Sorry for not getting back to you on Friday- I didn't get a chance to post until today and forgot about this thread!MikeS said:I did say to close the holes... besides, the holes are much too large and not nearly long enough to act as ports. Instead, it's act like an open back cab. Additionally, sealed speaker enclosures are about as opposite as you can get from an infinite baffle (or free air). An open back cab would be an infinite baffle design. A sealed enclosure would only act as an infinite baffle if the volume of the cab (or in this case, half the volume) exceeded the VAS of the driver. It's possible that I could exceed the VAS of the driver. All that will do is effectively lower the power handling of the speaker, but not below the recommended rating (most peak and rms values are calculated for infinite baffle. As the ratio of volume/VAS decreases, the speaker's power handling capabilities actually increase). The resulting effect is that you double the volume to VAS when two speakers are cut out of the loop. Now, the reason your friend's cabinet sounded terrible likely has as mush to do with impedance mismatches as it does with volume. I should have added that I'm not disconnecting two speakers, but rather using (2) 8 ohm drivers in series for a 16 ohm load to match the output on the transformer.
In the end, you may very well be right that it won't sound the greatest. You'd be right, but not for the right reasons...
Kommerzbassist said:
The Golden Boy said:
No need to go calculating the frequency of ports vs. the volume of air vs. the amount of speaker space vs. the resonant frequency of 6 layer Baltic Birch Plywood vs. insulation space vs...MikeS said:Given the diameter of the openings and the depth of the ports, these are not tunable openings. The openings will likely cause some cancellation if left open since they are in the front of the cab. If you like I could calculate the frequency of the ports... but it ain't going to be pretty.
Easy... it's gar easier to replace to speakers in an existing 4x12 cab that I never move than it is to build myself a custom 2x12 cab for some drivers I have laying around. Additionally, double the speakers DOES NOT = double the volume. The volume increase between a 4x12 and a 2x12 receiving the same wattage is barely noticable.
Additionally, I did in fact try this over the weekend by removing two original speakers (leaving two in and disconnecting them), and replacing them with a pair of greenbacks. As soon as I digest the tone a little more, I'll let you know what I think.
Regardless of a pleasant, desired effect, as with matching drivers with cabs, the openings would serve the same purpose as a port- again, not saying that that purpose would be pleasing or desirable.I'm not vouching for the scientific validity of that- however to my untrained ear it comes out about right. For years I lugged around a 100w head because I was convinced I'd need that extra volume. After realizing I got a better tone out of similar 50w heads, I A/B'd stuff and the 50 to 100w volume difference in any practical application is negligible. The figure I hear most often is a 12% difference in volume. The reason I don't like gigging with my 19w combo has more to do with issues with the tone of an open back cabinet than it does with any volume issues. I currently have 3 bass heads, 2 old 600w Seymour Duncan heads, and a 900w SWR head. The practical volume of each head is comparable, where the difference comes in is in the headroom and the usable bottom end.
Gearjoneser said:
tone? said:
Besides, half the fun of owning all this gear is modding it, right? I mean, that's why we're all interested in Seymour Duncan pickups, right? Or maybe we should have all bought guitars with Duncan pickups preloaded and "got it right the first time."
There's loads of information here, and especially with trying things that aren't commonly done- there are plenty of opinions that can go either way. I hope I'm not coming across as pushy or confrontational (I always wonder how things come across in this medium).MikeS said:
Think of "high gain" as being the signal your preamp sends to the power section. You can have a 200w Marshall Major, anyone that's played an unmodded Pig can tell you, it's not high gain, to get it to sound "good" it's got to be ear bleedingly, cabinet blowingly loud. However, an amp that really cooks the preamp (or induces distortion in the preamp stage) would be considered high gain. Think something like a Mesa Triple Rectifier.Kommerzbassist said:
The Golden Boy said:
Kommerzbassist said:
MikeS said:That sounds an awful like a "go big or go home" mentality... which is very tough to have when you are a younger player without a lot of cash flow
That's interesting! My two older (pre-96) SWR cabs are both rear ported and have a white nylon type insulation covering most (if not all) interior surface area. I haven't had my 2x15 apart, and don't know if there's insulation in there, but it's also front slot ported.MikeS said:
