Very Small OB

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While I figure out what wood to use to make my Full Range Reference box I took some scrap poplar I had and made a 14x7 3/16 OB for my Planet 10 modified FE126 drivers. I knew from the begining that the bass would be nonexistant but I wanted to hear the drivers and play with what I had. The highs and mids sound surprisingly nice all things considered.

What if anything besides a building a Frugal Horn around it could I add to these to get something in the bottom end? Would a foot long piece of PVC tubing attached to the back do anything? I figure it will be fun to play with and see if anything can be done to help them along as a learning experience.
An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.
 
holy hell whats the LF cutoff on those?!

are those the fe 166es little brother? if so, im even more shcokerd, because i had my 166 in a 48x24 baffle and they had NOTHING under about 150hz, just becuase the Q is so low.

but damn, those mids and highs really ARE sweet arent they?....hell they were enough to keep me running them for a good couple of months!(well, that combined with lazyness)
 
DJ

Think about some of the inexpensive "pro" audio woofers from Parts Express, coupled with one of the equally inexpensive BASH plate amps with up to 180Hz Low Pass feature, build a bigger baffle, offset the 126's abit, use Golden Mean so build baffles sort of 42 X 27 and mount 126 above woofers finding the center using the ratio of W*/*H, spud the driver there, run the Fostii full range, woofers at the bottom, centered, and you would be surprised just how easy it can be integrating bass with this cheap and nasty OB method. It works. Any driver sounds its best on OB.

If you can budget $350, you can get 2 Dayton IB-385-15 woofers, and a 150 watt BASH switching plate amp with great contouring features, tank-like build, rise time of fork lightning, and have a great little OB rig. Stephane left his on for two months more likely because it sounded "right," to his brain. ...and laziness. Teens today:whazzat:
 
no i had a monopole ported subwoofer that was taking over half the time(not for jazz) and the other times i just lived without the extension! these arent the only speakers i have you know:smash:

and if hes goign to go through the trouble of doing an ob setup IMO he should do stereo bass! maybe passive line level filters on a pa amp?

but the long and short of it is....i like the way you think!

DJ, if youre looking for information on what we mean, google the term "basszilla".
 
Or, the de facto standard OB primer, www.linkwitzlab.com

I have done the math, the DarkStar was a condensation of the Orion, using the B200 and Ripol loading 2X Eminence Delta 15LF, active XO, and switching amp on bottom. This is resynthesis that can hurt you!!

I too would recommend stereo of course, but "cheap and nasty," is the qualifier, and it works; jus' depends what you want. My way is the shortes distance between A & B, and has been proven over and over. ... Of course, you could go whole hog, and employ a Rane RPM for active everything, even drawing FR, XO abnd EQ curves using a mouse. www.rane.com the all in one Dream Machine, the Rolls Royce of DIY audio playthings. ...Add another BASH amp later. Leave room on your Golden Mean baffle to carve out a bigga hole fo mo betta driver. Use the Hemp FR8 www.abrown.com or Visaton B200, this thing unloaded is wonderful. Sell a neighbor to medical research, and get the Supravox EXC, hell, it's only money.
 
Thanks for all of the replies so far but i'm not really wanting to spend much on developing these since they are just in place for a short period of time until I can build http://www.diyaudio.com/forums/attachment.php?s=&postid=1143794&stamp=1172375307

I am using an ASL mg-si15 dt running in 5W SET mode or I Can switch to PP for 15W. This is fed by a Dynaco PAS 3 preamp. For Sources I have a Dual 1245 TT and Playstation1 CD player.

Wow is the Linkwitz site full of good details. I expect to spend a lot of time going over it.

The LF cutoff was probably more into the mids than the LF for how little it had at the bottom.

All that said I now have acceptable bass !!!!

