15" Bass Driver for OB (40-200Hz)

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Pano

Pano

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Joined 2004
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Hey Poinz! Good to hear from ya. Howzit?

You'll have to come over sometime and listen to my OB "Lounge Lizard" beasts. Not as refined as your Fostex, but, um, bigger....
Bring one of your nice tube amps, I'd love to hear it. Bet it could really light up the Lizards.

I would not neglect the Dayton IB385
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Right. I've been told it makes a good OB woofer. Needs plenty power, tho.
 
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OTMOPO3OK

Member
Joined 2004
Stephan i have one Lambda 12 with Shorting rings as a HT sub but i believe John stopped selling 15IBs a year ago.

panomaniac, I'm more and more interested in Selenium15s since you say they sound so good, but still a little concerned with 3mm Xmax. I'm not worrying about bottoming out it's just with this little Xmax driver just produces less bass energy, it's still there just scaled down. You know what i mean? Notice you yourself mention that you'd like more energy by using two. So that is my point. Unless of course you have a big room and you really need 2 drivers to feel it, then you are absolutely right. I'm not arguing just trying to absorb as much info from your discriptions as possible.

Poindexter, Dayton IB385 is a great driver for it's purpose (IB would be one of them) but it's just not good for crossing over 150-200Hz since it abruptly falls after 700Hz. Look at the SPL graph on PE site.

tinitus, you are absolutely right about Fs=20Hz driver rolling off slower than 35Hz. I'd want a driver with as low Fs as possible.
My room simply physically won't hold 18"s since i have 2 more front speakers: huge B200 winged baffle, Bob Brine's FE167E MLTL, and a huge "refrigerator-sized MLTL sub of my own design". Now ALL THIS has too fit to accommodate center channel and 108" projector screen in between. I barely have space to sleep now as it is, lol. :):):) :bawling:

DeonC, very nice driver. 12" is a little small and Fs=18 seems almost unreal for $45 provokes thoughts that it was designed with sub application in mind and won't reach too high into mid-bass region. Maybe i'm being too cautious.

I'd like to thank everyone for their input,
I thought the decision is going to be easier but it's getting harder to choose! lol

:clown:
 
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Phergus_25

Member
Joined 2006
OB sub ideas

I was looking at all the discussion going on here and it got me thinking about a IB sub setup to go along with my A126 horns. I think I am getting down to around 50 hz with good force, so if I could use the horns natural roll off and then back them up with the sub that would be cool.
What of the above mentioned sub setus would be good for me? I am looking for cheaper the better.
-greg
 
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holdent

Member
Joined 2005
but still a little concerned with 3mm Xmax
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Zaph talks about Xmax here http://www.zaphaudio.com/lowxmax.html and comes out against high Xmax woofers for a number of reasons. He concludes with "My advice to all in factoring Xmax of a woofer into a purchase decision is to pick the woofer with the lowest Xmax that can sustain the peaks of your preferred music listening level. If you can't reach that level with one woofer of reasonable Xmax, consider using two or more."

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BTW I decided that the Augies were a little too rich for my blood and bought a pair of Alpha 15As and have been very happy. In the application I'm using them they've been excellent. I have not experienced any Xmax issues even at very high volume levels.

The Alphas are paired with Hawthorne Silver Iris drivers and rolled off at roughly 180 Hz using a 1st order slope (the Iris' are run fullrange). Since the Alphas only augment the bass of the Iris' everything can stay passive. Using Augies or the Dayton IB385s requires an additional plate amp with bass boast adding to the cost.
 
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OTMOPO3OK

Member
Joined 2004
After all the contemplation I got Augies and never regret it. I can't really compare it to the Alphas or lesser drivers since i never went for them but two Augies in my medium sized room provide all the bass i ever need. I disconnected the sub from the system cos it was too boomy and i just run Augies now, even for movies, YES even for movies.
Thanks to everyone and good luck in your driver search.:smash:
 
chops

chops

Member
Joined 2003
charlest.zenfolio.com/
I noticed a few posts here about the Pyle PPA15 drivers and just wanted to say a few things...

