RCA wiring my new amp.

[yooper]

I just got my new Exile Javelin 5 channel amp to power my cabin speakers and Sub. I also have an Exile Harpoon amp powering two XM9 tower speakers. Everything is run through an Exile Zone Line Driver.

Here is my question. I have one RCA output that comes from my ZLD for my cabin speakers and one for my Sub. The Exile has 3 RCA inputs: Front, rear, Sub. Can I use a "Y" splitter to send the signal to both inputs? Will this cause any signal loss, or is there any other reason NOT to do this?

Right now I have the switch on the sub set so that it only needs a single input for all 3, which works fine but that makes my sub frequency and level knobs on my ZLD useless.

[Brianinpdx]

In your configuration use y cable on front and rear it puts to the javelin.
Loosing voltage is a non issue. Especially with a zld feeding the amp.

Make sure your cabin is set to Highpass at 110 hz and you good to go.

-Brian

[yooper]

Cool. Thanks Brian. Roughly where is 110 htz on the dial? Maybe noon? 1 o'clock?

Also, keeping in mind it can be adjusted on the ZLD, where should the sub LPF be set? 80? And what about the bass boost?

[MLA]

Cool. Thanks Brian. Roughly where is 110 htz on the dial? Maybe noon? 1 o'clock?

Also, keeping in mind it can be adjusted on the ZLD, where should the sub LPF be set? 80? And what about the bass boost?

Yooper,

What you adjust on the face of the EQ is not at all the same as setting the cross-over on the amp. The EQ is a means to boost or reduce those 4 preset frequencies. The cross-over filter and frequency setting on the amp, is about setting the H-Pass floor for full-range speakers, or the low-pass ceiling for sub-woofers. Just keep in mind that this is no hard dead set come to a stop setting, but rather a point at which the amp begins to taper off/reduce the level of the frequencies below/above that set point. Its called roll-off and the degree of roll-off is different with each amp. Some are steeper (quicker) while some are slower (more gradual), kinda like the steepness or rampyness of a wake.

IMO, 110 Hz is WAY to high for a fill-range in-boat, especially if the in-boats are accompanied by a sub. That Hz or a little higher is perfect for a 6.5" full-range on a tower, but not in an in-boat application.

There was some tuning advice given in a recent thread = 110hz hi-pass for the full-range in-boats and 60hz low-pass for the sub. As noted, way to high for the in-boat and thats also way to low for the sub, and hear (yes, hear) is why. Those recommended settings have left about a 40 Hz gap in audible program material, when some roll-off is factored in. Thats a ton of music thats being tossed out the window.

Even further, that 60hz on the sub's low-pass ceiling, greatly narrowed the bandwidth that the sub has to operate in. This makes for a peaky one note wonder of a sub. The subs cross-over needs to be based on the sub, its size, the enclosure and the in-boats.

There are no arbitrary frequencies, but rather a starting point to begin the fine tuning and a window that we hope to stay in, where the speaker is comfortable operating. This is based on the size and type of speaker, application and amount of power its being driven with. For an in-boats set up with a sub, the goal is to have a seamless transition from sub to full-range. And again, those 4 EQ settings are completely independent of the initial amp settings, so put them as zero/flat to start with.

Start with BASS-BOOST at zero. I rarely like to use it. With out knowing anything about your sub and enclosure and without knowing if the amp has a fixed boost Hz or adjustable, its hard to suggest adding any.

[David Analog]

MLA (Mike),
You are spot on and make a very good point about gapping the crossovers with such a wide span. Most think in terms of amplitude but there is another major issue in the way of phase. With every filter, whether highpass or lowpass, there is a phase rotation. Not like an abrupt polarity change but more of a gradual rotation just like the filter amplitude function is gradual. Ideally you would want a condensed crossover span in order to obtain the most coherent phase relationship between the sub and satellites. Typically a symmetrical crossover frequency is better. This is important so that the subwoofer doesn't sound remote or detached. Its also important for good bass tonal construction.
I realize there is often a desire to keep the issue basic, easy to understand, and easy to implement. However, a simple tuning prescription based on a fixed frequency leaves a great deal of sonic performance behind.

[sandm]

not to spark up a debate but more a learning.. and remembering that each system is specific to the drivers/amps/wiring/etc so this is not a "one size" statement:
I seem to remember for years from my car audio days that high pass was best started at 110hz as the rolloff would extend down and subs were best at between 80-90 and again, due to rolloff, would be a smooth transition. again, just starting points and every system is different but good guidelines.

thoughts?

[David Analog]

not to spark up a debate but more a learning.. and remembering that each system is specific to the drivers/amps/wiring/etc so this is not a "one size" statement:
I seem to remember for years from my car audio days that high pass was best started at 110hz as the rolloff would extend down and subs were best at between 80-90 and again, due to rolloff, would be a smooth transition. again, just starting points and every system is different but good guidelines.

thoughts?

True. It's not a one size fits all. Even the coaxial mounting structure and location in a given boat can have a large impact on the final crossover selection. Precise tuning is a matter of following a set prescription and not using a set of fixed numbers.

