1/12 octave smoothed response: Ripole NearField (signal reduced by -12dB to prevent mic clipping) vs Ripole FarField . The emergence of room modes are clearly visible
On the 2nd curve, I've compared the nearfield bass response of the ripole to the rear-ported bass reflex minimonitor. Not a perfectly valid test since they are driven by different amps (with potentially different input sensitivity), but here it is anyway.
On the 2nd curve, I've compared the nearfield bass response of the ripole to the rear-ported bass reflex minimonitor. Not a perfectly valid test since they are driven by different amps (with potentially different input sensitivity), but here it is anyway.
Attachments
closer to quasi -aperiodic when stuffed with a shallow roll-off. Should be an interesting comparison. News to build an adapter plate to mount the sonotube first
Summary,
Today, I tried a variety of Eqs - both manual as well as biquads suggested by REW/minidsp and while at times, I could get the ripoles to sound good qualitatively, I had to
1. pad down the mains severely to level match
2. Even when I got the ripoles to sound good , the moment I turned off the mains and listened to the subs, I could easily hear the drivers overexcursing on bass transients (and not necessarily at very high SPL levels).
I think my main issue with ripoles is that
1. they are inefficient and thereby need a bucketload of power
2. When fed the requisite bucketload of power , they can easily overexcurse - since by definition, open baffled drivers can't handle a lot of power.
If anyone reading this want's to try a ripole, first make sure the chosen driver has a generous xmax and swept volume , and if possible use multiple units. This, in addition to other factors taht Calvin has mentioned.
On to the stuffed sonotube extension experiment, for better or worse - since I plan to somehow retrofit this to the ripole
Today, I tried a variety of Eqs - both manual as well as biquads suggested by REW/minidsp and while at times, I could get the ripoles to sound good qualitatively, I had to
1. pad down the mains severely to level match
2. Even when I got the ripoles to sound good , the moment I turned off the mains and listened to the subs, I could easily hear the drivers overexcursing on bass transients (and not necessarily at very high SPL levels).
I think my main issue with ripoles is that
1. they are inefficient and thereby need a bucketload of power
2. When fed the requisite bucketload of power , they can easily overexcurse - since by definition, open baffled drivers can't handle a lot of power.
If anyone reading this want's to try a ripole, first make sure the chosen driver has a generous xmax and swept volume , and if possible use multiple units. This, in addition to other factors taht Calvin has mentioned.
On to the stuffed sonotube extension experiment, for better or worse - since I plan to somehow retrofit this to the ripole
As you can see here sensitivity is quite low also in this commercial DIY design. But the test do not consider this an issue in the overall performance.
Strassacker: Speaker-search, DIY-kit search, component search
Strassacker: Speaker-search, DIY-kit search, component search
That link totally ripoled. Perhaps you meant this one?
Grand Orgue
Lists Petit Orgue (basically what Zobsky built) at 76dB
And the Grand Orgue (Stack of 4 of the above) at 82dB
List the kits by lowest efficiency first: Petit is right at the top.
And those figures are for 2W/1M, 2.83V into 4 ohms.
Standard 1W/1M efficiency actually -3dB less!
Absurd inefficiency we can maybe live with. Bottoming
out without getting the job done is really the problem.
It takes a lot of swept volume to overcome this flaw.
Grand Orgue
Lists Petit Orgue (basically what Zobsky built) at 76dB
And the Grand Orgue (Stack of 4 of the above) at 82dB
List the kits by lowest efficiency first: Petit is right at the top.
And those figures are for 2W/1M, 2.83V into 4 ohms.
Standard 1W/1M efficiency actually -3dB less!
Absurd inefficiency we can maybe live with. Bottoming
out without getting the job done is really the problem.
It takes a lot of swept volume to overcome this flaw.
Last edited:
I bet that Grand Orgue makes a terrific noise when that one bass drum kick in Flight of the Cosmic Hippo clacks 8 formers against 8 backplates all at the same time
You also need to look at the frequency range. The dipole constructions like the Darling Kit goes way deeper than en typical medium sized floorstander. Low frequenzy vs sensitivity and size is alway a matter of compromises.
