DAYTON sub120 mods ?

[just-some-guy]

hello

i just hooked up my new sub. only tried it for 2 mins. seems to have plenty of power for my needs. but it is pretty boomy in its upper Hz ranges(have not tuned its settings/localtion yet). i was reading reviews on it. someone said that it could be tuned to be a little tighter. if so, how ? i can give up some efficiency.

yes, i will tune it first. but if there is something i could try while doing this, i would like to compare as i am going.

i know this sub isn't the greatest. and i didn't/don't expect it to be. heck, what do ya what for $140 shipped. but a sub of this caliber for $140 = WOW !!!


tia

 

[TLS Guy]

hello

i just hooked up my new sub. only tried it for 2 mins. seems to have plenty of power for my needs. but it is pretty boomy in its upper Hz ranges(have not tuned its settings/localtion yet). i was reading reviews on it. someone said that it could be tuned to be a little tighter. if so, how ? i can give up some efficiency.

yes, i will tune it first. but if there is something i could try while doing this, i would like to compare as i am going.

i know this sub isn't the greatest. and i didn't/don't expect it to be. heck, what do ya what for $140 shipped. but a sub of this caliber for $140 = WOW !!!


tia

Do you know the model number of the driver it uses?

 

[just-some-guy]

no. but i will pull the driver and look.

i did a little testing yesterday. i will reserve judgement for now. but its not looking all that good. so far, my old home built blows it away.

 

[annunaki]

Without the T/S specs on the sub it is near impossible to diagnose potential issues accurately. If you can get the model of the sub, it will give us a better start.

Adding some bracing to the enclosure along with some rockwool will probably help some, but knowing the correct alignment & tuning of the enclosure for the driver will give better results.

 

[WmAx]

I can not recommend added bracing for such a small, low powered commercial sub. The subwoofer panel modes are not likely to be in the band of usage and there is no reason go increase panel strength for the type of drive used in it.

What you can do is add dampening in the sub. Add more and more until it is 'tight' enough in subjective sound. By adding dampening, you in effect are effecting the efficiency of the coupling with the port - the more dampening - the weaker the coupling - the less output and higher dampened the system becomes. It is a common method for improving ported box 'tightness'. You can just buy some cheap $3 pillows from Wal-Mart and add them in until you get the desired sound. This combined with ideal placement will yield good sound quality when used within it's physical SPL limits before distortion starts to occur.

It's the BEST for $150, but that's a mighty low dollar mark for a complete powered subwoofer, my friend.

-Chris

 

[Alex2507]

By adding dampening, you in effect are effecting the efficiency of the coupling with the port - the more dampening - the weaker the coupling - the less output and higher dampened the system becomes. It is a common method for improving ported box 'tightness'.

-Chris

"efficiency of the coupling with the port" is a term that I don't understand.
Would you mind dumbing that down a bit?

 

[WmAx]

"efficiency of the coupling with the port" is a term that I don't understand.
Would you mind dumbing that down a bit?

A ported system relies upon the air spring system in the box being itself, of being high in efficiency. You can interrupt this system, reducing the peak resonance efficiency of this air volume(expressed as Qa) and thus causing poorer physical connection to the port by this air volume. The result is lowered port output, which in turn is perceived as tighter bass. In addition, with the massive amount of added acoustic dampening in the enclosure, if there was any lower mid-band reflections/resonances causing sound quality degradation, they would also be reduced.

If you want more detailed information, please refer to the following link, which will explain the phenomena over several pages and give illustrated examples. Click the > arrow symbol by 'HOME' on top of the page to advance to further pages: http://www.geocities.com/kreskovs/Box-1.html

-Chris

 

[Alex2507]

Wonderful. Thank you for that.

