Speaker Guru's, Talk me off the ledge! (sub content)

[ThunderStik]

Ok, I understand the much of the mechanics that go into going low. I have built a few cabs in the past just to play around with. I play a 5 tuned to Bflat. After playing around and actually figuring out what im hearing for a few years I decided to "go big" ...at least for now.

I really love to get a healthy amount of the fundamental in my sound but have been looking for for a good driver to get me there.

I recently turned the cones inside out on my current rig and decided its high time to make a change.

http://www.parts-express.com/pe/show...number=294-689

That is the driver im looking at going with.

In win isd it looks very good in a 8ft box tuned to 24hz. I am planning on bi-amping and crossing over at 200-300.

Many of you will ask "why not just go with 3015lf". The answer to that is simple. Xmax!

The 2 3015's will need larger cabs (about 6ft each) to do what I want to do and still not have enough travel to compete with the B&C.

I could throw everything under the sun at this and never worry about killing it at all.

What say you?

[rpsands]

Have you ever really sat down and listened to the difference in live sound between your rig high passed at 30hz and high passed at 50hz? I've never met anyone who could tell the difference once it's mixed in.

That said, for that price of that driver you could put four 3015Lfs in an isobaric alignment and have some money left over. :P


bottom line: Just build a fEarful 1515/66 and thank me later I accept thank you notes via PM.

[Schecter4]

Originally Posted by ThunderStik

In win isd it looks very good in a 8ft box tuned to 24hz. I am planning on bi-amping and crossing over at 200-300.

I bet you have to cross over a lot lower; like 100hz or less. And consider tri-amp instead of bi-amp.

I agree with the previous post; don't try and do a 30hz fundamental. It just isn't that important. I used to use car audio subs crossed at 100hz or so, and gave it up because it just didn't make that much difference. Folks farther away could hear more rumble, but it didn't do anything useful for tone.

[Munjibunga]

Originally Posted by Schecter4

I bet you have to cross over a lot lower; like 100hz or less. And consider tri-amp instead of bi-amp.

I agree with the previous post; don't try and do a 30hz fundamental. It just isn't that important. I used to use car audio subs crossed at 100hz or so, and gave it up because it just didn't make that much difference. Folks farther away could hear more rumble, but it didn't do anything useful for tone.

I don't think I'd cross that thing over any higher than 90 hz. Then maybe a couple 12s and an 8 to carry the mids and highs.

[ThunderStik]

Originally Posted by rpsands

Have you ever really sat down and listened to the difference in live sound between your rig high passed at 30hz and high passed at 50hz? I've never met anyone who could tell the difference once it's mixed in.

That said, for that price of that driver you could put four 3015Lfs in an isobaric alignment and have some money left over. :P


bottom line: Just build a fEarful 1515/66 and thank me later I accept thank you notes via PM.

To answer your questions. Yes I have sat down and listened to my bass rig high passed with both 50hz and 30hz. Tried it a live situation also.

Even went as far as to try a blind test with the band (installed filters without them knowing).

Immediately everybody was looking around with that "what the hell is wrong" look on their faces. So not only does it make difference to me but my band members noticed it right off the bat.

My ears are pretty good and I know my frequencies pretty well so dont think im coming into this half cocked as many do just looking for alot of second/third harmonic.

High passed at 50hz to me is utterly nutless. 30 is not as bad but my B does not have the authorty that im used to. Keep in mind right now my rig is a 5ft cab with 2 3012lf's tuned to 40hz.

But even when I go to tune lower the driver excursion is just to much even with unloading at the volumes we play at which are somewhat loud.

I could go Iso's but I would need 2 cabs and they are a more complex build and would almost as pricey. Or I could go with just 1 big mean nasty driver in 1 reasonably sized cab (if 8ft is reasonable LOL).

