Vifa P17WJ + D27TG-35-06 TL (non MTM)?

[critofur]

Hello,
I have one pair of Vifa P17WJ drivers which I picked up at the tent sale. I recently also got a pair of Vifa D27TG-35-06 tweeters as I thought I would like to try them, and I think they will be a good match with those woofers (that, and, Parts Express doesn't seem to be carrying as many different models of Vifa speakers recently).

I know there are gobs of P17 designs floating around, but, most that I've seen are MTM.

I recently heard some TL designs for the first time at the Dayton DIY Audio event, and I liked the bass very much.

Andy G. has a design "The Pipes" that I could use, and I suppose I could fold it into a rectangular shape? But, I haven't done any TL/TQWT etc. designs yet and was wondering if someone knows of one already done in the more traditional shorter rectangular box shape (that uses one P17 woofer)?

I'll be happy to work out some sort of crossover for myself, but if someone has already worked out the box plans, quantity and placement of fill, etc., that would be helpful.

Anybody heard the "Pipes" care to comment further on how they sound relative to other DIY (or commercial) speakers you've listened to?

I may go ahead and build the Pipes, just to hear them, but, I don't think they'll pass the SAF test, being so tall. Rectangular boxes are also easier to move/fit in a car, etc.

 

[Ed LaFontaine]

Well, this is interesting.

I just "retired" a set of speakers which I replaced. They included a Madisound-designed crossover and used The P17 and D25AG-35-06. I had stashed them with the thought of working up a MLQW enclosure for them.

Can you provide the parameters for the P17's you have?

I've got the Quarter Wave subscription and MathCad...my treat.

Later on I'll reverse engineer the crossover and post that.

Of course, anything that is already worked out is welcome.

See Ya!

 

[critofur]

Cool, thanks Ed!

You want me to measure the impedance and fr so I can send you the .frd and .zma files?

I don't have a "test baffle" built, and I also don't have a calibrated mic - so, might be better if we can find somebody's existing .FRD file for now...

Maybe I should just go ahead and built a test baffle.

Here's the manufacturer's spec. sheet:

http://www.partsexpress.com/pdf/297-305.pdf

I was thinking of a first order series crossover?

Here's a link to a Madisound crossover: http://www.madisound.com/catalog/PDF/vifa/P17WJ00_D27TG45 Leap Design.pdf

Ah! Just found this: http://members.tripod.com/oakleyspeakers/MAIN.html

I think I saw that before, had just forgotten about it...

 

[critofur]

So I got these D27TG-35-06 tweeters because of the low 650Hz FS, but, Vifa recommends "at least 2'nd order" crossover, and, at 3.5Khz!!

http://www.partsexpress.com/pdf/264-526.pdf

Seems a bit high to me. But, I'll play with crossover designs more later...

 

[00940]

Hello,
I have one pair of Vifa P17WJ drivers which I picked up at the tent sale. I recently also got a pair of Vifa D27TG-35-06 tweeters as I thought I would like to try them, and I think they will be a good match with those woofers (that, and, Parts Express doesn't seem to be carrying as many different models of Vifa speakers recently).

I know there are gobs of P17 designs floating around, but, most that I've seen are MTM.

I recently heard some TL designs for the first time at the Dayton DIY Audio event, and I liked the bass very much.

Andy G. has a design "The Pipes" that I could use, and I suppose I could fold it into a rectangular shape? But, I haven't done any TL/TQWT etc. designs yet and was wondering if someone knows of one already done in the more traditional shorter rectangular box shape (that uses one P17 woofer)?

I'll be happy to work out some sort of crossover for myself, but if someone has already worked out the box plans, quantity and placement of fill, etc., that would be helpful.

Anybody heard the "Pipes" care to comment further on how they sound relative to other DIY (or commercial) speakers you've listened to?

I may go ahead and build the Pipes, just to hear them, but, I don't think they'll pass the SAF test, being so tall. Rectangular boxes are also easier to move/fit in a car, etc.

