Bipolar speakers are where you have two drivers in a cabinet, one on one baffle, the other on the opposite baffle (i.e. magnet to magnet). They are wired in-phase, so it's a push-push configuration. Works very well. Eliminates the worst panel resonances. Here's a cheap version Dave (planet10) designed. I'm not suggesting you should build this specific one, but it's worth considering. http://homepage.mac.com/tlinespeakers/FAL/box-plans/ApexJr-Super8-PP-BR-map.gif
ME2's and subwoofers
Hello,
I just discovered your Ariel/ME2 thread. I've built Ariels for a friend and ME2's for myself after hearing the Ariels. Thought I would add my experiences with subwoofers and EQ.
The ME2's have a fairly high -3dB of around 150Hz. You can change the port tuning and get much better low end to below 100Hz or set your active crossover higher. I use a passive 6dB rolloff at the input to my tube amp and use a Marchand clone for the bass. My subwoofers are 12" driver transmission lines which recently I EQ'd with a Behringer 1024 Ultracurve that I read about on some HT web pages. It's only in the bass channel. I thought it took the life out of the music when I had it connected full range. I now have measured flat bass from 20Hz to 200Hz and it's a revelation in clarity. The drawback is you can only get it adjusted this way in the one location you measure.
Keep having fun,
John
Hello,
I just discovered your Ariel/ME2 thread. I've built Ariels for a friend and ME2's for myself after hearing the Ariels. Thought I would add my experiences with subwoofers and EQ.
The ME2's have a fairly high -3dB of around 150Hz. You can change the port tuning and get much better low end to below 100Hz or set your active crossover higher. I use a passive 6dB rolloff at the input to my tube amp and use a Marchand clone for the bass. My subwoofers are 12" driver transmission lines which recently I EQ'd with a Behringer 1024 Ultracurve that I read about on some HT web pages. It's only in the bass channel. I thought it took the life out of the music when I had it connected full range. I now have measured flat bass from 20Hz to 200Hz and it's a revelation in clarity. The drawback is you can only get it adjusted this way in the one location you measure.
Keep having fun,
John
nerdorama,
Thanks. So let's see if I have this straight. You roll your ME2s off with a 6dB passive low-pass filter at around 150Hz at the input to your amp. You have a TL sub and you use an adjustable EQ unit to flatten the measured bass response. Sounds good. What design of sub did you use?
I've seen some designs for sonotube TL sub woofers. Can anyone recommend these?
Thanks. So let's see if I have this straight. You roll your ME2s off with a 6dB passive low-pass filter at around 150Hz at the input to your amp. You have a TL sub and you use an adjustable EQ unit to flatten the measured bass response. Sounds good. What design of sub did you use?
I've seen some designs for sonotube TL sub woofers. Can anyone recommend these?
A shorter version of Nelson Pass El Pipeo, using good, fast 8in woofers (take your pick) will work well, and be an excellent match. Someone has done just that:
http://www.teresaudio.com/haven/subs/subs.html
http://www.teresaudio.com/haven/subs/subs.html
No, but personally, I'd design something along the lines of El Pipeo for these: http://www.seas.co.uk/acatalog/H1411.pdf
Not cheap. But worth every penny, and should prove a good match.
Not cheap. But worth every penny, and should prove a good match.
Scott,
Thanks for the info. Unfortunately I have neither the time nor the skill to go designing my own enclosures. I'm good with wood and electronics but a klutz with acoustics. I wonder whether the 10" SEAS driver you mentioned would work in the enclosure you linked to in your previous post?
Thanks for the info. Unfortunately I have neither the time nor the skill to go designing my own enclosures. I'm good with wood and electronics but a klutz with acoustics. I wonder whether the 10" SEAS driver you mentioned would work in the enclosure you linked to in your previous post?
OK, looking at the various 10in drivers, it's possible to do it, but it depends how large a room you have and just how big an enclosure you can cope with. You need a big CSA to give a sufficient Vb for the larger drivers. Unless you use that, you actually will end up with a higher cut-off than you would using a smaller driver.
Here's one that should work nicely in a real-world environment. 1 8in Seas driver per side: http://www.seas.co.uk/acatalog/H1208.pdf as a bonus, it'll be an even better match to Ariel than the 10in types. 12in diameter Sonotube or whatever tube you feel like, 72in tall. 0.35lbs ft^3 of stuffing in the lower half of the line only. Should be pretty flat to 30Hz, probably a bit lower with room gain. Think of them as bass-extenders rather than subwoofers. Better to be integrated than have a disconnected freak-show.
Best
Scott
Here's one that should work nicely in a real-world environment. 1 8in Seas driver per side: http://www.seas.co.uk/acatalog/H1208.pdf as a bonus, it'll be an even better match to Ariel than the 10in types. 12in diameter Sonotube or whatever tube you feel like, 72in tall. 0.35lbs ft^3 of stuffing in the lower half of the line only. Should be pretty flat to 30Hz, probably a bit lower with room gain. Think of them as bass-extenders rather than subwoofers. Better to be integrated than have a disconnected freak-show.
Best
Scott
Scott,
You're worth your weight in gold! When you say one 8in Seas driver per side, I assume you mean per side of the enclosure that supports the sonotune (or do you mean one for the left and one for the right channels)? Sorry for all the questions, but I don't want to go off half-cocked by making incorrect assumptions.
