Looks like 3 identical windbander drivers to me. Technically, a 1.5 speaker has no true xover point, just an overlap area. So how do we determine whether or not the .5 driver is only operating below 1k? Regardless of xover parts used, the woofer will always have "some" output above 1k.
It's the point of being a 1.5way that the widerange play full bandwidth, and the woofers be used as mainly BSC, which generally means they don't play full range. I don't know how that part could be misunderstood. I thought that we discussed this at Dayton and your design was good.
Added....
The point was to have the woofers start their rolloff below 1kHz to facilitate the 1.5way arrangement, and not get entries with essentially 2 or 3 of the same drivers running full bandwidth. This makes them 1way designs, and thwarts the 1.5way mantra. We still want point source designs here as far as the widerange goes.
Most x.5ways involve a minimum 6dB electrical rolloff on the BSC drivers. As long as that rolloff starts by 1k, and is 1st order minimum, we're good, regardless if the response doesn't fully rolloff due to an inherent rising spec response. This means that by 2k, the woofers in theory should be at -6dB.
I suppose that is one way to do it... I was wondering how you'd pull off 3x drivers sharing the same volume like that without too much BSC. Whatever the result, I'm interested in listening to the speaker.
So anyone can model this. 3 of the same relativity flat drivers. One full range two in parallel with bsc and an inductor. I thought everyone would be doing this.
@jhollander said:
So anyone can model this. 3 of the same relativity flat drivers. One full range two in parallel with bsc and an inductor. I thought everyone would be doing this.
Sounds like a good design idea. Wish I would have thought of this. The only potential drawback that I can see is perhaps limited low frequency extension. I went with a big subwoofer for deeper bass, but then I could only use one subwoofer.
This might be a really stupid question (I've had lots of them) but why do you have the fence on your router table? I see a flush trimming bit with a bearing sitting way proud of the fence.
Aside - you could use a shop vac to initially collapse the vacuum bag then finish up pulling it negative with an old refrigerator compressor instead of buying a commercial unit - just sweat some Shrader valves into the suction side . . .
Comments
Looks like 3 identical windbander drivers to me. Technically, a 1.5 speaker has no true xover point, just an overlap area. So how do we determine whether or not the .5 driver is only operating below 1k? Regardless of xover parts used, the woofer will always have "some" output above 1k.
As long as the rolloff starts below 1k, that's all there is to that criterion.
InDIYana Event Website
The filter has a roll off but the FR after baffle step is pretty flat. I hope you’re not insinuating that the woofers can’t play full range.
It's the point of being a 1.5way that the widerange play full bandwidth, and the woofers be used as mainly BSC, which generally means they don't play full range. I don't know how that part could be misunderstood. I thought that we discussed this at Dayton and your design was good.
Added....
The point was to have the woofers start their rolloff below 1kHz to facilitate the 1.5way arrangement, and not get entries with essentially 2 or 3 of the same drivers running full bandwidth. This makes them 1way designs, and thwarts the 1.5way mantra. We still want point source designs here as far as the widerange goes.
InDIYana Event Website
Guess I am out
If they are rolling off, bit still playing up to 20k, kind of a grey area.
Most x.5ways involve a minimum 6dB electrical rolloff on the BSC drivers. As long as that rolloff starts by 1k, and is 1st order minimum, we're good, regardless if the response doesn't fully rolloff due to an inherent rising spec response. This means that by 2k, the woofers in theory should be at -6dB.
InDIYana Event Website
So the woofers are -6db at 2k but that’s flat to maybe 5k
Overall response being flat is normal in speaker design.
I'm not certain as to what "that's" is in your query.
InDIYana Event Website
Game on!
Parallel RC?
I suppose that is one way to do it... I was wondering how you'd pull off 3x drivers sharing the same volume like that without too much BSC. Whatever the result, I'm interested in listening to the speaker.
So anyone can model this. 3 of the same relativity flat drivers. One full range two in parallel with bsc and an inductor. I thought everyone would be doing this.
Sounds like a good design idea. Wish I would have thought of this. The only potential drawback that I can see is perhaps limited low frequency extension. I went with a big subwoofer for deeper bass, but then I could only use one subwoofer.
Did some veneering work
This might be a really stupid question (I've had lots of them) but why do you have the fence on your router table? I see a flush trimming bit with a bearing sitting way proud of the fence.
BTW, they look awsome John. Way better than my shed.
My guess - dust collection.
For those of us without perfectly aligned routers it can help to prevent the bit from gouging slightly if you rotate the part around the bit.
Nice grain matching.
Is the vacuum pump for hvac or a specialty item?
The router fence does both things mentioned, dust collecting and preventing the bit from taking to big of a bite and splintering the veneer.
The vacuum pump is a commercial item I got when work was having a surplus sale. It's way bigger than a HVAC pump.
I should start another thread but I'm lazy. Here's the Indy competition speaker build
Missing ^ link - JH.
Aside - you could use a shop vac to initially collapse the vacuum bag then finish up pulling it negative with an old refrigerator compressor instead of buying a commercial unit - just sweat some Shrader valves into the suction side . . .
My computer and iPhone are fighting, standby
Trimming out the removal back is a pain. I'm ironing on the vertical pieces