Deep bass down to 20 Hz and below, and good sensitivity will always be very very big, no matter the construction principle chosen.
Deep bass down to 20 Hz and below, and good sensitivity will always be very very big, no matter the construction principle chosen.
Well zobsky, you're still comparing apples&oranges and making the typical mistakes when comparing them to traditional monopole designs:
Ripoles have to be placed well away from walls (NOT like in the pic you posted) as otherwise the rear-facing sound will cancel out the front too much.
Also you lose some of the ripole's advantage with room modes if you place it paralell to the walls, you should tow them both in to some extent.
Finally, why do you expect a bass dipole speaker to match a traditional concept in efficency/volume int he first place?
You probably knew from the start that's not the case?
If you're then adding the not very well suited drivers to all the above, of course the result can only be sub-par. Also:
Why didn't you more aggressively EQ the low bass frequencies to achieve a more uniform response if you're using the miniDSP anyway? After all, that's what all subs with similarily small footprint are doing...
And from the measurements is looks like you didn't correct the higher frequency chamber resonances in the ripole? You have to implement a low pass for that or at the very least cut it off in the miniDSP. Then the waterfall and FR would look a lot less messy.
With your experiment you're not proving that the ripole design makes no sense (which some in this thread may believe) but rather your implementation is flawed and/or unsuited for you application.
I personally want to listen to music and movies in the best possible way from 20Hz to 20kHz and at volumes that will not leave me deaf in the long term (usually below 100dB). Also, I have neighbors...
In my room and the way I built/placed the ripoles, they easily provide the bass end of all the above and the bass quality itself is notably (also "measurably") better than my previous SVS subwoofer.
I'm not saying this kind of sub is the holy grail, it's just a design that can work very well, especially in problematic rooms, if a clear bass and not a lot of SPL is what you're after.
If you have a lot of drivers left and prefer the latter, better build something like that:
Wall of Death
Ripoles have to be placed well away from walls (NOT like in the pic you posted) as otherwise the rear-facing sound will cancel out the front too much.
Also you lose some of the ripole's advantage with room modes if you place it paralell to the walls, you should tow them both in to some extent.
Finally, why do you expect a bass dipole speaker to match a traditional concept in efficency/volume int he first place?
You probably knew from the start that's not the case?
If you're then adding the not very well suited drivers to all the above, of course the result can only be sub-par. Also:
Why didn't you more aggressively EQ the low bass frequencies to achieve a more uniform response if you're using the miniDSP anyway? After all, that's what all subs with similarily small footprint are doing...
And from the measurements is looks like you didn't correct the higher frequency chamber resonances in the ripole? You have to implement a low pass for that or at the very least cut it off in the miniDSP. Then the waterfall and FR would look a lot less messy.
With your experiment you're not proving that the ripole design makes no sense (which some in this thread may believe) but rather your implementation is flawed and/or unsuited for you application.
I personally want to listen to music and movies in the best possible way from 20Hz to 20kHz and at volumes that will not leave me deaf in the long term (usually below 100dB). Also, I have neighbors...
In my room and the way I built/placed the ripoles, they easily provide the bass end of all the above and the bass quality itself is notably (also "measurably") better than my previous SVS subwoofer.
I'm not saying this kind of sub is the holy grail, it's just a design that can work very well, especially in problematic rooms, if a clear bass and not a lot of SPL is what you're after.
If you have a lot of drivers left and prefer the latter, better build something like that:
Wall of Death
The official woofer selling with this kit is: SP-382PA
Not even a bumped backplate, and XMAX conveniently is not listed.
TS parameters are dead nutz what I measured for Zobsky's driver.
Excepting Zob's do have bumped backplates, and therefore greater
clearance to avoid cratering the coils.
