| Nelson Pass |
Like the title sez:
Merry Xmas.
(later) Oh, uh, correct to www.passdiy.com
:)
- Moderator Note: Fixed the title ;) |
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| eLarson |
It's... it's...
BEE-YOO-TI-FUL!!
Thanks, Nelson for a terrific Christmas present
and may God rest ye merry.
Erik |
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| Dennis Hui |
That's stunning looking... Probably the neatest use of
sonotubes since sonotube telescope tubes.
Thank you for another fun project.
Merry Christmas!
Dennis |
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| eLarson |
| quote: | Originally posted by Dennis Hui
That's stunning looking... Probably the neatest
use of sonotubes since sonotube telescope tubes.
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That's it! It reminded me of a Dobsonian reflector
telescope (the pre-party version with the box, that is.)
Always did want to build a 12" reflector... maybe
now it will be a 12" El Pipe-o. :)
Best,
Erik |
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| stefanobilliani |
| Thanks! and Merry Xmas to all. |
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| vpharris |
| N. P: That's just super! Thank you, and Merry Christmas. |
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| grataku |
Nelson, that was a very funny article. Sounds like the name alone brought back the good times in a grand scale. Must have been alot of fun to use an $20,000 amps to blow up $400 woofers. I wonder what it must have been like just before that happened. ;)
Thank You and Happy Holidays! |
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| Duck-Twacy |
I only see Dells
:confused: |
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| Won |
Did you try just typing it in? That seemed to work for me.
In the student center at the 'Tute, there used to be this ice cream store that had damn good icecream, and this big sonotube sub. Naturally, it was a Bose sonotube. What was interesting is that both "phases" of the woofer were loaded with transmission lines of different length. It's basically the transmission line equivalent to the acoustimass bass reflex alignment. Has anyone tried something like this?
-Won |
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| Keld |
Hi
Only see dells :
the link is dot com dot, so remove the last dot |
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| Peter Daniel |
| quote: | Originally posted by Keld
Hi
Only see dells :
the link is dot com dot, so remove the last dot |
I fixed the problem.;) |
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| Duck-Twacy |
Much better :)
D*mn, that woofer (21") is discontinued :bawling: |
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| Digi |
I need a sub for my new project, El-Pipe-O may fit the bill. I wonder what Nelson's sub would look like if he built it like one of his own smoking appliances? J/K Time to track down some sonotubes and give it a whirl. Cool execution of a trannie line Nelson, thanks!!!
Rob |
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| GRollins |
If the original drivers Nelson used are no longer available, you could try for the Hartley 24" of legend. Last I heard, they were still available.
I believe Magnat also has a driver in that class.
If all else fails, you could try to score one of the old JBL or EV 30" drivers, though you'd have to locate somewhat larger tubing...
Grey |
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| apassgear |
Stunning project Nelson, thanks for this remarkable Christmas present.
My girlfriend agrees with Nelson. Size does matter!
Merry Xmas to everyone. |
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| Nelson Pass |
| quote: | Originally posted by eLarson
That's it! It reminded me of a Dobsonian reflector
telescope (the pre-party version with the box, that is.)
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You know, I believe I must have subconciously remembered
the Dobsonians. Such elegant telescopes.
:santa2: |
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| stefan |
| Santa Claus make gifts only for Christmas and Nelson Pass make this all the time! |
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| jh6you |
When I first saw El Pipe-O, I thought it as a gift box dropped into the fire place through the chimney.
:)
Merry Christmas! |
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| Duck-Twacy |
I have a 8 foot ceiling.
What happens when you lay the tubes on the floor (against the walls)?
Maybe a bit offtopic here under amps :) |
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| GRollins |
Horizontal transmission lines work just fine. Better in fact, with the port being at the floor, you'll get a nice boundary to help things along. If they're at the junction between floor and wall, so much the better.
For that matter, the same principle works for reflex cabinets. It's not the laying down that makes the difference, it's the final position of the port.
Grey |
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| planet10 |
Cool article Nelson... it will get a link from my TL site.
Just a note to those who want to build something like this.