I agree with you about the 'freak show'- that's definitely not what I'm after. 'Bass extenders' is exactly what I need.
Thanks for going to the trouble. I'll see if I can source Seas drivers in Oz and get cracking.
You're worth your weight in gold! When you say one 8in Seas driver per side, I assume you mean per side of the enclosure that supports the sonotune (or do you mean one for the left and one for the right channels)? Sorry for all the questions, but I don't want to go off half-cocked by making incorrect assumptions.
I agree with you about the 'freak show'- that's definitely not what I'm after. 'Bass extenders' is exactly what I need.
Thanks for going to the trouble. I'll see if I can source Seas drivers in Oz and get cracking.
You're welcome!
Ask away. Better to do that than waste a lot of money. One driver per channel, so a total of two drivers is all you'll need. As I say, in-room they should be pretty flat to about 30Hz, particularly if you position them in corners. In fact, their roll-off looks a lot like the Ariel's -just 20-30Hz lower down the frequency range.
Let us know how you get on. If you can't get the Seas drivers down in Australia, look for something with similar T/S parameters. If you keep the Qts and Vas similar, then it should perform well enough. Just avoid plastic cones. They can work fine, but they're not a good match for the Ariels.
Here's an alternative if you don't mind a bit more woodwork. Build a rectilinear enclosure with a tapered line. Make the closed end 103in^2, and the open end 17in^2. Total line length of 90in. Driver centre 22.5in down from the closed end. That will give you an extra 10Hz of bass, and be just as flat in-room as the Sonotube versions. Not as simple to build, obviously, but not too hard either. Just a normal box with a sloping internal baffle to form the tapered line. Your choice!
Cheers
Scott
Ask away. Better to do that than waste a lot of money. One driver per channel, so a total of two drivers is all you'll need. As I say, in-room they should be pretty flat to about 30Hz, particularly if you position them in corners. In fact, their roll-off looks a lot like the Ariel's -just 20-30Hz lower down the frequency range.
Let us know how you get on. If you can't get the Seas drivers down in Australia, look for something with similar T/S parameters. If you keep the Qts and Vas similar, then it should perform well enough. Just avoid plastic cones. They can work fine, but they're not a good match for the Ariels.
Here's an alternative if you don't mind a bit more woodwork. Build a rectilinear enclosure with a tapered line. Make the closed end 103in^2, and the open end 17in^2. Total line length of 90in. Driver centre 22.5in down from the closed end. That will give you an extra 10Hz of bass, and be just as flat in-room as the Sonotube versions. Not as simple to build, obviously, but not too hard either. Just a normal box with a sloping internal baffle to form the tapered line. Your choice!
Cheers
Scott
Scott,
I found a Seas dealer in Oz. Good prices too.
I like the idea of the tapered line box. More like a conventional speaker enclosure- should keep the wife happy. she seemed a little perturbed at the idea of a huge pipe stuck in the corner of the lounge!
No problem with the complexity- after the Ariel everything else is a cinch.
So the internal baffle is angled to give a FOLDED taper? i.e. the line is 90 inches long in a box a bit over 45 inches tall? I'm guessing driver is mounted on front 22.5 inches from TOP and opening at rear top as well? Or driver and opening towards bottom?
I found a Seas dealer in Oz. Good prices too.
I like the idea of the tapered line box. More like a conventional speaker enclosure- should keep the wife happy. she seemed a little perturbed at the idea of a huge pipe stuck in the corner of the lounge!
No problem with the complexity- after the Ariel everything else is a cinch.
So the internal baffle is angled to give a FOLDED taper? i.e. the line is 90 inches long in a box a bit over 45 inches tall? I'm guessing driver is mounted on front 22.5 inches from TOP and opening at rear top as well? Or driver and opening towards bottom?
something similar to this only with the single driver?
http://www.madisound.com/pdf/Kits/thor cab in.pdf
http://www.madisound.com/pdf/Kits/thor cab in.pdf
I had another look at it. Assuming the TL is 2 inches wide at the open end and 90 inches long with a 6:1 taper, the closed end will be 17 inches wide. 103 square inches divided by 17 inches gives an internal cabinet width of about 6 inches. If I use 1 inch MDF for the cabinet I get an overall width of 8 inches which is too narrow to mount the 10 inch driver.
I'm sure I've got something wrong here and would be grateful if you could point me in the right direction.
I'm sure I've got something wrong here and would be grateful if you could point me in the right direction.
Forget Thor. Vile thing.
The 6:1? All the taper ratio is, is the area of the top / by the area of the bottom. So divide the area of the sealed top of the line, 103in^2, by the area of the open end of the line, 17in^2. That'll give you 6.05882. OK, so not quite exactly 6:1, as 17 x 6 = 102, but near enough. Sorry for any confusion.
Best
Scott
The 6:1? All the taper ratio is, is the area of the top / by the area of the bottom. So divide the area of the sealed top of the line, 103in^2, by the area of the open end of the line, 17in^2. That'll give you 6.05882. OK, so not quite exactly 6:1, as 17 x 6 = 102, but near enough. Sorry for any confusion.
Best
Scott