Braced the cabinets

audiochef · « **on:** 21 Feb 2004, 10:16 pm »

Extremely coherent , is what I first noticed .
The bass is extremely fast and tight without any reduction in weight.
Images are now rock solid.
Completely different , no bs.

All I did was ad four side to side braces using 3/4 by 3/4 inch dowels ,cut to 1 millimeter wider than widyh of inside of cabinet ,pulled tight and wood glued. Just under 10.5 inces each.

A must do ,only cost about 3 dollars !!!

warnerwh · « **Reply #1 on:** 21 Feb 2004, 10:28 pm »

After I added bracing to my ST/R SE's I was literally stunned at the improvements. Took a few minutes for it to digest. Absolutely amazing especially for the money and time involved. Everything is much more coherent but the bass is what shocked me the most. The midrange and treble are both audibly improved too. You won't have to try to hear this as it will be obvious. Then of course you have to readjust your speakers as the difference is major.

Glad someone else has tried it. Like I said earlier, there's a reason the RM/X has a SIX inch baffle and some of the best sounding speakers are those with unusually rigid cabinets. Learned this while reading up on speaker design and took the risk. While I was in there I also used hot glue on the shelf braces and the corners of the boxes, at least where it was easy to do so. Also I took some 1x2" oak pieces and glued them to the sides near the middle of the panels furthest away from the shelf bracing. This oak wood can be bought at Home Depot and is actually closer to 3/4" by 1.7" so it doesn't take much volume. It's nice and straight and flat too.

Was trying to figure out a way to mount an extra hundred pounds. Maybe a couple of 50 pound plates on top would work but not look too good. Anybody got a great idea for adding mass?

zybar · « **Reply #2 on:** 21 Feb 2004, 10:37 pm »

Any pics guys before you mounted the braces?

Where exactly did you put them?

GW

maxwalrath · « **Reply #3 on:** 21 Feb 2004, 10:38 pm »

can I do this to my RM1's?

audiochef · « **Reply #4 on:** 21 Feb 2004, 10:45 pm »

Hi Zybar,
sorry no pics, but they are evenly spaced from right on top of lower woofer, just below upper and two spaced in upper and lower center.

You must do this ,Zybar. Took me 2 hours, I'd pay a thousand dollars for this upgrade.

audiochef · « **Reply #5 on:** 21 Feb 2004, 10:49 pm »

Max, a friend of mine has the original Rm1s and I'm now going to insist on doing this for him.
I'll make him post a review afterwards.

HarleyMYK · « **Reply #6 on:** 21 Feb 2004, 11:16 pm »

audiochef,

Could take some pics when you do the RM 1's? A friend of mine, who has built many sets of speakers, recommended this to me also, but I have not yet taken the initiative. Some pictures might motivate me.

Thanks!

zybar · « **Reply #7 on:** 21 Feb 2004, 11:36 pm »

Does the glue stick to the soundcoat?

GW

audiochef · « **Reply #8 on:** 21 Feb 2004, 11:46 pm »

good question ,I was just discussing that very thing with my Rm1 friend who is now working on his.
If it dosn't stick,
Warnerwh was suggesting hot glue which would be better anyway.
When the wood is wedged in place , it should'nt be too much of a concern.

Enrico · « **Reply #9 on:** 21 Feb 2004, 11:57 pm »

I'm puzzled by the fact that a 3 dollar/2 hour upgrade can make a dramatic improvement in the sound quality. If bracing is so good (which I don't doubt)...why doesn't VMPS make its speakers this way in the first place?

UTLaw · « **Reply #10 on:** 22 Feb 2004, 12:01 am »

Great question, Enrico!

Brian Cheney · « **Reply #11 on:** 22 Feb 2004, 12:09 am »

Sal Salgado built all the RM 40 cabinets to date and could not find room for window braces, the only kind I like, using his manual cutting equipment (pin routers, table saws).

Dorne Dibble found a way to fit them in with some fancy tongue-and-groove CNC work. We will make these braces available on a cost basis to DIYer's.

All other VMPS cabinets are braced at the usual points.

maxwalrath · « **Reply #12 on:** 22 Feb 2004, 12:26 am »

Thanks audiochef...a description of what to do would really help. I've never taken apart a pair of speakers, and I'll do it but not unless I'm really clear on the instructions. Looking forward to hearing from you.

audiochef · « **Reply #13 on:** 22 Feb 2004, 02:12 am »

I don't know Enrico,
I suppose it's a cost issue. The same reason electronic components don't include cones and damping sheets which is obviously advantages to them.

