So from my previous posts on this thread you will see I was blown away by how good a prototype open baffle speaker did against my previous reference sealed box systems...
So I decided to up my open baffle game, upgrading the neo 6 to neo 10 (well the GRS copy to be fair) and adding in open baffle, clamshell configuration compound subs.
And....wow. just wow.
My previous reference system is probably going to be dismantled or moved out....
The woofer and subs are suspended so not touching the frame at all - so no vibrations are transmitted at all into the structure.
Also both speakers are on castors so can be moved out into the middle of the room easily for listening.
So I decided to up my open baffle game, upgrading the neo 6 to neo 10 (well the GRS copy to be fair) and adding in open baffle, clamshell configuration compound subs.
And....wow. just wow.
My previous reference system is probably going to be dismantled or moved out....
The woofer and subs are suspended so not touching the frame at all - so no vibrations are transmitted at all into the structure.
Also both speakers are on castors so can be moved out into the middle of the room easily for listening.
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Nice. I like the wheels🙂 but what is rationale of such subs arangement? Polar response or something else?
This 'compound dipole woofer' is described here:
Electro-acoustic models
Basically they act as two standard 15" woofers would mounted side by side or above and below each other. But you can bolt them together so they are easy to then sling as a single unit, and obviously it saves space.
One is obviously wired out of phase to the other so they don't cancel.
There is evidence to suggest this arrangement reduces non linear distortion and has a stronger dipole polar response. But I will need to do more measurements before coming to any conclusions.
The nice thing is it's easy just to unplug one of them and then make direct comparisons.
Electro-acoustic models
Basically they act as two standard 15" woofers would mounted side by side or above and below each other. But you can bolt them together so they are easy to then sling as a single unit, and obviously it saves space.
One is obviously wired out of phase to the other so they don't cancel.
There is evidence to suggest this arrangement reduces non linear distortion and has a stronger dipole polar response. But I will need to do more measurements before coming to any conclusions.
The nice thing is it's easy just to unplug one of them and then make direct comparisons.
I did some tests, the results are shown in post 29 Celestion System 6000 vs GR Research dipole bass. In those tests it turned out that the compound woofer has 3dB more ouput, putting the drivers side by side gives 6dB more output. As probably always, you can read a lot about it, but little firm evidence, eg, somewhere it is written that the dipole roll off would be 12dB/octave instead of 6dB/octave.
To Bushmeister: nice indeed, these dipole speakers, congratulations with them!
To Bushmeister: nice indeed, these dipole speakers, congratulations with them!
Interesting!
I will sort some measurements over the next week and probably start a thread to share my findings! I will be very interested in distortion and dipole roll off too!
I will sort some measurements over the next week and probably start a thread to share my findings! I will be very interested in distortion and dipole roll off too!
Sorry, I've been out a while...
So, these are better, to your ears, than the synergy horns?
Surely a different sound and approach.
So, these are better, to your ears, than the synergy horns?
Surely a different sound and approach.
I was expecting a different sound and approach.
But, they are simply better in all areas. Period.
Better detail and resolution, better sound stage, wider listening window....basically better than anything I have ever build or heard in all metrics.
Everyone who has heard them agrees. And I have gotten everyone to have a listen to make sure I wasn't going mad....
It was a complete surprise to me. I was actually upset by this as I love my synergies and my spherical multiways and had put so much work and planning into building them.
But, they are simply better in all areas. Period.
Better detail and resolution, better sound stage, wider listening window....basically better than anything I have ever build or heard in all metrics.
Everyone who has heard them agrees. And I have gotten everyone to have a listen to make sure I wasn't going mad....
It was a complete surprise to me. I was actually upset by this as I love my synergies and my spherical multiways and had put so much work and planning into building them.
High praises. Thanks!
Very interesting.
And they have enough reach up high? Although my ears don't pick up anything above 15kHz, looks like the AMT starts falling at 12kHz or before.
Using active XO?
Sorry! So many questions! 🙂
Very interesting.
And they have enough reach up high? Although my ears don't pick up anything above 15kHz, looks like the AMT starts falling at 12kHz or before.
Using active XO?
Sorry! So many questions! 🙂
No probs at all! - I have started a thread in which I will put lots of details!
https://www.diyaudio.com/forums/mul...om-baffleless-range-speakers.html#post6705023
https://www.diyaudio.com/forums/mul...om-baffleless-range-speakers.html#post6705023
I believe he is using a Neo 3 as a tweeter and this driver has useful output beyond 20kHz:
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My first OB. Pretty clueless just going along adjusting as I make mistakes. I started off based on, or at least inspired, by Troels Gravesens OB. The front I made slightly slanted but some mistakes during cutting dictated the final dimensions.
