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Seeking Advice for More ‘Woofage’ - Page 2

post #31 of 70
Quote:
Originally Posted by Axel View Post

shady, thank you for posting the charts and also providing an analysis. I would like to better understand how to read the charts. From what I understand you were comparing MAX PASS SPL levels at different frequency points. Here the criteria seems 'the higher the better', with 6 dB being a doubling is perceived loudness. Correct so far? What else is of importance? What about the color coding?   
I would greatly appreciate if you could provide a bit more insight here.



My SVS Ultras have the earlier BASH amps. I believe they have some 700 W or maybe 800 W, not 1000 W, what Ricci measured. Is there a way to assess in what way this would reflect in above charts?

_____
Axel 

You are correct about higher numbers being better, and 6 dB being a doubling of loudness. Regarding the color coding, green means the sub stays relatively clean at it's highest output level. Yellow means that is the output level the sub can reach before distortion goes over permitted CEA2010 levels standards. Red is simply how loud a sub can get when trying to play back a certain frequency including any distortion.

One thing I should add is that to fully double the loudness of a sub by adding another (basically adding 6 dB), you have to co-locate the subs, by that I mean you have to place them together, either right next to each other or right on top of each other. The further apart they are placed, the less their total output will be summed at your listening position, until the second sub can only contribute 3 dB. Spacing the subs does bring other advantages though. The room acoustics can cause peaks and nulls in the frequency response, and by co-locating the subs, you are reinforcing the peaks and nulls. Spacing them apart can tame the peaks and shore up the nulls, which is many cases is better than simply increasing total output. You have to take care of where you place the subs for the optimal placement though, they can't simply be set apart for the best result on the frequency response. Each placement has to be measured.

As for the SVS subs, there wouldn't be a tremendous difference between the BASH amps and the Sledge amps. Maybe a couple dB here and there, but the comparison between them and the sealed 18"s would still hold.
post #32 of 70
Thread Starter 
Quote:
Originally Posted by shadyJ View Post

Quote:
Originally Posted by Axel View Post

shady, thank you for posting the charts and also providing an analysis. I would like to better understand how to read the charts. From what I understand you were comparing MAX PASS SPL levels at different frequency points. Here the criteria seems 'the higher the better', with 6 dB being a doubling is perceived loudness. Correct so far? What else is of importance? What about the color coding?   
I would greatly appreciate if you could provide a bit more insight here.



My SVS Ultras have the earlier BASH amps. I believe they have some 700 W or maybe 800 W, not 1000 W, what Ricci measured. Is there a way to assess in what way this would reflect in above charts?

_____
Axel 

You are correct about higher numbers being better, and 6 dB being a doubling of loudness. Regarding the color coding, green means the sub stays relatively clean at it's highest output level. Yellow means that is the output level the sub can reach before distortion goes over permitted CEA2010 levels standards. Red is simply how loud a sub can get when trying to play back a certain frequency including any distortion.

One thing I should add is that to fully double the loudness of a sub by adding another (basically adding 6 dB), you have to co-locate the subs, by that I mean you have to place them together, either right next to each other or right on top of each other. The further apart they are placed, the less their total output will be summed at your listening position, until the second sub can only contribute 3 dB. Spacing the subs does bring other advantages though. The room acoustics can cause peaks and nulls in the frequency response, and by co-locating the subs, you are reinforcing the peaks and nulls. Spacing them apart can tame the peaks and shore up the nulls, which is many cases is better than simply increasing total output. You have to take care of where you place the subs for the optimal placement though, they can't simply be set apart for the best result on the frequency response. Each placement has to be measured.

As for the SVS subs, there wouldn't be a tremendous difference between the BASH amps and the Sledge amps. Maybe a couple dB here and there, but the comparison between them and the sealed 18"s would still hold.

 

 

Thanks, shady. So looking at the Rizzi charts again, I am not quite sure I understand the color coding quite yet: I guess the color you would like to see is green for as low as possible. This would mean the SVS perform much better, because they reach 16 Hz before they turn yellow, while the SI or DA turn at 50 / 40 Hz. However, if I look at the output levels the SI and DA are a lot higher than the SVS for a given frequency. A little help, please? smile.gif

____

Axel 

post #33 of 70
delete.
post #34 of 70
You might check out the DIY projects on Data.. Not all the DIY are aiming at optimal because of enclosure size or power involved but it’ll give you a idea of what can be achieved. Not a absolute, but a good look-see. I deduce you have most likely seen this because of your post count.



http://www.data-bass.com/systems
post #35 of 70
Quote:
Originally Posted by Axel View Post


Thanks, shady. So looking at the Rizzi charts again, I am not quite sure I understand the color coding quite yet: I guess the color you would like to see is green for as low as possible. This would mean the SVS perform much better, because they reach 16 Hz before they turn yellow, while the SI or DA turn at 50 / 40 Hz. However, if I look at the output levels the SI and DA are a lot higher than the SVS for a given frequency. A little help, please? smile.gif
____
Axel 

Green means the subwoofer will not generate enough distortion to go over CEA2010 limits no matter how hard you push it. Yellow means the sub can be driven to distort past CEA2010 limits, and the number in the yellow block is how loud it gets before going past acceptable distortion limits.

