Bass Extension (20-30Hz range)

[Halon451]

I'm not sure if I am liking my new JBL Sub12. I want to give it another week or so before taking it back to the store yet again and swapping for another.

I really would like to thank everyone for their great advice in my other threads, and now it's getting down to the nitty gritty of this sub issue. I would love to be able to afford one of those SVS or HSU subs a lot of you keep referring to, but they are simply out of my price range and would be quite a while before I could save up the $$$. Meanwhile, I need to get the JBL back into BB before I lose out on the 30-day return opportunity, so what I am looking at is trying out some of the other BB options.

Question #1: What kind of real-world difference is there in bass extensions from the upper 20's, to the lower 20's? I know that below 20Hz, the audibility becomes irrelevant, but if it can still push air, then you can still feel it - does it comes down to sheer power at this point?

Question#2: I am looking at the Definitive Technology Pro Sub 800 (which is an 8" driver compared to the JBL's 12" driver), but has a lower bass extension (down to 20Hz), which I find appealing, depending on the answer to #1 above). The JBL bottoms out at 25Hz, according to the specs - I have yet to run a sweep test to find out for sure. Does anyone have any experience with Def Tech subs in general, or can anyone provide me with feedback regarding this actual sub?

My budget is already stretched beyond what it was originally for a decent sub - at about $400 or less. Finite. No more - it will not happen. I have to keep within that margin due to a brick wall WAF.

The JBL seems to be sloppier than a sty full of pigs so far, and is all over the place as far as lower end frequency response. I can't dial it in, no matter what I try. Even the old Sony I had before this seemed to perform slightly better. What a disappointment.

At any rate, thanks gentlemen. You guide me well on my ongoing quest for a great HT setup.

 

[j_garcia]

For movies in partiuclar, there is a HUGE difference in a sub that can achieve 20Hz with decent ouput vs one that can only hit 30Hz with decent output. JBL's low to midrange subs are very average as you have found. For that $400 there is a HSU sub that will meet your needs: the VTF-1 which is $399. It also only goes to 25Hz, but it won't be sloppy doing it and it likely won't give you much in the 20Hz range. The SVS PB-10 CAN do 20Hz and is $429; I've owned it and it is an excellent sub.

 

[annunaki]

Question #1: What kind of real-world difference is there in bass extensions from the upper 20's, to the lower 20's? I know that below 20Hz, the audibility becomes irrelevant, but if it can still push air, then you can still feel it - does it comes down to sheer power at this point?

Question#2: I am looking at the Definitive Technology Pro Sub 800 (which is an 8" driver compared to the JBL's 12" driver), but has a lower bass extension (down to 20Hz), which I find appealing, depending on the answer to #1 above). The JBL bottoms out at 25Hz, according to the specs - I have yet to run a sweep test to find out for sure. Does anyone have any experience with Def Tech subs in general, or can anyone provide me with feedback regarding this actual sub?

Getting a sub to play from the upper 20hz-30hz range is one thing, getting it to play down to 20hz accurately and below is completely different. It requires a high quality driver with fairly good excursion capability and a linear motor/suspension out to its excursion envelope. It will also typically require a larger enclosure and vent area to prevent vent noise and compression. It typically requires more input power as well but that will depend upon the subwoofer driver used.

Just because a sub is rated down to 20hz does not mean it has usable response there. The lowest end frequency number (20hz) is useless without a tolorance (+/-3db), range (20hz-110hz), and a reference volume level (95db). without those it is just a number. I believe Definitive has been noted in the past to make some of their numbers appear better than they really are buy subscribing to some of these practices.

The other thing deep bass response requires is air movement. To make 20hz be heard and felt you need to move some pretty serious amounts of air. A standard wimpy 8" driver is not going to cut it. I would look into a sub of around 12" and larger if the extreme deep bass is what you are after. The SVS PB-10NSD is one of the few 10" subs out there that can go down to the 20hz area pretty well. At least in a modest to small room. That would probably be my pick for prebuilt subwoofers in your price range.

One of the only 8" drivers out there I could see doing well playing that deep would be the JL Audio 8W7. Even it may have some issue playing that low at a high output level.

 

[Halon451]

For movies in partiuclar, there is a HUGE difference in a sub that can achieve 20Hz with decent ouput vs one that can only hit 30Hz with decent output. JBL's low to midrange subs are very average as you have found. For that $400 there is a HSU sub that will meet your needs: the VTF-1 which is $399. It also only goes to 25Hz, but it won't be sloppy doing it and it likely won't give you much in the 20Hz range. The SVS PB-10 CAN do 20Hz and is $429; I've owned it and it is an excellent sub.

Thanks - I had looked up both of these brands and had found to my disappointment that they were quite expensive. This shows me that they do have more affordable models. These are at the limit of my aforementioned budget, but I am particularly drawn to the SVS. I like the fact that it has a rotary phase adjustment dial, instead of the typical 0 and 180 degree toggle switch you see on a lot of subs, and the fact that it can extend down to 20Hz.

