View Full Version : Why so many speakers on tower....

02-01-2012, 01:16 PM
I have been watching, reading, and learning but still donít fully understand the full benefit of having multiple speakers (2,3 pair) on the tower. Would a single pair of XM or Rev properly powered not accomplish getting great sound to a wakeboarder?

02-01-2012, 01:49 PM
I have been watching, reading, and learning but still don’t fully understand the full benefit of having multiple speakers (2,3 pair) on the tower. Would a single pair of XM or Rev properly powered not accomplish getting great sound to a wakeboarder?

IMO I think of it as like head lights on a vehicle. One set you can see sufficiently, but if you have the money and decide to put more sets of head lights on your rig, you can see much better... well I would think of it the same way with speakers, different angles to set them at, different soudn qualities from one set to another. There is nothing but benifits from adding more than one set of speakers, the trade off is more power to run them and of course the money to purchase them. Hopes this helps.

02-01-2012, 01:56 PM
and two sets just look cooler

02-01-2012, 02:05 PM
I like the way two sets look as opposed to one set but personally I only have one set of bullet hollowpint 770's and I can easily hear them while riding.

02-01-2012, 02:06 PM
until you need 2-3 guys to help raise or lower the tower...

I know - quick disconnects. I'm thinking a nice big pair of XM9's would look as good as any pair of 6.5's...

KG's Supra24
02-01-2012, 02:12 PM
I was debating between 4 and 6 for the longest time. I wanted a full tower look. I think people mostly go with 4 or 6 for cosmetic reasons but there is definitely more output, not double, but more.

Yes, I think a pair of xm9's or Rev's would easily reach the rider.

Maybe the audio gods could give insight into this statement: 2 8" speakers are going to sound better than 4 6.5" speakers in real world application because surface area rules. This may only be true for HLCD's?

New Guy
02-01-2012, 02:25 PM
Because I can. LOL

I wanted more midbass so that is why I went with the 6-pack from Kicker.

02-01-2012, 04:49 PM
I am sure David will probably chime in here (and correct me), but I will relay something he said in another post. Now the other post was referring to subwoofers, but I assume the conclusions would be similar.

He was saying that each speaker you add will result in approx. a 6dB increase in volume, if it is amplified to the same level. He also said that a 10dB increase is perceived as twice as loud.

So I am not that best at math, but if you have one pair of tower speakers with say 100W RMS to each and it is playing at say 100dB (just chose a random number) if you add another pair with 100w RMS to them as well, it will play about 12 dB higher, which would sound more than twice as loud. Two more, and it would be twice as lound as that, so would that be 4 times louder than one pair?

Maybe I should just let David (or Brian) chime in. I could be blowing a lot of smoke... but it sounds good doesn't it!

02-01-2012, 04:50 PM
Personally, for me...


02-01-2012, 04:58 PM
That is an excellent question. Why so many speakers?
*Partly cosmetics in the eye of the beholder...and the guy who dies with the most tower speakers wins!!!
*Early HLCDs where smaller and brutally bright for near field listening so double-ups or hybrids using a mix of four or six speakers of contrasting types became popular. Now that more larger tower speakers are available that have a warmer balance that trend is in decay. Going forward you will see fewer numbers of tower speakers with slightly larger tower speakers.
*"That Guy" who wants to be the center of entertainment at the sandbar or dock wants and needs an inordinately powerful tower system.
As for IF you need the extra speakers...
If the construction of two speakers are equal then the surface area will determine the capability for the most part.
Six 6.5" tower speakers would have an effective total surface area of 104.16 sq.in.
Four 8" tower speakers would have an effective total surface area of 128.08 sq.in.
Two 10" tower speakers would have an effective total surface area of 106.96 sq.in.
As you can see you can pretty much do as much with two as you can four and you can do as much with four as you can with six speakers using the above size comparisons.
Now, ten 6.5" tower speakers will play louder and be more impactful than one 6.5" but the midbass extension whether one or ten will be the same. However, the larger 10" in a larger pod displacement will have an inherently lower natural resonance and will play much lower. And a larger speaker will generally have a much warmer complextion, particularly related to vocals.
The more complex a horizontal line source is the more comb filtering effect you will have with off-axis cancellations/peaks/valleys. You can reduce some of this affect and actually improve the dispersion width by fanning the speakers out on the tower a bit. But sometimes the simplest configuration of just two larger tower speakers sounds more coherent from an at rest listening standpoint.

