A few driver questions

[kuribo]

First, thanks for adding me to this amazing forum!

I am building an audio listening room in my basement and discovered that I have the space and dimensions to try an IB woofer set up. Unfortunately, perhaps, I acquired a pair of AE Dipole 18 drivers I originally planned to use as a stereo pair of u-frame open baffles. Having read the awesome FAQ here, I realize these aren't optimum to use in an IB configuration. I am wondering if they might still work? Their Qts is a bit higher than recommended at .81 and their Xmax is only 12mm.

Regardless of whether or not these drivers would work well, is the preferred configuration-  mono pair(s) or as stereo set(s)? I could place them on the front wall behind my main speakers, or use them together in a manifold between the main speakers, or together mono on the front wall....

A little more info: Main speakers are electrostatic panels for mid/treble with a slot loaded bass array of 8 8" drivers per side for the 40Hz to 100Hz band. My room is 7' tall by 11.25' wide, by 18' long (the height and width were by coincidence at the golden mean, I can build walls on each end to give the length meeting the golden mean). Walls and floor are poured concrete, ceiling is 3x8" wooden joists on 12" centers. I plan to treat the room with the usual absorbers, etc.

Thanks in advance for any feedback!

[dan77]

their Xmax is only 12mm
Never heard/read of anyone using IB’s with such small xmax. Seems counter intuitive

is the preferred configuration- mono pair(s) or as stereo set(s)
So about every year or 18 months I get all antsy and start re-wiring all my subs. I monkey with cross-overs, placement and for sure, the old concern of ‘steering subs’ (stereo) or mono.

If you poke around enough on forums you will find this a very lively topic. Everyone is very passionate to share what they think is best. I have tried both for extended periods of time. I love both setups. Ultimately you should wire them up one way, then the other and see how you feel about them.

But hopefully you do know that when we discuss ‘stereo’ subs we are not talking about LFE. LFE, for every single pre-pro sold today is mono. There is no such thing as a movie track that has stereo LFE. It’s just not a thing. Not part of the Dolby spec.

If you meant to say “2 manifolds for LFE rather than 1”, I would emphatically say yes. Sure one works, but 2 manifolds really helps with room nodes like nulls and possibly even room gain. But if your goal is to have immersive bass, then I would recommend 2 manifolds. It all depends on what your goals/budget/interest/WAF, etc are.

IB’s and stats are a thing. My HT is stats and IB’s and I have never heard anything that comes close to the clarity and immersion.
With the stats you get rid of the point source box sound
With the IB’s you get the articulation that keeps up with the stats.

[kuribo]

Thanks for your reply.

I plan to use dsp crossovers and room correction. By stereo subs, I mean an active set up with a dedicated two channel amp with the left and right stereo channels each driving a sub.

[dan77]

Got it. No home theater, no LFE channel to worry about
So not 5//7/9.x.x, only 2.x
Sure, IB subs would sound great with your speakers.
But of course, with stereo only, placing all the subs into a single manifold might take away from the stereo effect to some degree. Either way it would sound awesome.

[kuribo]

Yeah, no center, surround, etc.

Now I need to figure out what to do with the AE Dipole 18's as I really would like to try the IB set up. I have read through most of the faq's, etc., but don't think I came across a list of driver specs that make for good IB usage. Assuming a low Fr of 20Hz or so, what sort of Qts and Xmax should I be looking for?

Thanks again for your comments.

[dan77]

I am not a pro, only an avid hobbyist that has read too much and spent way too much time playing around with subs and speakers.
From what I know there is no ‘perfect’ specs that you must chase.

All I can say is that your speakers will work, but, will they sound as good as the widely accepted IB3’s? No. They won’t have the range/dynamics/SPL, etc. But they will work.

You may want to go about this in the opposite direction. What are you chasing for your listening env? If it is a reference level listening room, consider other options. If you just want to augment your lower end a bit, then you might be happy. It’s all about what you are chasing and what will make you happy.
I go for reference level (equally in SPL as well as low distortion), so a speaker like what you have would not work for me. The Xmax is just not there. To make up for such a lack of Xmax I would have to triple or quadruple the number of drivers to get the impact that would make me happy.

Here is a quote I snagged off the web:
“
ANYTHING can be used IB with success. It's just the degree to which it will perform.

If you want the most output: Lots of XMAX and VAS are a good thing
If you want the best sound quality: QTS as close to .707 as possible
If you want them to dig deep: low FS
“

I think that the IB3 ticks all these boxes and more.

Here are 2 of the leading IB speakers that are currently available as of today:
In order of popularity based on alll the articles that I have read:

IB3
This is the venerable IB3 that was first sold by Fi Car Audio and is now sold by One Audio
Xmax is 36

Historical note: the original IB3 was made by Fi Car Audio. They sold the rights to One Audio who then increased the xmax from 34 to 36 as well as increasing the watts from 600 to 1125

IB18HT
By AE Speakers
Xmax is 36

[ThomasW]

Hi

Who's panels are you using? I run a pair of Acoustat 1+1's on each side as woofers, an RD75 for midrange and 16 Panasonic leaf tweeters. This system is what led me to develop the floor mounted manifold,

As Dan indicated your AE drivers will certainly work, they're excellent drivers, you'll need to run them carefully since the lowish Xmax is the limiting factor.

The drivers can be run in any configuration you want wall mount, in-floor manifold, whatever is easiest to create. Just be careful not to exceed their excursion limits.

With an IB the system should sound great!

[kuribo]

Thanks for the thoughtful replies.

Perhaps I will try the AE Dipole 18's in a few different configurations and if I am not satisfied, try to sell and get the IB models.

Thanks again!