Vifa Floorstanding Speakers

Hi everyone,

I've got some bookshelf speakers at the moment but I've been hearing a few floorstanding speakers and they have so much more depth than my bookshelfs. Because I'm on a reletively tight budget I've been looking at making my own floorstanding speakers. I've done a bit of research but I'm still a bit confused. At the moment I've decided to go for a tower with:

Vifa Silk Dome Tweeter Flate Plate 4 [D27TG-35-06]
Vifa 6.5" Mid-Woofer [P17WJ-00-08]

and have the box at around 25 Litres tuned to 42 Hz (using WinISD).
I was looking at making a 2nd order crossover (using WinISD again) but if this crossover wont be that good or if I can find out how to make somthing better (like a 4th order) I would like to go with that. My only other concern is that the tweeter is 100W nominal while the woofer is only 40W. Does this matter? I was thinking of maybe going for two of the woofers in a TMM or MTM arrangement but only if its really nessesary or makes a huge imporvement as I want to keep costs down.

This is my first time at building a speaker by myslef from scratch so any advice, suggestions or anything at all would be greatly appreciated. Thanks a lot :)


Edit: Sorry, I've just done a search and I've found a few threads on the Vifa tweeter and woofer combo. (still have questions though ;)) Is it worth me saving up for more/better drivers because 25 litres isnt exactly floorstanding size and I'm looking for speakers that sound nice and deep without a sub (...for now :D). Could I make a transmission line box or would that have to be really big? Cheers
 
Well...

You could do something like that, but it sounds like you either need to brush up on the finer points of speaker design (x-over topologies, bsc, etc), or do a pre-existing kit.

This kit reminded me of what you were wanting since it had a vifa woofer :): http://www.speakerbuilder.net/web_files/Projects/Eros Project/eros.htm

If you want any more help drop me a line, and sometime when I am more awake, I'll do my best to help :)
 
Kev, you seem to be on the right track so far and have selected some excellent drive units, certainly the tweeter's reputation stands it out from the budget crowd. I am not familiar with the woofer but looking at the specs and doing a few searches, it seems a sound choice. Of course you can spend more money and get something with more extension and resolution, but that would be almost doubling the woofer budget, and you already seem to have chosen an excellent unit that is within a price range you feel comfortable with.

Kits are often recommended for a first build, and I have recommended them too, but that's usually for those people who want to save money, have a bit of fun and have a reliable solution they can fit and forget for years. Just like if they'd bought them in a shop. The fact that you seem to be having such fun selecting drivers and considering what box alignment will suit them and your tastes best, and have been doing a lot of research, leads me to believe that you wouldn't be satisfied taking someone's else's design and copying it. I wouldn't be, for me the design was everything, and learning from mistakes is fun as it means you get to do ANOTHER design! :D

Certainly, it is unlikely your own design will be as good as someone else's with mountains of experience behind it, but I think you will feel greater pride and satisfaction by getting help to make your very own speaker. I've never built a kit and my first speakers, listening now, sound pretty rough compared to newer, pricier designs. At the time though, they were better than anything I could buy for the price and I adored them, and beamed with pride when I played them. Back then though my only resource was Radio Shack, who sold me the drivers and a book on rudimentary design, paired with 'a crossover' from the shelf! You are already way ahead of that, and have a fantastic resource here and on the web at large. Your first speaker, already, is way ahead of mine.

So, if you want a fail-safe speaker to whip-up on a budget and enjoy for years to come, build a kit. If you are liking the design element, and think you might want to continue this as a hobby then design, build, learn and have fun. They won't be awful, they will be damned good, just maybe not wringing the absolute best from the units in hand.

If you are tempted by a TL, many will say it's ambitious for a first project. There are certainly a lot more variables to consider, and the box building is more complex than a basic speaker. I think with help from people here though you will be able to come up with a satisfying design, and on preliminary calculations for your woofer, your cabinet won't be too massive either. Certainly bigger than 25l, about 50l I'd say. That is based on tuning to the 37Hz Fs (resonant frequency) of the woofer with a 3:1 line taper, should work out with about a 6ft line. With one fold you should have some perty looking floorstanders about 3ft tall and a foot deep say. OK, that's not subterraneous bass, but I doubt you'd feel the need for a subwoofer. As you say, for now! ;) No doubt you've already visited the sub design forum. As for adding a second woofer I think that budget would be better spent on a higher quality woofer (like Vifa's XG18WH00-08, glass fibre cone, lower mass, lower Fs, better basket etc), if it was going to be spent. A second cone would help bridge the sensitivity gap between the tweeter and woofer, but as long as you don't plan on splitting your eardrums a single woofer and some attenuation on the tweeter will be fine. Look how many commercial designs do the same after all.