Granted, Pyle drivers are a bit on the "cheap" side, but the PPA15 is really well built. It has a nice heavy magnet, vented pole, pulp cone and a solid stamped chassis.

And believe it or not, even with that cheesy logo on the inverted dust cap, these drivers don't sound half-bad up to 600Hz or so. I'm still using one of these drivers for part of my center channel combined with an Altec 511B/902-8T and it does a pretty decent job. The only thing is that it's output nowhere matches the Altec horn, and even after dropping the output of the Altec considerably, it's still a few dB too loud over the Pyle.

And as for dipole use, these PPA15 drivers were excellent in my H-frame dipoles. To this day, those were still the best sounding subs I have ever heard. The tightness, quickness and extention of the bass was just "real" and very natural. I was able to get usable output down to 16-18Hz, but pretty much nothing after that.

If I were to do it again, I would still go with Pyle PPA15's. The specs of the Pyle just seem nearly perfect for an OB design, which is exactly why I went with them. Even Mr Linkwitz agreed with me on these drivers.

The Eminence Alpha-15A driver's Fs is a little higher than I like at 41Hz, and the small VC and magnet just seem too weak to provide good control over the bass. I could be totally wrong on that though. Only if its Fs was a little lower and its motor structure was beefier...

If I had to go with another driver, my next choice would be the Selenium 15PW3-SLF driver. Yes, the Fs is back up higher, but at 37Hz. The rest of the specs are somewhat similar to the Pyle. One of the other good things about the Selenium is that its SPL is 98dB, which is much better than the Pyle's 90dB. Having that extra 8dB there might possibly help on the low end extention.

Anyway, just my 2 cents.


BTW, I still have all four of those Pyle PPA15's sitting here. I plan on building a pair of small W-frame subs out of them for my bedroom system! :devilr:
 
chops

chops

Member
Joined 2003
charlest.zenfolio.com/
Ang said:
chops - wrt your pyle woofers - do you have them playing down to 18Hz and up to 600Hz in and OB or are you talking about two separate setups? Thanks.
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Yes, two different setups.

When I was using them as dipoles, they were crossing over at 125Hz IIRC via an Audio Control Richter Scale Series II.

Richter_Scale_01_Thumb.jpg


The Richter Scale had a 5-band 1/3 octave EQ built into it, and I only used it to reduce the levels a bit from 90Hz up. I did not use it to boost bass output at all. I didn't need to. In fact, the fact that I kept stating that I was getting good output down to 16Hz with these dipole subs always drew a lot of scepticism and doubt. But if they're weren't willing to try it out for themselves, then so be it... My gain, their loss so to speak. ;)

**************

Now I'm still using one PPA15 in my center channel, which is a 4.23cf sealed enclosure (my old sub enclosure). The xover point is at 600Hz, give or take a few Hz. Since it is a center channel and I have a very good DIY subwoofer for the LFE information, I have all of my loudspeakers crossed over at 80Hz via my Pioneer Elite reciever.

I've tried running the center channel fullrange before, and eventhough it sounded good throughout the lower midrange, it just didn't have any reall bass extention due to the much smaller than optimal enclosure that it's in.

All in all though, I still say these Pyle drivers are pretty darn good for the money, especially if you want great results in an OB design on the cheap!

Just an FYI, I plan on upgrading both my mains and center channel with dual Usher HM15 drivers in the near future. I already have four of the 6 drivers needed and eight of the ten 4" flare ports for the project. I just need to get to designing and building the things.
 
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holdent

Member
Joined 2005
The Eminence Alpha-15A driver's Fs is a little higher than I like at 41Hz, and the small VC and magnet just seem too weak to provide good control over the bass. I could be totally wrong on that though. Only if its Fs was a little lower and its motor structure was beefier...
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I, like Chops, also wish the Alpha 15s had a lower Fs etc. but still think they are a great choice for the cost.

