bass problem in a sailboat

Hello again,
I't's been suggested to me that my idea of running a dual voice coil woofer directly from two (at 45 watts each) of my four channels wouldn't be satisfactory. I still think it might work, especially since I'm only after the missing low pitches, NOT great volumn. Thoughts, please?

Regards,
Troy

WRT "bass shakers", I do remember from long ago a device that could be attached to a wall to transform the wall into a speaker. I'm guessing that's what the "bass shaker" is. I'll check into it.

BTW, the sailboat in question is a Cape Dory 36. The displacement is over 16,000 pounds, and there are two nice cabins which are probably acoustically similar to a small room.

Regards,
Troy

Baffled Bob,

Thanks! Your response is the most helpful so far! Right now I'm trying this: a dual voice coil subwoofer (hate that term) operated by two of the head unit's four channels. The other two channels will operate two of the original four PolyPlanar box speakers. We'll see. I intend to keep playing with this until I get it "right". I'm learning a lot!

Regards,
Troy

Linkster,

In fact, I bought my Cape Dory 36 from Robinhood Marine. I'm in the midst of a major refit now, doing the work in my hangar. When I'm finished, it will look like the R36 brochure boat!

Regards,
Troy

Baffled,

I'll let you know!

Regards,
Troy

Elevick,

I agree. Bass requires power. That's why I'm inclined to believe the RMS output of the PolyPlanar MRD-60 is closer to the 45 watts per channel that the 15 watts that has been suggested. It drove the first dual voice coil subwoofer quite well. I'm hoping this Infinity will be even better.

Regards,
Troy Scott

Baffled,

I'm optimistic too. The speaker hasn't arrived yet, but I've made the preparations. The speaker should be sensitive enough to do enough with a little. Regardless how much power the head unit actually has, it would play the four bookshelf speakers and the dual voice coil subwoofer (without a low-pass filter!) louder than I would ever listen. I'm hoping that this new, 2" larger and probably much more efficient DVC subwoofer (this time WITH a low pass filter) will be even better. Thanks for your help! I'll let you know.

Regards,
Troy

Gentlemen,

Last evening I finally had the opportunity to try a new tactic. I reinstalled the PolyPlanar powered subwoofer in the boat, except I added a 70hz 12db per octave crossover (to override the 200hz crossover built into the bass amplifier). WOW! What a difference! With only the 200 hz crossover, I had to turn the bass speaker down so low (to avoid upper bass boominess) that it didn't help the 25hz range at all. With the 70hz crossover, I was able to turn the bass amp volumn up to about 90%, enough to really help the very low pitches. Today I plan to try a 50hz crossover and possibly turn the bass volumn up to 100%. I'll let you know!

Regards,
Troy Scott

I'm still working on the problem of getting better bass from the system. As I said, I have a four channel head unit with four times 45 watts, 180 watts total. I'm currently using four 6" by 6" by 9" box speakers with it. The sound is generally good with the exception of very low bass notes. I'm missing really low notes that I hear on the home system. So far I've bought three things. I've bought a Sony woofer. I also bought a device which I thought would enable me to combine the bass from two channels of my head unit to run the one woofer. Fortunately a consultant from Crutchfield explained to me that receiver/"head units" aren't "bridgeable" and that the device is incompatible. He also showed me ( and sold me) a Profile HA700M, which is designed to combine two channels safely, amplify the signal some more, and run a woofer. However, I'm trying to keep this simple. I'm now thinking that I don't need ANY of what I've bought so far! I came across some dual voice coil subwoofers in Crutchfield's online catalog. I'm now thinking that I could simplify this whole installation and probably end up with better sound. I think I should eliminate two of the four full range box speakers. That would free up two 45 watt channels which could then run one dual voice coil subwoofer. The whole system would then consist of:
One head unit with four times 45 watts,
Two full range speakers, and
One dual voice coil woofer with two 70 hz low pass filters.

Thoughts, please?

Folks,

If anyone here is still interested in my sailboat stereo project, here's the latest:
I bought the PolyPlanar model 250 amplified subwoofer (which includes a dual voice coil subwoofer) and added it to the system. When I adjusted the gain on the bass amplifier, it ended up very near the lowest level. The overall effect was a substantial improvement. The lowest notes were much better, but the upper bass still seemed boomy. Out of curiosity, I removed the bass amplifier from the system and connected the DVC subwoofer directly to the two front channels in place of the two bookshelf speakers that had been there. To my surprise, the subwoofer was actually LOUDER that the level I had set with the bass amplifier. Of course, without the bass amplifier there was no crossover for the woofer, so I had some out-of-place treble on the woofer. Another oddity: the sound from the subwoofer was not perceptively less when I added the two bookshelf speakers back to the front channels along with the subwoofer. However, to my ears the bass actually sounded better than the system sounded with the bass amplifier. Lesson learned: I think all I really need to do is add a very good DVC subwoofer to the set of four book shelf speakers. I've ordered an Infinity 12.1 dual voice coil subwoofer from Crutchfield, along with three different sets of low pass filters: 50hz, 70hz, and 100hz. I plan to try all three to see which works best.

Interestingly, almost everyone I've talked to about this problem has misunderstood. I'm after something subtle here, not a floating boom-box. We have an audiophile system at home, and I'm accustomed to hearing all the notes on my CDs. All I want to do is improve the system enough to hear everything clearly.

Regards,
Troy Scott