Subwoofer recommendation help av/hifi

[10PSPMemSticksForMiku2007]

I've spent a lot of time looking at subwoofer drivers and simming designs recently. If you're willing to make a large enough cabinet I've found it really hard to beat the GRS 12SW4-HE for solid performance around ~20hz. One is not that impressive, but they're 65 bucks so you can easily get 8 of them in a big box. I have not been able to find a driver around ~$500 that beats 8 of these.

My plan for now is to have a 25 cubic foot box with 8 of them in a 6th order bandpass. Two groups of 4 with powerd with a stereo amp rated for 4 ohms.

 

[DVDdoug]

If you are building a speaker I always recommend speaker design software. (WinISD is free.) It will help you to optimize a sealed or ported cabinet and it will model the performance. If you're using a smaller than optimum sealed cabinet it will give you an idea of what kind of EQ you need (not including acoustic room modes).

The software will also allow you to virtually compare different drivers in the same or similar box before you buy.

A random speaker in a random ported box is more likely to turn-out very-bad than in a random sealed box but as long as you have the Thiele-Small parameters for the driver you can model either one first.

A sealed design will usually go lower with EQ* as long as you have enough amplifier power, and I think you do. You probably won't get the SPL as the JBL but it should be enough for a home environment.

This post shows the generalized trade-offs between sealed and ported designs. You can fool-around (virtually first) with box size or port dimensions to create a 1-2dB boost (or more) before the cutoff. That can extend the -3dB cutoff lower and the slight bump may not be objectional or even not noticeable (or maybe even desirable).



* Ported speakers usually go lower but they drop-off more steeply after the cut-off frequency. If you try to compensate by boosting the deep bass, the woofer ends-up flopping around uncontrollably without putting-out much-more sound. Active home subwoofers are frequently sealed and EQ'd internally for very deep bass. Pro subs used live and dance clubs are often ported, highly efficient, and tuned to go down to around 40Hz (that's about the lowest note on a standard bass guitar). It's a set of compromises that can fill a large venue with bass you can feel in your body.

 

[Flaesh]

(I have 3 )

I don't understand anything. Make or buy smaller boxes if there's no room for 4645.

 

[Chrispy]

It's an upgrade when you have more control of the system and also you can use a better mic

Just not the normal meaning of firmware/software upgrades. There have been some Denon avrs that significantly had added features with such....just not the one you mentioned.

 

[10PSPMemSticksForMiku2007]

OP, what are your requirements for box size, frequency response, and budget? Are you set on a sealed design?

 

[Oli.mac]

If you are building a speaker I always recommend speaker design software. (WinISD is free.) It will help you to optimize a sealed or ported cabinet and it will model the performance. If you're using a smaller than optimum sealed cabinet it will give you an idea of what kind of EQ you need (not including acoustic room modes).

The software will also allow you to virtually compare different drivers in the same or similar box before you buy.

A random speaker in a random ported box is more likely to turn-out very-bad than in a random sealed box but as long as you have the Thiele-Small parameters for the driver you can model either one first.

A sealed design will usually go lower with EQ* as long as you have enough amplifier power, and I think you do. You probably won't get the SPL as the JBL but it should be enough for a home environment.

This post shows the generalized trade-offs between sealed and ported designs. You can fool-around (virtually first) with box size or port dimensions to create a 1-2dB boost (or more) before the cutoff. That can extend the -3dB cutoff lower and the slight bump may not be objectional or even not noticeable (or maybe even desirable).



* Ported speakers usually go lower but they drop-off more steeply after the cut-off frequency. If you try to compensate by boosting the deep bass, the woofer ends-up flopping around uncontrollably without putting-out much-more sound. Active home subwoofers are frequently sealed and EQ'd internally for very deep bass. Pro subs used live and dance clubs are often ported, highly efficient, and tuned to go down to around 40Hz (that's about the lowest note on a standard bass guitar). It's a set of compromises that can fill a large venue with bass you can feel in your body.

As I mentioned before the driver I'm considering is the Dayton ultimax 12 and the recommended sealed boxes are small and ideal for my application.
I have more than enough control with the eq I'm using.
So this driver should fit the bill provided I get the box spot on

 

[Oli.mac]

OP, what are your requirements for box size, frequency response, and budget? Are you set on a sealed design?

I'm not set on sealed design as much as I'm set on what's best for the specific drivers I'm looking to use. As mentioned the ultimax 12 is best suited to a sealed cab and that works for me as I can EQ down low. .the other thing is ideally I want the boxes small as possible without a massive drop in output.
My current 4645c is ported and obviously huge but I never even get close to pushing that driver so 2 12s with EQ should be plenty still on the power I have available

 

[levimax]

I'm not set on sealed design as much as I'm set on what's best for the specific drivers I'm looking to use. As mentioned the ultimax 12 is best suited to a sealed cab and that works for me as I can EQ down low. .the other thing is ideally I want the boxes small as possible without a massive drop in output.
My current 4645c is ported and obviously huge but I never even get close to pushing that driver so 2 12s with EQ should be plenty still on the power I have available

When chosing or designing sub woofers, Hoffmans Iron Law makes things hard https://techtalk.parts-express.com/forum/tech-talk-forum/13916-hoffman-s-iron-law. Regarding sealed vs ported I like sealed, especially for DIY, because the design and construction is MUCH easier to execute successfully and they tend to have better time domain behavior and are easier to accurately measure and integrate. The down side is 6 dB to 10 dB lower effieciency which means 2 sealed subs to equal one ported sub all things bring equal which they never are.