Driver design is a series of trade offs. One of the trade offs with the Alpha 15 results in a higher Qts. The higher Qts allows the user to have an acoustic rather than electronic solution to bass drop off in OBs. Drivers with lower Qts' need some kind of electronic bass boast at lower frequencies. This virtually ensures that you'll have to use an active crossover and seperate amp (like a sub plate amp). The Alpha 15A is also relatively sensitive at 94 dB. Two together will be 97 dB. This means they won't have to be driven hard to acheive reasonable (loud!) sound levels and will have lower distortion levels at the same volume. If you're looking for deeper bass with a greater "punch" I'd argue that you'd have use a conventional subwoofer instead.

I read a lot of posts with concerns about "bass control" and smaller magnet drivers. I believe this refers the the driver's transient response and concerns about "one note bass" or "boom". I do not have these issues with the Alphas but have heard them with other high Qts drivers (small magnets) used in inappropriate situations (such as when installed in a bass reflex cab). Similarly I have heard horrific (nonexistant) bass from low Qts drivers (large powerful magnets) put in sealed or bass reflex cabs. Of course the room and cab location play a huge part in poor bass.

I don't doubt that there are many better drivers out there (like the Hawthorne Augie), but you can generally buy two or more Alpha's for every one of these and still have to get a plate amp (or equivalent).
 
chops

chops

Member
Joined 2003
charlest.zenfolio.com/
holdent said:
I, like Chops, also wish the Alpha 15s had a lower Fs etc. but still think they are a great choice for the cost.

Driver design is a series of trade offs. One of the trade offs with the Alpha 15 results in a higher Qts. The higher Qts allows the user to have an acoustic rather than electronic solution to bass drop off in OBs. Drivers with lower Qts' need some kind of electronic bass boast at lower frequencies. This virtually ensures that you'll have to use an active crossover and seperate amp (like a sub plate amp). The Alpha 15A is also relatively sensitive at 94 dB. Two together will be 97 dB. This means they won't have to be driven hard to acheive reasonable (loud!) sound levels and will have lower distortion levels at the same volume. If you're looking for deeper bass with a greater "punch" I'd argue that you'd have use a conventional subwoofer instead.

I read a lot of posts with concerns about "bass control" and smaller magnet drivers. I believe this refers the the driver's transient response and concerns about "one note bass" or "boom". I do not have these issues with the Alphas but have heard them with other high Qts drivers (small magnets) used in inappropriate situations (such as when installed in a bass reflex cab). Similarly I have heard horrific (nonexistant) bass from low Qts drivers (large powerful magnets) put in sealed or bass reflex cabs. Of course the room and cab location play a huge part in poor bass.

I don't doubt that there are many better drivers out there (like the Hawthorne Augie), but you can generally buy two or more Alpha's for every one of these and still have to get a plate amp (or equivalent).
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Don't get me wrong, I like the Alpha-15A's a lot. And with them being on an OB, the motor only needs to cope with the cone's movement. It doesn't have to try and fight a "spring" of trapped air like in a typical sealed or ported enclosure. So with that in mind, the smaller VC and magnet probably is enough to privide decent cone control. Which is why I'm sure some say the Alpha has a smooth, warm sound to it.

Honestly, the ONLY thing that would keep me looking for another suitable driver would be the Alpha's Fs of 41Hz. Even with a high Qts of 1.26, I just don't know if these would be capable of even reaching down to 25-30Hz. At least with the PPA15's, their Fs is 27Hz, so they have the ability to reach down to 16-20Hz with very little to no EQ at all (depending on the baffle size of course).


Another option of course could be moving up to an 18" driver. Most 18's have an Fs of around 25-30Hz or so, most are pretty efficiecnt at 94dB+, and some even have a somewhat high Qts around 0.5 or so. The only drawback is that they can get pretty pricey really quick, but not always...

Here's one for example, the Goldwood GW-1858. It is rated at 94dB, Fs of 30Hz, Qts of 1.07 and an Xmax of 3.36. Being that it's a fairly efficient driver and you'd be using two per channel, that's at least 97dB, and since they would be sharing the load, the low-ish Xmax probably wouldn't be an issue.
 
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