Sub Cabinet

[Alex Avakian]

Based on the article it doesn't seem like stuffing is going to do enough to get it to sound like it should.

The 55Hz was the low end for the cabinet, not the sub. The sub low end is 30Hz.

 

[TLS Guy]

The sub I bought is the Peavey Low Rider 15" (00560310) which was around $200, the Gemini XGA-4000 amp I bought was around $200, and then I've prob spent a little more than $100 on parts to refurbish the enclosure.

I've also heard I can fill the inside with Poly fill or some material that essentially makes the space seem larger to the sub, will that work well for my case so I don't need to scratch everything I've done so far?

It is a highly sensitive driver and so will not play low. Free resonance is 34 Hz. My guess is that when I model it, it will play no lower than 40 Hz. It will need a ported cabinet correctly tuned and not a sealed one. The T/S parameters are not suitable for a sealed cabinet at all.

I will model it later, and post the file. I have three of the grandchildren here now.

 

[MrBoat]

The ports in the enclosure matter a lot also. Too many/too large and the less it acts as an enclosure at all and could damage the driver as well. With what you have right in front of you, I would start by plugging the vents just for the heck of it. Sealed enclosures are more forgiving, in spite of it losing the lower frequency capabilities. This would also perhaps, teach you a little about the effect of port tuning.

 

[TLS Guy]

Unfortunately that driver is not a sub driver. It is actually only a crude loud blaster. I know of no product from Peavey that I would ever recommend or own, and certainly not that driver.

Basically the motor system is too powerful for the poor suspension.

Although the TS parameters would at first glance suggest a ported alignment the driver will not tolerate it without damage and only tolerates about 10 watts if that below 70 Hz. Even then ported xmax cone excursion is exceeded.

The driver tolerates full power above 100 Hz.

The F3 is at 80 Hz sealed which has to be the alignment. It needs a box of 1 cu. ft. The box should be filled with Polyfill.

The driver even sealed tolerates progressively less power below 70 Hz. So if this is a high powered application there needs to be a second order high pass filter at 70 Hz. So the total roll off would be 24 db per octave.

The bottom line is that this driver is a total waste of space, except to produce a vulgar loud noise. I have noted at gatherings I have been invited to, that that is the Peavey modus operandi.

 

[Winkleswizard]

I tried to model in Bassbox Pro and tried to verify Peavey's specs. For a 3 cubic foot cabinet tuned to 38 hz, the f3 is 88 Hz. Not close to being a subwoofer and not the 40 Hz that Peavey claims...

Ww

 

[shadyJ]

The bottom line is that the Peavey driver will give you some bass, but not accurate bass. If you are not picky about sound quality, sure, put the driver in the cabinet and give it some power. Just don't invest a lot of money, time, or resources into this project; that driver does not warrant a big effort.

 

[TLS Guy]

I tried to model in Bassbox Pro and tried to verify Peavey's specs. For a 3 cubic foot cabinet tuned to 38 hz, the f3 is 88 Hz. Not close to being a subwoofer and not the 40 Hz that Peavey claims...

Ww

Yes, but look at the power cone excursion below 70 Hz. In a ported box it exceeds xmax with minimal power. The thing is useless except for blasting sound above 80 Hz. You can not make that driver work as a subwoofer. For a sub it is 100% money down the drain.

 

[Winkleswizard]

Yes, but look at the power cone excursion below 70 Hz. In a ported box it exceeds xmax with minimal power. The thing is useless except for blasting sound above 80 Hz. You can not make that driver work as a subwoofer. For a sub it is 100% money down the drain.

I went to check if Bassbox showed this excursion issue too and found that the driver database had a different part number than was posted. Using the posted part number, could get a usable vented alignment in a 3 cubic foot box. If box is tuned to 38 hz, Xmax is not exceeded at 10 watts.

I still cannot match Peavey's alignments, but at least the original poster may be able to salvage his design after all. From the response graph, at box tuning of 60 hz, expect a more boomy sound.