With two drivers i would think that loading the drivers push-push would gain some advantages in terms of keeping the box from moving around (sonically & physically). A step further might be to take them a step further and make them (push-pull)-(push-push) as in these two examples which might be considered smaller pre-cursors.
Steve's Shiva Woofer and Chris Brady's which were inspired by Steve's (but finished 1st).
And despite its large size, El Pipe-O may well be far to small (actually far to small) to be optimal for the drivers used.
I wondered if the el pipe-o's line was actually big enuff. I don't currently have Martin King's software up & running (%$^& PCs), but i have gotten a preview copy of Rick Shultz's upcoming (audioXpress) alphaTL article. Rick has been using George Augspurger's software to explore quarter-wave space. The alphaTL is a TL with certain variables frozen so that a simple nomograph generated design can easily be produced. El Pipe-O falls into the definition of an alphaTL.
Early in his work, Martin found that TLs were often made with far to little cross-section to get the best performance out of them -- ironic that in a design intended to get magnificent bass, many TL are literally choking their potential. Running the numbers on the MCM drivers in the 144" long pipe, Rick's alphaTL indicates that an optimal pipe for a single one of these drivers is about 20" radius. For 2 drivers a 28" radius is suggested (and over 50 pounds of poly-fluff in each enclosure!).
I will try to get my "PC" up & running and see if i can run some more detailed sims using Martin's sw, but from Rick's work it is suggested that shortening the line and only running one driver per enclosure would actually be more effective.
It would be interesting to see how el pipe-O performed with a single driver in each.
(Note: i can't say much more about the alphaTL until such time as it is published in audioXpress -- but it (and future variations on the same theme from Rick) will make plug-n-play TL design a reality)
I currently have my 1st alphaTL running in my living room, and it is quite promising. The Mk IIs are on the drawing board, and a set of subs using 10" lambdas is in the pre-planning stage (i have to aquire drivers before they are no more).
dave |
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| relder |
Looks like these suckers can reproduce the brown noise:
| quote: | | You have to be careful about your tone arm, your windows, your neighbors, and your bowels. |
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| Nelson Pass |
| quote: | Originally posted by planet10
It would be interesting to see how el pipe-O performed with a single driver in each. |
We did that. (See the 2nd set of curves) |
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| Nelson Pass |
| quote: | Originally posted by relder
Looks like these suckers can reproduce the brown noise |
We were exploring that when we blew out the
drivers, so to speak. |
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| planet10 |
| quote: | Originally posted by Nelson Pass
We did that. (See the 2nd set of curves) |
:^)
I missed the whole part after the 1st XO... christmas dinner...
very cool. they look better as a single. Properly disguised it would be: "speaker, what speaker ... BTW what do those big columns do?"
dave |
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| GRollins |
If you planned ahead, you could build the TLs into the house, cleverly disguised as columns supporting the ceiling.
Shades of the houses they used to build with concrete horns under the floor...
Grey |
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| Dennis Hui |
| quote: | Originally posted by planet10
:^)
I missed the whole part after the 1st XO... christmas dinner...
very cool. they look better as a single. Properly disguised it would be: "speaker, what speaker ... BTW what do those big columns do?"
dave |
Yeah, if you finish them up nicely enough, those columns look
like funky modern art. :)
BTW, the post--party El Pilp-O's have drivers mounted facing
up. It seems then the driver cone will be resting a bit further
in the voice coil. Does this have any appreciable effect on
TS parameters, power handling and general longevity of
the driver? (I'd imagine the effect is minimal with a light
cone and a large magnet.)
Dennis |
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| Nelson Pass |
| quote: | Originally posted by Dennis Hui
Yeah, if you finish them up nicely enough, those columns look
like funky modern art. |
Finish? What's that? |
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| Bricolo |
| quote: | Originally posted by Nelson Pass
Finish? What's that? |
maybe some painting |
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| cyclotronguy |
My instructions from Nelson are to either make it look perfect or like I just don't care.
Cyclotronguy |
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| Dennis Hui |
Actually I was thinking about how El-Pipe-O clones (or
smaller ones) can double as funky home decoration.
Hmmm...there are some 8" drivers in the basement.
Should see if any might be suitable for such a project.
