Need advice on a subwoofer setup

[jazzman53 1,276]

Thanks for the compliments.  I'm totally intrigued by the Ripole concept, which is essentially a dipole speaker with a compact folded baffle.  The big difference is the chambers' impedance drops the resonant frequency of the woofer approximately 10 hz-- which allows these things to play quite a bit lower than a conventional dipole or even a large boxed speaker; although you pay for that with reduced efficiency.       

[zumbini 6,150]

Lookin good Jazzman!

 

Questions:

Are the drivers configured as a stereo pair (one left, one right), straight mono or push-pull?

Will you be adding binding posts to the box or do you intend to wire them direct from the amp(s)?

 

As for signal path I'd start simple and feed an output from your C-1 to your XO.

 

[TNRabbit 371]

 

 

Thanks for the compliments. I'm totally intrigued by the Ripole concept' date=' which is essentially a dipole speaker with a compact folded baffle. The big difference is the chambers' impedance drops the resonant frequency of the woofer approximately 10 hz-- which allows these things to play quite a bit lower than a conventional dipole or even a large boxed speaker; although you pay for that with reduced efficiency. [/quote']

 

I'm confuses; how can a chamber have impedance? Isn't that a function of the driver voice coil alone?

[jazzman53 1,276]

 

 

 

Thanks for the compliments. I'm totally intrigued by the Ripole concept' date=' which is essentially a dipole speaker with a compact folded baffle. The big difference is the chambers' impedance drops the resonant frequency of the woofer approximately 10 hz-- which allows these things to play quite a bit lower than a conventional dipole or even a large boxed speaker; although you pay for that with reduced efficiency. [/quote']

 

I'm confuses; how can a chamber have impedance? Isn't that a function of the driver voice coil alone?

 

 

"Impedance" would not be technically correct but I think it's a pretty good

analogy insofar as the compliance of the air in the Ripole's chambers

coupled with the restricted size of the chamber openings constrain the

woofers' motion in a manner similar to how DC resistance and back EMF

impede current flow thru a voice coil. The strange and beneficial effect

is a lowering of the woofers' resonant frequency as compared to an open

dipole, which doesn't change a woofer's resonance at all, and and a sealed

box, which actually raises a woofer's resonance. So, in effect, a Ripole

trades off efficiency for compact size, deeper bass extension and it's

radiation pattern excites fewer room resonances (hence; less "boom") as

compared to a sealed or ported box.

 

[jazzman53 1,276]

Lookin good Jazzman!

Questions:

Are the drivers configured as a stereo pair (one left' date=' one right), straight mono or push-pull?

Will you be adding binding posts to the box or do you intend to wire them direct from the amp(s)?

As for signal path I'd start simple and feed an output from your C-1 to your XO.

[/quote'] Hi Zumbini,The woofers will be wired in parallel and in-phase (push/push). I'mwaiting to order the binding posts until I decide what other components Imay need and then do it all on one order to save shipping.Ripoles have the characteristic 6db/oct dipole roll off and a chamberresonance peak somewhere around 250 hz, which I haven't yet decided onwhether to EQ those away with a passive notch filter in the speaker or doit upstream with my Behringer DEQ2496. It all hinges on the crossover.I've been looking at an inexpensive programmable little digital crossoverwith parametric EQ called a "Mini-DSP". Then I would need to decidewhether to use it only for the subwoofers or for the total system,replacing my current analog crossover. One problem is that I've grownrather fond of the Beghringer DEQ and replacing my existing systemcrossover with the Mini-DSP would add a third A/D-D/A conversion in thesignal path (not sure that's a good idea). I will anguish over the optionsuntil I make a choice. As I said earlier, these subs are forcing me torethink my entire signal path (should I ditch the C1 and go all digital orgo back to all analog or some mix???) - it's making me so crazy I may endjust flipping a coin to save my sanity.

[RichP714 3,163]

.....I'm confuses; how can a chamber have impedance?

 

The function of the physical waveguide you're building for your AL-III's is to reduce the acoustic impedance (and therefore resonant peak) of the driver cavity by coupling its air mass more effectively to the external air mass.