 

[just-some-guy]

well, i can't give any more info other than the pics. the blue driver was to be the replacement for the rotted surround pioneer driver that i had in my home built. i ordered a dvc, they sent me a svc . 1 week and no rely from newegg. it was $30 shipped(yeah, i know, but hey). and i am going to dispute the charge. anyway, it "looks" better than either the dayton and pioneer drivers. it would not be an easy swap into the dayton box

blue driver :
Hz 23.90
qms 4.088
qes 0.289
qts 0.270
vas 5.851
spl 90
500w max

 

[just-some-guy]

It's the BEST for $150, but that's a mighty low dollar mark for a complete powered subwoofer, my friend.

-Chris

yes sir, indeed. i guess i got wrapped up in the overflowingly positive reviews over at P/E, and expected more. perhaps these reviews were by the, uuummm, shall i say, ummm, ignorant. or, perhaps i have yet to find its sweet spot. i have yet to use my audio test cd and meter on it. but so far, the funny(not) thing about it, is that it ROCKS everything, except my listening position. things in other parts of the home were falling on their shelves. so HOPEFULLY there is hope.

 

[WmAx]

yes sir, indeed. i guess i got wrapped up in the overflowingly positive reviews over at P/E, and expected more. perhaps these reviews were by the, uuummm, shall i say, ummm, ignorant. or, perhaps i have yet to find its sweet spot. i have yet to use my audio test cd and meter on it. but so far, the funny(not) thing about it, is that it ROCKS everything, except my listening position. things in other parts of the home were falling on their shelves. so HOPEFULLY there is hope.

Well, obviously, this implies your seating position is in the middle of a null.

I recommend you stick with the Dayton driver. That replacement is not any better I wager. In fact, it's probably worse. The paint job really had nothing to do with actual performance and Dayton has a solid reputation for providing drivers that are better than the price suggests.

Add the pillows as I suggested and try different placement.

If you want to upgrade it, you need to get a much better driver and re-tune/replace the port.

-Chris

 

[Alex2507]

If you want more detailed information, please refer to the following link, which will explain the phenomena over several pages and give illustrated examples. http://www.geocities.com/kreskovs/Box-1.html

-Chris

Wow, talk about 'over my head'.
It makes me appreciate the kind of knowledge base advice from you has behind it.
This is not going to be an easily (if ever) understood quick read.

 

[annunaki]

A ported system relies upon the air spring system in the box being itself, of being high in efficiency. You can interrupt this system, reducing the peak resonance efficiency of this air volume(expressed as Qa) and thus causing poorer physical connection to the port by this air volume. The result is lowered port output, which in turn is perceived as tighter bass. In addition, with the massive amount of added acoustic dampening in the enclosure, if there was any lower mid-band reflections/resonances causing sound quality degradation, they would also be reduced.

If you want more detailed information, please refer to the following link, which will explain the phenomena over several pages and give illustrated examples. Click the > arrow symbol by 'HOME' on top of the page to advance to further pages: http://www.geocities.com/kreskovs/Box-1.html

-Chris

Chris,

At that price point it would not surprise me if the panels were fairly thin and or made of pretty low quality material. Some bracing definitely would not hurt. The damping is the easiest and cheapest solution though.

 

[just-some-guy]

Well, obviously, this implies your seating position is in the middle of a null.

I recommend you stick with the Dayton driver. That replacement is not any better I wager. In fact, it's probably worse. The paint job really had nothing to do with actual performance and Dayton has a solid reputation for providing drivers that are better than the price suggests.

Add the pillows as I suggested and try different placement.

If you want to upgrade it, you need to get a much better driver and re-tune/replace the port.

-Chris

yes, perhaps. or it could be the rear firing ports. ya think ? my home made had front firing ports.

yes, i will. i understand what you are saying.

would regular speaker stuffing work ? i think i have a bunch of that.

i'm not looking to upgrand any parts. just tweek, if possible.



updates :

this thing had no instructions. so i just ran 1 rca to its red input. yesterday, i put a Y in and connected 2 rca's to the left/right inputs. i "think" that gave me another channel of power, but i am still checking on that. what do you think ?

i put my audio test cd in the player = nothing, didn't work. mucis cd, nothing.
so i have to figure that out.

the movie THE BRAVE ONE. didn't have much bass nor suround at all, or i have my settings wrong. MCACC was run, with the mic on the couch, facing up, right behind where my head would be. correct placement ?