One thing that does jump out at me is the SPL for this driver is listed
as 94dB 1W/1M. But the Ripol with this driver lists only 77dB 2W/1M
by their own measure. Somehow, just putting a recommended driver
into ripole managed to kill off an entire -20dB normalized to 1W!
Good luck producing enough bass to match cheap bookshelf SPL
levels without bottoming... You will need to commit to wasting at
least 8 subs of typical XMAX per side just to fulfill swept volume.
Subs with extreme XMAX do exist that could help with that, but
also going to push that horrible inefficiency down even further.
Just to match bookshelf speakers! Bookshelf!!!
And of course all this directly on-axis in the near field.
Not even penalizing for far field and off-axis cancellations.
Yes, we tried every available floor level position in the room.
The best was firing up, with the back sealed against the carpet...
Last edited:
*IF* you could power Darling with all 300W that single recommended woofer
is rated for without bottoming (and Zob's bumped pair in Petit form bottom at
far less than 100W) Max SPL for one Darling, and 300W, and no room modes
adds up no more than 97.7dB (about as loud as a hand drill) *IF* you could
hear or feel any bass at that level over the sounds of the voice coil being
mechanically destroyed by XLIM.
"Usually below 100db"? Unless we speak of many multiple ripoles in tandem,
the listening level will for coil's sake have to be a good deal lower than that...
is rated for without bottoming (and Zob's bumped pair in Petit form bottom at
far less than 100W) Max SPL for one Darling, and 300W, and no room modes
adds up no more than 97.7dB (about as loud as a hand drill) *IF* you could
hear or feel any bass at that level over the sounds of the voice coil being
mechanically destroyed by XLIM.
"Usually below 100db"? Unless we speak of many multiple ripoles in tandem,
the listening level will for coil's sake have to be a good deal lower than that...
Last edited:
The OP wants to do something with his existing pro 18's.
Rather than wing an un-recommended driver with ripole
and fail, or spend 999euro per side for recommended
plans and drivers (according to popular legend, the only
way ripole is assured to work)
Let me give you some free plans of mine. For a pro 18".
An untried hybrid of Karlson and tapped horn. If it fails,
at least you didn't pay some snake oil salesman a dime.
I can waste your time on improbable nonsense for free!
Rather than wing an un-recommended driver with ripole
and fail, or spend 999euro per side for recommended
plans and drivers (according to popular legend, the only
way ripole is assured to work)
Let me give you some free plans of mine. For a pro 18".
An untried hybrid of Karlson and tapped horn. If it fails,
at least you didn't pay some snake oil salesman a dime.
I can waste your time on improbable nonsense for free!
Attachments
Last edited:
I suspect we've (unintentionally, in my case) scared off and / or confused the original poster away
In any case, I think this is going to be one of those "qualified agreements" + "agree to disagree on the rest" conclusions - since I don't feel like buying any more drivers at the moment.
To a couple of points raised earlier today:
1. I did perform some sever EQ'ing and crossing over on the ripole to kill the peaks some more. They just aren't on my charts. That said, every ripole I've ever built has been easy to bottom out. Unless someone wants to send me over some 12" peerless or other recommended drivers, I'm about ready to see what else I can accomplish with what I've built.
2. I suppose I could pull the ripoles out some more from the wall to investigate the difference in response and improve the performance. Thanks for raising that. However, this arrangement probably won't work for long term listening, given the way the room is laid out and furnished. This is not a critique, .. merely an observation
3. I've already established that the ripole with my drivers is next to useless in the larger spaces I have available (which was the whole point of moving it into a smaller space).
Once again, to summarize, I'm not completely knocking the ripole concept (and I still have some more tweaks to try). All I'm saying (as per my observations is that:
unless you have mutliple units and drivers with suitable T/S params and suitably large swept volumes, there is a quick transition from being under-powered to being overloaded
I'm not sure the OP's drivers have enough motor to drive Ken's creation, so take his suggestion with a cup of salt. I'll report back with the results of moving the ripole around
What I said above was referencing to my ripole build (Quad-Ripole with 8 Peerless SLS10), not a single unit with the OP's or zobsky's drivers.
