Polk's LSi9s VS Vifa studio kit?

Mark T. Montgomery · « **on:** 17 Jan 2004, 05:37 pm »

I Plan to To use one of these two pairs of speakers along with a Rava sub from DIY. Which is better? If I get the studio kit I'll get it along with cabinets sold for it because I'm not about to build cabinets from scratch, and I can't find better cabinets anywhere else (partly because I dont know where to look except at parts express) even though I don't really like the ones sold with the kit Because I don't even think they are ported. Also it appears that the Lsi9s are pretty good, include good crossover ect. ect. but I still think that the studio kit could possibly beat the pants off the LSi9s. The M22ti bookshelf from Axiom looks pretty good too. Thanks for the help guys.

Arctos · « **Reply #1 on:** 17 Jan 2004, 09:42 pm »

Hi,
I can't say that I have heard any of these speakers, but can tell you that in most cases a well designed DIY speaker will easily outperform an off-the-shelf speaker in the same price range. I would guess, based on the drivers in the Vifa kit that it would be nice (I am considering this one myself, but will probably go with the North Creek Okara II).

As far as cabinets go for the Vifa kit, again, I don't know much about the cabinets from Parts Express, but they look OK to me. You can also have cabinets made for you by a carpenter. Look around on this site and you will find mention of a few of them have done very nice work for some of the members here.

Lastly, remember that this speaker is designed to be used with a passive radiator, not a port.

Regards,

RDS

Zero · « **Reply #2 on:** 18 Jan 2004, 05:36 am »

The Polk Audio LSi-9 bookshelves are incredible speakers for the dime. They definately beat to a different drummer than the rest of their line, which could be described as adequate at best. Many of my friends have done direct comparisons of this particular speaker against famed Von Schweikert VR1, B&W Nautilus 805, and a Revel bookshelf *forgot the model*. None of us were prepared to favor the Polks out of the group.

However, I have had no experience with the vifa kit. So long as you know what you are doing, I would say the DIY path always yeilds the greater value.

Though the LSi's are worth their price tag.

WerTicus · « **Reply #3 on:** 19 Jan 2004, 02:38 am »

i have a vifa kit... not the same one but im very happy with vifa.

i did built the cabinets myself though - and i have heard the same kit with the 'kit' cabinets

and i can tell you its worth getting decent cabinets made - they MAKE the speaker without a doubt.

Mark T. Montgomery · « **Reply #4 on:** 20 Jan 2004, 03:18 am »

Hey guys thanks a lot. Just one thing what is your definition of good cabinets. My Grandfather is a professional carpenter but I don't what the best wood for cabinet building is? Again thanks for the help.

Rob Babcock · « **Reply #5 on:** 20 Jan 2004, 03:43 am »

MDF is about the best for cabinets. Real wood tends to resonate too much; it's just not inert enough. I've also heard of good results with cabs made of marine plywood. You can veneer them with any wood you like.

There are some companies that make their cabs from all wood. Meadowlark immediately comes to mind.

Mark T. Montgomery · « **Reply #6 on:** 20 Jan 2004, 04:18 am »

Thanks , but I could really use the their site just the name doesn't help much...

Brian Bunge · « **Reply #7 on:** 20 Jan 2004, 04:25 am »

Rob,

Meadowlark uses MDF cabinets with veneered sides and back and solid wood outer top and outer baffles.

Mark,

The website is www.meadowlarkaudio.com

Mark T. Montgomery · « **Reply #8 on:** 20 Jan 2004, 04:44 am »

Just what I needed thanks.

Brian Bunge · « **Reply #9 on:** 20 Jan 2004, 04:51 am »

Any time!

Rob Babcock · « **Reply #10 on:** 20 Jan 2004, 05:55 am »

Sorry, guess I read that wrong. I wondered how the hell they'd get good sound out of solid hardwood.

They sure are pretty, however they're made.

WerTicus · « **Reply #11 on:** 20 Jan 2004, 08:34 am »

for good cabinets think thick! (33mm mdf) and think braced!

and think HEAVY!!

(which it will be if you use the first two rules)

also recess the drivers into it so they are flush and have rounded off corners. (to reduce diffraction)

WerTicus · « **Reply #12 on:** 20 Jan 2004, 08:35 am »

oh yeah and have it only as wide as needed to fit the drivers on... and if you can have separate chambers for each driver type it would be good too!

