Mini custom SDA's with Vifa tweeters

ben62670

Well this one is for the nay sayers. You know the guys with teeny tiny minds that think that SDA's have to be big, and that is why they don't make them any longer:rolleyes:
Recipe
http://www.madisound.com/catalog/product_info.php?products_id=844
http://www.madisound.com/catalog/product_info.php?products_id=843
http://www.madisound.com/catalog/product_info.php?manufacturers_id=153&products_id=8402

The mid woofers were chosen based on recommendations from when I started my big project a long time ago. If you feel the urge please indulge yourself with a little reading/reviews on these. They rate very well. Another reason for the speaker choice is my friend wants a set of SDA's, but traditional styled SDA's will not work well in his house. The SRT's with the sat's sitting on top of the bass modules would work well. His speakers will most likely be built like the SRT's with mmmm dimensional, and mmtmm stereo arrays. While I like the if it falls over it will kill you look most others would not like it in there living room;) Well back to the mini's. The Vifa ring radiator speaks for itself. No need to waste time on that. As I have stated numerous times small SDA's could be built to resemble LSI9's on their sides. Well guys here you go. I will soon be the owner of the largest SDA's, and smallest SDA's in the world;) I will even make these look nice

Face

Is the crossover network going to be active or passive?

ben62670

Face wrote: »

Is the crossover network going to be active or passive?

Passive at first with close enough components, then active(mostly for tuning purposes), and finally I think it will be passive. All I have is big amps, and it would be overkill to drive them with GFA-565's, and a 585. I was thinking about building an integrated GC amp so I could have a channel for each of the drivers(6 channels). A 2 channel amp, and sonicaps on the tweeter should be just fine. The only thing that sucks is I can't afford the Vifa's yet. They are 4ohms, and my Morel's are 8. I have 2 Vifa's coming, but they are going to be in the big ones. I can swap back and forth for now, but that will grow old very quick. I really want the Vifa's in the mini's. I have heard better tweeters, but at the price of the Vifa's you can't beat them.

ben62670

The lower -3db should be 40hz in a 1 cubic foot box. This is a little lower than the LSI9's which are -3db at 50. The efficiency Should be 91-92db. I want the box narrow, short, and deep. Again think LSI9's on their sides.
Ben

ben62670

Well I can't friggen edit. This really sucks for threads like this.

Edit:
The -3db point will be slightly below 50hz like the 9's. I could add a little mass to the cone to get it to drop to -3db at around 35hz, but I would lose 5db efficiency! No thanks. I want to be able to drive these with a smaller amp! I could do anything in between, but for a few HZ down low forget it. Also I don't know what would happen to the SQ in the upper ranges.

Cab Specs so far

16 wide
10 tall
17.5 deep
A little bigger than 9's, but this gives me a cubic foot. If I wanted to design it for use with a sub I could go much smaller, but I want to be able to use these by themselves. I think;) It's cheap, and easy to build another set of boxes so I may do both:)

leroyjr1

Make sure you post pics when you are done

ben62670

I will. This should go pretty quick. These are a little easier to handle than my other ones I did:D

Systems

Interesting,I was thinking of doing something like this but using 4 of these per side ,actively xovered from 300-2k with a woofer handling the below 300hz. http://www.madisound.com/catalog/product_info.php?products_id=1643 Those SF drivers look great for price with the cast basket and all .

ben62670

I did look at those drivers. The 1200hz dip threw me off though. How were you planning on driving the array's? If you had a seperate amp for the dimensionals, and stereos you could use 4ohms in both arrays, but to use one amp for the stereo, and dim arrays you need to have the stereo array at 8ohm, and the dim at 4.
Ben

Systems

ben62670 wrote: »

I did look at those drivers. The 1200hz dip threw me off though. How were you planning on driving the array's? If you had a seperate amp for the dimensionals, and stereos you could use 4ohms in both arrays, but to use one amp for the stereo, and dim arrays you need to have the stereo array at 8ohm, and the dim at 4.
Ben

The vifas are 4 ohm,so my plan was to have the DA pair wired in series and the SA pair wired in series giving me 8 ohms per pair.I didn't like that nasty dip in their response either but for $10 each I thought it would be a cheap experiment.

ben62670

GV#27 wrote: »

The vifas are 4 ohm,so my plan was to have the DA pair wired in series and the SA pair wired in series giving me 8 ohms per pair.I didn't like that nasty dip in their response either but for $10 each I thought it would be a cheap experiment.

The DA has to be 4ohms, and the SA has to be 8. If not you will not get the effect. Silver Flute has some 5.5's for $15;) very efficient, and they dig pretty deep:)
Ben

Systems

ben62670 wrote: »

The DA has to be 4ohms, and the SA has to be 8.