[cracker75]

This caught my eye a bit ago....might give you some ideas of what to do with a speaker that big.

http://www.ramsdellproaudio.com/prod...bs/BP-SD21.htm

[Gearhead17]

If you want more low end, you need more speakers - more of what you already have. Still though, you are a tad bit crazy to think you need a cab that can do 30hz at a loud volume. To get a 30hz tone loud enough to compete with a band, it's utterly insane to do so. It won't matter because that guitar solo is still going to cut through your mountain of low end.

Seriously though, a good response at 60 and 120 hz is what to shoot for. Boosting to all hell in that range will create a low end that is felt and heard. It will bug everyone in the room much quicker than a rumble below 60 hz.

Most bar PA systems and the big PA systems at outdoor concerts are not focusing on much below 40hz. Along with that, creating a monstrous boom on stage is useless - let the PA system do the grunt work. I understand you want to achieve the sound in your head and so on.....but you have to understand the limitations of audio. I suggest putting a crossover of some sort at 40hz and go from there. It will solve your pushing the speakers past their breaking point.

You don't have to listen to me.

[rpsands]

Are you counteracting for the dip at the high pass frequency with eq? I want to say you lose 3db at least with a shelving right at the crossover frequency. Which is why most high passes for bass guitar are much more complex than a simple 24db/oct high pass or so @ 30hz.

Because I've run my fEarful 15/6 with a 12db/oct 30hz and 50hz and no one could tell the difference (because I used the bass knob on amp to counteract it) Right now I use a 12db/oct 75hz passive high pass in line with my signal and a good bit of VPF (boost 50hz, cut 350hz or so) or bass to counteract it.

[ThunderStik]

rpsands,
I have played with eq seven ways from sundayand what i have figured out is i and others miss those lows.

Believe me i didnt come to this conclusion lightly. I have sat and played with studio equipment with variable filters and inline filters, 2nd, 3rd and 4th order. Its just impossible to get that feel/sound when those frequencies are gone.

[1n3]

Have you considered a folded bass horn for this application?

[ThunderStik]

Yes I have considered a horn. I have played with them before and I dont care for the feel of them. Its a very different feel than a DR.

[BassmanPaul]

Originally Posted by ThunderStik

Yes I have considered a horn. I have played with them before and I dont care for the feel of them. Its a very different feel than a DR.

Just get an Acme B4 and call it a day!

Paul

[rpsands]

Originally Posted by ThunderStik

rpsands,
I have played with eq seven ways from sundayand what i have figured out is i and others miss those lows.

Believe me i didnt come to this conclusion lightly. I have sat and played with studio equipment with variable filters and inline filters, 2nd, 3rd and 4th order. Its just impossible to get that feel/sound when those frequencies are gone.

What cabinets were you using?

If you really really need 30hz content, get an Acme for stage monitoring and put more subs in the PA I guess. but buying an 850 dollar driver that doesn't perform as well as two 3015LFs is crazy talk. Slight size reduction for 550 extra dollars in driver price

[ThunderStik]

Originally Posted by rpsands

What cabinets were you using?

But buying an 850 dollar driver that doesn't perform as well as two 3015LFs is crazy talk. Slight size reduction for 550 extra dollars in driver price

rpsands,
This is the discussion I wanted to have. Can you elaborate on the "doesnt perform as well as 2 3015lf's" part?

Of course I wouldnt naturally just want to spend more money for the sake of spending it. From my standpoint I dont see the 3015lf's performing as well.

Thanks to all the contributors so far.

[rpsands]

The driver has a vD of 2520 vs the vD of 1700 or so of two 3015Lfs.

The missing component of that equation is that two 3015LFs have a sensitivity down to 45hz or so of +/-2db of 101.5db vs. 96db or so of the B&C driver (so you'll need 4x the amplifier power to get the same volume @ 45hz as the 3015Lfs with the B&C driver).

I haven't modeled the B&C but its lower Fs suggests it'll probably be smoother down to 30 hz but I still have my doubts that you're really hearing that and not some other artifact. For example, the harmonic distortion introduced by 30hz signal into a speaker that can't really put out that frequency might be something your ears are accustomed to hearing.

