Originally Posted by Jesse S
This thread is going nowhere. On page 2 you declared that the box size is irrelevant. Now we're on page 7 and you are still bandying this nonsense about.
If you are happy with undersized boxes that require a lot of correction and don't mind the resulting degradation in sound quality, then that is great, for you.
Some of us are bothered by box coloration. We can hear it. You can't.
"Undersized boxes" (This is also to address Cat's and Penn's comments about power requirements/headroom, etc.)
For my example, I chose the AE IB15, which is .71-.73 Q mounted and the Fi IB15, which Cat mentioned, which is .63-.65 Q mounted. My current box subs are .63-.65 Q mounted.
The cited IBs are excursion-limits-amplifier systems, mine are amplifier-limited by the drivers thermal handling, which, with active cooling and program source, is extremely high.
Both of the cited IB drivers require more than twice the amplifier to give the same output above 30Hz (86dB vs 90.5dB).
The Le of the AE IB15 is similar to the AV15H, but the Fi driver doesn't tell us, so the actual performance above the knee is an unknown and we'll assume a best case scenario for the IB drivers, unless someone can post the actual close mic responses.
OK, we have the "undersized" sealed box with native Q equal to or lower than the cited IBs.
We add +6dB of LT boost below the knee to the "undersized" sealed subs and we add +5dB to the IBs above the knee to end up with same response and output at 1W/1M from 20-80Hz.
All 3 subs are using the same amplifier.
All 3 subs have the same system Q.
Please explain where I'm missing the "degradation in SQ" part of this equation?
Please take it further and detail a scenario in which the IB happens to require -10dB cuts at 3 frequencies to arrive at a flat response at the LP, but the box system only requires -3dB cuts at 2 frequencies to arrive at the same response at the same LP, will there be an audible difference in SQ?
Cat has mentioned the only measurable advantage of the IB systems, which is ASD, but I countered that with mention that the ASD formula assumes some things that may not actually conform to the formula. Still, this is a valid point that's worthy of being on the table. After all, there is an actual formula to mathematically calculate the potential difference and even identify the order or harmonic.
The other is the tons of power thing, which, hopefully, I've addressed at least as a dose of reality vs measuring watts by the pound.
This is basically all we have to this point to discuss 'box coloration' (and no, Soho, this is not directed at you. The term has been around for years and has been used by countless posters over many forums).
It would help if we put some more potential differences on the table, unless no one is really interested in anything more than lobbing grenades over the fence.
For example, I noticed what could be called coloration, if I lacked a better term, in the IB because the drivers were directly coupled to the super structure of the house.
Here is my simple illustration:
As a bass player, many times I've played my bass with no amplification while writing a song, a bass line for a song, or just noodling for fun. Since my basses are not acoustic, there is nothing to amplify the low end other than the wooden mass of the actual guitar itself.
If I sit near a larger wooden structure, a desk, a chair, a wall, etc., and rest the body of the bass firmly against that structure, FR at the ears is immediately and very audibly changed (FR is tilted more toward the lower end). Yes, in an actual IB, opposing drivers may affect this effect, but remember, the only thing vibrating in the example of my bass is a string.
I also mention this example because, although it's very difficult to explain the difference in sound, I would have to say that it sounds 'better', which has invariably led me to couple the bass to a larger structure when I play without amplification.