Earmark Marine

02-01-2012, 05:38 PM
LOL! I knew that was coming. Good work, David.

02-01-2012, 06:06 PM
Not exactly sure what we were discussing related to subs with reinforcing planes, enclosure types, etc.
But relating to tower speakers it would be fairly simple. There are two ways to increase amplitude.
Surface area and excursion.
If you double the surface area by running a larger speaker with the same power assuming that the internal efficiency of the smaller and larger speakers are consistent then you could gain 3 dB.
If you double the power to the same speaker you will double the excursion and gain 3 dB.
This continues to a point. Every speaker will continue to increase in amplitude as you double the power until it reaches dynamic compression (I can explain this if needed) at which time it takes an inordinate amount of power to see a very small gain and eventually it hits the wall. Amplifiers continue to increase power until the supply voltage sags and then they hit the wall.
You have challenges on the tower like competing engine noise, turbulence, wind and distance. It may take a ton of power to just overcome the environmental noise floor. It may take four times the power to maintain the same amplitude as you double the distance.
So core issues like speaker surface area and amplifier efficiency can be big. You don't want to be pushing a train up hill.

Earmark Marine

02-01-2012, 06:27 PM
and the guy who dies with the most tower speakers wins!!!

well put. end of discussion. /thread closed. :)

02-16-2012, 07:23 PM
Guys, I want to open this thread up because I have been thinking about this. A few years ago, I ventured into the tower speaker world, as some of you know. I got a set of Monster Tower Double Barrel cans with (4) Polk dB65s (or whatever they are called) powered by a Rockford Fosgate Punch 400-2. I have this wired so it is pushing 200 watts RMS x 2 @ 2 ohms, so basically each speaker is getting 100 watts RMS. It is actually a bit more since the amp generates more than its rating. Based on my recollection and current pricing, I think I spent about $1200 on this setup.

As far as this setup goes, as I have mentioned before, I am not very pleased with the result. The speakers sound great, but turned up to where the distortion starts in, I can just barely hear them 70' behind the boat. Meanwhile, at this level, the ears of everyone in the boat are almost bleeding, and they have to yell to talk to the person next to them. Its like being at a rock concert and sitting next to the speakers. Keep in mind that currently I have a DD Outback with the old style, almost vertical, tower.

Based on these results, (and pleading from my fiance) I have determined that tower speakers are not really for me, and that I will not be putting them on my next boat. My assumption thus far is that to get quality sound to the rider, super expensive HLCD tower speakers with giant amplifiers are needed. Once I have this, I will become "that guy" blasting his dirty hip-hop across that lake causing all the parents on the I/O's and pontoons to "earmuff" their kids and the shore fishermen to cast their rusty hooks at me. All the while, causing more ear bleeding in the new boat, ruining the carpet. Sound about right?

Okay, this is where my curiosity has gotten the better of me and I would like some opinions from you guys.

So I was lurking on the Exile Audio website the other day and noticed that I can get a pair of XM7s and a Harpoon amp for around $1300 on sale. I was surprised. That is barely more than I spent on my Polk coaxial setup.

So here are the questions:

1. How would (2) XM7s with 300 watts RMS (I think this is the rating of this amp in this setup) sound compared to my setup?

2. Would I be able to hear it well at riding length?

3. Would there be spontaneous eardrum explosions in the boat?

4. Would I be "that guy" and have to get a wrap on my boat that reads "Parental Advisory: Explicit Lyrics"? I know that sound travels very well across water.