 

[mazersteven]

The SVS PB-10 CAN do 20Hz and is $429; I've owned it and it is an excellent sub.

Just what I was going to recommend. Look at B-stock to keep it close to $400.

 

[Halon451]

Getting a sub to play from the upper 20hz-30hz range is one thing, getting it to play down to 20hz accurately and below is completely different. It requires a high quality driver with fairly good excursion capability and a linear motor/suspension out to its excursion envelope. It will also typically require a larger enclosure and vent area to prevent vent noise and compression. It typically requires more input power as well but that will depend upon the subwoofer driver used.

Just because a sub is rated down to 20hz does not mean it has usable response there. The lowest end frequency number (20hz) is useless without a tolorance (+/-3db), range (20hz-110hz), and a reference volume level (95db). without those it is just a number. I believe Definitive has been noted in the past to make some of their numbers appear better than they really are buy subscribing to some of these practices.

The other thing deep bass response requires is air movement. To make 20hz be heard and felt you need to move some pretty serious amounts of air. A standard wimpy 8" driver is not going to cut it. I would look into a sub of around 12" and larger if the extreme deep bass is what you are after. The SVS PB-10NSD is one of the few 10" subs out there that can go down to the 20hz area pretty well. At least in a modest to small room. That would probably be my pick for prebuilt subwoofers in your price range.

One of the only 8" drivers out there I could see doing well playing that deep would be the JL Audio 8W7. Even it may have some issue playing that low at a high output level.

I've followed many of your posts on this forum, I have to say thanks not only for this reply for for the more than abundant amount of information you have shared about subs in general. I have indeed learned a lot, and am craving more knowledge as I go.

I never really realized I would get this deep into it until my old HTIB system broke on me and I had to upgrade. Now that I'm getting into more serious spending, my expectations are growing linearly with the costs. I put down $400 for that JBL, and expected it would at least wow me to some extent, but so far... nay.

I'm re-re-re-recalculating my budget as I speak with my eye on the SVS sub!

 

[mazersteven]

Question#2: I am looking at the Definitive Technology Pro Sub 800 (which is an 8" driver compared to the JBL's 12" driver),

Don't do it.

Look at one of these subs first.

http://www.theaudioinsider.com/product_info.php?cPath=21_32&products_id=68

http://www.outlawaudio.com/products/lfmcompact.html

 

[Halon451]

Don't do it.


Nah, don't worry - that's why I ask you guys before I go spend my heard earned $$$.

 

[mazersteven]

Nah, don't worry - that's why I ask you guys before I go spend my heard earned $$$.

Are you sure about that? LOL

JBL Sub12

 

[j_garcia]

I measured good output at 18Hz and still had some output at 16Hz with the PB-10 in my rather large room previously. Annunaki is correct however, to get real tactile feel and room pressurizing, you will generally need a larger driver. The PB-10 gave me the sound, but was not able to adequately pressurize a room the size I had it in (19x20, high vaulted, open to kitchen), which is why I upgraded. Even for the size of my room though, the PB-10 still impressed me.

 

[Halon451]

Are you sure about that? LOL

JBL Sub12

LOL - you got me. I guess I'm in a pinch, because I've spend money at BB thus far, and it's easier to do the old swap and exchange method if I don't like something, rather than have to be responsible for return shipping. I'm not too worried about what I buy at a major retail store - buying online is a whole different story, which is really where I could use some advice before I commit to a purchase.

By the way - Garcia - I do have a similar room setup; vaulted ceilings, open to the dining room area. My original Sony 12" seemed to be able to fill up the room, but a.) it was cheaply made (cheap plastic knobs, less than quality build, etc.) and b.) it simply lacked in overall performace, as is to be expected from a Sony sub I presume.

So. Maybe I would find myself in the same predicament as yourself even with the SVS's 10" driver?

 

[j_garcia]

I promise the SVS will outperform your previous 2 subs, but yes if your room is large like mine then you may need to look at a more serious sub, likely a 12" at least, for impact and air movement.

Parts Express has this kit: http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=300-762 That is $460 on sale right now and should also be an improvement.

 

[mazersteven]

buying online is a whole different story, which is really where I could use some advice before I commit to a purchase.

So. Maybe I would find myself in the same predicament as yourself even with the SVS's 10" driver?

Buying on-line is scary. I remember when I first joined all these audio forums looking for information. When you see a products name being brought up time and time again. It's hard not to wonder if this is the right thing to do. Well in my case, I was sold on getting my SVS. I was excited, and couldn't wait for the day it arrived. Today I am still stoked that I purchased my SVS.

Am I a fan-boy? You better believe it.

I purchased a PB10-ISD a few years ago for my step-son. His family room is large then what you guys are talking about, and it does a fine job.