Cheers,
Dennis |
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| pinkmouse |
Cool project Nelson, shame my room's far too small:bawling:
If you all out there can't find the 21" drivers Nelson uses, you might want to look at these Precision Devices drivers, they are widely used in the PA industry, and are absolutely stonking:D |
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| lieven |
| it's that scandinavian guy with the typo who wasn't arround that day... |
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| Oz_Audio |
I have been playing around with ideas for a new sub, I have been using a single Linkwitz Phoenix using 2 Peerless 12" XLS.
Having just seen this this morning, I shot down to the local concrete builder and aquired 2 12" storm water pipes (plastic), one is 1.5m long and the other is 2.5m long, unfortuanately not the some long length, but that was all be had and I got them for the correct price ($0), so I will have to play with what I've got.
After seeing the single driver. I fell in love, so the 2 tubes in the corners will do.
Now, if my thinking is right, there should be no 6dB baffle step problem, because the floor is infinately wide and if placed in a corner, some more dB in the lower range will also help?
Now out with the saw and router!
Mark |
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| lieven |
sorry jean-pierre,
dacht werkelijk origineel te zijn, mijn kennis vantengels is nie zo goe.
ps kennekiku?
transaltion:
Sorry, tried to invent warm water it seemed, but NP also did.
Something to add: See for Karlson-coupler: is also based on quarter-wave tube, but with exponential cut-out.
http://home.student.utwente.nl/e.j.j.ulfman/ |
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| mrfeedback |
| quote: | Originally posted by Nelson Pass
We were exploring that when we blew out the
drivers, so to speak. |
That's called El-Pooped-O. :D |
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| miguel2 |
| In the article the lengh of the pipe is well defined by the wavelenght but it seems that the diameter is only related to the driver's one. Always looked at the pipe organs and wondered how is the pipe diameter calculated. Hints? :confused: |
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| lieven |
could be related to air volume passing trough.
same with bass-reflex tubes: minimum diameter (breathing surface) required for not hearing whispering of air motion.
in other words: to avoid things like brown noises:) |
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| uvodee |
nie erg, maar dat np een beetje oude koeien uit de gracht zou halen, dat had ik niet verwacht.
ik denk dat we mekaar nie kennen, woon al een jaarthe of 4 in de US
hebt gij eneige amps of pre amps van NP gemaakt?
ben mijne soz aan het ineenflansen. |
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| MikeW |
| Can I get 800 watts out of a Zen to run EL-pipeO? |
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| cyclotronguy |
Stock up on the sun screen.
Cyclotronguy |
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| Mark A. Gulbrandsen |
My house has several extra unused chimneys at the moment....gives me some ideas here to ponder! Dang those would make solid tubes!
Mark |
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| MikeW |
| Don't fall off the roof while you are mounting your speakers. |
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| Dennis Hui |
| quote: | Originally posted by Mark A. Gulbrandsen
My house has several extra unused chimneys at the moment....gives me some ideas here to ponder! Dang those would make solid tubes!
Mark |
Hmmm...neat. A house with built-in subwoofers. :D
Dennis |
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| lieven |
| quote: | Originally posted by cyclotronguy
Stock up on the sun screen.
Cyclotronguy |
more noise to come? |
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| MikeW |
| I came back from the Home Depot with the tubes for El-Pipe-O. I showed them to my sons. As I was leaving to put them in the work shop they said "I think dad has gone insane.". We'll see after I get that 4000 watt peak subwoofer amp going. Is that El-Pipe-O V.2 ? |
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| uli |
how do you call those amps?
"ALEPH 2000":D :D :D
Thinking of amps with their own builtin powerplant
Call it "Aleph Diesel"
Uli;) |
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| xsnailx |
| should we invent an NUCLEAR ALEPH???;) ;) ;) ;) |
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| Nelson Pass |
Don't tempt Cyclotronguy like that.
:santa2: |
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| G-Daddy |
I was under the impression that a crucial feature of transmission line designs was the lack of parallel faces, in order to remove as many structure resonances as possible. All the MDF jigsaw-nightmare transmission-line designs I've seen have obviously taken care to flare the line in some way or another. So what about el-pipe-o? Is it a case of just living with the resonance as the price for such a convenient building material, or is there something more subtle going on here? If the batting packing can remove the resonances well enough, then why do the woodshop guys go through such pains to avoid parallel faces?