5. I guess related to that last one, do the HLCDs throw the sound more directly behind the boat than my coaxials? (I notice that my system is almost just as loud while turning around to come pick me up with the boat facing away from me. The sounds seems to go everywhere.)

6. And lastly, my next boat will be a V-drive. Will this help with the in-boat loudness, and how much? I guess the rear swooping older tower would be better that the new forward sweeping ones?

I think that is all the questions I have. Thanks for the input gang!

KG's Supra24
02-16-2012, 08:21 PM
1. It would be much louder at riding distance but it would sound harsher when chilling behind the boat because a 6.5" HLCD lacks midbass.

2. yes

3. It might sound higher pitched compared to larger speakers? Not sure if it would be harsher than a coaxial. However your coaxials sound like they are being pushed HARD.

4. I guess that depends on your music taste, right? Just bc music is loud doesn't make it bad, right?

5. Yes they would be more direct

6. all depends on tower placement versus seating placement but you got the idea. The forward sweeping towers put the speakers closer to the bow so they affect the rear boat passengers more.

Not to knock what you have but I don't think the DB series is a very applicable tower speaker. If you are pushing 100 watts to each, you are likely pushing them past what they can handle. High end coaxials such as the exile sxt (or whatever they are) would be more ideal. I ran bullet hollowpoint coaxials with 150 watts to each my first year and they sounded great right behind the boat but barely reached the rider.

Have you considered something like a large coaxial? Something like the JL or Bullet used to make one, not sure if they still do?

FWIW, I don't hate every boat that comes by with loud music. I get annoyed by the ones that sound like hell or if they are playing music they shouldn't when they know it carries that far.

02-17-2012, 12:20 PM
The Polk dB series is undoubtedly a great value and one of the best sounding speakers in the sub $100 bracket. But you have to realize that this is an automotive speaker designed for wide dispersion and listening within a 5 ft. proximity. It has a 60 watt RMS power handling rating. You can push it harder run in the highpass mode so its not surprising that it holds up from a reliability standpoint. However, the complextion of that speaker is going to change dramatically around 100 watts when you are trying to push it to the rider.
There are two primary reasons for in-boat occupants to complain about the tower speaker radiation.
The first one is the volume. You can never escape the fact that what is loud at 70 feet is going to be perhaps 30 dB louder at 5 feet away.
The second reason is distortion which can come in any number of forms. A speaker and amplifier driven to their limits will exhibit the effects of 'dynamic compression'. Certainly the distortion is much higher. Definitely the balance of the speakers become brighter and harsher as it becomes louder. The dynamic range compresses so that even the background passages are nearly as loud as the foreground peaks so the radiation is consistently loud which causes considerably more trama. Those who do not listen to music as loud with such frequency may have not had the same degree of permanent hearing losses. These losses are usually most pronounced in the midrange/treble bandwidth which are coincidently in the realm of where speakers tend to focus as they are over-driven and the exactly in the region where most women are more sensitive.
Turning to horns...Many look at the final flare of a horn tweeter and wrongly interpret this as a means to wider dispersion. Actually a horn inherently has a narrower dispersion pattern which serves your purpose.
But a horn was selected because its more powerful and higher output impacts everyone regardless of the proximity.
The six best things you can do to reach the rider and lessen the discomfort level in the boat is 1. get enough amplifier and speaker that they can be driven more conservatively to limit the various types of distortions and non-linearities. 2. Get a larger 8 or 10-inch speaker that has a much warmer balance to begin with. 3. Tilt the speakers slightly upward to correspond with how the boat squats when loaded and pulling so that the tower speaker radiation is more level with the water and more off-axis with the rear in-boat occupants. 4. Do more with less. A horizontal speaker array still has great vertical dispersion (which you do not want) and diminished horizontal dispersion (that you do want outside of the wake). So go with the largest tower speaker that you can tolerate and fewer of them, like just two for example. Then aim each one a bit to the outside so that they do not beam as much down the middle. 5. Mount the speakers on the rear tube so that they are farther back and also more off-axis from the rear in-boat occupants. 6. Tune the tower speakers correctly which is far too protracted for this discussion.

