I'm with studiotech and Murphys Law on this one. You gotta slow down a little bit and tinker with what you have. There absolutely no need to keep buying more drivers. The mids definitely need a baffle to come down to 100Hz and you still might need to EQ them or put in a battle step circuit passively to raise the bottom end up. I believe the SSpeaks could sound absolutely great (fuller) with just a few changes to your setup.
Those 18s that you have are killer, but once again, you have to either EQ them or put in a filter.
Have a look through my OB thread - I'm using 21s with a 30Hz low-pass (~12db/oct)! That might sound extreme, but they play relatively flat to 100Hz where a 10" mid takes over. The driver and baffle contribute to the crossover point, not one that I forced with circuitry. If I just run the mid and tweeter, the sound is just like are saying - thin. The woofers bring everything back in line.
Also - just remember that OB has horrible inefficiency for any kind of bass. Don't be surprised if you need to considerably up the gain on amplifiers or boost bottom frequencies (same effect). That'll get the LMS moving a bit more.
Additionally, if I'm running just test tones through the 21s, anything above 50Hz-60Hz has almost no movement. SPL is still displacement and frequency dependent - higher freqs need much less displacement for the same pressure level than lower ones. The OB rolloff means that your driver will have to move even more for the lower end.
Those 18s that you have are killer, but once again, you have to either EQ them or put in a filter.
Have a look through my OB thread - I'm using 21s with a 30Hz low-pass (~12db/oct)! That might sound extreme, but they play relatively flat to 100Hz where a 10" mid takes over. The driver and baffle contribute to the crossover point, not one that I forced with circuitry. If I just run the mid and tweeter, the sound is just like are saying - thin. The woofers bring everything back in line.
Also - just remember that OB has horrible inefficiency for any kind of bass. Don't be surprised if you need to considerably up the gain on amplifiers or boost bottom frequencies (same effect). That'll get the LMS moving a bit more.
Additionally, if I'm running just test tones through the 21s, anything above 50Hz-60Hz has almost no movement. SPL is still displacement and frequency dependent - higher freqs need much less displacement for the same pressure level than lower ones. The OB rolloff means that your driver will have to move even more for the lower end.
Using the router I would cut the top and bottom butterfly pieces, and using a double 19mm MDF baffle board, it would be slightly longer than the centre section so a bit overhung both ends.
Dowels and glue, or screws coming up from the bottom would be spaced out and go the length of the baffle board.
The 4 Y end pieces would be cut at a 30 degree angle so at the baffle face they seamlessly join at a 60 degree angle. Screws coming up from the bottom again to hold Y boards in place.
Some custom [ shaped piece made from a router jig template would be stacked up both end to cap off the butterflies wings.
Top same as bottom and it should be stable enough to be free standing.
would look a bit like some heatsinks but with the ends capped off.
Edit:
might look more like a bow tie than butterfly wings.
Dowels and glue, or screws coming up from the bottom would be spaced out and go the length of the baffle board.
The 4 Y end pieces would be cut at a 30 degree angle so at the baffle face they seamlessly join at a 60 degree angle. Screws coming up from the bottom again to hold Y boards in place.
Some custom [ shaped piece made from a router jig template would be stacked up both end to cap off the butterflies wings.
Top same as bottom and it should be stable enough to be free standing.
would look a bit like some heatsinks but with the ends capped off.
Edit:
might look more like a bow tie than butterfly wings.
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This thread is growing so fast.
The woofer's Q is too low, you have to 'loosen' the motor.
http://www.diyaudio.com/forums/multi-way/155022-low-q-woofer-ob-high-zo-amp.html
The woofer's Q is too low, you have to 'loosen' the motor.
http://www.diyaudio.com/forums/multi-way/155022-low-q-woofer-ob-high-zo-amp.html
Those little angled walls aren't going to do anything for "reflection" at the frequencies it sees. What you will have is a 1/4 wavelength resonance based on the depth of the frame. A simple h-frame will give your bass drivers adequate baffle to account for the ob losses (eq will still be needed), is easy to build, and when sized properly the resonance can be moved up out of band.
