Originally Posted by Decadent_Spectre
If it hasn't already been mentioned, the setup/integration and room are key for punch. Playing with different responses and delays/phase on your DSP will yield different results.
The limited experience I've got (with drivers, DSP and audio in general) has lead me to the same conclusion. The findings are that – in the current system – there is a tradeoff between the cleanest and most impactfull lows and the tightest midbass punch. It can be explained physically as you either get pounded in the chest or have the pants flabbing, but not both at the same time.
If I xover the two closed LMS Ultra 5400 in the 60-80 Hz region and optimize for phase at the xover (indirect by time aligning), then the lows are clean, rumbling and absolutely wonderful. However, this tilts the balance of the system towards the lows and the midbass from the 2235h drivers does not seem to have enough energy output relatively to the lows, hence they're not able to penetrate through to give an impactfull punch.
If the xover for the Ultras is set higher, such as between 150-200 Hz, and optimize there, then the midbass impact is quite good, but slower than that of the JBL 2235h alone w/o the subs. It does punch, but it doesn't seem to have the same quick transient punch which is desired. Also, the cleanest lows is gone by the wind, and the pants no longer flap.
The conclusion is that the best way to get both of these desired traits simultaneously is to xover the ultras low to get the clean, rumbling, pants shaking lows, and add more help to the 2235h in order to be able to penetrate through that "layer" or sound-preassure-field of rumbling low end bass. By adding more drivers I can optimize those for the midbass region, while the Ultras are optimized for the lows.
PS: Lots of self-invented words here, as I'm not familiar with the terminology, but I hope the explanation is still clear.
Originally Posted by shepjk26
I use two jbl 2226h per main in my setup. Adding dual 18 jbl 2242's per left and right front as stereo subs took everything to a whole different level. It also smoothed out the frequency response. I run them from 35-150hz and sum them with my 2226's. I would definitely go the 4 18 route instead of 4 15's. Since I have both I have compared and from 35-200hz the 18's stomp the 15's in midbass. The 2242 is my favorite driver for its intended purpose.
Thank you. Could you tell us a little bit more about the configuration and volume of your enclosures? Have you tried other 18's for the same purpose? It's not that I'm not willing to spend $ on the JBLs, but they do cost a lot of money.