Hello,
A new fast fun inexpensive OB project. It is my second attempt to do a FAST OB. Several reasons to this defect but not suitable drivers.
Looking for a woofer usable for OB, I found this one, a driver for bass guitar : Lavoce LBASS15-15-8
Some challengers were simulated Fs < 40Hz Qt > 0.6 Not a lot of contenders.
The choice for the mid-tweeter : I saw a lot of tests and based on return of experience on the web : Markaudio seems to be the way to go. There are also Fostex FF85WK.
I want a good treble as good as dome tweeters. Many fullrange i listened to has not the treble I want it very realistic. And the mid is couloured... It is my opinion
.
For the mid_tweeter I tried first an Alpair 7ms, good mid but treble miss extension to my ears. Go to Alpair 5.3 the sound became ok to my ears.
I tried first a 6dB crossover, LR2 slope but the sound was sometimes muddy in the midrange. Go to LR4 slope, all things are OK.
I wanted to test the MAOP 5, my opinion it is a more refined and neutral driver than Alpair 5.3 . The two drivers have the same response on the baffle.
This design should work with FF85WK or Alpair 7ms, not tested with a LR4. The crossover is a little different, 8 ohms drivers.
It is not a very expensive speaker 500-600€/$ for a very good sound.
The bandwidth is 50Hz-20kHz 87db/2,83V . The Qt of the woofer on the panel is 0.8 and 36Hz resonance. I made some measurements, the response curve of the speaker is honest. The crossover frequency is 640Hz.
I was a little lazy for the construction, the panel is a shelf board with standard dimension 80cmx40cm.
It is a compact open baffle. I add a shelf bracket in the back to tilt the panel.
There are some similar old projects :
John Busch (RIP) Fast, fun, Inexpensive OB project
Martin J. King MV Model 3P OB Loudspeaker Project
I enjoy a lot the speaker, it works good to my ears.
Have fun.
A new fast fun inexpensive OB project. It is my second attempt to do a FAST OB. Several reasons to this defect but not suitable drivers.
Looking for a woofer usable for OB, I found this one, a driver for bass guitar : Lavoce LBASS15-15-8
Some challengers were simulated Fs < 40Hz Qt > 0.6 Not a lot of contenders.
- SB Audience 15OB350 design for open baffle, has the best max output level. My second choice because the Lavoce has a lighter cone and less expensive, less crossover cost.
- Celestion Pulse XL 15 Interesting but too much crossover work to have the same bass extension as the others.
- Eminence Alpha 15 Best bass response 40Hz less sensitivity 85dB and a peak in the group delay. The most expensive in the group 200€ ! Harder to find in Europe
The choice for the mid-tweeter : I saw a lot of tests and based on return of experience on the web : Markaudio seems to be the way to go. There are also Fostex FF85WK.
I want a good treble as good as dome tweeters. Many fullrange i listened to has not the treble I want it very realistic. And the mid is couloured... It is my opinion
.For the mid_tweeter I tried first an Alpair 7ms, good mid but treble miss extension to my ears. Go to Alpair 5.3 the sound became ok to my ears.
I tried first a 6dB crossover, LR2 slope but the sound was sometimes muddy in the midrange. Go to LR4 slope, all things are OK.
I wanted to test the MAOP 5, my opinion it is a more refined and neutral driver than Alpair 5.3 . The two drivers have the same response on the baffle.
This design should work with FF85WK or Alpair 7ms, not tested with a LR4. The crossover is a little different, 8 ohms drivers.
It is not a very expensive speaker 500-600€/$ for a very good sound.
The bandwidth is 50Hz-20kHz 87db/2,83V . The Qt of the woofer on the panel is 0.8 and 36Hz resonance. I made some measurements, the response curve of the speaker is honest. The crossover frequency is 640Hz.
I was a little lazy for the construction, the panel is a shelf board with standard dimension 80cmx40cm.
It is a compact open baffle. I add a shelf bracket in the back to tilt the panel.
There are some similar old projects :
John Busch (RIP) Fast, fun, Inexpensive OB project
Martin J. King MV Model 3P OB Loudspeaker Project
I enjoy a lot the speaker, it works good to my ears.
Have fun.
Attachments
It can't if you are 1000 m distant (as you defined in edge).
(Edit: I agree it's a bit confusing that the mic distance needs to be defined in m, but the rest in mm!)
Yes it plays bass very well !
The magic is equalization : the big 10mH coil extend the speaker response down to 50Hz (-10dB less level) and the room contributes to the lower notes.
See my references in the first post and Martin j king website for a starting point : http://www.quarter-wave.com/OBs/OB_Theory.html
Please read the references. The problem with your simulation is all 15" drivers have the same behaviour on the same open baffle. It is a false assertion if you don't take into account TS parameters like Qts. Imagine the same thing with a box : All drivers have the same bass response in the same box !?
Well, your 1st plot shows 28Hz @ 90dB which is -6dB, so plenty of output.
But for better simulation try Basta with room gain, box/baffle in free space and so on. You might find a different result.
I guess you are familiar with Basta as you are using Edge. And Basta is the big brother of Edge with more advanced capabilities.
But for better simulation try Basta with room gain, box/baffle in free space and so on. You might find a different result.
I guess you are familiar with Basta as you are using Edge. And Basta is the big brother of Edge with more advanced capabilities.
All things combined, it works. The 10mH coil lowers the output leaving the bass high, and this is why a high sensitivity woofer with high Q and low Fs is needed. The coil also places a boost at Fs if low enough DCR. This is a benefit here.
Perry Marshall's primer on boosting passively could also be used.
I've yet to do an IB as this, but it would be fun and I would likely approach it just as Jerome did here, with maybe a tweeter too.
Perry Marshall's primer on boosting passively could also be used.
I've yet to do an IB as this, but it would be fun and I would likely approach it just as Jerome did here, with maybe a tweeter too.
I have seen also real magic with this kind of OB speakers, at least with two of them..
Measurements shows good bass level as also listening, but not any simulation, also AKABAK simulation with precise speaker data and filters did not confirm this, but bass really exist and it is not room gain.
Measurements shows good bass level as also listening, but not any simulation, also AKABAK simulation with precise speaker data and filters did not confirm this, but bass really exist and it is not room gain.
If it was an inexpensive project you would have used the CHN-50.
I’m not big into OBs (abandoned them to a persistant issue) i am very interested in the MAOP 5 (a really pricey 3”, but probably worth every penny [based on experience with my MAOP 7]).
Now i will go read the thread ;^)
dave
Not a great woofer. Took me a lot of effort to make them tolerable.
The XO seems a bit high. I was under the impression (MJK) that XO is dependent on baffle size (width) and the LP(f3) ≠ HP(f3). An electrical hole trading lower bass for woofer sensitivity.
dave
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