Which 12"

[K-amps]

I am working on a 3-way system with 2 enclosures. The LF enclosure is basically a pair of 12"ers in a 3.76cuFt box, with each driver in its own 1.88cuFt area and a vent of it's own. I was hoping to get this to work from 30Hz to 300Hz.

The HF enclosure is a baffle-less MTM comprising two Vifa P13's and a Vifa XT25. They operate 300z upwards I got that part pretty well settled. The problem I have is with the bass unit.

I initially had two PPI Pro12's as the Bass units. However regardless of what PPI says that the Pro12's liked small enclosures, .... they don't! The output at 100Hz is maddening.

Each driver is in 1.88cuFT and tuned to 37.4Hz.

Now I am looking at other drivers that give me a more flat response, heck even exaggerated response below 60Hz is acceptable to take care of the bafflestep. I WinISD'd 3 drivers all in the same price rage of $150 per driver or so.

1) THe PPI Pro12
2) Peerless XLS12
3) Dayton Titanic Mk.III (12")

and got the following results... which one would you guys choose for the given application? Should I consider other 12"ers in this application with the enclosure around 1.9 to 3cuFt? In the same price range?

I always prefer deep bass ... My vents are more or less fixed $" by 10"...

[morbo]

Now I am looking at other drivers that give me a more flat response, heck even exaggerated response below 60Hz is acceptable to take care of the bafflestep. I WinISD'd 3 drivers all in the same price rage of $150 per driver or so.

Unless your baffle is very wide, baffle step usually starts around 4-500hz and flattens out close to 100hz, so a peak at 60hz is not really going to address it. If you don't mind a peak at 60hz thats fine.

Out of those 3, I would choose the purple line. However, I would not port any of those drivers that high, may as well go sealed, at least then you won't be bottoming them with sub-30hz material all the time. If you really want them ported I would go with 1 12" a side, otherwise do 2 12" a side sealed.

[K-amps]

If I choose the Peerles XLS12 (Purple plot in the previous image) and go with the sealed version, I get these 2 plots:

Purple = vented
Yellow = Sealed

Both 1.88cuFt... the sealed does not look very promising here.

[LineSource]

B&W claims on their website white papers that one 15" woofer was "better" and "more coherent" than two 10" or 12" speakers. B&W mentioned that new low mass cone materials and new magnet motor structures really improve larger diameter woofer transient response. B&W sells both a single 15" and dual 10" Nautilus speaker, so they don't believe that one size fits all.

A single 15" JBL class woofer in your total cabinent volume might be worth simulating.

[Audiophilenoob]

have you thought about lambda woofers???

their 12s and 15s are unmatched

if you're looking for 15s... the TD15x is a good route... and it's fairly cheap

a pair of 12s of these (these sound slightly worse than the 15" version in SQ) could easily get you to -3db down at 25-27hz with a tune of around 30hz

also everyone knows what those faraday rings do

[morbo]

Well I don't have modelling software in front of me but that curve looks suspect to me, f3 above 60hz? Is that in winisd?

I'll try modelling the peerless at least later. You could always port lower, certainly IMO it would be far preferable if the 12"ers are going to see a full range signal.

[ShinOBIWAN]

Originally posted by K-amps
If I choose the Peerles XLS12 (Purple plot in the previous image) and go with the sealed version, I get these 2 plots:

Purple = vented
Yellow = Sealed

Both 1.88cuFt... the sealed does not look very promising here.

Don't put to much faith in the ISD plots, this is one example where they are just plain wrong.

The XLS is suited to sealed and performs well.

BK electronics in the UK has a sealed design here:

http://www.bkelec.com/Special_Offers/Cherry.htm

http://www.bkelec.com/Special_Offers/sp5.htm

The measurements tell of a -6dB at 17hz using the XLS10 sealed in a 1cuft enclosure.

[K-amps]

Originally posted by ShinOBIWAN


Don't put to much faith in the ISD plots, this is one example where they are just plain wrong.

Great, what freeware should I use then?

Anyone got plots for the XLS12 in a sealed cabbie of about 1.9cuFt?

[K-amps]

Originally posted by morbo
Well I don't have modelling software in front of me but that curve looks suspect to me, f3 above 60hz? Is that in winisd?

I'll try modelling the peerless at least later. You could always port lower, certainly IMO it would be far preferable if the 12"ers are going to see a full range signal.

Win ISD pro..... Yes. The XLS will be actively crossed at 300Hz.

thanks!

[kan3]

the ppi pro shouldn't even be in the comparison - at 5mm xmax its going to be extremely output limited compared to the other two