JohnR · « **Reply #13 on:** 20 Jan 2004, 08:49 am »

Quote from: Rob Babcock

Sorry, guess I read that wrong. I wondered how the hell they'd get good sound out of solid hardwood.

I don't understand. MDF resonates too, and a lot of people dislike the "MDF drone." Not that I'm an expert, but I use void-free ply and hardwood.

bubba966 · « **Reply #14 on:** 20 Jan 2004, 08:54 am »

Wouldn't MDF resonations be virtually eliminated (or at least drastically reduced) if you used 6/4 MDF for the entire cabinet?

It'd be a pain to build speaks out of 6/4 MDF (because it'd be damn heavy). But it could also be done with 2 layers of 3/4 MDF.

You certainly wouldn't have to worry about the cabinets moving if they were constructed out of 6/4 MDF...

JohnR · « **Reply #15 on:** 20 Jan 2004, 10:10 am »

I've seen people recommend:

Use two different materials laminated together, or

Use two identical sheets of material laminated together but with a damping layer sandwiched between them.

What I've tried to do in the past is place the bracing so that the unbraced parts of the panel are different sizes. Can't really say how well it works but my Minotaurs "talk" less than MDF speakers I've had in the past. I guess the test will come when I make a bigger speaker with 19mm panels but this kind of bracing... speaking of which I've finally decided which router to get ($$$) but I think I will get a cheap (Ryobi) table saw.

WerTicus · « **Reply #16 on:** 20 Jan 2004, 03:45 pm »

yeah i know someone with 64mm mdf cabs (two layers of 32mm)

litterally backbreaking sound!

bubba966 · « **Reply #17 on:** 20 Jan 2004, 06:53 pm »

Quote from: JohnR

I've seen people recommend:

Use two different materials laminated together

So for the 2 different materials lam'd, are you talking about something like MDF & hardwood, or MDF & high ply count marine plywood.

Which would be preferable on the inside? A softer material, or a harder one?

Quote from: JohnR

I've seen people recommend:

Use two identical sheets of material laminated together but with a damping layer sandwiched between them.

So are we talking about something along the lines of 2 sheets of say 1/2" MDF with a layer of 1/8" double sided hardboard (Masonite)?

Or would 2 sheets of MDF with something softer between them be better? Like industrial grade partical board. Or even softer would be just regular partical board.

All this talk of enclosure material is making me wish I had the shop & materials to make a bunch of speaks to figure this out. My cabinet making knowledge doesn't cover how things sound, and I'm a bit curious right now...

Brian Bunge · « **Reply #18 on:** 20 Jan 2004, 07:24 pm »

The biggest benefits of MDF over hardwood are:

1: MDF has consistent density throughout whereas solid wood does not.
2: MDF is very stable and does not expand, contract and split like solid wood.
3: MDF machines very easily.
4: MDF is a great substrate for veneering.

Using something like Baltic Birch is great for subwoofers because rigidity is first and foremost in a sub. Also, if you look at the North Creek Music website, www.northcreekmusic.com, they actually recommend building your speaker enclosures out of MDF with baltic birch for the bracing. The front and rear baffles are double thickness with baltic birch inner baffles and MDF outer baffles. They also recommend staggering the braces at non equal distances so that there will not be a single resonant mode within the cabinet.

I've never done this, mainly because the baltic birch is a special order item at most places around here. But I definitely like North Creek's approach to cabinet building!

Christof · « **Reply #19 on:** 21 Jan 2004, 04:48 pm »

On the topic of solid wood used for baffles. One can quickly conclude that this is a very touchy subject and opinions vary greatly. A few things to keep in mind if you try to use solid wood for your baffles. Thin strips cut from the same board work best. Every other strip should be flipped over so the grain is opposite. Also you should look for quartersawn lumber which will move less than plain sawn. Lumber like maple will move 1/8" in 1 ft. and nothing is going to stop it. Solid wood is a horrible idea to use alone as a baffle especially in a sealed enclosure. Laminated to a inner baffle of 3/4 mdf using a flexible adhesive like silicon will allow it to move and not destroy the seal. If you use plan to use screws to hold it down you should only place screws down the meridian of the baffle and float the sides in a flexible adhesive. Even the screws holding your drivers in, if protruding through to the mdf subbase will eventually lead to a broken baffle. Wood is dynamic and MDF for the most part is static. I don't want to discourage anyone from using solid wood, just proceed with extreme caution.
C.