I've been using my OB system for a good while. It runs 4 sealed 12" subs below 80Hz, a nude OB 18" Faital Pro 18HP1010 up to 300Hz, B&C 8PE21 in OB, and Beyma TPL-150H open in the back. The system is active and I use Acourate to develop the filters to get to the target in-room response. At the time, I purchased the 18" to try OB out, and I like the midbass definition that OB brings, but I'm missing the "body" unless I turn it up quite a bit. I don't think it's a matter of amount/SPL as the system delivers on the target curve, but there is something missing unless I turn up the volume beyond what is acceptable while others are in the house. With good records and volume turned up to 90dB I get the grin in my face, but then that's not too often.
The Faital is not particularly well suited for OB. Nor I think I need a 18" midbass. Thinking 12" or maybe 15". I was planning to upgrade to something like Acoustic Ellegance LO12, SB Bianco, or Beyma 12BR70 used in the Caladans, but my current experience has me hesitating. I read references to OB bass being more often liked for classical and jazz. While I listen to both, I mostly listen to rock/blues where kickdrums and bass guitar play a significant role as well as synths.
Looking to get input from experienced users. You like OB midbass and like rock, compared to sealed midbass? Is the poor choice of the Faital as OB midbass a likely explanation for what I'm (not) hearing?
Thank you!
The Faital is not particularly well suited for OB. Nor I think I need a 18" midbass. Thinking 12" or maybe 15". I was planning to upgrade to something like Acoustic Ellegance LO12, SB Bianco, or Beyma 12BR70 used in the Caladans, but my current experience has me hesitating. I read references to OB bass being more often liked for classical and jazz. While I listen to both, I mostly listen to rock/blues where kickdrums and bass guitar play a significant role as well as synths.
Looking to get input from experienced users. You like OB midbass and like rock, compared to sealed midbass? Is the poor choice of the Faital as OB midbass a likely explanation for what I'm (not) hearing?
Thank you!
Lewinski, how well does the 8pe21 in OB do down to 300 Hz? Do you think going down a little more, like 250 Hz, would still be ok?
Regarding you question, I will be going another route, OB down to 250 Hz and sealed or BR below. As this is my second system in a smaller room, I want it to stay small, so I am thinking of a 10" or 12" below the OB mid. If the 10/12" turns out not to go low enough. I'll add one of my small LAB12 subs
Regarding you question, I will be going another route, OB down to 250 Hz and sealed or BR below. As this is my second system in a smaller room, I want it to stay small, so I am thinking of a 10" or 12" below the OB mid. If the 10/12" turns out not to go low enough. I'll add one of my small LAB12 subs
I think you should consider re-voicing your system. You said you are on your target curve, try changing it to taste. There's nothing wrong with your drivers.
You tuning up quite a bit nude 18HP101 range or sub range?
Problem can be caused by different polar plot of OB and sealed subs, sub is omnidirectional, OB is dipole. So total radiated energy levels are very different for them than on axis measured SPL. Or maybe there are some phase problems in sub and OB overlap range what are difficult to measure.
I had little similar problem with U-frame bass and flat panel OB midrange. U-frame is nearly omni on dipole peak what was upper range of bass. Solution was to built totally new OB with H-frame bass and H-frame mids.
Problem can be caused by different polar plot of OB and sealed subs, sub is omnidirectional, OB is dipole. So total radiated energy levels are very different for them than on axis measured SPL. Or maybe there are some phase problems in sub and OB overlap range what are difficult to measure.
I had little similar problem with U-frame bass and flat panel OB midrange. U-frame is nearly omni on dipole peak what was upper range of bass. Solution was to built totally new OB with H-frame bass and H-frame mids.
I wouldn't attempt to prescribe a solution for you without looking at detailed polar measurements, which I know are hard to do indoors, and looking at how you've got these drivers stacked up on a baffle. The issue could be something simple that can be solved with toe-in and positioning or something fundamental that indicates you need to redo the baffle, assuming you have one. More likely there are some polar response variations that can be ameliorated by peaking or depressing the axial response in the problem area to bring up the reflected sound, which I suppose is another way of describing re-voicing the system.
Where is the floor null in this system? Can you extend the 18" passband up high enough to provide some overlap with it?
Where is the floor null in this system? Can you extend the 18" passband up high enough to provide some overlap with it?
I agree with @cowanaudio , an 18” woofer isn’t that much smaller than a rock kick drum……that should be slamming’ mid bass with all the tactile force of the real thing.
That being said, realistically, mid bass slam is an SPL thing………I wouldn’t expect much tactile sensation from anything below 90db.
All the above is assuming that your derived target response is from in room measurements?
That being said, realistically, mid bass slam is an SPL thing………I wouldn’t expect much tactile sensation from anything below 90db.