I assume this is so levels between will match when using a single amp? I would likely Gainclone the DA section so levels would adjustable.

Silver Flute has some 5.5's for $15

Yeah they look like a great deal,don't know how I overlooked them as I usually have a good look at the Madisound sale page.They would likely outperform the Vifa's.

ben62670

I was thinking that option with 6 channels in all. It would be very easy to build a 6 channel amp fully active XO'ed. A master pot, a stereo pot, and a high pot. The DA would never need to be cut. Its the SA that would need to be trimmed. I just implemented a pot on my GFA-585 to cut the SA. Very fun. If you did a GC integrated with pots like above you would have a stereo SRT type speaker setup. Very fun indeed. Also you could implement a selectable LP XO on the dims for traditional stereo with a little bass boost.
Ben

Systems

ben62670 wrote: »

I was thinking that option with 6 channels in all. It would be very easy to build a 6 channel amp fully active XO'ed. A master pot, a stereo pot, and a high pot. ... Also you could implement a selectable LP XO on the dims for traditional stereo with a little bass boost.
Ben

I like what your saying here.;)That would be a fun project.

Face

Hmmm....I have a 6 channel amp here.

ben62670

2 channels need to be common ground;)

MillerLiteScott

Ben,

I am really looking forward to seeing a picture of these and hearing more about how they are built and sound.

Scott

ben62670

Cab options so far

16 wide
10 tall
17.5 deep
or something like
14 wide
12 high
16 deep
or a cube
14 w
14 h
14 d
What do you guys think.
I am thinking an SDA cube might be fun? Plus I could do a 12" pr on the back instead of a port;)

treitz3

Ben, will the Vifa's give you the SDA effect? Not confronting, just asking....

ben62670

treitz3 wrote: »

Ben, will the Vifa's give you the SDA effect? Not confronting, just asking....

In my big ones, or the little ones? The tweeters don't really have anything to do with SDA.
Ben

Systems

SDA can be done with drivers other than Polks.In general there is nothing special about the drivers, its all in the crossover and the special connection of the dimensional drivers and the horizontal driver spacing.

ben62670

Well I am tired of looking at these drivers. I am ready to get it done. I have decided that the tweeter will be my morels. The Vifa's are very happy in my big SDA's, and the little ones will be crossed higher. This is where the morels are happier. If the Morels are crossed to low the mids are not near as sweet as with the Vifa's. Also the Vifa's are too efficient, and would need to be padded. I should have them running this Sunday:)

ben62670

Well They are kinda done! The worlds smallest SDA's next to the worlds largest. The SDA is working great. I just listened to Styx Mr Roboto. The SDA is full wrap around:) I have them actively crossed over for now. 2500hz is too low with the crap tweeter I have in there now. I am now running the mids full out letting them roll off. The tweeter is still at 2500hz. I am tired. I am going to listen to some tunes. I am very happy minus the lame tweeter.
Ben

engtaz

very nice work, Ben

engtaz

ben62670

Thanks E. I was up from 10pm-5:30am listening to them. I am very very happy. These are making me rethink what direction I want to go in my audio.

zingo

ben62670 wrote: »

Thanks E. I was up from 10pm-5:30am listening to them. I am very very happy. These are making me rethink what direction I want to go in my audio.

Oh really...

(They do look great though)

Conradicles

Ben, let me borrow one of those Adcom amps to see how it makes my SDA's sound!

ben62670

You can borrow one of the 565's

Well I just moved the big guns out of the room:) Time to clean up here. I keep messing with stuff so my wire management is atrocious. No hum, but butt ugly. I am anxiously awaiting for my DAC board to get here. I am needing to consolidate. I just bought an Adcom GSA-700 surround amp Pro Logic decoder for $50 with some issues. I will attempt a repair(for fun), but I am more interested in the case. I want to make an integrated 4 channel amp/DAC/Passive Pre/phono Pre/active XO/tube buffer in one case. It should be big enough, and has heat sinks. I figure I can put everything inside with the amp transformer in an external box. If I do all that I can sell off my IC's and get some hookers, and blow:)
Ben

DollarDave

What dimensions did the cabinets end up being?

Seems like a project for a couple of CS-400s?

ben62670

DaveMuell wrote: »

What dimensions did the cabinets end up being?

Seems like a project for a couple of CS-400s?

http://www.polkaudio.com/forums/showthread.php?t=75762
Post 18, and 24 have the dimensions of these, and the next ones.

engtaz

Whay is the lastests on how they sound? Have you figured out which tweeter you like the best?

engtaz