TL are indeed really nice. Here's my take on a P17WJ+DT26 in rectangular boxes. They are now at my parents' house so I cannot provide any real measurements : http://www.diyaudio.com/forums/showthread.php?threadid=85736

For the 350€ I've invested in this project, I'm extremely happy with their sound. They like space to breath though, imaging suffers when they're too close to walls. Efficiency is quite low too and that combined with the low power rating of the p17wj means you cannot get very loud listening levels (which is perfect for my parents )

 

[Andy G]

There is no reason the "Pipes" cannot be folded.... ( except they will look like an box )

You may have to put the tweeter below the P17 to get the drivers to fit.

I even have a series crossover for the P17/D27 somewhere at home, (I'm at uni at the moment)..... email or PM me.

ps. be aware that the response of the P17 will be different in a "Pipe" style design from in a vented or sealed box, the sound is distinctly different.

pps.. the PE showcase may still have Dave's kids' build of the Pipes, where you can get his opinions of sound quality etc.

ppps.. as for saf, I should note that at least 4 pairs I sold were sold because the female really like the look !!! And if you finish them in, say, the same colour as the walls or to match your room cabinets etc, they really are not very intrusive at all.... more like "slim and elegant" (just like her)

 

[critofur]

There is no reason the "Pipes" cannot be folded.... ( except they will look like an box )

You may have to put the tweeter below the P17 to get the drivers to fit.

I even have a series crossover for the P17/D27 somewhere at home, (I'm at uni at the moment)..... email or PM me.

ps. be aware that the response of the P17 will be different in a "Pipe" style design from in a vented or sealed box, the sound is distinctly different.

pps.. the PE showcase may still have Dave's kids' build of the Pipes, where you can get his opinions of sound quality etc.

Well, when reading people's reviews of speakers I prefer to have a comparison to some other model [discussed in the review], otherwise, I don't really find it useful. Kind of the way people like their own children, they generally like the speakers they make. Without comparing them to some other speakers, hard to know what they're really saying...

pps. as for saf, I should note that at least 4 pairs I sold were sold because the female really like the look !!! And if you finish them in, say, the same colour as the walls or to match your room cabinets etc, they really are not very intrusive at all.... more like "slim and elegant" (just like her)

Yes, I heard TL speakers for the first time at this last Parts Express DIY audio event (as I mentioned in the OP) and that was what impressed me most at the show. I haven't heard any P17 speakers, so, no concern about them sounding "different" as I haven't heard them in the first place, other than listening to them in the garage upside down with a tweeter on top with just a cap on the tweeter as the "crossover".

I've heard various people talking about liking the bass from P17s (including in small BR boxes) ~ with TL, there'll be even more bass to like.

Even if I don't end up liking the speakers, I still want to have a pair of TL speakers for a while to listen to at home (mostly in the garage, prob.). To be a fair trial of TL, I suppose I should build a BR box for the same drivers as a comparison...

TL are indeed really nice. Here's my take on a P17WJ+DT26 in rectangular boxes. They are now at my parents' house so I cannot provide any real measurements : http://www.diyaudio.com/forums/showthread.php?threadid=85736

For the 350€ I've invested in this project, I'm extremely happy with their sound. They like space to breath though, imaging suffers when they're too close to walls. Efficiency is quite low too and that combined with the low power rating of the p17wj means you cannot get very loud listening levels (which is perfect for my parents )

Thanks for the info/link, I'll read that now...

Are you sure they won't play loud? One guy's web page where he had a little project w/them and a review said they were great as party speakers in his loft apartment and the bass was booming (in a good way).

 

[Andy G]

Well, when reading people's reviews of speakers I prefer to have a comparison to some other model [discussed in the review], otherwise, I don't really find it useful. Kind of the way people like their own children, they generally like the speakers they make. Without comparing them to some other speakers, hard to know what they're really saying...