Sorry to go on, don't know if any of that has helped solidify your goals. As bjackson said, do a bit more research and I think you'll be set. I think a series crossover (as opposed to the standard parallel) would suit those units nicely as both have extended bandwidth and the tweeter an exceptionally low resonance. Still, plenty of time for all that later! Have fun. :)

Ben.
 
Noksukau said:
I wouldn't be, for me the design was everything, and learning from mistakes is fun as it means you get to do ANOTHER design! :D
:D


Thanks a lot for the reply Ben :) I've already built a kit a while ago, some M5's from TLSK, for the price I paid I'm quite happy with them and there nice for little bookshelfs. Back when I had my receiver and my sub they were a quite nice setup, but you know how it goes ;) I was looking at some kits but here in Australia the floorstanding kits are now a bit expensive and I want to desgin my own speakers to suit my room and my price range. (plus they sound so much nicer when you can say you made them ;))

I'm leaning away from starting off with a TL design and just sticking with a vented box. I'm still a bit confused with the crossover design and everything but I'll keep reading :)

I'll post more later but at the moment I'm in the middle of fissling with WinISD ;) Thanks for the posts, any other help or ideas definalty wouldnt go astray, cheers :)
 
Well I've been having a look at the Peerless 850122 driver which seems to be pretty similar to the Vifa but has a nicer gain slope in a larger box. However it isnt as sensitive and it still has very high group delay at the tuning frequency (although I'm not sure if this matters if I have a sub???). I think I'm gonna stick with the Vifa because I've only heard good reports about it and its meant to have a nice midrange.

I also had a look at this design:
http://www.mass.com.au/pdf/designs/mp17h.pdf
which is very similar to what I'm making, the only difference is the tweeter which is the Vifa D25AG-35-06. Its the same price as the D27 I was looking at and its aluminum compare to silk. To be honest I'm not really sure which is the better tweeter. (sensistivity on the D25 is only 90dB so I wouldnt have to dampen it as much) If I used the D25 I would have a nice crossover design (making the crossover - well a good one - is kinda confusing me. I dont really have the experience to know what actual difference to the sound it would make)

One other concern I have is the Vifa woofer only has a nomial power rating of 40watts which seems a little to low to me. I want the music to be able to go loud as well as sounding good. I may be on the wrong track here though, just wanting some clarification :)

Cheers
 
Re: Size Does matter!

mwmkravchenko said:
Hi Kev

I'm writing this in front of two boxes with the same woofers. THey are floor standing. One hundred liltres, shelved low end. Decent reponse to 30 hz. And thats where it is tuned. You don't always have to go with a so called optimal alignment. Try fiddling with the numbers and see what happens!

MArk

Any other pictures or info?

Cheers

Edit:
chainenoble said:
i put together a low price mtm using the silver flute 6.5" woofers and the seas tdfc tweeter.i was very impressed with the sound for what they cost.check out the silver flute woofers,they are a low priced jem.

I'll have a look but to keep costs down I would prefer to use drivers I can easily get over here. I'll have a look around.
 
Pics?? what pics??

No digital camera!

They are 10" wide ( 245 mm ) by 56" tall ( 1422 mm) by 17" deep ( 416 mm ) deep. Double port 3" ( 75 mm )

Driver complement is two vifa 6 1/2" and a BGcorp Neo 8 set up in a MTM. The tweeter panel is crossed over at 700 hz. The tweeter driver is set at ear height 34" ( 833 mm ) on centre. Great sound and imageing. Not the best X-over point theoretically but tuned with a lot of thinking and listening. It's a first order electrically but quickly turns into an acoustical third order at 300 hz so it's not that bad of a choice. It's soon to go active.

The interior is shelf braced and there is a shelf at a level to install a massive 15" I picked up. So the box will have a side firing 15" sub. I'm going to go with an equalised box design alla graham maynard ebass. And the rest will be in the listening. The two 6 1/2 approach the displacement of a decent 10" so the bass is not all that bad. With the larger box as it is there is decent low bass response with a shelf starting at 60 hz dropping by 3db and then rolling off around 35 hz. It has scared more than one person. Do a simulation and see the total possible output. Use x-max plus 10% for your calculations as it is a little more realistic. If you want to go with an MTM only a high pass filter or low cut would be a good idea. It would give you a lot more headroom.

Mark
 
Could I make a transmission line box or would that have to be really big?

Greets!