I made a "bass tube" just like the angular spirals made on this site http://www3.ocn.ne.jp/~hanbei/eng-angular.html

It is 16x6 with three fins separated by 4.5" and made of cardboard. It is then placed flush with the back of the OB and the entire assembly pushed against the wall so that it is wall loaded(hope that is the right way to describe it). If anyone wants pics i'll be glad to post some. The bass is not huge but is clearly there now. In Superman from REMs Life Rich Pageant the bass guitar was clearly missing from the sound but after I added these it came right out:)
 
Hey dmason.....!!!!!!!!!!!!!!!!

May I pick your brain on any mods to BASH amps for boost or contour, & if you now how to get it to 180hz.? mine are the 300S versions. I see they have listed in there literature a boost you can do with simple resistor changes, but I only see 1-5db for 30-40hz only listed, if you got tricks up your sleeve...PLEASE..let this poor fool know...lol
 
I have no personal experience with the BASH amps other than published anecdotes from users indicating that they are clearly a very stout product, well implemented, and PE sells a ton of them with little hassle. High speed switching amps powering unloaded 15 inch woofers X 4 has to be heard to be believed. On two DarkStar rigs we used Carver Pro ZR1000 and active EQ/XO.:bigeyes:
 
Tone Testing

I downloaded test tones and made a CD to test with. With the "Bass Tube" removed the first barely audible tone is 80hz the first tone with good volume is 200hz. I then added the "Bass Tube" back to the system and the first audible tone is now 63hz with good volume occurring at 100hz. The port opening on the rear of the "Bass Tube" is 1"x2". I will cut it larger to see if I get any more bass. So far this has been a fun project.
 
Sorry I have not had a chance to get pics. I will be rebuilding the "tube" in wood this weekend and will report back. At the same time I will also be extending the length of it an inch or two and increasing the number of fins as well as reducing the distance between them. One other thing was I redid the masking tape to get better seals and now can clealry hear 40hz with decent volume at 63hz!! I have high hopes for the wooden rebuild.
 
Rebuilt it in wood and extended the length. It is now 6x18 with a port size of 2 inches. I did not calculate the angle of the fins correcly so ended up making a "Tasuki Path" rather than the angular spiral I had intended. The Tasuki Path is explained near the bottom of this page http://www3.ocn.ne.jp/~hanbei/eng-angular.html That said it still worked very well. 31.5hz is just barely audible with decent volume coming in at 40hz. I could definately live with what I have and my wife likes how they sound and look. The bottom end is very well filled out compared to the cardboard version but the cardboard version was a worthy experiment to see if this would work in any way. PS the glue is not very visible in person but looks very bad in the pics. Notice the rear port is screwed in place and is easily removed to try other openings. Next will be smaller as well as different shaped ports.

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.
 
this is inspiring indeed.

The only thing I cannot gather is which angular spiral you intended to use in the first place: The only spiral on that site that matches is the AG150 but that one has increasing pitch. Were you trying to adapt the AG100 spiral (intended for 8cm FRs) to the 127 (i.e. 12 cm FRs) ?

IOW what is the logic of computing the shape/size of the spiral and the pitch btw the fins ?

I understand that you ended up with the Tasuki spiral, but that's a diff story :)

Looks really nice and tempting as first time project :)

Rgrds,

Florian
 
I based most of what I did on his "design principles" near the top of the page rather than on a specific design. Particularly 1 and 4. This made me go with as many fins as I could fit in the space I had and not go too close together. In one of his designs(ag100m) he had a spacing of 41mm which is about 1.6". In my original cardboard design I had them at 4.5". I settled on 2" since it gave me an even number of fins in the space I had and didnt seem too close together. In other words I took a guess at it and it has worked out quite well. Sorry for the lack of actual science and true logic behind my decisions but that is how it worked out.

I just made new port plates with 1.5" holes and the bass volume jumped up again! I wonder how far I can restrict the ports before damage to the driver occurs or I stop getting more bass?
In the Dark Side of the Moon just as the clocks start to quite down I can now clearly hear the heart beat in the background. The only other system i've heard it on is my friends system with Vandersteen 3A(lots of $$$) speakers:) I spent 1/10 the price and while I can't say my system sounds as good as his it sounds very good for the money and i've definatley had lots of fun playing with making the speakers.
 
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