I'm lookiing at building a scaled down version of these monsters to back up some electrostatic panels, and I'd like to make the proper informed decisions now, before I start buying and constructing. Thanks for the info.
- Jonathan |
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| planet10 |
| quote: | Originally posted by G-Daddy
I was under the impression that a crucial feature of transmission line designs was the lack of parallel faces, in order to remove as many structure resonances as possible. |
That is really a side effect and not a purpose. It has been recently shown that a T-Line is just a name applied to a subset of quarter-wave speaker designs (includes Voigt pipes & horns). A TL is usually that subset that have no taper (straight pipe to designs that have a taper going from large (closed end) to small (open end). In a tapered line the geometry acts as a high pass filter for the terminus output, and moves the lines resonant frequency downward yielding a shorter (not necessarily smaller) line. Folding the taper into a rectangular box results in a box with 2 non-parallel sides and bracing running the long length of the cabinet at an angle -- both positive attributes that can be incorporated into any enclosure.
In el pipe-o the side-to-side standing wave of 2 feet is short enuff that it shouldn't be an issue given the frequencies it operates at or given the amount of stuffing in the line.
dave |
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| Nelson Pass |
To put a finer point on it, you will experience a resonance
at 1/2 wavelength for the diameter of the cylindrical pipe
which in this case is around 275 Hz. With a low pass filter
beginning at 22 Hz and stuffed with Dacron (tm), the
excitation at this frequency is slight. |
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| xsnailx |
Nelson,
I didnt want to tempt any one ;)
just tried to go further than aleph diesel:) and write something funny
but if i offended someone by writing this
i say sorry and i won't do it anymore |
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| uli |
| quote: | Originally posted by xsnailx
Nelson,
I didnt want to tempt any one ;)
just tried to go further than aleph diesel:) and write something funny
but if i offended someone by writing this
i say sorry and i won't do it anymore |
Hi xsnailx,
Maybe NP fears a new design by cyclotronguy, which he has
to declare to some officials in the government and to customers
when he wants to sell that ALEPH 239 (Plutonium)
:clown: :clown: :clown:
Uli |
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| cyclotronguy |
I'm thinking a simple"flash reactor in the basement" Several thousand kilo-rad of neutron flux would be 'bout right for food storage. Could take the waste heat run an absorber..... drive a chiller into a thermal mass and cool the house in summer. Light from electrons jumping orbitals. endless possibilities.
Cyclotronguy:cool: |
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| roddyama |
| quote: | Originally posted by cyclotronguy
I'm thinking a simple"flash reactor in the basement" Several thousand kilo-rad of neutron flux would be 'bout right for food storage. Could take the waste heat run an absorber..... drive a chiller into a thermal mass and cool the house in summer. Light from electrons jumping orbitals. endless possibilities.
Cyclotronguy:cool: |
Mmuuuhaha, It Starts!:devilr: |
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| Dennis Hui |
How about the Aleph P-P (proton-proton)? I hear it
comes with a fusion generator. :)
Dennis |
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| xsnailx |
hmm seems like diesel is not enough
i live near russia so it will be cheap to get fuel for nuclear power plant
;) ;) ;) ;) ;) |
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| jag |
Quote from el-pipe-o article
| quote: | | If you have an 8 foot ceiling, you can make two out of a 12 foot piece of 8 inch diameter, and find yourself decent 8 inch woofers resonant at about 40 Hz. Then you can start having parties, too. |
Is this woofer okay for the application: PIONEER B20FU20-54F. The stereo pair will be driven by a 50-100w per channel stereo amp. Also, the low pass filter used with the original el-pipe-o is 12dB low-pass to provide a 13-75Hz response. Does this imply that I should use approx 40Hz 12dB low pass with the 8" woofer? Is such a low cutoof required to equilize the woofer response? Will a low Xmax woofer like the Pioneer mentioned above behave well in this kind of a situation? Any other suggestions for 8" driver appereciated...
