I think it's too soon to make that claim 🙂 I might have just gotten one bad apple. I'm looking forward to see what USRFobiwan finds and hoping I will get a response from PE to my follow up email soon.
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I got a reply from PE. The tech said Dayton has not gotten back to them on the issue. He stated he doesn't think that the numbers aren't far enough off published specs to be considered defective but I can ship it to them for testing.
IMO he can't be serious. From your measurements, BL is about 30% off spec. And there's also the matter of the 18" version of these drivers having their published specs suddenly revised for the worst, also with BL quite off spec. I'll bet that it's the same build house too.
Revisiting sims with this design and the 3012LF. Is the 3012LF "legit"?
Still would sacrifice 1-2db @ 50hz to get 97-98db @ 40hz from that 190L design. 😀
Still would sacrifice 1-2db @ 50hz to get 97-98db @ 40hz from that 190L design. 😀
The 3012LF has been around for awhile and it's been my experience that Eminence drivers usually measure pretty close to published specs. If you do choose to go with the 3012LF, let me know what your experience is like, as so far it's a choice between them and the Magnum 12 for POC#5. And if you go with the 4 ohm version, you'll get an extra 3dB in sensitivity... 🙂
What's this POC5? That reminds me, I need to sim a few other drivers in the POC3, I like that design.
It's another "proof of concept" design I'm working on, using what I learned from the previous POCs, i.e.
1. It won't be an "underdamped" (HornResp) alignment. It's been suggested here that designing for some ripple in the HornResp sim would result in a better response. My experience has shown it to be not true, at least as far as my preference is concerned. POC#2 had over a dB of sim'd ripple at the lower end of the passband, POC#3 had less than half a dB, and POC#3 sounds MUCH better.
2. No major suckouts between 100 Hz and 200 Hz. Again, sounds much better.
3. Slowly rising response from lower cutoff frequency: This seems to be feature of many pro audio subs. My last POCs were designed for a flattish passband. This one will have a slow rise instead.
4. Cone correction. This was not included in POC#2 and POC#3. It worked well in POC#4, so I'm going to use it in POC#5
The sim shows where I am at the moment with the design. I have to work on it a bit more. Box size is a bit too large (I'm shooting for ~150 or less) and lowest resonance frequency of 42 Hz (so I'm giving up a bit of extension for SPL).
Attachments
Anyway i was experimenting in HR to use the THAM15 as kick/midbass bin between 70 - 250hz.
Below is a sim with 4 parallel. Thoughts?
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Below is a sim with 4 parallel. Thoughts?
Why cut off the low end like that?
The whole point of a cabinet this big is to get useful loading down to around 40Hz. Stopping at 70Hz is, IMO, a waste of a lot of potential. You could tune to around 70Hz and gain a lot of SPL and make the cabinet much smaller to boot. Sure, the THAM15 will work like that, but its like using a big lorry (truck, in the US 😛) to move your food shopping. Sure, it'll work, but you could do so much more with the THAM15.
Chris
The whole point of a cabinet this big is to get useful loading down to around 40Hz. Stopping at 70Hz is, IMO, a waste of a lot of potential. You could tune to around 70Hz and gain a lot of SPL and make the cabinet much smaller to boot. Sure, the THAM15 will work like that, but its like using a big lorry (truck, in the US 😛) to move your food shopping. Sure, it'll work, but you could do so much more with the THAM15.
Chris
Thanks Chris, But the tham15 is 'small' in my eyes and i was thinking of stacking 8 or so per side where four/or 6 of them do bass and 2 or 4 of them do hi-bass mid-bass. They have different drivers, one more oriented to lower bass duty and one for upperbass mid duty.
Like you said, you can do much more with tham15 😉
Like you said, you can do much more with tham15 😉
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Aren't mid bass horn designs typically more efficient than tapped horns, say 105db 1w/1m and above? Maybe a bit harder to build tho but that's where I'd go.
In any event, with Brian's POC5 (rising response) it might be possible to achieve both decent low corner AND mid bass response. Seems to me that cone correction really helps the mid bass.
In any event, with Brian's POC5 (rising response) it might be possible to achieve both decent low corner AND mid bass response. Seems to me that cone correction really helps the mid bass.
I agree Zwiller, I have Community TFR64 horns but I was fiddling with the tham15 sim and seeing it can somehow be useable to 250hz or so maybe I can do half/half with the same bin and some EQ. I quess I have to test it in practice and do some measurements.
Yeah one of the reasons why I want to look for some other solutions, the TFR's weights is like 3 times the tham15. But it is indeed a brilliant box that is until the mid Compression horn blows. It is almost non existing anymore 🙁
Is there anyway to sim adding the effect of a v plate restriction type fold within the the first fold of the design at post 10? Kinda aimilar to screamer did on his fury? http://www.diyaudio.com/forums/subw...ss15-bjorno-sub-plans-needed.html#post3915026
Very curious if there could be some way to cram a longer path length into typical designs or even if they have to slightly adjusted if it might yield something.
http://www.diyaudio.com/forums/subw...ss15-bjorno-sub-plans-needed.html#post3915026
Very curious if there could be some way to cram a longer path length into typical designs or even if they have to slightly adjusted if it might yield something.
http://www.diyaudio.com/forums/subw...ss15-bjorno-sub-plans-needed.html#post3915026
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