Subwoofer amp volume effect on cabinet tuning?

[yepimonfire]

I'm considering using an external amp to power my subwoofer, it's much simpler than trying to modify the cutout to fit a new amp in. This leaves me with two hookup options, I could run the wires out of the down firing port and simply leave the internal amp installed, or I could remove the internal amp, cover the cutout with MDF, and install binding posts.

My concern is that removing the internal amp will change the cabinet tuning, as it obviously takes up space in the cabinet. I'm not really concerned about aesthetics, I listen to the speakers, not watch them. How would removing the internal amp and simply filling the cutout with same thickness MDF affect the tuning?

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[lovinthehd]

You could also drill thru the plate amp, or another place on the box, for wires and just leave it in place, don't think a port's a good way to route wires. What do you expect to gain with a different amp in this case? If you did remove it should be simple enough to approximate the same volume but why bother removing it and patching the hole? Waste of time AFAIC....

ps you could just model it and see how much volume it takes to make a change to be concerned aboiut...

 

[yepimonfire]

You could also drill thru the plate amp, or another place on the box, for wires and just leave it in place, don't think a port's a good way to route wires. What do you expect to gain with a different amp in this case? If you did remove it should be simple enough to approximate the same volume but why bother removing it and patching the hole? Waste of time AFAIC....

ps you could just model it and see how much volume it takes to make a change to be concerned aboiut...

Remember my previous post concerning my sub being unable to exceed 105dB without what I believed to be the driver running out of xmax? Turns out that sound I was hearing was clipping. I plugged the amps power rating along with the drivers sensitivity into the max spl calculator, turns out 120w gets me 100dB at 9'. It's near a wall so I can add 3dB. Parts express claims the amp can deliver an instantaneous peak power rating of 240w, so that again, adds 3dB.

A repeated test showed the sub can hit 106dB peak, but only during a CEA 2010 burst. Play a continuous sine wave and it begins making the clipping noise after about half a second.

The drivers RMS rating is 150w. That means it can handle a program of 300w and a peak of 600w, so I seriously doubt a 120w amp is causing the driver to run out of xmax, especially far above the tuning frequency.



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[TLS Guy]

Remember my previous post concerning my sub being unable to exceed 105dB without what I believed to be the driver running out of xmax? Turns out that sound I was hearing was clipping. I plugged the amps power rating along with the drivers sensitivity into the max spl calculator, turns out 120w gets me 100dB at 9'. It's near a wall so I can add 3dB. Parts express claims the amp can deliver an instantaneous peak power rating of 240w, so that again, adds 3dB.

A repeated test showed the sub can hit 106dB peak, but only during a CEA 2010 burst. Play a continuous sine wave and it begins making the clipping noise after about half a second.

The drivers RMS rating is 150w. That means it can handle a program of 300w and a peak of 600w, so I seriously doubt a 120w amp is causing the driver to run out of xmax, especially far above the tuning frequency.



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Yes, taking out the amp will affect the box tuning.
However the bigger point is that if you increase amp power you will swap clipping for driver damage.

As I frequently point out driver power specs are universally overstated. Loudspeaker drivers, even the best of them, are much more frail than you might imagine.

If you fire up a 150 watt incandescent light bulb, see how long you can keep your hand on it. Well that is the power going into a tight gap space. Now use common sense.

As far as driver excursion is concerned it is lowest at tuning and rises above tuning and a lot below tuning. Don't assume you won't exceed x-max above tuning, as you likely will.

The bottom line is that if you really want to add spl. then the way to do it, is to add drivers. This spreads power between VCs.

There is a reason I use four 10" drivers with Fs of 20 Hz rather then two 15" with the same Fs. The radiating area is identical, but dynamic thermal compression is much reduced because heat dissipation is increased.

 

[j_garcia]

I think most of us have said this already, you need a better sub not a new design of one that can't do what you want it to.

 

[TLS Guy]

Please remind me of what Dayton driver is in that sub. There is a good chance I have already modeled it. If not I will. Then I can tell you exactly the maximum power and output with frequency.

 

[lovinthehd]

Remember my previous post concerning my sub being unable to exceed 105dB without what I believed to be the driver running out of xmax? Turns out that sound I was hearing was clipping. I plugged the amps power rating along with the drivers sensitivity into the max spl calculator, turns out 120w gets me 100dB at 9'. It's near a wall so I can add 3dB. Parts express claims the amp can deliver an instantaneous peak power rating of 240w, so that again, adds 3dB.

A repeated test showed the sub can hit 106dB peak, but only during a CEA 2010 burst. Play a continuous sine wave and it begins making the clipping noise after about half a second.

The drivers RMS rating is 150w. That means it can handle a program of 300w and a peak of 600w, so I seriously doubt a 120w amp is causing the driver to run out of xmax, especially far above the tuning frequency.



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LOL remember me asking you to remove your tapatalk ad? No, don't really remember your other post's details. I think you should model the sub, or take TLSGuy up on his offer if you provide the details....

I'd just build a new sub to do what you want....

 

[yepimonfire]

Please remind me of what Dayton driver is in that sub. There is a good chance I have already modeled it. If not I will. Then I can tell you exactly the maximum power and output with frequency.

