Well, I built a test baffle using the Pyle drivers and the same size H-baffle baffle as Chops. I plopped them down next to my Orions and it seemed to me that the bass from the Pyle drivers was noticeably slower than from the Orions. I always had a thing against 15" drivers in terms of transient response and was reminded why I did. Extension seemed pretty good though. I tried tweaking the setup a little but was too discouraged and so sent back the Pyles. 
bilbobaggins said:Well, I built a test baffle using the Pyle drivers and the same size H-baffle baffle as Chops. I plopped them down next to my Orions and it seemed to me that the bass from the Pyle drivers was noticeably slower than from the Orions. I always had a thing against 15" drivers in terms of transient response and was reminded why I did. Extension seemed pretty good though. I tried tweaking the setup a little but was too discouraged and so sent back the Pyles.
The poor results with the Pyles is why I advocate shopping locally if you want to try the cheapie route, so you can hear them first. Many of the cheapies just sound horrendous and the slowness you encountered is likely to be due to a high Le, which is common with cheap drivers.
Grandma´s_SUB said:
The shape of a flat baffle is not important. Mount the driver at least somewhat off center for smoothest response. Keep in mind that the floor forms an infinite baffle width in that direction, so a woofer can be mounted at the bottom which increases the effective vertical baffle width. Having the sides folded back increases the effective baffle width using the same amount of physical baffle because it increases the distance the rear wave must travel to reach your ears. Folding back the sides, while much more compact, can introduce cavity resonances, but those are normally outside the operating range of a sub.
tubesguy said:
While I'm sure that Le is just part of the equation and subjective "speed" is strongly influenced by motor strength and other factors. Check out what Dan Wiggins has to say regarding Le at http://www.adireaudio.com/Files/TechPapers/WooferSpeed.pdf
The only evidence I have personally is that every time I have tried woofers wired in series and the same exact setup wired in parallel the parallel wiring has sounded far better. This has held true with multiple drivers and with dual voice coil drivers. Other than the impedance the only difference is Le. Series connection doubles it and parallel cuts it in half. The sonic difference is not subtle. The series connection (higher Le) results in a sound that is less dynamic, muffled, and dare I use the word......slow.
JohninCR
This really struck me when I read it. I have a ported blueprint 1503 and 2 sealed av12's. Aside from the much louder lower bass of the BP1503 I always thought the dual 12's were fuller sounding(best way to descibe it). I never really could attribute it to anything really, But the BP1503 has a very high le value and the strkyes have a much lower value as the dual voice coils ran in series then both subs were wired parallel. This may explain what I heard.
This really struck me when I read it. I have a ported blueprint 1503 and 2 sealed av12's. Aside from the much louder lower bass of the BP1503 I always thought the dual 12's were fuller sounding(best way to descibe it). I never really could attribute it to anything really, But the BP1503 has a very high le value and the strkyes have a much lower value as the dual voice coils ran in series then both subs were wired parallel. This may explain what I heard.
Someone said this same thing about series wiring causing phase shifts a few weeks ago on another forum. I asked for support for the statement, but none was provided. I don't believe it. Line arrays would be impossible if the inductance of the voice coil caused a phase shift. I hope one of the resident experts jumps in and sets this matter straight. Maybe the naturally occuring phase shift of a driver is different when 2 are wired in series vs parallel.
One way of looking at the potential problems of series wiring is to assume that there ARE small differences between drivers of the same make, model, and even production run (not really a far-fetched assumption).
These parametric differences would result in slightly different phase responses. Since any direct acoustic consequences of these phase differences would also be present in a parallel wireing scheme, we can discount them for now.
The important thing about phase differences in a series-wired set is that the individual drivers' instantaneous impedances will peak at slightly different times. In series, these impedance maxima displaced slightly in time each project across the rest of the series.
These parametric differences would result in slightly different phase responses. Since any direct acoustic consequences of these phase differences would also be present in a parallel wireing scheme, we can discount them for now.
The important thing about phase differences in a series-wired set is that the individual drivers' instantaneous impedances will peak at slightly different times. In series, these impedance maxima displaced slightly in time each project across the rest of the series.
About open baffle;I will build 12db variable gain, to reach as close as possible 0db, "from eye" Iål need about 16W(88db@1m/1w).I have 100w tda 7294 amp(my 1st home made amp
), so it should be about 100db maxSPL(84W).
-Maybe this will be little of SPL for home parties
-But if I build sealed enclosoure ,there is a 6db peak;
qts 1.36
qes 1.75
qms 6.17
Fs 32.2hz
-I KNOW,that the open baffle is good,because S. Linkwitz has done a lot on it
-Of course,I must hear "open baffle"design first, maybe there can be suprise
comments?
), so it should be about 100db maxSPL(84W).-Maybe this will be little of SPL for home parties
-But if I build sealed enclosoure ,there is a 6db peak;
qts 1.36
qes 1.75
qms 6.17
Fs 32.2hz
-I KNOW,that the open baffle is good,because S. Linkwitz has done a lot on it
-Of course,I must hear "open baffle"design first, maybe there can be suprise
comments?
So whats the hack here?
At open baffle, you need more power and more drivers as you said, because bass response is bad
-only good thing is,that you can use "crap" drivers
I read a lot of posts and get this:"dipole/open baffle ruls at hi-fi"
-I compared standard enclosoure and open baffle tran. magnitude graphs(bass response in shortly) and there is no diffirence at all(dipole was equalized and gained..), just dipole had a little beter bass response, but maxSPL is terrible(4 drivers needed)
I will keep researching
Dean
At open baffle, you need more power and more drivers as you said, because bass response is bad
-only good thing is,that you can use "crap" drivers
I read a lot of posts and get this:"dipole/open baffle ruls at hi-fi"
-I compared standard enclosoure and open baffle tran. magnitude graphs(bass response in shortly) and there is no diffirence at all(dipole was equalized and gained..), just dipole had a little beter bass response, but maxSPL is terrible(4 drivers needed)
I will keep researching
Dean
Better then pyle ppa 15 (i think)
Ravemaster vtx1524
If you use only one voice coil you get 2x qts (0,44x2=0,88)
or you can use a pot meter to get qts from 0,44 to 0,88.
FS lower then pyle ppa 15
Qts bette then pyle ppa 15 (you choise 0,44-0,88)
Xmax the same as pyle ppa 15 (4mm +/-)
~ 94db/w when only one voicecoil in use
cheap ! !
I will buy it an try it out.
Hope to get my new amp this week (h/k citation sixteen)
so i can play on my new sub.
I need a good preamp with remote... help wanted ! Thanks
Ravemaster vtx1524
If you use only one voice coil you get 2x qts (0,44x2=0,88)
or you can use a pot meter to get qts from 0,44 to 0,88.
FS lower then pyle ppa 15
Qts bette then pyle ppa 15 (you choise 0,44-0,88)
Xmax the same as pyle ppa 15 (4mm +/-)
~ 94db/w when only one voicecoil in use
cheap ! !
I will buy it an try it out.
Hope to get my new amp this week (h/k citation sixteen)
so i can play on my new sub.
I need a good preamp with remote... help wanted ! Thanks
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