[martin1970 361]

       Do you have adapters to go balanced/unbalanced? It looks like the Behringer has no unbalanced input, yet your C-1 is unbalanced. The reason I ask is because there's a guy on Tybee who had 4 Rane AC23B stereo 3-way crossovers for sale a few months ago. I bought one when I decided to biamp my Amazings. He had 3 more and I doubt he sold them to anyone. You could probably get one for $100 and sell the DBX on Ebay. I can PM you his number is you think you could make it work. I know you've got to be anxious to hear those ripoles!

      You could come directly off the Behringer (balanced) to the AC23B, but you'd have to figure out what to do on the other end to get the 6 output channels to your amplifiers. I don't know if additional adapters would fit into your budget, or even if you'd want to do a 3/way with the ESLs/transmission lines/ripoles. Just thought I'd throw the option into the mix.

     All of your speaker work is really amazing build quality. I've dreamed of doing DIY ESLs for years, but it just seemed so difficult, especially trying to figure out how to match the fast ESL panels with bass drivers. Your OB choice is certainly the way to go. It's going to sound SO good when you get it all hooked up.

      I'm glad to see we have another planar fan here in Savannah. It seems like every time you talk to someone around here about audio, inevitably they say the "B" word. 

[TNRabbit 371]

 

 

 

.....I'm confused; how can a chamber have impedance?

 

The function of the physical waveguide you're building for your AL-III's is to reduce the acoustic impedance (and therefore resonant peak) of the driver cavity by coupling its air mass more effectively to the external air mass.

 

I've always associated "Impedance" with an electrical factor, whereas I would say the waveguide is more of a "air channel" to facilitate propagation of the sound out of the channel.  Wouldn't it more appropriately be called "Resistance" rather than "Impedance"?  Same thing, except different? 

[BillD 239]

I think the word "impedance" is more general.  Resistance (both electronically and dynamically) is typically linear.  Impedance is a non-linear quantity varying with a number of factors (like frequency).  The waveguide you are building will have properties that vary with frequency, also (like flow across an airfoil).

[RichP714 3,163]

.....Wouldn't it more appropriately be called "Resistance" rather than "Impedance"?  Same thing' date=' except different?  [/quote']

 

No

[zumbini 6,150]

....Ripoles have the characteristic 6db/oct dipole roll off and a chamberresonance peak somewhere around 250 hz' date=' which I haven't yet decided onwhether to EQ those away with a passive notch filter in the speaker or doit upstream with my Behringer DEQ2496.  It all hinges on the crossover....[/quote']

 

Instead of adding a notch filter why not cut them off below the resonant frequency, say 80 or 125Hz?

That will lighten the load on your mains and allow more efficient use of the amp driving the Ripoles.

[jazzman53 1,276]

 

 

       Do you have adapters to go balanced/unbalanced? It looks like the Behringer has no unbalanced input, yet your C-1 is unbalanced. The reason I ask is because there's a guy on Tybee who had 4 Rane AC23B stereo 3-way crossovers for sale a few months ago. I bought one when I decided to biamp my Amazings. He had 3 more and I doubt he sold them to anyone. You could probably get one for $100 and sell the DBX on Ebay. I can PM you his number is you think you could make it work. I know you've got to be anxious to hear those ripoles!

      You could come directly off the Behringer (balanced) to the AC23B, but you'd have to figure out what to do on the other end to get the 6 output channels to your amplifiers. I don't know if additional adapters would fit into your budget, or even if you'd want to do a 3/way with the ESLs/transmission lines/ripoles. Just thought I'd throw the option into the mix.

     All of your speaker work is really amazing build quality. I've dreamed of doing DIY ESLs for years, but it just seemed so difficult, especially trying to figure out how to match the fast ESL panels with bass drivers. Your OB choice is certainly the way to go. It's going to sound SO good when you get it all hooked up.

      I'm glad to see we have another planar fan here in Savannah. It seems like every time you talk to someone around here about audio, inevitably they say the "B" word. 