It's a 15" GRS poly subwoofer. I can no longer find the driver or T/S parameters on parts express.

The cabinet is approximately 4.0 cu feet and the port is tuned to 23hz.

If you don't think it can handle the extra power, I will just exercise restraint with the volume control until I can either upgrade or add a second sub.

 

[TLS Guy]

It's a 15" GRS poly subwoofer. I can no longer find the driver or T/S parameters on parts express.

The cabinet is approximately 4.0 cu feet and the port is tuned to 23hz.

If you don't think it can handle the extra power, I will just exercise restraint with the volume control until I can either upgrade or add a second sub.

I can't find it either and its not in the Bass Box data base. My view is that I would treat that driver with great care. I doubt it will take much abuse, looking at what GRS have on offer.

 

[yepimonfire]

Yes, taking out the amp will affect the box tuning.
However the bigger point is that if you increase amp power you will swap clipping for driver damage.

As I frequently point out driver power specs are universally overstated. Loudspeaker drivers, even the best of them, are much more frail than you might imagine.

If you fire up a 150 watt incandescent light bulb, see how long you can keep your hand on it. Well that is the power going into a tight gap space. Now use common sense.

As far as driver excursion is concerned it is lowest at tuning and rises above tuning and a lot below tuning. Don't assume you won't exceed x-max above tuning, as you likely will.

The bottom line is that if you really want to add spl. then the way to do it, is to add drivers. This spreads power between VCs.

There is a reason I use four 10" drivers with Fs of 20 Hz rather then two 15" with the same Fs. The radiating area is identical, but dynamic thermal compression is much reduced because heat dissipation is increased.

Would 3-4 smaller subs (like the sub 1200) or placed within 1/4 wavelength do a better job at achieving a high spl? The difference in the f3 between the two is a mere 2hz. I just figured the sub 1500 could likely handle the extra power, I'm really only looking for an extra 5dB, and only during brief peaks.

I realize there are better subs than the daytons, however, as I've previously stated, outside of a commercial grade cinema subwoofer, getting 115dB without distortion at the listening position is going to require multiple subs, a couple of svs or other comparable subwoofers is currently out of my budget range. I get a nearly flat frequency response at the listening position with the sub 1500, and I am satisfied with the sound in both movies and music, the only thing I'm lacking is spl.

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[TLS Guy]

Would 3-4 smaller subs (like the sub 1200) or placed within 1/4 wavelength do a better job at achieving a high spl? The difference in the f3 between the two is a mere 2hz. I just figured the sub 1500 could likely handle the extra power, I'm really only looking for an extra 5dB, and only during brief peaks.

I realize there are better subs than the daytons, however, as I've previously stated, outside of a commercial grade cinema subwoofer, getting 115dB without distortion at the listening position is going to require multiple subs, a couple of svs or other comparable subwoofers is currently out of my budget range. I get a nearly flat frequency response at the listening position with the sub 1500, and I am satisfied with the sound in both movies and music, the only thing I'm lacking is spl.

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If you put another sub in close proximity, you will gain 6 db, as long as the other sub has the same output or more as the other sub.

 

[William Lemmerhirt]

If you really like the 1500, I'd see what you can do to get a second one. It's 200 bucks. There are definitely better ones out there but it's hard to beat the daytons on price. If you're strapped, I'd try and go that way.
https://www.parts-express.com/dayton-audio-sub-1500-15-150-watt-powered-subwoofer--300-634
If you're thinking diy, the 1500 is the same price as an ultimax driver alone.

 

[lovinthehd]

If you really like the 1500, I'd see what you can do to get a second one. It's 200 bucks. There are definitely better ones out there but it's hard to beat the daytons on price. If you're strapped, I'd try and go that way.
https://www.parts-express.com/dayton-audio-sub-1500-15-150-watt-powered-subwoofer--300-634
If you're thinking diy, the 1500 is the same price as an ultimax driver alone.

But that is not the ultimax driver in the 1500....but starting with an ultimax driver and building a suitable box would be a better way to go for the OP's goals IMO.

 

[William Lemmerhirt]

But that is not the ultimax driver in the 1500....but starting with an ultimax driver and building a suitable box would be a better way to go for the OP's goals IMO.

Yes I do know that's not an ultimax driver in the sub series, and that's kind of why I started going down that road. The Dayton subs are good bang for the buck, but the "sub" series isn't going to do what he wants. Not with one anyway. IMO it's diy, or save up for more potent ID subs.

 

[lovinthehd]

Yes I do know that's not an ultimax driver in the sub series, and that's kind of why I started going down that road. The Dayton subs are good bang for the buck, but the "sub" series isn't going to do what he wants. Not with one anyway. IMO it's diy, or save up for more potent ID subs.

Yeah, I figured you knew....just thot I'd roll it down the road a bit.

 

[William Lemmerhirt]

Yeah, I figured you knew....just thot I'd roll it down the road a bit.

Appreciate that. Some times I don't know.

 

[yepimonfire]

Would a single ultimax comfortably hit 115dB though?

I see PE has a 3 cu foot cabinet, which would result in an f3 of 35hz. Seeing as it's a sealed box, could this be equalized down to 20hz or lower with enough power behind it?

If I did do the diy route, flat packs would be the way to go, as I have don't have the time to build one from scratch.