All I can assure you of, is that Dave has considerable experience with many different types and style of speakers and is very discerning on what he listens to. He also calls it as he sees it, without bias. Those who know him will vouch for that.

Note that I, myself, do not offer a comment on the sound of the speakers, for the very reason that they are my design (and the fact that I haven't listened to a pair for quite a long time).

 

[critofur]

Ed? Are you still here?

I see plenty of crossover designs out there, but not plans with dimensions for the ideal TQWT.

Also, I'm fairly new to TL speakers in general, not sure how to decide which type would be "best"?

(and the fact that I haven't listened to a pair for quite a long time).

Not good enough to compel you to keep them around permanently, I guess? (or to build another pair to keep for yourself)

 

[Andy G]

Not good enough to compel you to keep them around permanently, I guess? (or to build another pair to keep for yourself)

The P17 has not been available over here for a long time.

There are better drivers and certainly other designs to play with. I can't keep them all !!
I do still have the Corinthians, which is a similar TL using the Seas T17.
Having played with the P17 for quite a while, back when they were available, the Pipes or a similar TL is, IMO, the best way to optimise what it can do.

 

[Ed LaFontaine]

critofur,

My apologies, I certainly don't like to leave anyone in suspense...work has conspired against my input here. I just negotiated a change in scenery.
Look for some posting this weekend. First will be a MLQW, then on to the tapered pipe which I expect will take me through a learning curve. I might have to consult with Paul K as he certainly has more experience there.

 

[critofur]

critofur,

My apologies, I certainly don't like to leave anyone in suspense...work has conspired against my input here. I just negotiated a change in scenery.
Look for some posting this weekend. First will be a MLQW, then on to the tapered pipe which I expect will take me through a learning curve. I might have to consult with Paul K as he certainly has more experience there.

Oh, I totally understand, no problem. Good to hear you didn't just suddenly die or something terrible like that.

I just got a new job myself, starting Tuesday. I'll finally be able to afford my hobby.

There's nothing like working at a speaker company for being able to afford this hobby, ever since I moved away from NYC in 2003 I sure miss that, in addition to working with the great guys at Ohm (Ohm Acoustics, www.ohmspeakers.com ).

I am itching to build, and listen to, my first pair of TL speakers. I think the Vifa P17 is a good driver for TL.

I also have some of these drivers: http://www.tymphany.com/datasheet/printview.php?id=12 which I'm very excited about.

And, I have about four of the Tang Band W5-704D drivers that I haven't decided what I'll do with ~ though I may build Undefinition's (Paul) "Aethers" with. It would be interesting to compare a pair of P17 TLs with an equivilant pair of TB 704 TLs (using the same tweeters / tweeter crossover).

I most likely will end up using the Peerless Nomex HDS 6.5" drivers in Ohm "Walsh" style speakers.

I should be finished building my router table this weekend, that should help with the method I plan to use to construc the TL speakers.

You a few hours South of Columbus, Ed?

 

[Ed LaFontaine]

You a few hours South of Columbus, Ed?

Yes, the other Berea, in KY

I thought you attended DIY Dayton?...I may be confused.

There may be a diy get together in Lexington, KY around the 15th of Nov. I'll keep you informed.

 

[critofur]

I did go to the DIY Dayton, but I was only able to pop in for a couple hours, and they had LUNCH in the middle, darn them! I couldn't resist going back to the tent sale a second time after being a little discouraged at how hard it was to hear the speakers there at the show. I had my friend Devin, my wife, and my son with me, who was getting a little tired and cranky, so I didn't stick around.

I saw you there, and a few other folks I've talked to, but I didn't introduce myself to anyone that time, and I didn't get to listen to most of the speakers that I wanted to hear.

Well, the sad fact was, even if I was there when they played them, only the judges in the front row could really hear them decently, and even if I was in the front row, I'd say they were at about half the volume they'd need to be at to decently audition a speaker...