All the above is assuming that your derived target response is from in room measurements?
@LewinskiH01
I’m going through a similar experience…albeit with a less developed dipole bass system that has irked me for a while.
In my situation I’ve felt like maintaining the footprint and aesthetics that I put time into on my dipole bass panels has held me back (shooting myself in the performance foot?). I tried to build them based on guidelines in NP’s first SLOB article…obviously with space limitations. They use (6) 8” drivers per panel.
I thought it was never a large enough panel and had sort of given up on it.
However, XRK971 has a well developed and documented dipole speaker with a similar bass section of about the same size (possibly smaller) that seems successful based on feedback in his thread.
I decided to give my panels another shot by adding some wings to them to try and get some more extension and better performance from them.
I am using some horns on top with some Fostex 108ez mounted with no back chamber…a sort off “what if” idea.
I have a First Watt B5 that I use to filter and adjust these types of systems.
I couldn’t adjust this one by ear and had to drag out my old laptop with REW and the UMIK-1.
It was an enlightening experience.
In the end I was having to throw away 15dB on the horns and was maxing out the EQ for 20Hz boost and the bass level adjustment.
The horns are cut at 300Hz with a first order. The panels are cut at 100Hz..second order by default I believe.
I was able to achieve a reasonable in room response curve with a downward slope from 35Hz…not perfect. They are set up in the basement right now.
They sounded well balanced while playing jazz and even downtempo type music.
As soon as I put on a test album for Rock (In this case Radiohead OK Computer) they failed. The kick drum is just not there with any impact.
So the question I have again now is whether it’s worth it to try and continue with them.
I could try driving them with a Hypex amp and EQing them…I’d be able to bring them up to the output level of the horns at the same time.
I’m not convinced they’ll ever have the same impact as I have experienced with AE Dipole 15 drivers on an open baffle supporting an 8” wide band.
I’m going through a similar experience…albeit with a less developed dipole bass system that has irked me for a while.
In my situation I’ve felt like maintaining the footprint and aesthetics that I put time into on my dipole bass panels has held me back (shooting myself in the performance foot?). I tried to build them based on guidelines in NP’s first SLOB article…obviously with space limitations. They use (6) 8” drivers per panel.
I thought it was never a large enough panel and had sort of given up on it.
However, XRK971 has a well developed and documented dipole speaker with a similar bass section of about the same size (possibly smaller) that seems successful based on feedback in his thread.
I decided to give my panels another shot by adding some wings to them to try and get some more extension and better performance from them.
I am using some horns on top with some Fostex 108ez mounted with no back chamber…a sort off “what if” idea.
I have a First Watt B5 that I use to filter and adjust these types of systems.
I couldn’t adjust this one by ear and had to drag out my old laptop with REW and the UMIK-1.
It was an enlightening experience.
In the end I was having to throw away 15dB on the horns and was maxing out the EQ for 20Hz boost and the bass level adjustment.
The horns are cut at 300Hz with a first order. The panels are cut at 100Hz..second order by default I believe.
I was able to achieve a reasonable in room response curve with a downward slope from 35Hz…not perfect. They are set up in the basement right now.
They sounded well balanced while playing jazz and even downtempo type music.
As soon as I put on a test album for Rock (In this case Radiohead OK Computer) they failed. The kick drum is just not there with any impact.
So the question I have again now is whether it’s worth it to try and continue with them.
I could try driving them with a Hypex amp and EQing them…I’d be able to bring them up to the output level of the horns at the same time.
I’m not convinced they’ll ever have the same impact as I have experienced with AE Dipole 15 drivers on an open baffle supporting an 8” wide band.
You don't have enough displacement to be leaning on those bass drivers at 20Hz. The big dipole system you heard a while back that I designed uses four very high excursion 15" drivers per channel and much larger wings. That system is flat to 20Hz. Once you have enough displacement don't be afraid to boost the bass to taste.
I have 8pe21 on a 12" baffle and works well down to 300Hz. Doesn't do well at 250Hz with this baffle. A wider baffle would help, but then you're likely to have an issue in the top end.
You might want to examine the Consonus audio project. I'm going to try xrk's SLOB with 8x 6.5" per side that reportedly works very well up to 450/470Hz on a 12". Let's see!
I think this is good advice. I kept the same xo and filters but moved the speakers closer to the front wall and midbass improved. In my mind this is similar to re-voicing. You are likely right.
I have already purchased and received the 16x 6.5" for the SLOB units and I'm intrigued and hopeful they perform equal or better than the 18" while needing only a 12" baffle. Will build and try.
Hi Bill…I remember Rob saying that you were using some kind of custom long throw units. I thought it was (4) 12” units in the horizontal slots per channel. Either way, I feel like I’m banging my head against a wall with these panels. They are obviously not what I had hoped for.