They have to be large to go low with any authority. A ML-TL is much more flexible though. Here's a proven design that's slightly <25L for a single P17 tuned to ~Fs using these averaged measured specs of several units:

Fs = 46.17Hz
Vas = 21.93L (0.774ft^3)
Sd = 135.62cm^2 (21.021"^2)
Qes = 0.6
Qms = 1.28
Qts = 0.40851
Re = 5.83ohms
Le = 0.92mH
BL = 6.35 N/A
Cms = 8.3067e-04mm/N
Mms = 0.0143051Kg

L = 30.22"
pipe area (CSA) = 46.017"^2
vent = 2.5" dia x 4.5" long near/at the bottom
driver down from top 11.53"

Extend the bottom of the cab as required to get the desired tweeter height and fill the resultant cavity with kitty litter or similar to to keep it from resonating/mass load it. I recommend mass loading the top also with either a filled cavity, triple thick top plate, heavy potted plant, etc.. Of course allow for a tripod base to keep it from easily being knocked over since it's so tall/'skinny'.

WRT the XO, make the cab the same width with the tweeter location the same as John's (note they're mirror image) and clone his XO: http://www.audiodiycentral.com/sd200_johnk.shtml

GM
 
I like the look of those Vifa TL speakers, I feel like I've seen every Vifa P17 design on the net ;)

Now I'm pretty much wondering do I:

1. Stick with the one Vifa P17 and build a smallish tower.
2. Grab a Peerless 850122 or a driver that seems suited to a larger enclosure.
3. Save for two P17's and go for a TL MTM or just a plain vented MTM.

At least if I make a tower with just the one Vifa driver it will give me a bit of experience and later on I can always rip the drivers out and design again.

Just a bit of info about my setup, I recently sold my Pioneer VSX-C301 which is pioneer's slimline receiver range. Basicly the looks came a cost, my brothers DSE amp sounded noticably better. I have a pair of M5's (LSK kit speakers - there bookshelfs with (from memory) a 5.25" dayton driver *i think*) and at the moment I'm running a Technics Integrated amp (SU-X120) and some Technics 3 way speakers (SB-CD120), their the old chunky sort of speakers with a 1.5" tweeter, 3" mid, 8" woofer. I've been looking around for receivers for a while now and while I havent got anything yet I'm looking at getting a Cambridge Azur 540R (if I can find one at a good price - I've got about $1000AU to spend). I'm leaning away from the Yamaha receivers (even though their at really low prices) because 90% of the time it will be used for music. Anyway I was thinking (hehe :D this is going to really start getting confusing) I could use the preouts to go to my Technics amp and rebuild the technics speakers and just have the woofers running low passed.
......
Ok I've been thinking and ignore that idea ;) I'll probably stick to the single Vifa woofer (I'm guessing its ok only having a 40W nomal power rating and the tweeter 100W ???) and I'll see how it goes from there.
 
I'm guessing its ok only having a 40W nomal power rating and the tweeter 100W ???

Greets!

Obviously it's not an issue since it's such a well proven combo. Even if it wasn't, it's still not an issue since each driver will only use as much power as it 'feels' the need for based on the signal, and since acoustic energy falls at 1/f, the tweeter will only 'feel' the need for only a fraction of the total electrical power required.

WRT which to build, IMO it depends on what your long term goals are, i.e. want to build one set of speakers and get on with your life, or want it to be an on-going hobby. If the former, save up and build a proven hi-perf design. If the latter, then 'keep it simple, stupid' (KISS) and build a relatively inexpensive, well designed speaker to have something to enjoy while you're learning the craft and saving for the next project.

GM
 
Vifa D27TG-35-06 and P17WJ-00-08

I built a pair of tower speakers using the same drivers, and the crossover from the 'Pilatus' concreate tower published in the Speaker Builder magazine.

Initially the internal volume was too large to tune properly, but when cut back to about 25L and retuned via a rear 50mm diameter port the bass is pretty good.

A mistake was that the Pilatus crossover is optimsed for woofer on top and tweeter at bottom, but I built the speaker the traditional way with tweeter top. This has resulted in a speaker that sounds better from below the axis of the tweeter! However, with the considerable step response compensation of the woofer's 1.8mH inductor this is a rather 'warm' sounding speaker anyway. The crossover is 2nd order on woofer, 3rd order on tweeter.

I have also built the 'free' crossover for this pair of drivers published by Madisound in their Vifa catalog. (In fact the tweeter there is the D27TG-45-06, but the only difference is the bulged faceplate, in other respects it is identical to the 35-06) This crossover is 1st order with impedence compensation on the woofer, and 2nd order on the tweeter. With this crossover the speaker is much more forward sounding, and the bass is not very pronounced. I prefer the pilatus crossover. Let me know if you would like the component values for it, as right way up (woofer on top) it would make a nice sounding speaker. Tip : these Vifa tweeters have a reputation for harsh sound in some circumstances - Vifa recommends a notch filter tuned to the resonance frequency, and it may be that some folks don't know this, hence the harsh sound. Notch filter is resistor, capacitor and inductor in series with each other, in parallel to tweeter after the xover, with values : 6.8ohms, 69mF, 0.9mH. This will damp the tweeter at it's resonance frequency.