You can't judge a subwoofer by how much distortion it generates at the maximum edges of its performance alone, which is what the CEA2010 numbers are. For an example, Subwoofer X might exhibit much higher distortion at 20 hz when pressed to its limits than Subwoofer Y, but if the limits of Subwoofer X lay at somewhat distorted 130 dB and Subwoofer Y will only play 20 Hz up to 100 dB, chances are Subwoofer X can play 20 Hz very cleanly at and beyond 100 dB. This is where the distortion charts come in handy.

Lets take a look at some distortion charts, here are some THD (total harmonic distortion) charts from the PB12 NSD and the Funk Audio 18.0:

As their name implies, these are measurements of the total amount of harmonic distortion at different volume levels, with the highest distortion measurements taken from the maximum output levels these subs can possibly achieve. You would think from just glancing at those charts that the PB12 seems to be a cleaner sub above 20 Hz, but what you have to look at is the output level these measurements were taken at. The loudest sweep the PB12 can achieve is 110 dB, it can not run a sweep louder than that. The sweeps which the Funk 18.0 is being run at are start at 115 dB, because its distortion at 110 dB is so low it is probably too insignificant to include in this data set. So you can see the Funk sub is quite a bit more powerful, although it will generate more distortion above 30 hz at the edges of it performance than the PB12. However, for the same loudness levels it is going to play cleaner than the PB12.
post #36 of 70
Thread Starter 
Quote:
Originally Posted by steve nn View Post

You might check out the DIY projects on Data.. Not all the DIY are aiming at optimal because of enclosure size or power involved but it’ll give you a idea of what can be achieved. Not a absolute, but a good look-see. I deduce you have most likely seen this because of your post count.



http://www.data-bass.com/systems

 

Thanks steve! Yep, I already saw this. Very, very cool builds out there. However, with my DIY limitations (no full blown wood workshop, lack of skills with the sub modeling tools, etc.), I need to stick to a proven of design with minimal/no need for cutting, routing, etc. That's why EricH's flat packs are so appealing to me.... but also why I have also not quite ruled out the manufactured sub route (Captivators or SubMersives) yet.

 

____

Axel

post #37 of 70
Quote:
Originally Posted by Axel View Post

Thanks steve! Yep, I already saw this. Very, very cool builds out there. However, with my DIY limitations (no full blown wood workshop, lack of skills with the sub modeling tools, etc.), I need to stick to a proven of design with minimal/no need for cutting, routing, etc. That's why EricH's flat packs are so appealing to me.... but also why I have also not quite ruled out the manufactured sub route (Captivators or SubMersives) yet.

____
Axel

Hey I totally understand! When it comes to subs I’m Bi, no doubt about it! wink.gif
post #38 of 70
Subs? Bi? Well, it is pride week rolleyes.gif
post #39 of 70
Great explanation shady. Just have one counter.

Double your displacement (i.e. 2 identical subs vs 1) while using the same power = +3db

Double your power (i.e. 1000watts vs 500watts) while using the same sub(s) = +3db

Double your displacement and power (i.e. 2 subs with 1000watts vs 1 sub with 500watts) = +6db

However!

It takes 10db to double perceived volume. Here is a link for a quick reference.
post #40 of 70
Here is another good reference link that gets a bit more technical...
post #41 of 70
Quote:
Originally Posted by lovinthehd View Post

Subs? Bi? Well, it is pride week rolleyes.gif

Ha ha Lol.. biggrin.gifbiggrin.gif


post #42 of 70
Thread Starter 

shady, popalock et al., thank you so much for your educational posts - this has been very helpful for me!

 

I think the take away from here is that I need to further explore the 'multiple DIY 18" flat box' route. I'll probably start a newbie thread in the DIY sub forum to learn about building the cabinets, selecting amps and DSPs, etc.

 

Thanks again everybody! Much appreciated!

____

Axel

post #43 of 70
No prob!

Shady did all the work...lol

Here is a good starting point...

http://www.avsforum.com/t/1461175/first-build-octo-si-18s-with-flat-packs/0_100
post #44 of 70
Quote:
Originally Posted by popalock View Post

It takes 10db to double perceived volume. Here is a link for a quick reference.

