Having owned an open baffle speaker, I found it irritating to listen to my floorstanders in the study room. So over the weekend I built a "bookshelf open baffle" with some degrees of pessimism.
But bass aside, I was blown away with its sound signature. They are as open and natural as my larger dipole (the size is about half a door)
I have retired my floorstander as a result, and so the question remains: how to fix the bass. I tried normal subwoofer and was dissapointed. Some obvoious experimentation will follow such as
- active equalization
- dipole subwoofer (h-frame, u-frame??)
But with space constraint I'm not sure if it's possible for mini-dipole to have good bass ???? help!
But bass aside, I was blown away with its sound signature. They are as open and natural as my larger dipole (the size is about half a door)
I have retired my floorstander as a result, and so the question remains: how to fix the bass. I tried normal subwoofer and was dissapointed. Some obvoious experimentation will follow such as
- active equalization
- dipole subwoofer (h-frame, u-frame??)
But with space constraint I'm not sure if it's possible for mini-dipole to have good bass ???? help!
nice OB's gainphile! I have been fooling with some recently. Currently have a 10" Lil Buddy and B&C horn. Sounds quite good. Couldn't get good bass with either an OB or a boxed subwoofer. So I'm using them both. The box is about 60 ltr ported and adds tremendous bottom. The 15" OB is the woofer part of a silver iris which is similar to an eminence alpha I believe. Tho it's much higher efficiency than the boxed woofer, the combo seems to work. I'm driving both woofers with one amp; just under 3 ohm load. The 10" LB and horn are powered with my better amp. Once you get the OB bug it is hard to go back.
An externally hosted image should be here but it was not working when we last tested it.
Don't know how much it will help but I would experiment with about 4-6" deep wings and stuffing to damp out the rear wave. Basically a short heavily damped u-frame, focus more on damping the sides near the wings and less right behind the driver and above it.
Minimal cost and effort and it might be enough for nearfield listening.
Let me know how it works out.
-J
Minimal cost and effort and it might be enough for nearfield listening.
Let me know how it works out.
-J
Bonjonno, that's a massive system 
it must sound a real treat. Yes I've been querying the Hawthorne coaxials but with my room size I don't think it's going to happen. I can do that with my living room setup but it means fighting with my kids' power ranger sessions
Bonjonno, thanks that's a great idea. It just so happen that I have a pair of 10" lying around. I will try to add this into the system. Now, about the wings, is there any particular calculation I need to follow (why 4-6"?) -- and is it better using H or U wing ?
it must sound a real treat. Yes I've been querying the Hawthorne coaxials but with my room size I don't think it's going to happen. I can do that with my living room setup but it means fighting with my kids' power ranger sessions Bonjonno, thanks that's a great idea. It just so happen that I have a pair of 10" lying around. I will try to add this into the system. Now, about the wings, is there any particular calculation I need to follow (why 4-6"?) -- and is it better using H or U wing ?
the 4-6" was based on the appearance of how much space there is behind your baffles. The wings almost make it a U-frame, minus the roof. The important part is going to be the damping, I would keep adding more until it adversely affects the sound then pull a little out. You will basically be experimenting with over stuffing to damp the low frequencies while moderately stuffing above and behind for the mid band. At some point you should approach a cardioid type radiation pattern, which will solve your bass problem. Notice I said should, with only 4-6" I don't know if over stuffing will accomplish the goal.
bonjonno said:
nice system. What woofer is in the boxed woofer?
Does the bass quality of teh selaed box woofer and OB integrate well? How much more sensitive is the Iris than the boxed woofer?
My object is to use 2 Augies (or similar woofers) mated to a OB midbass (Supravox 215) and tweeter (B&G Neo 3), I wonder if I would need a selaed box woofer to augment the bass for this.
thanks navin. The boxed woofers are loaded with 10" dvc madisound woofers. I've used them for years. Had them in the corners and they were great, but had to move them in to support my OB project. They really make the system sound huge, but are boxy sounding. That isn't a bad thing, but it doesn't integrate so well with the wide open mids and highs. The OB 15" has a wonderful string bass sound, but not much bottom on electric bass or kick. No slam. Together they get the job done. I think the 15 is rated at 98db and 10 is about 90db. But the vented box adds alot.
I've not heard the augies, but from all I've read they seem to have all the low impact the SI's are missing. They are not nearly as efficient tho. Need lots of watts. When I save up some more loose change I may try a couple of selenium PW315 15" woofers. Four can be had for less than 2 augies and they are very efficient.
I've not heard the augies, but from all I've read they seem to have all the low impact the SI's are missing. They are not nearly as efficient tho. Need lots of watts. When I save up some more loose change I may try a couple of selenium PW315 15" woofers. Four can be had for less than 2 augies and they are very efficient.
bonjonno said:
I dont want my system to become more complex than a 3 way and I want the bass to be able have the delicacy of OB and the slam of sealed/ported boxes. I have lived all my life with the slam (and boom) of boxed woofers (my system eariler had 2 JBL 2245 in JBL B460 ported boxes and later 4 x Audio Concepts DV12 in 2 sealed boxes).
