Advice First Sub Build

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Hi Guys,
I'm looking to commence my first sub build and was hoping to get some feedback/advice on members experience on similar builds. I'm looking for a small
Dual sub build sealed/radiator. The subs will be to complement a two way setup for 2 channel audio only. Now my listening space is pretty small around 13x13 and real estate is at a premium so I want to get the smallest foot print possible.

I don't need/want subsonic extension I would be more then happy with an f3 of 30hz if possible!? Box size, as small as I can and open to any shape that can help reduce taking what little space I have :) I guess 1f/30L or under enclosure would ideal. I do have rack space so I am open to external amplification so passive/active I don't have a preference. Ultimately looking for quality bottom end to extend out the two ways and given size of room don't need significant SPL either. My budget for drivers and amp/s (excluding cabs)would be around 1,000 give or take abit. I would be really interested in people's experience with
Small enclosure builds? Recommendation on drivers/amp that are suited for very small/small boxes that still can achieve relatively deep bass despite size.

Thanks for listening! Appreciate any experience, feedback you may have!

Peace
 
On your budget, I'd go for...

1x Behringer NU3000DSP iNUKE 3000 Watt Power Amplifier with DSP
1 or 2x Dayton Audio UM10-22 10" Ultimax DVC Subwoofer 2 ohms Per Coil

Spend the rest on measurement gear, silent fan mods, and a really nice cabinet.

Chris


Hey Chris thanks for rely and feedback mate I'll check out the DVC, can you run those in a small cab? I've got a minidsp mic USB somewhere I think, been a while since I used it but think I used it with REW from recollection
 
The MiniDSP mic with REW will do just fine.

The Behringer amp's stock fan is quite loud, but you'd be able to run one or two of those drivers off it without any issues. The built-in DSP means you've got options for active crossovers, delay, EQ etc.

I'd recommend you try WinISD or Hornresp and see what's what when it comes to drivers. When size is a concern, I'd recommend looking for something with a powerful motor and plenty of power handling - you're likely to need to EQ up the bottom end of a small sealed box. The 10" Ultimax gives a Qtc=0.7 in just over half a cubic foot, so you might squeeze two in there if you want a bit more output at the bottom end.

Chris
 
The MiniDSP mic with REW will do just fine.

The Behringer amp's stock fan is quite loud, but you'd be able to run one or two of those drivers off it without any issues. The built-in DSP means you've got options for active crossovers, delay, EQ etc.

I'd recommend you try WinISD or Hornresp and see what's what when it comes to drivers. When size is a concern, I'd recommend looking for something with a powerful motor and plenty of power handling - you're likely to need to EQ up the bottom end of a small sealed box. The 10" Ultimax gives a Qtc=0.7 in just over half a cubic foot, so you might squeeze two in there if you want a bit more output at the bottom end.

Chris




Thanks again for feedback something less then cubic feet is what I'm looking for would be great to be able to hit a solid 30hz :)
 
Some random thoughts on this:

30Hz in a 13x13ft room might be harder than you think.

With due respect to Chris, everything about the driver he pointed out screams Car Audio - which along with the 3000W amp might be serious overkill for the cited application.

My personal experience with small subs is the CSS SDX7 in approx 1 cu ft sealed, and 50 -100 plate amps - works very well in a much larger room than 169 sq ft

There must be at least a dozen competent drivers in the 8-10" range that would be more than sufficient to the task, and the Daytons are very well respected.

I generally like to avoid installing the amp in the same enclosure as the driver, but if space is very limited, that might be your best option - just be sure to seal off a separate section of the enclosure for the amp. As for power - once again, keeping the application in mind, I think anything more than 300W would be superfluous, and again using PE / Dayton as an example, there are lots of options in the less than $300 price range .
 
Hi,

For sure 3000W is over egging the pudding, and asking for trouble.

This is more than plenty :
Behringer NU1000DSP iNUKE 1000 Watt Power Amplifier with DSP

If you want small, good car subs are the place to go to.
Go sealed, and use the DSP for room EQ and extending
the bass to whatever the sub and room can support.

Picking a driver and box intended to be actively EQ'd
is very different to choosing the same for no EQ.

rgds, sreten.

WinISDpro can be very useful for the modelling.
 
Some random thoughts on this:

30Hz in a 13x13ft room might be harder than you think.

With due respect to Chris, everything about the driver he pointed out screams Car Audio - which along with the 3000W amp might be serious overkill for the cited application.

My personal experience with small subs is the CSS SDX7 in approx 1 cu ft sealed, and 50 -100 plate amps - works very well in a much larger room than 169 sq ft

There must be at least a dozen competent drivers in the 8-10" range that would be more than sufficient to the task, and the Daytons are very well respected.

I generally like to avoid installing the amp in the same enclosure as the driver, but if space is very limited, that might be your best option - just be sure to seal off a separate section of the enclosure for the amp. As for power - once again, keeping the application in mind, I think anything more than 300W would be superfluous, and again using PE / Dayton as an example, there are lots of options in the less than $300 price range .