 

[just-some-guy]

i did some testing yesterday. i didn't write anything down. but it has a fair output at 20hz, i was supprised. i wil test again, and write the results down and post them. placement didn't make any difference. other than the turbulance from the port = LOTS of that.

Chris
what do you think of this ? i'm thinging that a reason i am rocking the structure, and not so much my couch, is that the ports are facing the wall. what would happen, if i made the ports "external", as opposed to internal, as they are now. and face the ports forward.
watcha think ?

 

[just-some-guy]

almost forgot :

i have a radio shack meter. should it be a or c weighted ?

 

[WmAx]

yes sir, indeed. i guess i got wrapped up in the overflowingly positive reviews over at P/E, and expected more. perhaps these reviews were by the, uuummm, shall i say, ummm, ignorant.

Not at all. The reviews are accurate when you consider the price. If you want appreciably better commercial subwoofer, you need to move to the $400 range mark, and that opens you up to the entry level SVS unit, for example.

-Chris

 

[WmAx]

i did some testing yesterday. i didn't write anything down. but it has a fair output at 20hz, i was supprised. i wil test again, and write the results down and post them. placement didn't make any difference. other than the turbulance from the port = LOTS of that.

Chris
what do you think of this ? i'm thinging that a reason i am rocking the structure, and not so much my couch, is that the ports are facing the wall. what would happen, if i made the ports "external", as opposed to internal, as they are now. and face the ports forward.
watcha think ?

If you want to reduce port turbulence, you have to increase port cross section area. Let's say you added a 2nd port of identical diameter to reduce turbulence; you then need to increase the length of both ports to 2x what the original single port was in length. This is one option for the turbulence and it will allow you 2x the SPL output at the lowest frequency range also; the current port is causing substantial port compression.

You have the option to radically increase the internal stuffing as I suggested earlier to reduce the port output and dampen it. Cheap pillows are the easiest things to use. 2 or 3 pillows is probably sufficient. This is going to 'tighten' the subjective sound of the bass radically if you use enough pillows.

As for ports; it does not matter if they are external or internal - the only thing this affects is looks. As for pointing towards the wall or towards you directly; pointing to the wall generally reduces port sounds a little bit and increases lowest frequency output by some degree, since it's closer to the reflective boundary when pointed towards the wall. Of course, at least 12" clearance is recommended for port to wall spacing.

As for the meter weighting, set to C and find the radio shack SPL meter correction chart online and use these correction values to chart your results.

If you ever do budget about $500 for a better subwoofer, please do not go commercial, but instead build a DIY unit, as I can recommend specifically, because the performance will be far higher than what is possible with a commercial device anywhere near the same price range.

-Chris

 

[just-some-guy]

thanx a ton. i now have to comprehend what you say.

this sub has 2 ports, 2 3/4" x 14ish".

so far, port noise is not an issue. as while the port is making noise, i can't hear it because of the other audio from the sound track. my goal is to focus the low end more to my couch, and less to my neighbors. i have no problem making mods to the back and/or bottom and/or inside of the cabinet.

as i am thinking now. how about removing the current ports. and adding ports outside that make a U turn under the cabinet and aim to the front ? watcha think ?

after i get a bassline on it as is. i will then stuff it and test again. i have a 4 day weekend coming up

 

[just-some-guy]

ok, i found this
http://www.subwoofer-builder.com/SPL-corrections.htm

if i am understanding it correctly. for example, if i measure 90db at 20hz, i then add 7.5db to get the actual spl, correct ?

btw. i would build my own sub if i could have better.