The problem with that is it is a very subjective metric. Some might say 10 dB is a doubling of loudness, but others don't. Even your own link draws attention to this:
Quote:
Recent research by Richard M. Warren, on the other hand leads to a level difference of only 6 dB.
and further on...
Quote:
When known experimental biases were eliminated, half loudness was equal to half sound pressure level (−6 dB) from 45 to 90 dB.

I might be biased by the knowledge of the amplitudes, but a 10 dB boost sounds like more than a mere doubling to my ears as well. I suppose I should try it blind sometime.
post #45 of 70
True true...
post #46 of 70
Quote:
Originally Posted by Axel View Post

shady, popalock et al., thank you so much for your educational posts - this has been very helpful for me!

 

I think the take away from here is that I need to further explore the 'multiple DIY 18" flat box' route. I'll probably start a newbie thread in the DIY sub forum to learn about building the cabinets, selecting amps and DSPs, etc.

 

Thanks again everybody! Much appreciated!

____

Axel

What's your budget (sorry if I missed)? Do you have the room for 8-16 subs? If not...

 

Have you looked at this:

 

http://jtrspeakers.com/home-audio/orbit-shifter-lfu/

 

These won't get you reference at 10hz, but will likely get you to 15hz or so if I had to guess. These are massive output subs.

 

I'm all for striving for low extension, but for larger rooms it starts to get exponentially more difficult because you don't get the benefit of room gain.

 

IMO, to beat the performance of the OS's, you'll need to go all in with the sealed multiples. If you only go half way, I think you're better off with the OS, as reference at 15hz will sound/feel better than non-reference at 15hz but more output (compared to OS) at 10hz.

 

So go Big or go OS. wink.gif

post #47 of 70
Everyone has room for 8 sealed 18's... They just don't know it.

tongue.gif

I love the OS though. I recommend it whole heartedly and I think it is one of, if not the, highest performing subs on the market...
post #48 of 70
Thread Starter 
Quote:
Originally Posted by popalock View Post

No prob!

Shady did all the work...lol

Here is a good starting point...

http://www.avsforum.com/t/1461175/first-build-octo-si-18s-with-flat-packs/0_100

 



This thread is indeed a great read - lots of very useful information and very inspiring.

_____

Axel

post #49 of 70
Thread Starter 
Quote:
Originally Posted by dominguez1 View Post

Quote:
Originally Posted by Axel View Post

shady, popalock et al., thank you so much for your educational posts - this has been very helpful for me!

 

I think the take away from here is that I need to further explore the 'multiple DIY 18" flat box' route. I'll probably start a newbie thread in the DIY sub forum to learn about building the cabinets, selecting amps and DSPs, etc.

 

Thanks again everybody! Much appreciated!

____

Axel

What's your budget (sorry if I missed)? Do you have the room for 8-16 subs? If not...

 

Have you looked at this:

 

http://jtrspeakers.com/home-audio/orbit-shifter-lfu/

 

These won't get you reference at 10hz, but will likely get you to 15hz or so if I had to guess. These are massive output subs.

 

I'm all for striving for low extension, but for larger rooms it starts to get exponentially more difficult because you don't get the benefit of room gain.

 

IMO, to beat the performance of the OS's, you'll need to go all in with the sealed multiples. If you only go half way, I think you're better off with the OS, as reference at 15hz will sound/feel better than non-reference at 15hz but more output (compared to OS) at 10hz.

 

So go Big or go OS. wink.gif

 

I like your comment about 'going only half way'. It shows nicely how very crazy we are here. Half way still means 4x or 8x 18". That said, my wife suggested last night in no uncertain terms frown.gif that I should proceed in smaller steps. So I will probably start with 4x smile.gif.

 

I have read a lot of good things about the OS. Since I want to have at least 2 subs for smoother room characteristics, we are talking over 6 grand with shipping, which is a bit more than I currently like to spend.

_____

Axel 

post #50 of 70
Quote:
Originally Posted by Axel View Post

I like your comment about 'going only half way'. It shows nicely how very crazy we are here. Half way still means 4x or 8x 18". That said, my wife suggested last night in no uncertain terms frown.gif that I should proceed in smaller steps. So I will probably start with 4x smile.gif .

I have read a lot of good things about the OS. Since I want to have at least 2 subs for smoother room characteristics, we are talking over 6 grand with shipping, which is a bit more than I currently like to spend.
_____
Axel 

You know, if you got eight sealed 18"s and made two stacks, you could have two 18" woofer line arrays. It would be simpler to configure because an array is considered a single source, so it would be like one sub, so you functionally only need to room EQ two subs that way.
post #51 of 70
Thread Starter 
Quote:
Originally Posted by shadyJ View Post


You know, if you got eight sealed 18"s and made two stacks, you could have two 18" woofer line arrays. It would be simpler to configure because an array is considered a single source, so it would be like one sub, so you functionally only need to room EQ two subs that way.