The materials on hand was some old office table tops which looked like high quality but when cut I saw it was relatively open pore particle board. So I had some oak flooring that I epoxied to the front, and portions of the rear is laminated with heavy and armored drywall pieces. This drywall is 15mm and made for sound dampening, armored with fibers, much heavier than normal dry wall. I used sikaflex. The baffle turned out ok I think considering the materials I had.
The speakers are Wild Burro Betsy and DAS15P. The Betsy appears to be a great buy. The DAS15P I bought mostly due to relatively low price, and for the price they seem pretty good.
I did some tweaks to the Betsys, no idea if good or not... I have some very heavy wool blankets, military stuff, and laminated some pieces inside the basket with sikaflex. I also made a frame that presses against the Betsy and holds it on to the front baffle. On this frame I have about 3kg of lead. It all seems very solid and I think it is beneficial. Certainly does not sound bad, so it stays.
The XO is 4.8mH and 110uF for the 15, and nothing but a pad for the Betsy, 2.5ohm and 30ohm.
These are still under construxion. I am building some SS amps for the 15s and will use my standard 8W SE tube amp on the Betsys.
So far I am pleased, and expect to be more pleased when the SS bass amps are finished.
I do recommend OB after this experiment, the sound and the sound stage is great. But building these was not as simple as I thought. So building OB to save work compared to a normal box...I dont know...
As for the Wild Burro Betsy, I dont know why I hadnt heard about it before. Great buy!
The materials on hand was some old office table tops which looked like high quality but when cut I saw it was relatively open pore particle board. So I had some oak flooring that I epoxied to the front, and portions of the rear is laminated with heavy and armored drywall pieces. This drywall is 15mm and made for sound dampening, armored with fibers, much heavier than normal dry wall. I used sikaflex. The baffle turned out ok I think considering the materials I had.
The speakers are Wild Burro Betsy and DAS15P. The Betsy appears to be a great buy. The DAS15P I bought mostly due to relatively low price, and for the price they seem pretty good.
I did some tweaks to the Betsys, no idea if good or not... I have some very heavy wool blankets, military stuff, and laminated some pieces inside the basket with sikaflex. I also made a frame that presses against the Betsy and holds it on to the front baffle. On this frame I have about 3kg of lead. It all seems very solid and I think it is beneficial. Certainly does not sound bad, so it stays.
The XO is 4.8mH and 110uF for the 15, and nothing but a pad for the Betsy, 2.5ohm and 30ohm.
These are still under construxion. I am building some SS amps for the 15s and will use my standard 8W SE tube amp on the Betsys.
So far I am pleased, and expect to be more pleased when the SS bass amps are finished.
I do recommend OB after this experiment, the sound and the sound stage is great. But building these was not as simple as I thought. So building OB to save work compared to a normal box...I dont know...
As for the Wild Burro Betsy, I dont know why I hadnt heard about it before. Great buy!
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The cross over. 4.8mH and 110uF (two 220uF electrolytics back to back).
The inductor I made using three windings 250turns each. The inductance turned out to be just under 4mH for the inner winding (smallest loops), just over 4mH for the middle winding, and 4.8mH on the outer winding.
I only use the outer winding. I placed the inductor coils in a jar and filled with marine lacquer, the elastic kind. I have a vacuum pump from an old refrigerator which has been my vacuum pump for over 15years. (Check google for diy vacuum pumps).
Edit: the 2uF oil cap is in series with a 10ohm resistor to shave off high end treble. I have a switch in series so I can switch this in and out, and so far I have it out, I do not think I need to shave off any highs from the Betsy.
The inductor I made using three windings 250turns each. The inductance turned out to be just under 4mH for the inner winding (smallest loops), just over 4mH for the middle winding, and 4.8mH on the outer winding.
I only use the outer winding. I placed the inductor coils in a jar and filled with marine lacquer, the elastic kind. I have a vacuum pump from an old refrigerator which has been my vacuum pump for over 15years. (Check google for diy vacuum pumps).
Edit: the 2uF oil cap is in series with a 10ohm resistor to shave off high end treble. I have a switch in series so I can switch this in and out, and so far I have it out, I do not think I need to shave off any highs from the Betsy.
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Mmmmm sorry. I need to update my profile. Been trying to keep a low profile but thats not relevant any more. Living in Norway. Had a few days on Wake back in the day...
SemperFi, +1 on the Betsy drivers - great bang for the buck. I haven't tried any tweaks (yet) because they sound great after just some break-in. Nice DIY on the coils.
Karl
Karl
Question for Perry Marshall....
In post #3443 your grilles look inset and fitted around the speaker chassis. I'd like to do something similar so can I ask what your grille frames are made of and are they fixed using anything more than a snug fit? Any other tips or tricks which might be relevant would be useful too. Many thanks!
In post #3443 your grilles look inset and fitted around the speaker chassis. I'd like to do something similar so can I ask what your grille frames are made of and are they fixed using anything more than a snug fit? Any other tips or tricks which might be relevant would be useful too. Many thanks!