Thanks for your feedback mate, I assumed somewhere between 200-400w depending on how hard the speaker was to drive would be around right. I really only want to dial in enough to subtly give the shelves some bottom end to give me of presence of a 3 way, reaching close to 30 would be nice but I don't need it at vibrate house levels :)
 
Hi,

For sure 3000W is over egging the pudding, and asking for trouble.

This is more than plenty :
Behringer NU1000DSP iNUKE 1000 Watt Power Amplifier with DSP

If you want small, good car subs are the place to go to.
Go sealed, and use the DSP for room EQ and extending
the bass to whatever the sub and room can support.

Picking a driver and box intended to be actively EQ'd
is very different to choosing the same for no EQ.

rgds, sreten.

WinISDpro can be very useful for the modelling.


Sreten - thanks for feedback, when you say looking for driver box intended for EQ, what exactly am I looking for to make it suitable for EQ?
 
I was also looking at round shapes for enclosure, now I've seen a lot of sono builds, how to you think 3/8 maple ply drum she'll would go? I know that 3/8 is relatively thing compared to a box design but I would have thought that a circle would distribute force more effectively therefore maybe it's a thought? Anyone seen/heard of cylinders of ply being used for build?
 
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Round shapes do offer something in the strength department but it's all relative. The inside of the box is still exposed to the same modal behaviour when wavelengths get smaller, is your cylinder long and pipe like?

Round enclosures are also often associated with external qualities that suit middle/higher frequency performance that likely won't apply to a sub box.
 
Round shapes do offer something in the strength department but it's all relative. The inside of the box is still exposed to the same modal behaviour when wavelengths get smaller, is your cylinder long and pipe like?

Round enclosures are also often associated with external qualities that suit middle/higher frequency performance that likely won't apply to a sub box.


Hey Allen, I was more thinking 12inches wide X 16, with say one brace in middle
 
diyAudio Moderator
Joined 2008
Paid Member
Assuming you were going to put the driver in the 'lid', you'd have the potential for a cancellation around 200Hz. Not that this should be a problem but all good below this frequency for what it's worth.

The optimal bracing for a cylinder with solid ends is more likely to be a 'rim' brace, rather than one cross brace which might even compromise the round shapes self strengthening quality by causing it to buckle.
 
Assuming you were going to put the driver in the 'lid', you'd have the potential for a cancellation around 200Hz. Not that this should be a problem but all good below this frequency for what it's worth.

The optimal bracing for a cylinder with solid ends is more likely to be a 'rim' brace, rather than one cross brace which might even compromise the round shapes self strengthening quality by causing it to buckle.


I was thinking internal rings
 
Some random thoughts on this:

30Hz in a 13x13ft room might be harder than you think.

With due respect to Chris, everything about the driver he pointed out screams Car Audio - which along with the 3000W amp might be serious overkill for the cited application.

My personal experience with small subs is the CSS SDX7 in approx 1 cu ft sealed, and 50 -100 plate amps - works very well in a much larger room than 169 sq ft

There must be at least a dozen competent drivers in the 8-10" range that would be more than sufficient to the task, and the Daytons are very well respected.

I generally like to avoid installing the amp in the same enclosure as the driver, but if space is very limited, that might be your best option - just be sure to seal off a separate section of the enclosure for the amp. As for power - once again, keeping the application in mind, I think anything more than 300W would be superfluous, and again using PE / Dayton as an example, there are lots of options in the less than $300 price range .

Not sure why 30Hz in a 13' square room might be difficult.

The Ultimax drivers are designed for high-end home theatre, but can be used in cars etc if the T/S parameters add up. The design allows for lots of clean output from a relatively small driver, even in a very small sealed box. The NU3000DSP has been bench tested and gives 300w/600w/1200w/ch into 8/4/2ohm loads. The NU1000, AFAIK, hasn't been tested, so I wouldn't bother with it when the price gap is that small.

Of course, the downside of a small sealed box is that LF efficiency is through the floor. I'd expect around 10dB of EQ to be applied to get the bottom end up, which means a lot of power is needed. Taking the pair of coils in series for a 4ohm load, we'd get up to 600w from one channel of the NU3000DSP. The sensitivity of the driver is around 85dB @1w. Assuming we'll get that sensitivity at the top of the sub's range (ie, 75dB at the bottom end, where EQ is required), we're looking at around 102dB when the amplifier clips at the bottom end. That certainly isn't excessive. Now, 600w peaks might cause this driver to get a little warm, but given the fairly low LF duty cycle of most music, I don't think it'll be a problem. Cone excursion should be okay too, but that would need simulating.

Given the budget, I'd argue for the extra headroom. According to the speaker voltage test on the other page, it looks like a lot of people aim for around 105dB peaks.

Chris
 
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