Amplifier used is Pioneer A400 (poor mans audiophile amp, 50W/channel and very sweet sound) and oldish Philips CD player.

Someone has built a TL using these drivers and pilatus crossover, so it can be done. They used the Voight tapered pipe design which is very simple to make and results in a floor standing tower. (See the David Weems book called 'Great Sounding Speakers'.

My next project I hope is a 'budget' Ariel with MTM TL design using P13WH-00-08 drivers and the D27TG-05-06 tweeter. I have been working on the Xover using the CMP program which comes with the Weems speaker book.

Thats it. Good luck.
 
Hi everyone :)

Been doing a bit of thinking and playing around with different ideas lately. What I've decided to do is make some largeish bookshelf speakers using the P17J and D27TG. While I do want floorstanders unless (in the future ;)) I get two woofers the box will simply be too large for what I want to tune it to. So my "bookshelfs" will most likely look like floorstanders just internaly the box volume will be halfed. I'm working on/looking for the crossover at the moment. The sensitivity of the P17 is 88dB and the Tweeter is 91dB so I've been told I have to damp the tweeter which makes sense but how do you do this? I'm also planing on making a matching centre but I have a question. I know ideally you should have an identical centre but is it ok if I use the same woofer/tweeter/xover but put it in a small sealed box instead?

Cheers :) Hopefully when I get the drivers and stuff (and my digital camera back) I'll take pics and show you the finished result. Thanks for all your help. Ooo by the way I got a new receiver... an Azur 540R. Its very lite on in the features department but the sound is very nice, and theres lots of power. :)
 
Possible box tuning and Xover

Big Kev :

A recommended box tuning for the P17WJ-00-08 woofer is :
Internal volume : 22 Litres
Port : 60mm diameter, length 65mm

Crossover of the Pilotis :
Tweeter :
1) series resistor 6.8 Ohm (unusual, the padding is most often put immediately before the tweeter, but this must go here at front).
2) series capacitor 3.9 micro farad
3) parallel inductor 0.27 mH
4) series capacitor 6.8 micro farad
5) parallel D27TG-35-06 tweeter.

Woofer :
1) series inductor 1.8 mH
2) parallel capacitor 4.7 micro farad.
3) parallel P17WJ-00-08

The above will work - but maybe someone else on this forum with crossover software can tune the above better and provide required inductor resistances? Results can vary if you don't use exactly the right values.

The above values are for woofer on top, tweeter at bottom !

good luck.
 

tktran

Disabled Account
2003-03-17 4:30 am
Perth
kram0.com
Hi Big Kev !

I've got 2 friends building a P17WJ/D25AG-35 2 way floorstanding based on Dennis Murphy's (www.murphyblaster.com) crossover. Dennis built his own pair in an Ellis Audio (www.ellisaudio.com) 1801 cabinet, but my friends built their cabinets based on the floorstanding 1801f cabinet. By maintaining the same box volume and port tuning, and keeping close to the driver layount/spacing.

My friends and I like building speakers, but we don't have measurement equipment, crossover design software nor expertise to design a customised and optimised crossover, from scratch. If you are like this, for further info please see our website is www.kram0.com/gallery. Take a look at Mark's P17/D25 floorstander, with Dennis' crossover and measurements.

The design is fairly recent (2004) and I believe is based on modern P17/D25 drivers, which apparently, have changed a little over time, although manufacturer spec sheets do not reflect this.

The inductors arrived yesterday and we'll be ready to listen today/Friday, and will be able to report back on how they sound.

I feeling is that they should be pretty good. Not the last word in detail retrieval, but at moderate listening levels should suit pop/rock fine.

regards,
Thanh.
 

tktran

Disabled Account
2003-03-17 4:30 am
Perth
kram0.com
Ok the P17/D25 is a wrap!

Unfortunately it was too good, and revealed all sorts of up-stream and down-stream problems.

The CD player clips it outputs, and needs to be turned down whenever it's power on.

The RCA cables are unsheilded. Although humming is a pretty common problem, this is the first time I've heard an A/C 50Hz hum through a subwoofer. :eek: hmmm.

The room is too live, almost like a bathroom. Now I should have guessed this, I mean- look at that room. Wooden floorboards, modern deco, venetians blinds and not much soft furnishings at all.

As soon as we fix up all these problems, and throw a rug down, I'll play more Keith Jarret, Diana Krall, Patricia Barber, Rod Stewart, as well as Black Eyed Peas and post some comments about how they REALLY sound.

As the moment all I can hear is 1) the room (if it's loud) or 2) the hum (if it's soft)