Have you got any comparision of the Selenium woofer vis-avis the Hawthorne or Eminence or even Haskin's OB specific 12"? In short I am looking for slam without boom.
bonjonno said:
Amen to that! Since I discovered open baffles regular speakers doesn't really sound the same anymore. :-/
Once you've learned how the the box affect the sound reproduction it doesn't seem possible to "unlearn" it. Regular speakers just tend to sound unnatural for me now. On the good side, there's a whole new greatsounding world to explore!
Gainphile:
Hi, nice build! I also use OB's for my computer consisting of a pair of fullrange 3 inchers. For bass I use a really cheep vented sub with a five inch woofer (xover around 200). It was really a lucky match and I didn't have any expectations whatsoever. Anyway, it blends incredible well and overall sound is really nice, especially considering the total price!
Cheers!
Nice idea Gainphile. I've been wondering what to do with some of my cheap drivers that seem to have multiplied into every corner of my house.
Bonjonno - I see you got your LBs okay. I wanted to order 4 more and saw they were out of stock last week. Word of mouth is the best advertisement.
BTW, are you sure your horn is oriented the right way?
Bonjonno - I see you got your LBs okay. I wanted to order 4 more and saw they were out of stock last week. Word of mouth is the best advertisement.
BTW, are you sure your horn is oriented the right way?
ttan98- so far so good on the Lil Buddy's. I've only had 20-30 hours listening time with this setup. Active x-o between subs and LB/horn at around 200hz 24dbLR. The LB & horn xo are passive. 12db at ~1400 on the LB, 2.5K 12db on the horn. And a -6db eq adjustment at ~2.7K hz with my computer (source). Being a guitar speaker the Lil Buddy shouldn't have much problem playing well down to 80hz; maybe a little eq would allow a lower xo. But I was inspired by magnetar's recent build where I believe he xo at 250 and was not ever trying to get low notes out of it.
AJ- Parts Xpress saved the day for my second LB; shipped fast and free(!) but they only had 3 in stock when I ordered. There are so many eminence choices, probably no one stocks alot of any given model. My two LB's seem to be from different batches 6 weeks apart, but appear and sound quite similar. Thanks to your hard work, the orientation was a snap.
AJ- Parts Xpress saved the day for my second LB; shipped fast and free(!) but they only had 3 in stock when I ordered. There are so many eminence choices, probably no one stocks alot of any given model. My two LB's seem to be from different batches 6 weeks apart, but appear and sound quite similar. Thanks to your hard work, the orientation was a snap.
... ok so for the past few weeks I have been experimenting with ported sub, etc. to complement the bookshelf OB. The conclusion is they all sound not so good as proper dipole.
So tonight I completed a pair of dipole bass using 10" drivers. The overall project has gone from passive to fully active which means tri-amping the whole thing.
The dipole bass is, as predicted -- eargasm. No boomy slow bass whatsoever, when it's required to be there it's there. However there is still apparent lack of slam.
Summary of the system now:
mid/high: active 24db/oct at 3.5kHz
mid: natural 6db/oct baffle rollof
bass low-pass: 12db/oct at 120Hz and equalised at 6db/oct towards low frequency
The three amps being used are 3875 gainclones. They are powerful enough to drive these equalised woofers
http://youtube.com/watch?v=GOD2kmrPlKA
So tonight I completed a pair of dipole bass using 10" drivers. The overall project has gone from passive to fully active which means tri-amping the whole thing.
The dipole bass is, as predicted -- eargasm
. No boomy slow bass whatsoever, when it's required to be there it's there. However there is still apparent lack of slam.
Summary of the system now:
mid/high: active 24db/oct at 3.5kHz
mid: natural 6db/oct baffle rollof
bass low-pass: 12db/oct at 120Hz and equalised at 6db/oct towards low frequency
The three amps being used are 3875 gainclones. They are powerful enough to drive these equalised woofers
http://youtube.com/watch?v=GOD2kmrPlKA
cool system! Looks good!
Could you share the dimensions?
Here are a couple of ideas - I'd bring the tweeter back down to ear level by putting the H frame above the mid/high baffle. Point the H frame down and towards you - you'll get less rear wave cancellation the less the bass driver is parallel the wall. Just a though..
Could you share the dimensions?
Here are a couple of ideas - I'd bring the tweeter back down to ear level by putting the H frame above the mid/high baffle. Point the H frame down and towards you - you'll get less rear wave cancellation the less the bass driver is parallel the wall. Just a though..
gainphile said:... ok so for the past few weeks I have been experimenting with ported sub, etc. to complement the bookshelf OB. The conclusion is they all sound not so good as proper dipole...The dipole bass is, as predicted -- eargasm
Is the apparent lack of slam a side effect for all OBs including bigger 15" woofers?
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