Axiom Home Page Forums General Discussion Home Theater Ian and Tom Video interview re: A1400-8 & EP400.

Well Mojo thankyou for your kind words. Pretty soon I hope to compare single and dual 400s in my HT room next to my 600, and other subs. If I'm lucky I'll also get to put the a1400-8 through its paces. I'll post my perceptions and some data.

So what is stoppng you? I want to hear one too! It's a liberal return policy...

That would be awesome. Thanks.

I'm kind of worried that the 400 will sound similar to my 600. And actually being a sealed design, it may even sound better.

John (jakeman), in the comparative chart for the various Axiom subs, the 3 dB sequential difference from EP400 to 500 and 600 appers to be in max sound pressure level. That 3 dB difference does not seem to be the difference in "audio signal level", which would indeed imply doubling of the SPL. If the SPL is not doubled, why would we assume twice the acoustical energy going from one sub to one higher in the sequence? I am not trying to dispute your point, just trying to understand your reasoning and the chart. Thanks.

John

PS: is there yet a 4th John who would like to join in this discussion?

You say that "the SPL is not doubled". It is doubled. A 3dB SPL difference does indeed double the acoustic energy.

Perhaps I'm not understanding your question. But then again, it wasn't directed to me .

Mojo,

What threw me off was that "SPL" is not doubled by going from say 112dB to 115dB, but the "energy" is doubled. I was trying to read more into jakeman's (John's) post and when he used "doubling SPL", I didn't think he meant this. I think he meant doubling the energy, which is clearly the case among these 3 subs (or nearly anyway, since the difference is 2dB between the EP500 and 600).

John

Edit: SPL/energy is indeed doubled from 112 dB SPL to 115 dB SPL. Use of "twice as loud" and "twice the SPL" interchangeably on John's post threw me off.

This paper that John (jakeman) has pm'd me a while back was quite interesting. Four subs is perhaps the way to go if one has the room, funds, and WAF in their favor.

John

The WAF would definately be higher with 4 EP400s than any other sub I can think of. Now just to get that cost past the accountant......wait that's me..... but the CFO isn't me.

Why worry? Just enjoy that awesome 600. Its impossible to say without hearing it but I suspect the impulse response of the sealed 400 will be different than the ported 600. But even there its not clear without listening and examining a graph which will sound better in your room when blended with your speakers. A well designed ported sub can also exhibit excellent transient behaviour which contributes to that "tight" sound.