Well that's all beside the point, which is trying to find the best TL design for a pair of P17 woofers...

I imagine, in a TL design, you can get just enough good sounding bass out of a pair of P17s to make them fun and pleasant to listen to at decent levels. Maybe not front row rock concert levels, but something that'll get your feet tapping.

I'm starting my new job next week, so, I will finally be able to afford this hobby again , but, my work week is Saturday - Thursday, which means I'll have to accrue some vacation time before I make it to any more weekend DIY events

Off topic question: Hmm, what do you think of the "Enable" treatment of speakers? I'm a little skeptical, I'm sure MOST of the "effect" is biased perception of people hearing a difference because they WANT to ~ but, I do know, putting stuff on speaker cones can change their response / sound... I guess until we get somebody with one of those laser vibrometers to scan them, we won't know exactly what (if anything) is going on there.

 

[00940]

Are you sure they won't play loud? One guy's web page where he had a little project w/them and a review said they were great as party speakers in his loft apartment and the bass was booming (in a good way).

Well, I might be influenced by the fact the room they're used in is quite big: 12m long, 5m wide, 4m high (and it's connected by a very wide bay to another 5m/4m/2.5m room). The room has also large areas covered by books and thick carpets. I honnestly don't remember how was the bass in the smaller room where I built those (I tweaked the filling inside the final room).

From the sims, it was quite clear though that my design would be way less efficient than Andy's.

 

[Ed LaFontaine]

The simulation above is a first draft, using manufacturer's spec's. Below is a simulation in the same cabinet as that above using the parameters in 00940's attachment in this thread above.

Which parameters to use? Which type of response should be intended?

Consider there is no baffle step represented in either sim'.
Consider also there may be a small amount of room gain to increase the apparent bass response.
And one more, in the top sim x-max is breached at ~12 watt input, providing a spl of ~96 dB. The lower sim would allow slightly higher input for the same x-max. I think reason would limit the output to something less than that.

The internal casework dimensions are as follows:

Height: 36"
Width: 7.5"
Depth: 9.0"
The P-17 is located 10.6" down from the top
A 2" dia. x 5" long port is located 29.95" from the top
Moderate stuffing is used, totaling 0.172 pounds

I submit this to you for your consideration. I look forward to your questions and direction.

 

[Ed LaFontaine]

critofur,

I think the EnABL treatment produces a difference in speaker response. It is subtle. There are aspects of the treatment that others report which I can't confirm. Consider what I say in light of the fact that my ears are 55 years old. I've worked a long time in and around construction. My perceptions are likely to be limited by my equipment.

My offering of the EnABL kit is motivated primarily by an interest in making it available to more people for them to evaluate and judge for themselves. I whole-heartedly agree there is more testing to be done.

 

[critofur]

Cool! I'm headed to California for a week for new job training, when I get back I'll have to get started on building a pair.

 

[critofur]

...The internal casework dimensions are as follows:

Height: 36"
Width: 7.5"
Depth: 9.0"
The P-17 is located 10.6" down from the top
A 2" dia. x 5" long port is located 29.95" from the top
Moderate stuffing is used, totaling 0.172 pounds

I submit this to you for your consideration. I look forward to your questions and direction.

I'm confused why you specified a round port for a transmission line?

How do we determine the length and placement of the internal boards and the size of the TL opening? I thought your spreadsheet would do those things?

 

[Ed LaFontaine]

Hi critofur,

From an appearance standpoint, the Mxss Loaded Transmission Line, mltl, looks identical to a bass reflex enclosure. The "mass loaded" part of the system is the port. This may be round or rectangular like a slot.

In function, the internal dimensions are chosen to avoid resonances which would degrade the fidelity of the signal.

I think you anticipated a straight or tapered tl. That can be done. I chose the mltl for the ease of construction with most if not all of the benefits of other possibilities.

The basis for this is included in Martin King's site:

http://www.quarter-wave.com/