Also, Nelson, pl, pl, please: give us the AXO :bawling: |
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| planet10 |
Qt is too low to work well in el pipe-o. look for a woofer with 0.5 ->1.0.
dave |
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| uli |
what about the lambda woofers?
Pretty high Qts and unbelievable p-p displacement.
Theyre on sale now as lambda quits business.
Uli ;) |
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| jag |
| quote: | Originally posted by planet10
Qt is too low to work well in el pipe-o. look for a woofer with 0.5 ->1.0.
dave |
This Stryke satisfies the Q requirement but effeciency is low (87) - The Pioneer above is 93...
| quote: | Originally posted by uli
what about the lambda woofers?
Pretty high Qts and unbelievable p-p displacement.
Theyre on sale now as lambda quits business.
Uli ;) |
I do not see any 8 incher. Also, kind of expensive. I want to experiment with something inexpensive before I make an investment. |
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| planet10 |
| quote: | Originally posted by uli
what about the lambda woofers?
Pretty high Qts and unbelievable p-p displacement.
Theyre on sale now as lambda quits business.
|
The Lambdas are good. I am trying to wangle a set of 4 of the 10" for a stereo pr of push-push woofers.
The inexpensive Lambda LE series will be unavailable after March 31, get 'em while you can. The good news is that Lambda is not going out of business. Nick has been able to put things together such that he can continue it as a part-time business.
dave |
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| jag |
| quote: | Originally posted by planet10
The inexpensive Lambda LE series will be unavailable after March 31, get 'em while you can. |
No specs :mad: |
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| planet10 |
| quote: | Originally posted by jag
No specs |
You didn't dig deep enuff. ie TD10H. 10s are as small as they make thou.
dave |
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| planet10 |
| quote: | Originally posted by jag
This Stryke satisfies the Q requirement but effeciency is low (87) - |
Not exactly subwoofer territory...
an el pipe-o for a single SA071 would be 51.5" long, 11.25" internal diameter, stuffed evenly with 0.96 pounds of fiberglass insulation OR 58" long, 10.3" internal diameter, stuffed with 0.76 pounds of polyester wool.
dave |
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| jag |
| quote: | Originally posted by planet10
You didn't dig deep enuff. ie TD10H. 10s are as small as they make thou.
dave |
Thanks! The Q is pretty low on these as well. They are sweet otherwise - looks like I will have to give up on el-pipe-o and go with a sealed box. I do not want the subwoofers to go too low - small room (standing waves), amplifier power, concern for neighbors, and integration with small bookshelfs (better go high than too low). |
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| planet10 |
| quote: | Originally posted by jag
The Q is pretty low on these as well. They are sweet otherwise - |
I'm gunning for this Lambda 10" from Stryke ... don't be afraid to email Nick & ask him if he has anything suitable (just be patient thou, he is overwhelmed at the moment)
dave |
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| miguel2 |
Hi,
I am planning to use this unknown driver I have to try this sub. It has 27 cm diameter on the rubber side of the driver and 31 cm on the outer side (iron structure). In the back it says AD 12200/W4 and two other big numbers :scratch:. For now I do not want to buy a new one.
My problem is to know what is the difference between the active and the passive crossovers that are presented in the article. I believe that in either way a sub amplifier must be used.
I intend to run the main speakers with a ZenV4 and use my rotel 921 to the sub.
Miguel |
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| Nelson Pass |
| The passive version of the filter for driving a subwoofer off the main amp works very well. You will see that Vance Dickason did a similar one in his project for AudioXpress. |
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| Nelson Pass |
| quote: | Originally posted by miguel2
I am planning to use this unknown driver I have to try this sub. |
IMHO, one of the best aspects of a good, long, fat Transmission Line is that it is very forgiving of different driver characteristics. I just stuff it to taste to get more of what I want. |
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| miguel2 |
Thanks for answering Mr. Pass. If I understand correctly (my english is giving up on me now), I just connect a 940 ohm resistor to each output on the Zen and then put the rest of the crossover (except the 470 ohm input resistor of the crossover). After this I put the Rotel and then the driver.
Is this correct?