It is frustrating to have put so much time and energy into them only to come to the conclusion that “There’s no free lunch”.
I think a lot more information on slot loading and the drivers to use has come to light since I bought these almost a 8 years ago.
I kind of feel like all they are doing is adding complexity to the scenario if I still need to try and supplement them on the bottom end.
If I added some kind of sub (even dipole) to give me the impact that’s missing what would the panels be covering? One octave?
How low do you think I could “lean” on them? There are (6) drivers per channel wired in series/parallel for an 8 Ohm load.
Here’s a link to the limited info on them:
https://www.parts-express.com/Peerl...8-Paper-Cone-Woofer-12-Ohm-299-068?quantity=1
Using the small fullrange in the horn made it feasible to level match to the panel. There is no way I could have tried a CD and matched it using the B5.
The imaging from the horn is really quite interesting with a phantom floating in the air sort of quality.
I have always liked the idea if getting as much information from a single point source as I could. Going the Synergy route is a bit too daunting from my DIY perspective.
Those drivers are totally unsuitable for a dipiole bass application. The speaker I designed that you heard has around 32dB more displacement limited excursion.
Moving up to the SB23MFCL45 will gain you some 16dB without changing your baffle. That should work well from 40Hz up.
You really need the flexibility of a full DSP solution to dial in your system.
Moving up to the SB23MFCL45 will gain you some 16dB without changing your baffle. That should work well from 40Hz up.
You really need the flexibility of a full DSP solution to dial in your system.
OB simply isn’t sensible much below 80hz…..sorry and it saddens me to see the lengths folks will go to and then convincing themselves this was all a good idea.
But there’s some light at the end of the tunnel when honest folks post here and report their failures and the successes of those through utter brute force and excess.
But there’s some light at the end of the tunnel when honest folks post here and report their failures and the successes of those through utter brute force and excess.
My foray into this project was originally stimulated by reading NP’s SLOB article and the tip that the Peerless drivers would be a good way to try the concept out. They were cheap buyout speakers. You get what you pay for I guess?
Given my limited success, and the work/time I’ve already put into this particular project I’m not too sure I’d be willing to throw $1800 in SB drivers at it. There has to be a more reasonably priced alternative driver to try if that was a route I was going to pursue.
I would probably be better off pulling out my AE Dipole drivers and just going with a plain baffle of some sort…if I could live with it.
Trying the SLOB route (for me) was an attempt at having dipole bass with a more manageable footprint and aesthetics for a real living space.
The aesthetics of a horn over OB?…I know Rob did it pretty well. I’m not sure I’ve come up with any ideas I’d be happy with…especially since I don’t have a CNC router table.
That is on the table. I have several Hypex amps I have used on different projects. I just won’t use them for anything but bass support because I personally find them “sterile” sounding when used fullrange.
Maybe…but I have heard it successfully done (Bill’s system) and it is fantastic
It seems to me great OB bass cannot have all 3:
1. Small driver/baffle size
2. Low expense (e.g. inexpensive drivers, amplification)
3. Simplicity (e.g. DSP, EQ)
Workhorse drivers in well-designed bass reflex box is not a bad thing sometimes..
There are other ways you can flavour your sound with some low order harmonic distortion than via the power amp. The Hypex amps give you a clean slate to work from. Also, you don't need Hypex amps to run DSP.
Don't underestimate the amount of displacement I designed into that system. It has four 15" drivers per channel each with 34mm one way x-max. The 1kW/ch that is available to those drivers is enough to take them to their excursion limits. It was designed as a statement system and not one that will end up in many customers homes.
An interesting fact about those bass drivers, I designed in a cone out offset into the driver to counteract the sag caused by the cone up mounting that the drivers would see.
Two decent 15"s or a quad of suitable 12" drivers will do a really decent job to 40Hz. It's the first octave that's hard.
All that about OB bass is true but if I can believe the Fostek data sheet, your lack of midbass is due to its meager 0.28mm Xmax, That clearly isn't enough to support operation down to 300 Hz with first order XO and no rear chamber! Before giving up, I would add that missing rear chamber then add just enough absorption on the rear of your SLOB to make it cardioid-like. That isn't the full range OB you were aiming for but you might find you like it.
@nc535 Agreed…..for an OB application, 400hz with a 2nd order electrical is about as low as the 8PE21 should go……but in a high Q enclosure, 200hz is great adding that first harmonic energy to snare and Toms as well as the full weight and body of male vocal…….there’s really something special about this B&C driver. I don’t know if it’s the cone material or the unique rib in the cone……but I’ve used it right up to 3.5khz without any ill effects as the beaming isn’t a problem with the right filter on the HF driver to balance.