Since the group consensus seems pretty negative on Peavey, am skeptical of their specs. But am surprised our modeling results are so different...

Ww

 

[TLS Guy]

Xmax, but not x-mechanical is exceeded between 45 and 75 Hz. You have to reduced the power significantly to keep it in xmax which is only 9.6 mm.

Anyhow you come up with an F3 above sub range, so that is the bottom line.

Type: Vented Box
Shape: Prism, square (optimum)
Vb = 2.829 cu.ft
Fb = 36.11 Hz
QL = 6.605
F3 = 42.95 Hz
Fill = minimal
No. of Vents = 1
Vent shape = rectangle
Vent ends = two flush
Hv = 3 in
Wv = 14 in
Lv = 26.13 in

Bass Box pro does recommend a sealed alignment and I can see why. Then the F3 is 80 z

 

[Alex Avakian]

It manual says if I put it in a 4.5 cubic foot enclosure it will reach lower frequencies better, 3 cubic foot was the medium sized box which wasn't supposed to get as low as the sub can go.

But also, since I messed this up even more than I could imagine, would you guys recommend trying to salvage this and build a box for it, or just try to return or sell the sub and amp and just buy a already made sub?

 

[TLS Guy]

It manual says if I put it in a 4.5 cubic foot enclosure it will reach lower frequencies better, 3 cubic foot was the medium sized box which wasn't supposed to get as low as the sub can go.

But also, since I messed this up even more than I could imagine, would you guys recommend trying to salvage this and build a box for it, or just try to return or sell the sub and amp and just buy a already made sub?

I did model it with a larger box, at 5 cu.ft. I does extend the bass to the low 30 Hz range. However the port becomes far too long, and there will be port resonance issues. In addition those extended bass alignments are boomers.

I would try and sell the driver. I would strongly encourage you to build your own sub. You will get a much better sub for the money and learn a lot on the way. You have learned a lot already.

I have a design for an 18" Dayton driver that a number of members have built and its a real floor shaker and a tight good sounding sub as well. It does not require a mega amp to produce lots of sound and deep bass, and it does not need EQ. It is a clean straightforward project.

 

[William Lemmerhirt]

Trying to say this in a nice way. I think starting over and recouping as much as you can would be wise.

 

[Winkleswizard]

Xmax, but not x-mechanical is exceeded between 45 and 75 Hz. You have to reduced the power significantly to keep it in xmax which is only 9.6 mm.

Anyhow you come up with an F3 above sub range, so that is the bottom line.

Type: Vented Box
Shape: Prism, square (optimum)
Vb = 2.829 cu.ft
Fb = 36.11 Hz
QL = 6.605
F3 = 42.95 Hz
Fill = minimal
No. of Vents = 1
Vent shape = rectangle
Vent ends = two flush
Hv = 3 in
Wv = 14 in
Lv = 26.13 in

Bass Box pro does recommend a sealed alignment and I can see why. Then the F3 is 80 z

Here is the alignment I have in Bassbox:

Box Properties
Name:
Type: Vented Box
Shape: Prism, square (optimum)
Vb = 2.827 cu.ft
Fb = 24.46 Hz
QL = 6.606
F3 = 30.64 Hz
Fill = minimal
No. of Vents = 4
Vent shape = round
Vent ends = one flush
Dv = 2 in
Lv = 18 in

at 10 watts, here is the displacement plot:

Another at 500 watts, still seems workable (but would be very loud)...

From what you have indicated, these results are very different from your sim.

Thoughts?

Ww

 

[Alex Avakian]

I wouldn't mind trying to build another subwoofer because I have learned a fair amount through this forum (thanks to you guys) in the past couple of days. But it seems I have to learn a lot more in order to choose the right sub driver and which amp to get. And it seems like it will require a lot more time and money to learn about everything. So I think I'm just going to try and return everything and buy a pre-made sub from Behringer or something (I would have to do more research into that too). Honestly I don't really know what to do anymore, besides trying to return everything and trying to get back to square one, so any pointers would be helpful.