It tops out around 100dB (estimated). The overall sensitivity is pretty much on par with my Front Speakers (around 87dB, +/- one or two dB) as I don't have to attenuate them to get a flat frequency response.
So it is possible to get good (and to my taste loud enough) bass out of (perhaps multiple) ripoles. My drivers aren't ideal either as you should use 12 to 18in woofers with a lot of xmax in a ripole to get a good balance between low frequency (without too much EQing) and reasonable volume.
They also don't have to be as obtrusive as a "Grand Orgue", mine double as stands for my Fronts with a reasonable footprint (60x60x35 cm).
Opinions on the "Orgue" ripols are very divided on the German forums, there have been far better/more successful ripole builds around the forums I think. Also, Axel (the inventor) is always of great help in "getting it right", if one decides to get the build planned by him.
To call the whole design "snake oil" is really just a cheap, low blow and not worth commenting any more ... as it's working out pretty well for a lot of people who actually take the time to properly implement it. But to each his own... nobody forces you to use that design.
Yes your drivers aren't the best for such a concept but there are lots of other things to consider too, like the size of the chamber "mouths", the tightness of the chambers themselves etc. and especially the mentioned position.zobsky said:
I only meant you should EQ the lower frequency to your desired f3 (mine's at 19Hz but it's hugely room-dependent). The huge resonances at higher frequencies (above 200Hz) have to be cut off completely rather than being EQed.
Unfortunately they are an inherent part of the design that has to be dealt with. Axel usually supplies a passive corrective filter (basically a low pass) to do this. The have to be crossed over well below those frequencies (which wasn't apparent from your measurements), somewhere around 100Hz or so. E.g. I cross mine to the Fronts at 80Hz (or at 120Hz in a future setup), in addition to the built-in corrective filter.
That's a good point about these kinds of speakers, they are a bitch to position correctly. As mine are doubling as stands for my Fronts i didn't have too many options either (aside from tow-in) but it they work really well or me in their current position. But there are quite a few people who position them really close to the listener (e.g. as a coffee table).zobsky said:
However, all subwoofers (especially monopoles) aside from arrays will introduce problems if positioned near the walls and will have a party with your room modes. But especially the latter is something the ripoles can avoid to at least some extent with their different dispersion characteristic.
Well maybe they just aren't the right speaker for you and your drivers but you at least made quite an effort in trying out this concept vs. other people around here who are just ridiculing it probably without ever having heard one.zobsky said:
The thing is, once you can find a reasonable position (even if short-termed), try to listen to some of your favorite music with them. The bass (even when at the same volume as your usual woofer) will sound tighter and more controlled because the room modes should be significantly less dominant.
Mine made me ditch my SVS sub in pretty much a heartbeat and i really don't miss any of the volume I would have reached with "proper subs", if anything I can now listen at higher levels as the bass is no longer as present in the whole apartment (or at the neighbors) but rather at the listening spot only.
I'm totally with you on this one, the mechanical stress on the drivers far exceeds any power you could put into a regular woofer, but as mentioned above, it's about the quality of the bass, not the max SPL. After all the Ripole is very very similar to the Linkwitz W-Dipole concept, a man who most agree is not an idiot concerning DIY audio. Aside from other Dipole bass concepts like an M- or H-frame it's a cheap and small footprint solution to get good-quality bass of a whole different kind than a regular monopole.zobsky said:
At least you tried it and if it's not working out, there are plenty of other options (for the OP also) to build with the driver one has "lying around" or otherwise catching dust.
Last edited:
Played with moving the ripole away from the rear wall towards the mic.
- As the ripole is moved away from the rear wall towards the mic, the SPL goes up. This could be due to a combination of enhanced dipole sub action (rear wave delay) and also physically reducing the distance between the device close to the mic in a rather small room
- Pointing the slot directly at the mic removed a rather large null around 90 Hz . This was interesting to note (compare curves 2 and 3, for example).
Attachments
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.