 for $75) so if the 12 works very nearly as well paired with 1 15 I'd rather stick with that.... if it'll be a significant issue then I'll go for the 2 15s.

When I searched and read the previous threads (though as I say they're all from 2-5 years ago) some folks thought mixing subs was just fine, others though it'd cause ragnarok...
 

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well, the specs on the two are pretty similar... the 1200 is a 130W amp and listed frequency response is 25-140 Hz... the 1500 is a 150W amp and listed 23-140 Hz....

Selling the 12 for a small loss and getting 2 15s is an option, but bumps my cost by almost 1/3rd ($175 vs $275, figuring I can sell the 12 for $75) so if the 12 works very nearly as well paired with 1 15 I'd rather stick with that.... if it'll be a significant issue then I'll go for the 2 15s.

When I searched and read the previous threads (though as I say they're all from 2-5 years ago) some folks thought mixing subs was just fine, others though it'd cause ragnarok...
You are lucky to have an outlet to sell your old one.




I'm stuck with a 4 year old Elemental Designs sub that no longer works.


I don't have much of a budget at the moment but have to have a working sub !!!


The Dayton models are looking enticing right now. My HT room is 17' x 11".


I could place two units in the room....although I'm running a 7.1 receiver. I assume there is a way to split the outgoing cable from the receiver ????
 

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Discussion Starter #7
You are lucky to have an outlet to sell your old one.




I'm stuck with a 4 year old Elemental Designs sub that no longer works.

well, it's not actually that old... only a month or so.... In theory I could have actually returned it, but shipping back to do so would've been like 30 bucks... so a friend of mine, impressed with how great it sounds for a "cheap" sub, offered me $75 (which is $5 more than I'd get if I returned it paying $30 shipping)





The Dayton models are looking enticing right now. My HT room is 17' x 11".


I could place two units in the room....although I'm running a 7.1 receiver. I assume there is a way to split the outgoing cable from the receiver ????


Yeah you just get a Y splitter for like 5 bucks... heck on many "7.2" receivers that's all you're getting anyway, it's just built into the back of the receiver.




Though if your 17x11 space is a closed space (you can close doors to make it a sealed room) you may not need 2... Your space is actually smaller than my smaller room (which is 14x16x8) where I originally had the single Dayton 1200 and it sounded good in there... It didn't give the super deep bass the expensive subs do, but for anything 40Hz and up you could hardly tell the difference at normal volumes.






Anyway, appreciate the input guys, I'm going to go ahead and order one Dayton 1500 and see how it does with the 12 I've already got and go from there.
 

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well, it's not actually that old... only a month or so.... In theory I could have actually returned it, but shipping back to do so would've been like 30 bucks... so a friend of mine, impressed with how great it sounds for a "cheap" sub, offered me $75 (which is $5 more than I'd get if I returned it paying $30 shipping)









Yeah you just get a Y splitter for like 5 bucks... heck on many "7.2" receivers that's all you're getting anyway, it's just built into the back of the receiver.




Though if your 17x11 space is a closed space (you can close doors to make it a sealed room) you may not need 2... Your space is actually smaller than my smaller room (which is 14x16x8) where I originally had the single Dayton 1200 and it sounded good in there... It didn't give the super deep bass the expensive subs do, but for anything 40Hz and up you could hardly tell the difference at normal volumes.






Anyway, appreciate the input guys, I'm going to go ahead and order one Dayton 1500 and see how it does with the 12 I've already got and go from there.


Thanks on the Y-splitter advice.


Unfortunately it's not a fully closed room. One if the long walls has a 5' open doorway and the short wall has a 6' open doorway.


Good luck with your system. Keep us updated.
 

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Discussion Starter #9
well, one quick update- I ordered the single Dayton 1500 today for $169 shipped, so we'll see how it does with the existing 1200 when it arrives (couple weeks I'd imagine with the holidays) and then I'll have a more substantial update :)
 

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Discussion Starter #10
Got the Dayton 1500 today... was surprised how much bigger this thing is (given the size difference between 12 and 15 was pretty minor comparing an SVS 12 and a PSA 15)

Anyway, only had a chance to hook it up in the corner where the 12 was (and move the 12 to the secondary "good" spot from a sub crawl) and just play a couple of scenes without time to tune at all (just set the gain to 12 like the Sub1200 currently has after audessying with just that) and phase to 0... definite and nice improvement on the T-rex scene in Jurassic Park and the Lightning scene in WoTW... but unfortunately I won't get a chance/time to really do any proper tuning or testing tonight- probably will be at least a few days maybe a week before I get the chance.


Given the receiver doesn't tune them separately with audessy any thoughts on the best way to do the tune/test work?

Should I just run it with both attached and adjust gains till it gives me back something in the desired -6 to -8 db range? (obviously that's what I'd do if I was tuning for 2 identical 15s, but since they're different wasn't sure if there's some better way)
 

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Kurtz9 said:
Should I just run it with both attached and adjust gains till it gives me back something in the desired -6 to -8 db range? (obviously that's what I'd do if I was tuning for 2 identical 15s, but since they're different wasn't sure if there's some better way)
Here's what I have done in the past with varying results (some combinations work better than others, I suspect your 2 Daytons have approximately the same distortion levels but vary a bit in FR. And you mentioned you've already done the crawl, so I'll assume the subs are in their best positions, but you might want to do the crawl again):

From the MLP, and with room correction off, turn on sub #1 , turn off sub #2 . Run a test tone that's in the middle of your sub's FR (say 45Hz) adjust sub #1 's gain to a particular level (many opt for 75Db, I go around 65Db as I don't listen at reference levels) on your SPL meter. Note this level.