Miguel |
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| planet10 |
| quote: | Originally posted by miguel2
AD 12200/W4 |
That is a Philips driver. I just successfully put a pr of the 8 ohm version into a 2.5 cu ft aperiodic box.
dave |
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| Nelson Pass |
| quote: | Originally posted by miguel2
If I understand correctly (my english is giving up on me now), I just connect a 940 ohm resistor to each output on the Zen and then put the rest of the crossover (except the 470 ohm input resistor of the crossover). After this I put the Rotel and then the driver. |
If you are making mono, then you want a 1000 ohm (close enuf)
resistor off each output and tied together instead of the original 470 ohm resistor. |
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| miguel2 |
Yesterday I connected the driver to the output of the Zen without crossover and without the main speakers, just to see how it performs. Highs were inexistent and midrange was very shut in and muddy, but I think this is normal for a 30 cm driver. BUT the problem is that bass was absent too. My B&W 601 speakers go way more low, and they have the -3Hz point around 70 Hz.
I was not expecting to hear big bass, as it had no tube or box, but I was suprised not to hear any bass at all. Does this means that that driver is damaged? The middle part is wrinkled to the back but I think this has nothing to do with it.
IŽll try this weekend to build a crossover and see what hapens. For now I will build it with a 10 uF electrolytic before spending more money in a film one.
Miguel |
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| planet10 |
| quote: | Originally posted by miguel2
[B]Yesterday I connected the driver to the output of the Zen without crossover
I was not expecting to hear big bass, as it had no tube or box, but I was suprised not to hear any bass at all. Does this means that that driver is damaged? |
Not at all. Without a box the wave from the front gets cancelled by the anti-phase waves from the back for all frequencies below a 1/2 wavelength of the size of the driver. A trick to get some idea of how it will sound is to listen to the driver edge on.
dave |
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| miguel2 |
| quote: | | ...the driver edge on. |
What do you mean by this?
do you know of any (internet) source where I can find the parameters for this specific driver?
Thanks.
Miguel |
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| planet10 |
| quote: | Originally posted by miguel2
What do you mean by this? |
Hold the driver so that the edge of the basket is near your ear and the drivers centre axis is parallel to your head.
| quote: | do you know of any (internet) source where I can find the parameters for this specific driver?
|
No
dave |
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| miguel2 |
This weekend I finally built it. Got a 30 cm tube, cut it to 2.4 meters, so I have about 15 cm clearance to the ceiling and then put it over the driver. I was lucky because the tube fitted very well in the driver, with no other mounting material. I also used a rope to hold the thing standing up, as my 18 months kid found very funny to knock on it. BTW, as it is, waf factor is quite low :cannotbe:. Recommendations will be very welcome.
With the Rotel driving it, bass extension is quite nice. I had to be careful as windows were rattling every time I cranked the volume up. I used REM's "How west was won and where it got us" from New Adventures in HiFi to test it and was quite amazed. Now it seems that I have been missing a lot in the music I been hearing all this time.
Now I need to swap the 10 uF electrolytic I used in the xover to a film one (yes I made cheat at this). Maybe that is why I hear some voices in the subwoofer.
I also want to use the 2 channels of the Rotel to drive the sub. I am a bit afraid of connecting two inputs with the same signal and connect the outputs (+ with + and - with -). Any suggestions?
I didn't use any fibreglass inside the tube. Before buying some pillows to get some fibre, what modifications on sound should one expect?
planet10, before mounting this I used your advice to listen on the edge of the driver, and I could get an idea on its sound. It was nice as it gave me some confidence to built the whole thing after. Thanks.
Miguel |
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| dieringe |
I built small el-pipe-os with 15cm diameter and
tuned them to 30Hz or so (had some cheap drivers lying around)
The problem is, I run symmetric D1- and aleph-ono- output into the aleph 30 power amp (passive pre) and want to use an old Rotel for the pipeos.
How can I connect the active subwoofer filter described in the article? Do I need a transformer or is there a cheap trick that would do it?
Every time I tried connecting it so far I got big hum
I rather don't want to take the power amp output for a passive filter because they're too far away.
thanks -
martin |
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| miguel2 |
Hi Martin,
Try to connect some wire between and earth point of the Rotel (chassis for instance) and an earth point in your Aleph 30 or preamp.
Miguel |
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