 

Hi Martin,

Wow, a fellow Carver addict from Savannah!  Had I seen your first post I would have welcomed you to the forum sooner. Thanks for the tip on the X-overs, BTW.  I plan to make some choice on a crossover this weekend so I can get the Ripole show on the road.  And about DIY ESL's, if everyone knew how easy and cheap these things are to build, I think more people would be doing it.  Anyway, you now have an open invitation to drop by my place in Port Wentworth for a listen any time.  I would love to hear your Amazings too :-)  I will PM you my phone number and street address.

Have a great day!

Charlie 

[jazzman53 1,276]

....Ripoles have the characteristic 6db/oct dipole roll off and a chamberresonance peak somewhere around 250 hz' date=' which I haven't yet decided onwhether to EQ those away with a passive notch filter in the speaker or doit upstream with my Behringer DEQ2496.  It all hinges on the crossover....[/quote']

 

Instead of adding a notch filter why not cut them off below the resonant frequency, say 80 or 125Hz?

That will lighten the load on your mains and allow more efficient use of the amp driving the Ripoles.

 

A good analogy for that chamber resonance is blowing into a coke bottle-- and I'm told by the Ripole gurus that it's peak amplitude will be a whopping 20db.  Still, I think your suggestion should work using a 24db minimum slope and a low chop off point.  My goal is to make a decision over the weekend and order a crossover Monday morning.  

 

One of several options I'm considering is a Behringer DCX crossover but I would only go that route if I can move my Behringer DEQ from the my preamp's external processor loop and put it between the preamp and crossover-- I could then make a digital-to-digital connection from the DEQ to the DCX and eliminate a second A/D-D/A conversion.   I'll get it figured out soon-- I think these Ripoles are gonna blow women's panties right off!  

 

 

 

[martin1970 361]

 

 

 

       Do you have adapters to go balanced/unbalanced? It looks like the Behringer has no unbalanced input, yet your C-1 is unbalanced. The reason I ask is because there's a guy on Tybee who had 4 Rane AC23B stereo 3-way crossovers for sale a few months ago. I bought one when I decided to biamp my Amazings. He had 3 more and I doubt he sold them to anyone. You could probably get one for $100 and sell the DBX on Ebay. I can PM you his number is you think you could make it work. I know you've got to be anxious to hear those ripoles!

      You could come directly off the Behringer (balanced) to the AC23B, but you'd have to figure out what to do on the other end to get the 6 output channels to your amplifiers. I don't know if additional adapters would fit into your budget, or even if you'd want to do a 3/way with the ESLs/transmission lines/ripoles. Just thought I'd throw the option into the mix.

     All of your speaker work is really amazing build quality. I've dreamed of doing DIY ESLs for years, but it just seemed so difficult, especially trying to figure out how to match the fast ESL panels with bass drivers. Your OB choice is certainly the way to go. It's going to sound SO good when you get it all hooked up.

      I'm glad to see we have another planar fan here in Savannah. It seems like every time you talk to someone around here about audio, inevitably they say the "B" word. 

 

Hi Martin,

Wow, a fellow Carver addict from Savannah!  Had I seen your first post I would have welcomed you to the forum sooner. Thanks for the tip on the X-overs, BTW.  I plan to make some choice on a crossover this weekend so I can get the Ripole show on the road.  And about DIY ESL's, if everyone knew how easy and cheap these things are to build, I think more people would be doing it.  Anyway, you now have an open invitation to drop by my place in Port Wentworth for a listen any time.  I would love to hear your Amazings too :-)  I will PM you my phone number and street address.

Have a great day!

Charlie 

 

     Thanks for the warm greetings. Sorry to be such a lurker. Everyone here is so knowledgeable, it's hard to have anything useful to post. This ripole thing you're doing is kind of timely because I've been researching OB options to try to supplement the Amazings in the low frequencies. As it is now, I'm driving the voice coils on the woofers to their limits if I dare to move the HPF any lower than about 35 Hz. You're welcome to try the ripoles out on the Sunfire. I've got 3 channels free <grin> Anyway, can't wait to hear those ESLs!