I'm still curious as to where you're actually getting the 30hz from. To hear 30hz at a reasonable volume you're pretty much talking high end pro sound subwoofers or Acmes (which mind you are -6db @ 30.87hz).

[ThunderStik]

My sound sources have been a high quiality studio monitor setup and my current rig which is 5ft box with 2 3012lf's tuned to 40 with a mild boost at 40 hz.

Im not reall worried about power as its cheap. But to get usable spl's without killing cones this seems to me to be the easiest way to get what I want. That is my angle. I could go with acme's but those drivers fall out on a regular bassis also.

While I agree its somewhat absurd to put a $700 driver in a bass guitar cab, its also absurd to keep replacing cones when they are ill equipped for the task at hand.

If I was fine with 45hz or so we would not be having this discussion, I dont think LOL.

Mind you im not looking for ruler flat, -6db at 30 would probably be fine. But look at cone excursion as you start getting into the 800-1KW+ area and you can see why they die.

Excursion is the limiting factor here imo and thus far I have not found a better tool for the task. Plus with the 3015lf's even in a 6ft box the group delays start to get really long.

[rpsands]

Studio monitors are not really sensitive enough to give you the same perspective as standing 15-20 feet off of stage in the mix with high SPL 30hz.

Your current rig is by my estimation -13db @ 30hz (I want to say 3015Lfs and 3012Lfs go down to around -10db @ 35hz). So the idea that people can hear it clearly when it's gone is pretty absurd unless you're adding like 10db (especially when you take into account that there's probably twice as much native energy at 56hz as at 28hz, with open Bb, for example...because of the way electric basses work).

[ThunderStik]

I know the studio monitors are pretty flat, especially in the low end. 2 eminence lab 12 drivers tuned to 20 I believe . I would say that im boosting 3-6db at 40. But thats judging by my perception as I have not measured that.

I have been playing since I was 12 and am 38 now, I am also an engineer so please dont be so quick to dismiss what im saying.

I also play a 5 string neck thru spector which (35 scale) has arguably one of the best B's around. I have tried to make sure that I have not puled the wool over my own eyes. I know our drummer picked it off right off the bat as did I. Our drummer isnt the normal drummer LOL.

[rpsands]

I'm not trying to dismiss what you're saying I'm trying to understand it.

A 35" scale b-string is still putting out maybe 20% of its energy at 30hz. It takes a much longer scale to do much better than 20-30% (think dingwall's 37", or Quake 39.5", or that monster Lbow thing from basslab).

If you're +6db shelving at 40hz, your cab is probably putting out -6db @ 30hz. The chances of someone being able to hear that in the mix is pretty slim.

If you don't want to pull any wool over your eyes, have you tried recording and running the post-eq DI from your amp through a frequency analyzer? I'd be curious to see how much content with your open Bb string is actually the fundamental. That'd be the first step to understanding your real needs -- I'd bet the spector has about twice as much energy at the first harmonic than at the fundamental.

Also, model 2 3015LF cab in 8 cf. I believe they should get around 4db louder @ 30hz or so than the 3012LF cab at peak spl.

[ThunderStik]

Oh, no doubts and no arguments here as far as how much 30hz content is there in relation to the second and third harmonic. But what im say is, what is there is important to me. Its just trying to reproduce what is there to audible levels is creaming drivers.

I recently played a gig where I had to play thru a 610 of a well known brand and it was all mids IMO. The drummer and I could not believe how bad it sounded, it even had a $2000 head setting on top of it. Go figure.

I will contact a friend of mine and see if we can hook up to some of his equipment which I have done before but it was a while back and I dont want to spew forth incorrect info.

Even a modest boost of 3-6db in the 3015 cab you described pushes you close or over xmax. Yes while a driver does not blow up when xmax is reached it really time to put the brakes on.