Open baffle bass - Dayton or AE IB12?

[sfdoddsy]

I'm trying to decide between the Dayton RS315HF and the AE IB12 (or I guess OB12) for my dipoles.

Crossover is 100-120 at the top. Usually I use a sealed sub at 40Hz, but I'd like the option to go all the way down, albeit at lower volume.

Any thoughts?

[badman]

Below 40Hz, stick with a proper monopole sub. The AE speakers unit is probably (vastly) superior. I haven't heard either though.

Another option is a JBL 123A-3 or 2213. Might take some doing, but they're superb drivers well-suited to OB, due to their heavy, relatively high Qts (.5) low Fs (25Hz) nature.

But make sure you have a way to test them. They're very common and can be had for $150 the pair with some looking, but can have demagnetized motors due to overdriving.

GREAT drivers though.

[MisterTwister]

http://www.parts-express.com/pe/show...number=290-330
I'd choose these for open baffle bass.

[cuibono]

Originally Posted by MisterTwister

http://www.parts-express.com/pe/show...number=290-330
I'd choose these for open baffle bass.

Related to the above drivers, a build using GW 10"" Another Sensitive OB Woofer Design. Very different drivers from what the OP is looking at, but worth considering. Lets do a little work-up:

First, you could get more specific about what your concerns are, particularly as the AE drivers are quite a bit of money. Also, your planned enclosure.

The main thing the AE drivers have going for them is low non-linear distortion at high volumes. There is a decent argument that non-linear distortion is not a major factor in sound quality (particularly at 'home' listening levels) - ie,psychoacoustic masking of higher tones, and the harmonic structure of real instruments. The AE driver is a very well built driver, and has somewhat higher sensitivity (possibly 4dB, but it depends on the enclosure).

There are a couple of things to note here though - .68 Qts is high for a subwoofer, but OB people often look higher. It generally takes a value of around 1 to keep things flat down low. But this brings us to the enclosure/baffle - which has a major impact on the speakers response. Generally, a driver that is rated 'high sensitivity' will still fall dramatically when used OB. If you want to have a closer idea of what a driver with enclosure will be doing in room, you need to sim it with MJK's mathcad worksheets. This is the most reliable way to know before hand with OB. Does using active EQ matter to you? You will need it with these drivers.

Ultimately, I would not choose the AE driver. I currently haven't found non-linear distortion to be a significant enough issue to warrant lots of money. The Dayton driver is also a well designed driver, and the RS line has low non-linear distortion relative to most other drivers. The two drivers also have the same volume displacement (so have the same maximum output, theoretically), and almost the same Qts value. The RS driver is half the cost.

The link above is for a complete bass driver/enclosure design that I put together with some fairly specific design goals. The bandpass is 50Hz to 200Hz. It plays loud, needs little to no EQ on the low end, and has decent sensitivity (particularly as a completed design). It costs relatively less than other high output designs, and the use of multiple drivers brings up the sensitivity while lowering non-linear distortion. Also, it has a relatively small footprint for OB woofers.

I agree with Badman, below 40Hz is monopole sub territory. Hence the band pass of 50Hz for my design - there is no point in paying for something you're not going to use.

[MisterTwister]

All drivers that I've tried in OB, have very audible mechanical noise at full excursion. So high xmax is useless. When I look for OB woofer I look for high qts numbers, everything else is not important.
and I agree with cuibono, .68 Qts is high, but not high enough for use in OB.

[CLS]

If very high SPL or the sense of strong vibration (instead of 'sound') is not needed, then I'd suggest another monopole sub maybe skipped. (especially if you are going to build up a new system from scratch)

Around 30Hz is doable by OB bass, and with reasonable SPL for household use. Given that the major powerful bass notes in music are mostly in the 40~80Hz range, LF down to 30-some is actually coming with some portion of "sense of vibration" already (more than enough to scare those mini-monitor users). Rumbls and roars by pipe organ can be played cleanly and clearly with pretty strong energy by OB bass (you'll love it for sure).

If there're surplus woofers and plate amps lying around, then of course you may build any 'additional' monsters as you like. They will give you some more rattles on windows/furnitures/ceiling... etc.

[sfdoddsy]

Sorry, I should have been specific. I'm replacing the existing Adire DPL12 drivers in my Orion-style dipoles. There will be two a side in an H-frame. The DPL12s are a very good purpose-built dipole driver, but are at their best below 40Hz distortion-wise.

The Dayton RS315HF and the AE IB12 are the same price.

[cuibono]

Hmm, my bad about the price, I was looking at the OB12. I would go with the AE then - although the only significant differences I see are higher build quality, a bit more sensitive, and probably lower distortion.

I couldn't find any specs for the Adire driver, so I'm not sure what you're trying to improve on? Max output? Smoother FR? Higher sensitivity?

Particularly if you're using a sub, and limiting the woofers bandwidth to 45-120Hz, I wonder what improvements would justify the cost?

[Brett]

Originally Posted by sfdoddsy

Sorry, I should have been specific. I'm replacing the existing Adire DPL12 drivers in my Orion-style dipoles. There will be two a side in an H-frame. The DPL12s are a very good purpose-built dipole driver, but are at their best below 40Hz distortion-wise.

The Dayton RS315HF and the AE IB12 are the same price.

The AE, if for no other reason than the excellent motor and stonkingly good build quality.

Expect postage to be high.

[sfdoddsy]

Originally Posted by cuibono

Particularly if you're using a sub, and limiting the woofers bandwidth to 45-120Hz, I wonder what improvements would justify the cost?

There's probably not a major difference, but I'm redoing my sealed sub and the DPL12 works very well in that enclosure so I'm transferring them into that.

Also, I just feel like buying something new.