Isobaric set ups

[BassNazi 0]

Hi i'm new to SSA forums but been around for a while on others.

Who has run any type of isobaric set up before? The low end is efforless and immense and all from a smaller enclousere. Also the smaller cab plays the higher freqs really well and just makes for a very flat output over the whole range whilst still staying controlled.

Basicly the iso' only makes use of the extra motor and has no real use of the other cone. Or even the other basket for that matter although the other basket make the whole rig easier to mount.

I am thinking about a dual motor design and just simply linking the the 2 motors by extending the the formers so they meet.

Who thinks this is a good idea ?

Who thinks is a waste of a motor?

[95Honda 486]

Isobarik does nothing for upper end or change the sound or frequency response.

It cuts the Vas and efficiency in half of what the single driver would be, that's it....

There are marginal linear gains in stroke do to push-pull if you go that route...

I think your better off just using 2 drivers...

[BassNazi 0]

I think your better off just using 2 drivers...

I'm not talking about using 2 drivers. If i was i would then bolt an extra motor to the pair.

As nobody currently offes a dual motor driver an iso set up is just a diy method of making a driver that hammers out the lows in a small cab. Isn't that what everbody wants?

I am actully thinking about producing these in a limited run and was just getting peoples opinion of weather they think is is a waste of a motor.

[95Honda 486]

Morel has had dual motor drivers for years.... They were actually called push-pull... They didn't really catch on I guess...

From Bass Box Pro info window-

"Morel's push pull principle incorporated in this superb woofer has two distinct identical motors and double magnet for each motor, making the system for powerful inside the shallow chassis."

This driver is in a bunch of my Speakebuilder magazines from the late 90's

[BassNazi 0]

I can't find pics anywhere. You got any links?

My final design may even end up looking like morel anyway.

[95Honda 486]

Can't find a link so I scanned the back of a 1998 Speaker Builder issue....

It is the sub in the middle....

[BassNazi 0]

Thanks for the Scan.

Yeah thats what i had in mind. Except maybe using a extra basket to house the motor above the cone. Should make it a bit easier to align the gaps for now

Got a DD9515 and some other parts set aside for this little venture.

[95Honda 486]

Just don't forget that if you connect the two motors together with any kind of metal (I assume you will) and the connection is anywhere in the magnetic circuit, be sure and use a non-ferrous metal like aluminum or brass....

I think that big slug of metal in the Morel driver right in the middle is aluminum... Or maybe magnesium...

[BassNazi 0]

Thanks for the tips.

Chances are it will be an aluminum for now.

It's a shame i'm over in the U.K 'cos i really like the SS Kit .

The Premuim series would make a good base for a dual motor Driver. Imagine an 18" that will play pretty much as flat as a pancake from 80 hz all the way down to 20hz in say 5cuft vented?

It would 'only' need 2k rms to get them going towards there rated xmax ( more like Xmech if i owned 'em)

Shame it would all but double the cost of the unit. That has to be the reason no one bothers?

Edited December 5, 2008 by BassNazi

[95Honda 486]

I think it is the cost... The motor is the most expensive part of the driver. The steel is the what really hits you in the pocket book these days...

It really is a tough sell...

Also, don't forget that alot of the goals you are talking about are easily achieved with some of the current drivers on the market now. Getting low in small box can be done by either cuting efficiency or adding substantially to motor cost... I think the real benefits of what you are thinking about are the drops you will see in non-linear distortion from a driver that behaves equally both in forward and rearward stroke.... That would be my target goal for something like this....

[BILTD 60]

Also, don't forget that alot of the goals you are talking about are easily achieved with some of the current drivers on the market now.

Agree with that part. Not impossible but you need to consider the amount of motor your going to need at a cost of efficiency too. For which, theres a host of drivers on the market which will equally give you great results.

The idea you are thinking about has been done by Alpine on a series of bandpass enclosures they did for the Japanese market, i saw it in Vegas few years back at CES.

You'll also need to reverse polarity one coil... or reverse charge one of the motors, either way both work as good as each other.

[BassNazi 0]

Hey Am,

Not really looking at making a living from this just a little side project and if i break even i will be happy.

I've still not actually heard any of the AA/FI stuff yet but it seems to pretty much kill off the need for a dual motor designs.?

I have had lots of different installs over the years and the best sounding one i ever had was 4 X 15's iso' clamshell in a sealed 7 cuft. Sure it wasn't the loudest but i have yet to replicate the sound.

95honda you mention the sq side which is interesting. BILTD will be the first person to tell you that i'm not very SQ orientated! But looking back that i what i miss from the old boot install.

Also theroy and what BBP says will/won't happen isn't written in stone? It's a good starting point. Building and testing is the only way to be sure?

At the top of the thread i asked if it was a waste of a motor. It seems that the result won't justify cost ?

I will get the 15" prototye done a test it against the best of the rest. If it holds its own i will go from there

Edited December 7, 2008 by BassNazi

[tahoexfixssd 0]

dont forget vifas driver that they made for alpines plv-5 and 7 that had multiple motors!

[B7L|BL4Z3R 4]

isent a couple cerwin vega woofers like that

[Duran 387]

isent a couple cerwin vega woofers like that

If you are talking about the old Strokers then no. It was just a spider on the cone.

[B7L|BL4Z3R 4]

i see i never seen one just on yourtube and i seen some bullchit on top of them where the dust cap would be