I don't mind this personalized tweaing , It's very gratifying.

Oh and by the way, 4 hours later . My system kicks some serious A.

warnerwh · « **Reply #14 on:** 22 Feb 2004, 02:32 am »

I've posted pics out of a book on speaker braces in the Gallery. From left to right they are: Cross Braces, Horizontal Braces and Corner Braces. Here's a pic of some window braces: http://www.websterfam.net/monte/speaker/monte4.jpg

The cross braces are super easy and very effective. These must be fit very snugly. I used maple dowels for closets. There's no problem with the soundcoat as it appears it's something that soaks into the MDF. If you use hotglue get the kind that takes over a minute to dry to give yourself some time to work. Like audiochef said "he'd pay a thousand dollars for this upgrade". You guys will be surprised.

On the RM 40's I'd get some heavy dowel and do cross braces just above and below the woofers. Then some horizontal bracing with oak in other places. While you're in there hot glue the corners.

On a sidenote be very careful with hotglue while working in an enclosed area. Major pain, trust me on this. I had to keep my finger in icewater for 6 hours before I could take it out and not be in excruciating pain.

zybar · « **Reply #15 on:** 22 Feb 2004, 03:07 am »

There aren't any pics in the gallery.

Let us know when you have the pics up.

GW

warnerwh · « **Reply #16 on:** 22 Feb 2004, 03:44 am »

Pic is there now. Note the side braces. On mine I put the wide part against the cabinet wall instead of the thinner part. Use oak as it's rigid, dense, and different than the MDF. You want to remove the resonances. I suspect besides cost reasons Brian doesn't do these due to the fact you could run into problems shipping and moving them around. I glued the hell out of everything and it's not coming off. A little scary when doing it but like audiochef learned it is well worth the effort. No black magic or snake oil here, pure physics.

Also I put hot glue on the ends of the heavy dowel before putting them in. It helped to round the with a belt sander to get them in and make sure the fit is perfect before installing. Have your hammer or mallet ready as the hot glue drys fast. If you don't have a hot glue gun they're cheap.

Be sure to knock on the sides of your cabinet before and after. The cabinets are actually well made but you will find they become much more inert with the bracing.

Dunedain · « **Reply #17 on:** 22 Feb 2004, 05:04 pm »

Brian: From what you're saying, this lack of internal bracing only applies to RM40 cabinets, correct?
Do all RM2 cabinets have full bracing already built in when they were made?

Thanks for any info.

John Casler · « **Reply #18 on:** 22 Feb 2004, 05:38 pm »

If I might interject, cabinet rigidity and bracing is like "money".

YOU CAN NEVER HAVE ENOUGH!!! (Ok you probably can, but you get the idea)

That said, "any" improvement to the electronics, drivers, or cabinets will obviously increase production costs and speaker pricing.

Brian, just like all other designers has to look at the overall design and "balance" all the components and the costs to deliver them within his pricing window with the minimum/maximum performance goal.

It should be readily understood that the VMPS and particularly the RM40 is one stellar bargain, and with a few little DIY tweaks, it moves even higher up the ladder.

Although many don't percieve it this way, the average shipping charge on the RM40 is around $450. This means that the finished "stock" speaker is around $4150.

And as most of you know going through a dealer might get you substantially below that.

So, I think it is rather cool that you can buy a speaker for around $4K, play with the insulation, screw and glue in additional bracing, and even attach "acoustic foam" on the baffles for anti-defraction devices, and have a speaker that sounds like "thousands" more.

(Excuse my thinking out loud)

zybar · « **Reply #19 on:** 22 Feb 2004, 05:45 pm »

John,

I couldn't agree more with what you are saying!

What would be great if either VMPS dealers or Brian himself could help the people who are looking to make the already very good RM 40's even better.

You have done that with your foam and sonic director tweaks - thank you.

Now it seems bracing is a very cost effective and relatively simple way of improving as well. If we can get some simple directions and pics I feel comfortable making changes (having opened up the 40's multiple times now). If Brian wants to sell braces that I can put in myself that he approves, even better!

Let's keep the tweaking coming.

GW