I've always looked at tuning an open field boat very differently than the enclosed cabin of a car, truck or SUV. To begin with the inherent response of the environments is radically different. Most never grasp this transition.

Yet, a symmetrical crossover point is always important in either case if the goal is sound quality and bass with tight pitch accuracy. Now the bass head with a system that is defined by bass may separate the high and low pass filters so that the - 3 dB point is roughly at the same frequency for both. But that is an entirely different goal that casts off sound quality from the onset. You just can't have coherency when you expand the affected crossover region.
It's one of the fundamentals that apply to all systems in all environments. For example, when a home theater guy adds a mondo subwoofer to his tower speakers he might not use a highpass crossover on the towers or he may not plug up the ports on his tower speakers. With a bass-reflex sub, bass-reflex tower speaker, and no highpass filter on the towers he essentially has four different phase responses overlapping in a wide region. He knows the bass sounds terribly unmusical, especially on music, and every misdiagnosis follows except for the real problem.

[yooper]

WHOA. Excellent analysis! So, if anyone wants to jump in with some crossover suggestions, here are the components I'm using:

Exile ZLD: http://exileaudio.com/store/index.php/amplifiers/signal-processing/zone-controller-preamp.html
Exile 5 channel amp: http://exileaudio.com/store/index.php/amplifiers/amplifiers-1/javelin.html
6 Polk 6.5" speakers: http://www.polkaudio.com/products/mm651 (these speakers are 2.7 ohm, for what it's worth)
1 12" Alpine R-type sub in a .85cf sealed box, wired at 2 ohm, driven by the sub channel of the Exile amp : http://www.crutchfield.com/S-hdZiYP9IYJX/p_500SWR12D2/Alpine-SWR-12D2.html?XVINQ=DST&XVVER=CCC

[David Analog]

Hmmm. A 1.33 ohm load on two of the amplifier channels is not good. Instead try the Polk MM651UM that is 4-ohm and has a continuous cone for more midbass performance. Or, look at the JL Audio MX650 which is the best 6.5" coaxial I have heard by a good margin.
Alpine makes a good sub. But 0.85 cu.ft. is really small for a 12". Before building that box I would find out what the 'Qtc' is (damping at resonance in the box), what the Fc is (new and higher resonance in the box), and what the F3 is, (roll-off point of half power in the box). For example, knowing the system 'Q' of the woofer in the box will forecast how the box will sound before you trial and error. This is part of the normal system set-up. Tuning and crossover selection shouldn't have to repair major flaws.

[yooper]

Actually, I was a little off on the sealed box volume. Alpine says the IDEAL sealed volume is .85. The box I have is very close to that.... .91

As for the Ohm rating on the speakers, I spoke to Brian from Exile on the phone and was VERY clear as to which speakers I had, and specifically talked about the lower than usual ohm rating. He assured me that the Javelin amp could run 6 of those speakers "no problem" and if I had 8, it would do that too, with no overheating or instability issues at all.

Everything is installed and sounds pretty good. I'm just trying to fine tune.

This is the actual box, by the way: http://www.sonicelectronix.com/item_33868_Atrend-12SA-12-SA.html

[MLA]

Wired in series, that amp should have no issues driving 4 pair, but its pushing a lot with too chnls at 1.33 nominal impedance. During normal listening, this 1.33 will actually drop lower. This should put any 2 ohm stable amp into protect mode.

If the amp actually delivers its advertised 4 ohm and 2 ohm output, then I would suggest rewiring the 2 pairs of polks, to series. You will likely not have a noticeable drop in volume, but may actually pick up some sound quality at the higher impedance.

[David Analog]

This is not a step by step professional tuning prescription like you would get from Odin at Earmark Marine. Odin is a masterful acoustic engineer and walks his customers through a real pro tuning process. He can also dumb it down if you don't have the tolerance for the technical, however, he will take everything into consideration on his own as he instructs you. The following is just a few of the guidelines a pro might consider in making your particular crossover selections.
Alpine says that your woofer in your box will have a gradual deep bass roll-off starting at about 60 Hz, be at half power at 45 Hz, and roll-off rapidly below 45 Hz. Not bad for that small of a box. A typical active crossover is at half power at the crossover frequency so it also begins to roll-off gradually outside/lower-than the crossover region. The 'meat' of the bass is in the 50 to 80 Hz region ('meat' denoting the range that is perceived to be the loudest). So you are beginning to roll off on the bottom end below 60 Hz by nature of the enclosure/driver. If you select a lowpass crossover of 90 Hz for example you are beginning to gradually roll-off the top end of the sub below 90 Hz. That doesn't leave much bandwidth. Again, this would have you at half power at 45 Hz on the low end and at half power at 90 Hz on the top end. That is less than one full octave. That is also beginning to infringe on the power bandwidth of the bass (in other words the 'meat'). A 'Qtc' of 0.81 in your case will also generate a small peak in the response about an octave above the system (woofer in box) resonance. That becomes an accentuation of what could be an already pronounced peak by nature of the lower end and upper end roll-offs. So with what I am sharing with you, your conclusion should be that you do not want to crossover your sub below 90 Hz.... period. It's also to your advantage to have the lowpass of the subwoofer and highpass of the coaxials as close together as possible. Otherwise, as you spread the crossover points apart you get farther and farther out of phase with one another and any degree of coherency becomes impossible.
So why is coherency important and why do I place so much emphasis on having the best possible phase relationship? Because you are very dependent on your coaxials and the relationship between the sub and coaxials for bass tonal construction and pitch accuracy. Want proof? Easy. Just run your subwoofer in isolation in the lowpass mode and without the benefit of the coaxials or other fullrange speakers. No matter which sub you have it will sound drunk, soggy and muddy. Add the upper harmonics back in from the coaxials and you will find that structured bass tones actually are formed again.
If we change equipment or even change the sub enclosure we might be changing the crossover selection. It's a sequential process, a step by step prescription, and not a simple set of numbers that are commonly used and that would apply to all systems. And I've only scratched the surface. For a music lover it's a crime to simplify it.
But when tuned correctly the identical equipment can perform at twice the perceived level.