 

[lovinthehd]

I wouldn't mind trying to build another subwoofer because I have learned a fair amount through this forum (thanks to you guys) in the past couple of days. But it seems I have to learn a lot more in order to choose the right sub driver and which amp to get. And it seems like it will require a lot more time and money to learn about everything. So I think I'm just going to try and return everything and buy a pre-made sub from Behringer or something (I would have to do more research into that too). Honestly I don't really know what to do anymore, besides trying to return everything and trying to get back to square one, so any pointers would be helpful.

If you can cut your own ply/mdf you can follow an existing proven cabinet design for a given driver. I'd try the one TLSGuy referred to with the Dayton driver if so. If you just want to glue something together (literally) there are also flatpack pre-cut boxes available at parts-express.com and diysoundgroup.com for specific drivers. The amp may be useful altho I'm not familiar with that brand at all, think you can do better with Crown or QSC or even Behringer. For the money you were spending you could have bought an entry level sub from SVS, Rythmik or Outlaw ...

 

[TLS Guy]

Here is the design for the Dayton 18" sub I referenced.

It is a potent sub and your Gemini amp is more than powerful enough to drive it. In fact you will use only a fraction of its power likely.

Any questions just ask.

You must add the volume of the slot vent, driver and bracing to the volume of air required in Vb to get the total volume Vt.

 

[Alex Avakian]

So I would have to buy the "Dayton Audio RSS460HO-4 18" Reference HO Subwoofer 4 ohm" from Parts-Express, then build a box to meet the requirements of the sheet you sent, then use the Gemini Amp to power the sub, then I'd be al set?

But wouldn't the amp not work with the sub if its bridged because then its outputting 8 ohms as opposed to the subs 4? So would I only be using a single channel as opposed to bridging the amp?

Then I would build a box to meet the design requirements of Vb correct (7.672 cubic feet).

 

[TLS Guy]

So I would have to buy the "Dayton Audio RSS460HO-4 18" Reference HO Subwoofer 4 ohm" from Parts-Express, then build a box to meet the requirements of the sheet you sent, then use the Gemini Amp to power the sub, then I'd be al set?

But wouldn't the amp not work with the sub if its bridged because then its outputting 8 ohms as opposed to the subs 4? So would I only be using a single channel as opposed to bridging the amp?

Then I would build a box to meet the design requirements of Vb correct (7.672 cubic feet).

You are correct. The sub would be 4 ohm and I would not bridge the amp. That sub design is highly efficient and one channel of that amp has more than enough power to bring the walls down powering that sub.

I'm not keen on bridging anyway, a lot of amps get ruined that way.

 

[MrBoat]

So I would have to buy the "Dayton Audio RSS460HO-4 18" Reference HO Subwoofer 4 ohm" from Parts-Express, then build a box to meet the requirements of the sheet you sent, then use the Gemini Amp to power the sub, then I'd be al set?

But wouldn't the amp not work with the sub if its bridged because then its outputting 8 ohms as opposed to the subs 4? So would I only be using a single channel as opposed to bridging the amp?

Then I would build a box to meet the design requirements of Vb correct (7.672 cubic feet).

That driver has a high sensitivity and it does not take as much power as some others do. I use Dayton subs and they are righteous and one of the better values available. You can often times build two great performing subwoofers using these drivers for what one commercial offering costs. Being that you already have that amp, you could add a second subwoofer later on and be 'way' ahead of the performance of what you compared it to in the op and likely never look back.

 

[Winkleswizard]

MrBoat makes a good point, as you will get better results with 2 individual subwoofers rather than one. Also, it is better if they match. I have bulit 3 Dayton subwoofers. I started with 10 inch, but by the time I found I should buy a second, it was NLA.

My newer Daytons are 12 inch Titanics and are very happy with them.

If you have trouble returning the Peavey, let me know the port diameter and your cabinet dimensions. May be able to recommend tuning that would be good enough to make it sellable to someone doing sound reinforcement.

Guessing your amp does not have a crossover, so suggest adding a minidsp 2x4 to your plans as well.

Ww