[luidge]

Quote:

Originally Posted by Chops /img/forum/go_quote.gif So I guess my suggestion isn't even worth the time of day...

Nightfire :

Yeah, I was thinking that too. Though I'd rather the speakers aimed at my ears. I want to hear the 25-50hz band as well as feel it.

I believe that is why he didn't quote it and talk about it. But i believe your solution would be pretty altruist

 

[nightfire]

Quote:

Originally Posted by Chops /img/forum/go_quote.gif So I guess my suggestion isn't even worth the time of day...

Sorry Chops I didn't even see it the first time.

It would be great for movies, but I'm really looking strictly for audible bass, not just feeling. I'd like to hear the bottom octaves of pipe organs, bass drums, electronic effects, as if I was right there.

I'm going to try two conventional 6" polypropylene drivers mounted on a 1" MDF panel (maybe 10" x 18") with no back, mounted right in front of me, powered by a 10 watt class A mosfet amp, and see what happens.

I've got most of the parts to do this so nothing to lose. If it needs more power I'll order a tripath kit, and if it needs bigger drivers I'll move up to 8 or 10".

 

[Paragon]

How would you say your Grado's are for the bass compared to the k1000?

 

[nightfire]

Quote:

Originally Posted by Paragon /img/forum/go_quote.gif How would you say your Grado's are for the bass compared to the k1000?

A little deeper extension (fairly loud to about 35-40hz), overemphesized midbass at 100-150hz. Sloppy and boomy (relatively speaking) but great, as expected, for rock.

 

[diff_lock2]

So, what are you leaning for? 15"??? and a ported box (i just like ported more sounds more smooth, less punchy)...

 

[kingsqueak]

Quote:

Originally Posted by Chops /img/forum/go_quote.gif Instead of using a subwoofer, why not just use a couple of Bass Shakers and a small T-amp under your seat? It would/could achieve the same if not better results once tuned properly, and would be nearly 100% silent to others in the room.

X2

Look into transducers, they are shaker motors you drive with an audio signal into an amp. It's pretty remarkable how well they work.

I worked with many drummers that used them to augment their in-ear monitor systems. They would put the transducer under their drum throne. It's a very cool effect, your body perceives the sound coming from the mix in the IEM's/phones.

 

[nightfire]

Quote:

Originally Posted by diff_lock2 /img/forum/go_quote.gif So, what are you leaning for? 15"??? and a ported box (i just like ported more sounds more smooth, less punchy)...

Nah I'm going to try 2 6" drivers on an open backed panel/box, and see how it sounds. Then I'll adjust from there (bigger drivers, servo control, bigger amp, etc).

 

[diff_lock2]

Link us to what you think you might use...

Draw us some sketches, whats it gona look like... I cant wait to see this!

What AMP?

Start with a subwoofer amp, so you can move on to larger divers, once you find that 6" is not enough...

 

[nightfire]

Quote:

Originally Posted by diff_lock2 /img/forum/go_quote.gif Link us to what you think you might use... Draw us some sketches, whats it gona look like... I cant wait to see this! What AMP? Start with a subwoofer amp, so you can move on to larger divers, once you find that 6" is not enough...

Just imagine a 1" thick MDF board, 18" wide and 10" tall. Two 6-7" equally spaced holes cut, with speakers installed there. Nothing in behind. Mounted on some kind of stand in front of or behind my head. Probably I'll run them in stereo mode. While bass is "omnidirectional" due to the length of the waveform, you can certainly detect a drop in pressure in a stereo configuration when they're near your ears.

I might install steel or aluminum angle brackets around the MDF if there is resonance but I highly doubt there would be at the power levels I'll be running.

I'll put a soft buffer against the wall to minimize reverberation.

For an amp, because I already have the parts, I'm going to build a simple class A/B mosfet amp.

 

[bhjazz]

The lowest you are going to get with a 6" driver is somewhere in the mid 30s, and that is with a highly tuned box and possibly a port. There's no way to get past that without either adding two or more 6" drivers (to increase surface area) or moving up to a smaller number of larger drivers. It's just how physics work. I'm sure it'll be fun to experiment, but you can't fool nature.

 

[Paragon]

Quote:

Originally Posted by bhjazz /img/forum/go_quote.gif The lowest you are going to get with a 6" driver is somewhere in the mid 30s, and that is with a highly tuned box and possibly a port. There's no way to get past that without either adding two or more 6" drivers (to increase surface area) or moving up to a smaller number of larger drivers. It's just how physics work. I'm sure it'll be fun to experiment, but you can't fool nature.

He is using 2 drivers..

The idea is to use smaller drivers beacuse first, he has them already, and second, they will be faster (and easier to drive) than a single large driver. Same basic idea behind Vandersteen designs. small fast accurate.

Quote:

Vandersteen 2W series subwoofers use three active eightinch drivers rather than a single large woofer. The three eight inch drivers equal the cone area of a fourteen inch woofer, but with a much higher motor-to-cone-area ratio. The high ratio improves pitch definition and insures stable frequency and phase responses throughout and beyond the drivers’ operating range. This allows more crossover design flexibility since a steep-slope, high-order crossover is not necessary when the drivers perform well several octaves past the crossover frequency.

The one sub even has a passive 12" with the three active 8s.

Anyhoo.. good luck in your quest, nightfire.

 

[randytsuch]

I am not a speaker builder, but I would think it would be harder for an open baffle design to do low frequencies. I would think a ported or sealed design would work better, of course those are harder to make.

Randy

 

[bhjazz]

Quote:

Originally Posted by Paragon /img/forum/go_quote.gif He is using 2 drivers..

I caught that. But even combining them will still not get anything lower than 30. So that means either more drivers or bigger ones!

 

[Paragon]

Quote:

Originally Posted by bhjazz /img/forum/go_quote.gif I caught that. But even combining them will still not get anything lower than 30. So that means either more drivers or bigger ones!

I know. My dual 6" sub ported will supposedly only go to around 29Hz. I would be inclined to use a few 8s or perhaps even 10s..

 

[Zenja]

From playing around with WinISD in the last few days, it seems that you can go much, much lower with a ported box. It depends on the natural resonance frequency of the drivers though. I tried modeling a box for some car speakers I just got, and with a closed box they steadily drop past 100 and they're at -3db by like 70Hz. Using a ported design, I could get the response graph to stay almost flat until about 45Hz. If you try to go too much lower than the resonant frequency though, it falls apart.