Earmark Marine

New Guy
02-17-2012, 01:48 PM
A Bimmi would probably help too.

02-17-2012, 03:36 PM
depends on the bimini. some came with the fwd bimini that is 100% in front of the tower cans.

sure david can elaborate, but if you have the z5 and you are angling the cans up due to the bow rise, they may point more into the bimini. can't think that's a good thing for hlcds.

02-17-2012, 04:29 PM
In most cases, I was under the impression that the cargo top is under the speakers but not protruding past the rear (grill side) of the speaker when the speaker is mounted on the rear most tube. If that were to be the case then the cargo top would be of little consequence. We mostly see Supras with cargo tops so I may have the wrong picture in my mind's eye.
Looking at the model with the cast arch where the nutserts are fixed it would still be possible to rotate either a Wetsounds or Exile on the vertical surface using their rotating mounts. The top looks to be high enough above the speaker that a slight upward angle wouldn't conflict with the top.

Earmark Marine

KG's Supra24
02-17-2012, 04:41 PM
I don't think the Z5 does play into the equation. This is on the bar closest to the bow and it sits over the top of the Z5, the grab bar, not the canvas. The canvas is still behind the back of the cans ...


02-17-2012, 04:45 PM
I see it now with the overhead tops on the newer forward leaning tubular towers. The bimini, even in canvas, is going to reflect radiation down in the boat. And speakers mounted on the vertical section of either the tubular tower or cast arch are positioned lower than when mounted across the horizontal tube. That's not helping the cause at all.

Earmark Marine

02-17-2012, 05:55 PM
Interesting points guys, thanks for the responses. It all pretty much makes sense, and some of it I have already done. I do have the speakers on the back horizontal bar and have them tilted up and out slightly. That is one thing I really like about the Monster Tower cans, the mounts are infinitelyl adjustable in every direction. I also have a bimini which is right up under the speakers, which would help the in boat loudness more, if it were covered in lead! (Hmmmmm... more weight....???? J/K) I guess it just comes down to trying to do something that they were not designed to do. If I had to do it over again, and I knew that HLCD speakers weren't a lot more expensive than what I have, I would have gone that route. Back then (5 years ago?) the thought of buying Wetsounds was like spending a million dollars, "that was what all the guys with the crazy expensive Nautiques and Malibus had."

So you know what they say, hindsight is 20-20....

02-17-2012, 06:06 PM
don't know for a fact, but I would guess that 5 years ago, they were a lot more expensive and more for the mc/nautique income level. seems that companies like bullet/kicker/exile have driven the prices down(or kept prices from escalating with the economy) into the bracket that more can afford them.

heck, I have seen a couple of bayliner 19ft'ers on our lake that are sporting hlcd's... correction-heard them :)

02-17-2012, 06:35 PM
Do you know that Mike (MLA) is also in NC? I would shoot him a PM about your boat stereo needs. There is not that many specialists around and you have one of them in your backyard.

Earmark Marine

02-17-2012, 09:22 PM
Thanks for the plug David. I haven't checked in in awhile with our Charlotte boat show last weekend and trying to get a promo boat ready for the Greensboro show next weekend, its been CRAZY!


Feel free to hit me up if you have any questions. I know its about a 2.5 hr drive for you to come to the Charlotte area, but you are welcome any time if you wanted to stop by and demo some options.

With what you have, I see two pluses. 1) you have a 4 chnl amp that will do 200W rms x 2. That's decent power for a pair of 6.5 or 8 inch HLCD's, so an amp change may not be a must. 2) You've got a 4 pod setup. If you like the double pods and they are in good shape, there are options for just swapping the drivers for a whole new sound.

I do agree that you are pushing the polks to about as far as they will want to go. So if they are not getting it done, a change would be in order.