Dipoles ?

[LennyK]

Hello

I read www.linkwitzlab.com and my mind is totaly crazy about dipoles [for a long time, to be honest]

I think about making "el cheapo" version of SL Orions.

I read a lot [here and some other "places"] and these are the speakers that I'm thinking of right now:

- 27TDFC (H1189) or 27TBFC (H1212) as tweeter
- 205 WR [830884] driver for mids
- H frame 2x SLS 12" [830669] for bass


Now I'd like to ask some questions:

1. First of all - is that whlole "dipole thing" worth effort ? I don't have lot of money to experiment... I'd like to "build and enjoy". Four drivers for bass - its a lot.
Maybe it is worth more just to buy less but more expensive drivers [to go 2 way with Excel W18 and ScanSpeak 9700 for example] ?

2. Is enybody familiar with new HDS nomex Peerless drivers ?

3. Are those Seas tweeters MUCH worse than SS9700 or Excel Millenium ?

thanks for attention

best regards

Lenny

[Bose(o)]

Sooo, soooo, soooo worth it!

I don't think I'll build another enclosed loudspeaker for myself ever again. My OB speakers are my third go at DIY and it was the charm alright. I'm planning on using acrylic to make my final design and am anxiously waiting for the summer to do this.

The sound is incredible, clear, articulate and with the right cross-over and drivers (EQ too), you will enter two worlds; Audio Nirvana and the "I love OBs so much that I would...".

From experience you want mainly two things for woofers: High excursion and a low Fs.

[hobby1]

hi lenny

first,i use the same woofer,they work very well in dipole
for budget purpose,think about use only one woofer in U frame
because efficient is about 92Db plus 6Db for a equal lengh u frame then a H frame.
if your room is not too large it can be sufficient.....
about the 205 WR be sure it can go at about 1.5/2khz to cross tweeter
finally,like bose,i think dipole is far better than any enclosed things,read and apply all Mr Linkwitz's recommendations

greets

[sreten]

checkout :

http://www.musicanddesign.com/naomain.html

/sreten.

[Scottmoose]

Only one problem with dipoles: if you make a good job of them, it's unlikely you'll ever be able to listen to a conventional box speaker again. There's no looking back... says me. I had someting vaguly similar to his Phoenix, albeit with full-range units on the main panels, which I had to sell, as it was physically just too big for my listening room. My ML TQWTs and corner horns are great substitutes, but dipoles still haunt my musical dreams.

Don't assume BTW that more expensive automatically means 'better'. In a dipole, you have to have specific requirements, such as very long-throw for the bass drivers. In fact, in my view the primary benefits of dipoles are in the bass-regions, not the midrange, and certainly not the treble (observe that none of Linkwitz designs have dipolar treble... for good reason), as they activate far fewer room-modes. This is rather ironic, because that's where they are hardest to get working due to the acoustic cancellation a low frequencies! Oh well...

Some try a hybrid enclosure -part dipole, part sealed / vented / TL box enclosure. Most use the box for the low-frequencies and open-baffle for the mids and highs -fair enough. Yet, given the choice, and following Linkwitz guidelines, the better bet for optimum hybrid sound would actually seem to be a sealed box for the mids and highs and dipole for the low frequencies!

Dipoles? Do it. You will not regret it.

Best
Scott

[kneadle]

Originally posted by Scottmoose
Only one problem with dipoles: if you make a good job of them, it's unlikely you'll ever be able to listen to a conventional box speaker again.

I accidentally made this same mistake with a pair of midrange speakers leftover from an old set of Cerwin Vega's and a big piece of plywood.

I really like TL design, though, so I don't think I've been completely converted to the dark side yet. Of course, I haven't felt the power of the dark side, either; that's for my OB sub project.

Right after that, THEN I'll do another TL. I swear!

Dave

[PHilgeman]

Hmmm...

Having built several dipoles, I have come to the conclusion that cardioid, or sealed box bass has the edge on diple bass.

It really requires tremendous ammounts of EQ to get it right and in a good room, equally flat response can be had with sealed.

The midrange however is where the magic is, especially 150Hz-1000Hz. The lack of 'boxyness' and the problmatic transition from 2pi radiation to 4pi radiation is where the magic happens IMO.

-Paul

[gavinson]

I agree completely with most all of the previous comments, although some comments seem more appropriate for line-source systems than dipoles.

Dipoles lose all the box coloration simply by virture of their design. I eluded to some of this on the "Drivers" page of my project website. Build a sturdy box, and put a boxed speaker inside of it. Crank up the speaker inside and just listen to the box "sing". If the backwave from the driver can vibrate a .75 or 1.0 inch piece of MDF, what can it do to the speaker cone itself?

No box = No Box vibration (noise) and no captured waves coming back through the speaker cone.

IMO, this is effect is most apparent in the critical midrange and upper-midrange from 300 to 5000 cycles. Instruments (particularly keyboards and horns) simply are unveiled by this lack of box noise. Voices are also greatly (incredibly) impacted.

I had great dipoles for a time, then was forced back to boxes. Now, I'll never go back.

Best of luck with your project.


The Ribbon Project

[LennyK]

First of all -thank you so much for kind comments. I'm surprised how many posts.

Originally posted by Bose(o)

From experience you want mainly two things for woofers: High excursion and a low Fs.

That's why I'm afraid about those SLS speakers. They are not that powerfull as XLS. But in the other hand - I can build closed box subwoofer later, for realy low freq.

Originally posted by hobby1

first,i use the same woofer,they work very well in dipole
for budget purpose,think about use only one woofer in U frame

Do you use this speakrer this way ? Is is enough ? Can you tell us what kind of music you like to listen ?
I like very different kinds of music, but I sometimes like to turn Pat Metheny off, go to "wild mode" and play Chemical Brothers. So bass is important.

Originally posted by sreten
checkout :

http://www.musicanddesign.com/naomain.html

Thank you for that link.

Originally posted by Scottmoose

Don't assume BTW that more expensive automatically means 'better'. In a dipole, you have to have specific requirements, such as very long-throw for the bass drivers.

That's why I think about my "el cheapo Orions" vs "normal" closed [or vented] box with more expensive speakers. If you don't have to buy that many bass units - you can spent more on good 2 way speaker.


Can we now discus more about the speakers that I mentioned ?

Anyone have comments about new HDS Peerless or 27TxFC Seas speakers [comparing to more expensive Excel/Scan Speak ones] ?

best regards

Lenny

[hobby1]

hi,

"Do you use this speakrer this way ?"
yes,1 sls in U frame per voice and active eq

"Is is enough ?"
yes too...but my room is 18 m2

i listen to all kind of music,from classic to r'n'b (strong tr808 bassdrum) but Mainly live music
and this system is use as monitor in my home studio

the only limitation of the sls is fs (28hz) that it can demand big eq down this freq,but depend of your room too....

in my configuration 3 Db bassboost at 28hz is use and a Brickwall active hipass at 18hz to limit excursion

see the attach file it's comparison of xls and sls made whit "xlbaffle" spreadsheet

hope help you