 

[Halon451]

Buying on-line is scary. I remember when I first joined all these audio forums looking for information. When you see a products name being brought up time and time again. It's hard not to wonder if this is the right thing to do. Well in my case, I was sold on getting my SVS. I was excited, and couldn't wait for the day it arrived. Today I am still stoked that I purchased my SVS.

Am I a fan-boy? You better believe it.

I purchased a PB10-ISD a few years ago for my step-son. His family room is large then what you guys are talking about, and it does a fine job.

I guess, in my own defense that I have found myself leaning towards JBL on account of my short time as an A/V and broadcast technician a while back in time - we employed the use of a wide variety of JBL Pro loudspeakers for various functions (stereo, multi-channel and studio environments), and I always loved the way they sounded after we finished with the installations. However, I am discovering that the JBL Consumer line is quite a bit different than the JBL Pro line. After all it makes sense from a logical point of view, right? Well - I considered myself fairly intelligent regarding audio equipment before joining this site, and since then it's helped assure me that I still have lots to learn. Brand names for example - a company such as mine will often stick with a particular dealer or distributor, as we receive discounts and credits for 'X number of products purchased, as was the case with our use of JBL's, which is good for the economics of the company, but didn't really expose me to what else is out there. We also used quite a bit of EV speakers, which I found to be not as warm and friendly as the JBL's, but powerful nonetheless.

Now - I'm going into Best Buy (for example), and I see the following: Klipsch, Definitive Technologies, Sony, JBL, and a few others. With the exception of the Sony, all of these could be considered good or great speakers, but which one is going to stand out in my mind? The JBL of course.

Again, this goes back to my previous pre-conceived notions, which may or may not prove to be correct, or at the very least slightly off-axis.

Ah, decisions... isn't that what makes life so interesting?

 

[annunaki]

I promise the SVS will outperform your previous 2 subs, but yes if your room is large like mine then you may need to look at a more serious sub, likely a 12" at least, for impact and air movement.

Parts Express has this kit: http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=300-762 That is $460 on sale right now and should also be an improvement.

As good as this item is a low tuned, vented option may be a better choice as it will allow for more output in a large, open room. However, it will easily exceed performance of anything he has had yet.

I will vouch for the 15" as it easily fills my parents 15 x 28 great room, with vaulted ceilings, down to 20hz and below quite well. Actually, I was quite impressed with it, especially being sealed.

For me it would be a tough choice between the Titanic kit and the 10" SVS. With the Dayton the DIY option for a ported enclosure is always available later on.

 

[Halon451]

Holy cow... someone in this forum's classified section was just selling an SVS 20-39 PCi that was well within my budget, but looks like someone jumped on that deal with a quickness. I imagine for his selling price it wouldn't have lasted long anyway.

Too bad... I believe J Garcia would have appreciated such a buy.

 

[gus6464]

You are in the same boat as I am with a sub. I wanted a sub that could go low without bottoming out but I have serious WAF to deal with. And the only subs that could do what I want while still keeping to WAF standards can be pretty expensive. I may have finally found the sub that can do what I want (SVS SB12-Plus) but now I have to wait a it longer to get it because of its cost. It won't happen until tax return time which is right around the corner but in the end it will be worth it. Maybe you can wait a while so you spend a little more.

 

[mtrycrafts]

I've followed many of your posts on this forum, I have to say thanks not only for this reply for for the more than abundant amount of information you have shared about subs in general. I have indeed learned a lot, and am craving more knowledge as I go.

I'm re-re-re-recalculating my budget as I speak with my eye on the SVS sub!

Take his advice. To get low and powerful output takes a serious sub.

Yes, it will take so $$ but perhaps you can cut back on some other expenditures. Maybe in the new year?

 

[Halon451]

Take his advice. To get low and powerful output takes a serious sub.

Yes, it will take so $$ but perhaps you can cut back on some other expenditures. Maybe in the new year?

Indeed... I wish it were that simple, but right now we've got a lot of our money tied up in home renovations and varous other projects - even our tax return money this upcoming year is already reserved for a new fence.

I've got between $50 and $100 to put away each week for my newfound hobby (obsession), and I haven't yet even decided on what mains I'm going to get. The more I get into this, the more I'm realizing that my JBL affinity isn't all it's cracked up to be. I'm exploring some other options, but I've got my system setup with half JBL's now (excluding the front mains), and two of the three purchases (rear surrounds, and center) were purchased online with no chance of return - the sub of course I can take back.

I might need to just step back for a little while and re-evaluate the path I'm on with all of this, and figure out what I can do. I am really leaning towards the AV123 line - as I have heard plenty good about them on this site. Their X-sub however doesn't seem to be as powerful as I would like to have.

 

[Warpdrv]

I've got between $50 and $100 to put away each week for my newfound hobby (obsession), and I haven't yet even decided on what mains I'm going to get.

Do yourself a favor and save up the money for a good quality sub... Its so much better then you would think... Even a Parts Express DIY setup will blow away what you have by leaps and bounds... or something like a eD a5-350 for $600.00 would be a good start...