[Brax]

Let me start by saying I am no speaker designer, I leave that up to people that are way smarter than me. I use my system for 95% HT so the sub is very important to the overall sound. I dreamed of a VMPS sub but they were out of my reach, price wise.

I purchased my first subwoofer a few years ago, an SVS 16-46 PC+.  This had a TC sounds 12” driver in a 46” tall sono tube design with 3 (I think 3”) ports. I chose this sub because it could reach down to 16hz with decent output. It sounded great, I loved the feeling of that ultra low bass thumping your chest. When I would push it hard though, it would occasionally bottom out, so I wanted something with a little more muscle. I started down the path of a DIY Sono sub. I built this sub using a Blueprint 1503 driver. The tube is 18” in diameter and 55” tall with one massive 6” port tuned to 20hz. I drive this with a Crown CE1000 (1100 watts output @ 4 ohms in mono) and use a Behringer Feedback Destroyer to flatten out the response. Power and output are not a problem as I can rattle the neighbor’s windows when this beast brings it. Well I’m still not satisfied, I want it all, I want a sub with high output, clean and DEEP bass.

I had thought of going back to an SVS, maybe one of their ultras, but then I read about VMPS’s new 15” ULTRA-MegaWoofer. My question to Brian is, would his new driver fit the bill? I would like to just replace the Blueprint in a direct swap but I’m not sure his new driver would work in my sono setup because it is a ported design. My tube was designed (not by me) specifically for this blueprint driver. Here are the spec’s for the Blueprint driver from a DUMAX report :
Qts 0.376
Qes 0.411
Qms 4.458
Vas 92 liters
Fs 25.52 Hz
Re 3.93
Sd 737 cm^2
Xmax 25.9 mm
BL 22.35
SPL 87.74 dB
Pe 1000 Watts

In one of Brian’s posts he mentions his new driver has an Fs of 20 Hz and doesn’t need to be EQ’ed. This leads me to believe it should be better in the 16-18 Hz range and have a pretty flat response curve. The SVS had a flat response curve from 16-20 Hz but just couldn’t match the Blueprints output. The Blueprint driver had a slight dip in it's response curve between 17-18 Hz that I can not correct with the BFD EQ. I rarely listen to movies at earth shaking levels anymore so output is not as important as flat response down to 16 Hz.

Is the new 15” driver the answer? I see the driver upgrade is $350, is there any discound if all I need is the driver (minus the 12" plug)?

P.S. I'm picking up my RM40’s this weekend, I’m so excited. I wonder what the wife is going to say when she sees them? She doesn’t know I’m getting them (it’s easier to ask for forgiveness then permission).

[ctviggen]

You're in trouble.  I wouldn't doubt you get kicked out of the house.  (I'm not being facetious -- the RM40s are HUGE.)

[Early B.]

Yeah, you're living dangerously buddy, unless you have deep pockets and an understanding wife.

So here's how you gotta mitigate the damage. First, tell your wife about the speakers before you pick them up. Also, tell her they are HUGE! but they'll blend well with the decor. Then tell her this is the speaker you've always wanted and it's the last speaker purchase for many years to come. You gotta do these things, 'cause once you hear the 40's, you'll get the urge to upgrade some of your other audio gear, and you may need her tacit consent to do so.

Also, pump the brakes on the megawoofer.

[Brian Cheney]

The 15" VSS driver should only be used together with the matching PR. which provides most of the first octave output.

Except for the somewhat high Fs I think your driver is fine for what you want from it.

[Brax]

Thanks for the reply Brian, I thought it sounded too good (the easy swap). I'll just have to wait and get a true VMPS sub later on. I really need a good pre/pro before a sub upgrade, but I thought I could do a quick fix with the VMPS driver.

Well for the WAF, I already have a large TV, a 70" Sony that stands 60" tall, so the speakers won't look soooo big next to that. I will have to give up 2 of my deer mounts because they would be in the way, so the wife comes out even, two less heads in the livingroom vs larger speakers.

I do plan on sanding and restaining the speakers to better match the wood in the livingroom. I also have seen where someone used high gloss on the black base and it really looked sharp. These are the older style RM40's so I will also add a base plate to enlarge the footprint by 1" all around. I thing it's going to look great and sound fantastic.

[Early B.]

Well for the WAF, I already have a large TV, a 70" Sony that stands 60" tall, so the speakers won't look soooo big next to that. I will have to give up 2 of my deer mounts because they would be in the way, so the wife comes out even, two less heads in the livingroom vs larger speakers.

Well, I suppose removal of the deer mounts will satisfy the wife.

[DFaulds]

The 15" VSS driver should only be used together with the matching PR. which provides most of the first octave output.

Except for the somewhat high Fs I think your driver is fine for what you want from it.

Absolutely right Brian.  The BP's had a decent motor design and very large Xmax.  While there are better now, it would cost quite a bit to get that much Xmax in a similar quality driver.