Not quite (8) subs, but I plan to co-locate my (4) subs: 2 each in front and rear. If I have not sold my SVS Ultra by then (I have listed them in the Classified), I may try to integrate them in my setup: 2 Ultras in the rear and 4 flat packs in front.

 

 

 

BTW, I have started a new thread in the DIY section to get educated on amps and wiring.

 

______

Axel

post #52 of 70
Quote:
Originally Posted by Axel View Post

 

That said, my wife suggested last night in no uncertain terms frown.gif that I should proceed in smaller steps. So I will probably start with 4x smile.gif.

 

_____

Axel 

I saw in your build thread you're going with SI's.

 

Given to what you said above about the WAF, I'd go premium on the drivers. The SI's will give you the performance you are looking for but at the cost of a 2x to 3x number of drivers compared to higher end drivers (in order to get the low end performance). If your limited with your first sub installment, and subsequent installments might have to go to the Supreme Court for approval, I'd go for the premium drivers like:

 

UXL-18

FTW-21

LMS Ultra 18

RE Audio XXX 18

 

What are you looking to spend?

post #53 of 70
Thread Starter 
Quote:
Originally Posted by dominguez1 View Post

Quote:
Originally Posted by Axel View Post

 

That said, my wife suggested last night in no uncertain terms frown.gif that I should proceed in smaller steps. So I will probably start with 4x smile.gif.

 

_____

Axel 

I saw in your build thread you're going with SI's.

 

Given to what you said above about the WAF, I'd go premium on the drivers. The SI's will give you the performance you are looking for but at the cost of a 2x to 3x number of drivers compared to higher end drivers (in order to get the low end performance). If your limited with your first sub installment, and subsequent installments might have to go to the Supreme Court for approval, I'd go for the premium drivers like:

 

UXL-18

FTW-21

LMS Ultra 18

RE Audio XXX 18

 

What are you looking to spend?

 

 

A LMS is about $900 from what I have seen. So with cabinet, amp, etc. one gets quickly into ID pricing territory.

 

While I have not set a firm budget, 4 grand is probably my limit for this upgrade.

_____

Axel

post #54 of 70
2 subs get's you around 75-80 % of what you want for good bass in the room. 4 subs and your are about at 100% there provide they are appropiate for the room in terms of spl and low end performance. 8 subs increase headroom without much improvement in SQ or performance and, the return on investment is very little with the extra 4 subs. For THX levels a system need to reach 115 db for the LF and all speakers comined, 121 db witch is more spl than can be tolerated for very long in most HT. Chasing ghost is not that productive for that size room.
Edited by derrickdj1 - 6/30/13 at 1:10pm
post #55 of 70
More displacement = headroom = lower THD = (insert perceived interpretation here)
post #56 of 70
If you can't get the job done with 4 room appropriate subs, 8 is not going to be a magic fix. If you have 4 room appropriate subs, more headroom and displacement is not needed.
post #57 of 70
Quote:
Originally Posted by derrickdj1 View Post

If you can't get the job done with 4 room appropriate subs, 8 is not going to be a magic fix. If you have 4 room appropriate subs, more headroom and displacement is not needed.

What brand is that?

6db can work miracles in any room.

biggrin.gif
post #58 of 70
Quote:
Originally Posted by Axel View Post

 

 

A LMS is about $900 from what I have seen. So with cabinet, amp, etc. one gets quickly into ID pricing territory.

 

While I have not set a firm budget, 4 grand is probably my limit for this upgrade.

_____

Axel

The UXL-18 is 530 per driver. He is also making the FTW-21 again (although not shown on his website). I paid about $700 each for mine.

 

The UXL-18 is very close to the performance (max SPL) of the LMS Ultra. Above 20hz the UXL has a 1-2 db advantage. Below 20hz, the Ultra has a 1-2db advantage.

 

The FTW-21 should out perform both (max spl) given its displacement.

 

If there is a flatpack that fits these two, you can definitely get under $4K with quads of the UXLs with amps, and pretty close with the FTW-21.

 

The XXX is priced like the Ultra last time I checked and is much more thirsty for power...

post #59 of 70
Quote:
That said, my wife suggested last night in no uncertain terms that I should proceed in smaller steps. So I will probably start with 4x .

That’s a very good start! Knowing what just two good quality 18”s can do, four should get you going very well.
post #60 of 70
Thread Starter 

Quick update: In the meantime, I found a good deal for a pair of JTR Cap S2s. I think they will fit my ‘woofage needs’ quite nicely. So I will put my DIY project on hold for the time being.

 

Again, thanks everybody for all your recommendations and insights. Much appreciated!

_____

Axel

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