And please, do more measurements!!!
Stay the course man!
BTW, CLS, I am apologize for seeming dismissive of your post. I did not intend that at all. It's just that Silent is getting so many differing ideas thrown at him at once and learning as he goes, I just want him to keep it simple here. Obviously, he does as he wants, just trying to help him get through it.
And I think he is settled on augmenting the OB with some TC 5400 in cabinets, so getting anymore out of the 5100 is not necessary, hence the extra complication of your techniques is probably not needed.
Greg
And I think he is settled on augmenting the OB with some TC 5400 in cabinets, so getting anymore out of the 5100 is not necessary, hence the extra complication of your techniques is probably not needed.
Greg
No haven't bought them yet, but they are part of a future plan once all of the main drivers are sorted, because I do eventually want to use all of this in a home theatre, but I want to supplement the speakers with sub type bass not try to add them to music. So I still need to get reasonably low out of the OB for music.
CLS low qts is one of the trade offs. I think I know what your saying if I could get the qts higher it would help, but as Greg says really not at that level where that is something that should be even considered for quite some time, perhaps way down the track.
Just a bit of clarification are you talking wave length reflection or cabinet reflection?
The reason I am looking at the angles is to give the driver better breathing space directly off the cone not to necessarily to alter any wave length issues caused by the box.
I still need to understand how wavelength are calculated as that would help determine better designs rather than trying to make it look pretty.
Perhaps we should move all this design stuff back into the main thread as my question of how much the cone should move has been answered and to try keep some kind of continuity.
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I have been playing around with a whole heap of OB designs in fact all of them. Your concerns are valid
Just made several variations of a typical H box.
A little while ago I was reading through a thread about a 5 way horn set up and he is using a RAAL Lazy 9", and he tried a RAAL 140-15D wave guide on it and he reported several dB increase with it.
http://www.diyaudio.com/forums/mult...pped-bass-mids-tweeter-big-boy-system-10.html
(Post #99 down the bottom) "The waveguide gives a boost of some 5 to 10dB - Not insignificant! I do have to back the volume off quite a bit with the guide on..."
Well that got me to thinking, the best way to get the most bass possible out of an OB bass is not by doing anything tricky with the electronics but to minimise the bass losses through cancellation.
So I put together various ideas to see what I thought might work best... I like the green and blue ones because it would give a few dB gain from the very large wave guide, and not gain anything on the back with it being flat and negative.
A little while ago I was reading through a thread about a 5 way horn set up and he is using a RAAL Lazy 9", and he tried a RAAL 140-15D wave guide on it and he reported several dB increase with it.
http://www.diyaudio.com/forums/mult...pped-bass-mids-tweeter-big-boy-system-10.html
(Post #99 down the bottom) "The waveguide gives a boost of some 5 to 10dB - Not insignificant! I do have to back the volume off quite a bit with the guide on..."
Well that got me to thinking, the best way to get the most bass possible out of an OB bass is not by doing anything tricky with the electronics but to minimise the bass losses through cancellation.
So I put together various ideas to see what I thought might work best... I like the green and blue ones because it would give a few dB gain from the very large wave guide, and not gain anything on the back with it being flat and negative.
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Cool that will be handy...
I was looking at trying to keep the baffle small but now playing with something around 1 meter square.
Murphy's Law will no longer be participating at diyAudio. The account was created whilst his normal account was in the sin bin. He may decide to continue to participate in this thread. I ask people not to ask about it as he has been warned that further comments on moderation will likely result in his normal account being banned. If he so chooses he may reveal using his normal account that he WAS posting as Murphys Law provided that there are no comments on his time in the bin or other moderator decisions.
Probably not at low frequencies, unless the horn gets very very big. A typically sized H-frame will work as a kind of dipole horn from ~200 Hz and up...
Can you give us an idea of what is very very big?
I just measured the "horn" section and it would be about 280mm and 45 degree angles.
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