 

[10PSPMemSticksForMiku2007]

I'm not set on sealed design as much as I'm set on what's best for the specific drivers I'm looking to use. As mentioned the ultimax 12 is best suited to a sealed cab and that works for me as I can EQ down low. .the other thing is ideally I want the boxes small as possible without a massive drop in output.
My current 4645c is ported and obviously huge but I never even get close to pushing that driver so 2 12s with EQ should be plenty still on the power I have available

If you've already chosen the drivers this greatly simplifies the process because all you have to do is choose the dimensions of your box and whether to port it.

Anyway, you should download WinISD and enter the parameters of your chosen drivers. From there it has a very easy wizard to simulate a speaker cabinet of any dimensions and tuning you want. Make sure to go to the advanced tab and check "simulate inductance" and "spl limited by excursion." Then you can adjust the volume and input voltage. Finally, check the port dimensions if any, port air velocity, cone excursion, etc. Then you can build your box with a ballpark understanding of what it will do. Hopefully you can find a performance level that you are satisfied with in a box volume you are satisfied with.

Here are some comparisons. These are all with 600 watts input. I am using manufacturer specs for these drivers but look for independent measurements, especially klippel, if you can.

The red line is the 25 cuft box with 8 GRS 12SW4HE I mentioned earlier, just sealed and not a bandpass.

The Ultimax II sealed in 1.5 cuft is dark blue, light blue is same ported to 20hz. The ported alignment is just for show because the port would need to be too huge for this box size.

The JBL you have now, 8 cuft with 25hz port, is green. The pink line is the JBL sealed in 1.5 cuft. The Ultimax may have a little more headroom with its xmax but the low frequency performance is very similar and the JBL has so much stronger midbass.
This would be a box with inside dimensions of 18x12x12 inches.

I question whether it makes sense to buy new drivers just to make one of the box dimensions less than 18" when you already have good drivers. Is it really that big a deal to have your subwoofer be 18x12x12 rather than 14x14x14?

Another thing I've observed simming these sealed and vented alignments is their total low frequency performance is very limited by box size. With the 1.5 cuft sealed box you're losing 12db output at 30hz and more below. (If I turn off xmax limitation, winisd calculates the JBL in 1.5cuft needs 20,000 watts to equal the 8xGRS with 600 watts at 20hz).

 

[Oli.mac]

If you've already chosen the drivers this greatly simplifies the process because all you have to do is choose the dimensions of your box and whether to port it.

Anyway, you should download WinISD and enter the parameters of your chosen drivers. From there it has a very easy wizard to simulate a speaker cabinet of any dimensions and tuning you want. Make sure to go to the advanced tab and check "simulate inductance" and "spl limited by excursion." Then you can adjust the volume and input voltage. Finally, check the port dimensions if any, port air velocity, cone excursion, etc. Then you can build your box with a ballpark understanding of what it will do. Hopefully you can find a performance level that you are satisfied with in a box volume you are satisfied with.

Here are some comparisons. These are all with 600 watts input. I am using manufacturer specs for these drivers but look for independent measurements, especially klippel, if you can.

The red line is the 25 cuft box with 8 GRS 12SW4HE I mentioned earlier, just sealed and not a bandpass.

The Ultimax II sealed in 1.5 cuft is dark blue, light blue is same ported to 20hz. The ported alignment is just for show because the port would need to be too huge for this box size.

The JBL you have now, 8 cuft with 25hz port, is green. The pink line is the JBL sealed in 1.5 cuft. The Ultimax may have a little more headroom with its xmax but the low frequency performance is very similar and the JBL has so much stronger midbass.
This would be a box with inside dimensions of 18x12x12 inches.

I question whether it makes sense to buy new drivers just to make one of the box dimensions less than 18" when you already have good drivers. Is it really that big a deal to have your subwoofer be 18x12x12 rather than 14x14x14?

Another thing I've observed simming these sealed and vented alignments is their total low frequency performance is very limited by box size. With the 1.5 cuft sealed box you're losing 12db output at 30hz and more below. (If I turn off xmax limitation, winisd calculates the JBL in 1.5cuft needs 20,000 watts to equal the 8xGRS with 600 watts at 20hz).
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Mate this is super helpful.. I have done exactly this and I'm glad to see we have the same results.

My reason behind not using the 18s in a small sealed box was from what I concluded is that they would need way more power than the 600w per channel I have so for me using 2 x 12 ultimax subs will still be plenty loud enough for my application and power requirements compared to my single 18 4645c that I have at the moment.. unless I'm missing something... Are you in the UK ?
Would love to have a discussion with you

 

[10PSPMemSticksForMiku2007]

I'm not in the UK but I can try to answer questions. With those sims I see no advantage of the Dayton over the JBL in sensitivity in that box size. With that kind of performance you definitely want more than one box and do your best to make sure they sum well.