Now turn off #1 , turn on #2 , adjust gain on #2 to match the level on #1 .

Now run your room correction on the AVR.

If the subs are drastically different (I've been working my subs this past week, one PL-200, another DIY - completely different beasts) this doesn't work as well as I would like, but I haven't found a good way to deal with that yet. I've read that gain matching the subs (similar to what I describe above, but with each sub measured in the middle of the room with the meter an inch or so from the center of the cone to alleviate room modes), then performing the sub crawl with each, and THEN running room correction helps in these cases. Will be trying that next.

Remember the good ole' days, when we just put the speakers where we wanted them and wired it all up? :D

EDIT: Are you using a mic and REW to measure your responses, or just going by ear?
 

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Gain matching is used with identical subs. Level matching should be used. match each sub to 73-75 db at the MLP and this should get your avr trim to close to 0. If you want a trim of -5, then level match each sub to around 78 db. You are not likely to clip the preamp signal with a level of 0.
 

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Discussion Starter #13
One stupid question... where should my volume on the receiver be when running the test tone? or does it matter as long as I have it set the same place for adjusting the gain on each sub?


As to what I'm using- I've got a DB meter on my phone for doing what you suggest on the gain thing (and also as a double-check of my sub crawl results).

No Mic/REW, and not planning to buy a $75 mic to help position my $99 sub :p


If you think I'd really need to go to that level to be able to mix the two subs properly though then I should probably just go ahead and sell the 1200 and order another 1500 to save a lot of time/trouble.
 

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Gain matching is used with identical subs. Level matching should be used. match each sub to 73-75 db at the MLP and this should get your avr trim to close to 0. If you was a trim of -5, then level match each sub to around 78 db. You are not likely to clip the preamp signal with a level of 0.
Thanks, I'll give this a try.

What exactly is the difference between gain matching and level matching? Aside from the obvious (gain to same level vs. SPL metering), it seems like the terms are interchangeable?
 

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Gain match mean each sub is using the same amount of power. One sub could be 80 db and the other 75 db at the listening position if their distance to the MLP is different or one is corner located for example.

Most avr test tone are around 73-75 db. Set the level is not hard and no need to return a sub since this will not solved the reason the second sub was purchased.
 

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Thanks, I'll give this a try.

What exactly is the difference between gain matching and level matching? Aside from the obvious (gain to same level vs. SPL metering), it seems like the terms are interchangeable?
Nope, they're completely different techniques:
http://www.avsforum.com/forum/113-subwoofers-bass-transducers/1282064-two-subs-gain-matching-vs-level-matching.html

In your situation, with dissimilar subs, I don't recommend either technique. Gain-matching isn't possible when the gain structures of the susb are non-identical. Level-matching has the potential to set one sub significantly higher than the other sub. This would limit overall system output to the levels achievable by the higher-set sub.

In your situation, I suggest you take the sub with more output, place it in its' best location for smooth FR, and use it for the calibration with the speakers. Then take the lesser sub and move it around the room until you find the spot where it provides further FR smoothing. Set it's level to the lowest point possible to get the smoothing effect. Here is a guide that describes the technique:
https://mehlau.net/audio/multisub_geddes/

Good luck.

Craig
 
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One stupid question... where should my volume on the receiver be when running the test tone? or does it matter as long as I have it set the same place for adjusting the gain on each sub?
In the scenario I laid out it doesn't matter, so long as it remains constant through the measuring/placement process. However, if after running Audyssey you find that it set the sub trim to -12 (or whatever it's lowest point is on your AVR) you'll need to turn the gain down a bit and repeat the process. I've always tried to get Audyssey to put the trim around -3 to -5, but anything in the -6 to +3 range would be fine.

Kurtz9 said:
As to what I'm using- I've got a DB meter on my phone for doing what you suggest on the gain thing (and also as a double-check of my sub crawl results).
Yeah, I still use a phone app as well when I don't wish to break out the mic/REW. It's better than no meter at all!

Kurtz9 said:
No Mic/REW, and not planning to buy a $75 mic to help position my $99 sub :p
Understandable ;)


Kurtz9 said:
If you think I'd really need to go to that level to be able to mix the two subs properly though then I should probably just go ahead and sell the 1200 and order another 1500 to save a lot of time/trouble.
Reading through the information derrickdj1 and craig john have provided above, I think you could get those two Daytons integrated fairly easily. Level matching may work fine for you as the subs are very similar, but I think Craig's suggestion might end up being the best technique (for both of our situations).

Good luck, let us know how it goes!
 

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Discussion Starter #20
Slight sorta-not-really update


My wife has been keeping the downstairs system busy playing Dragon Age Inquisition and when I explained I'd need some time with it to try and tune the 12 and the 15, and then if that didn't work more time to tune the dual 15s, and she said don't waste your time, just order the other 15 so you only have to do it once :)


Even better, Partsexpress was willing to sell me a second 1500 for the same price I paid for the first one (they just raised prices about 20-30 bucks on the Dayton subs, but since I'd purchased it less than 7 days ago they matched the original price).

So, I guess the update is there won't be another update on the mixing subs thing... still wanted to say I appreciate the input and advice provided but looks like it'll be dual 1500s which should be simple enough to dial in correctly.
 
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