[yooper]

This is not a step by step professional tuning prescription like you would get from Odin at Earmark Marine. Odin is a masterful acoustic engineer and walks his customers through a real pro tuning process. He can also dumb it down if you don't have the tolerance for the technical, however, he will take everything into consideration on his own as he instructs you. The following is just a few of the guidelines a pro might consider in making your particular crossover selections.
Alpine says that your woofer in your box will have a gradual deep bass roll-off starting at about 60 Hz, be at half power at 45 Hz, and roll-off rapidly below 45 Hz. Not bad for that small of a box. A typical active crossover is at half power at the crossover frequency so it also begins to roll-off gradually outside/lower-than the crossover region. The 'meat' of the bass is in the 50 to 80 Hz region ('meat' denoting the range that is perceived to be the loudest). So you are beginning to roll off on the bottom end below 60 Hz by nature of the enclosure/driver. If you select a lowpass crossover of 90 Hz for example you are beginning to gradually roll-off the top end of the sub below 90 Hz. That doesn't leave much bandwidth. Again, this would have you at half power at 45 Hz on the low end and at half power at 90 Hz on the top end. That is less than one full octave. That is also beginning to infringe on the power bandwidth of the bass (in other words the 'meat'). A 'Qtc' of 0.81 in your case will also generate a small peak in the response about an octave above the system (woofer in box) resonance. That becomes an accentuation of what could be an already pronounced peak by nature of the lower end and upper end roll-offs. So with what I am sharing with you, your conclusion should be that you do not want to crossover your sub below 90 Hz.... period. It's also to your advantage to have the lowpass of the subwoofer and highpass of the coaxials as close together as possible. Otherwise, as you spread the crossover points apart you get farther and farther out of phase with one another and any degree of coherency becomes impossible.
So why is coherency important and why do I place so much emphasis on having the best possible phase relationship? Because you are very dependent on your coaxials and the relationship between the sub and coaxials for bass tonal construction and pitch accuracy. Want proof? Easy. Just run your subwoofer in isolation in the lowpass mode and without the benefit of the coaxials or other fullrange speakers. No matter which sub you have it will sound drunk, soggy and muddy. Add the upper harmonics back in from the coaxials and you will find that structured bass tones actually are formed again.
If we change equipment or even change the sub enclosure we might be changing the crossover selection. It's a sequential process, a step by step prescription, and not a simple set of numbers that are commonly used and that would apply to all systems. And I've only scratched the surface. For a music lover it's a crime to simplify it.
But when tuned correctly the identical equipment can perform at twice the perceived level.

Makes sense. Thanks. After a little trial and error based on a starting point of 80 HP on the cabin speakers and 80 LP on the Sub, I ended up at about 100 on the cabin speakers, and about 100 on the Sub and it sounds pretty good and fairly seamless. In fact, I found myself putting my ear down by the sub to make sure sound was coming out. It basically just sounded like all the bass was coming from the cabin speakers.

I'm going to change my speaker wiring to series and see how it sounds.

[David Analog]

Makes sense. Thanks. After a little trial and error based on a starting point of 80 HP on the cabin speakers and 80 LP on the Sub, I ended up at about 100 on the cabin speakers, and about 100 on the Sub and it sounds pretty good and fairly seamless. In fact, I found myself putting my ear down by the sub to make sure sound was coming out. It basically just sounded like all the bass was coming from the cabin speakers.

I'm going to change my speaker wiring to series and see how it sounds.

Yeah man!!! When the sub localization disappears and you have plenty of bass you have really accomplished something.

[yooper]

Cool. I'm there. I switched the 4 main cabin speakers to series, which now means the Amp is seeing 5.4 ohms from those 4. The two bow speakers are just wired directly to the amp.... 2.7 ohms. All things being equal, the bow speakers should now be louder, right? Would it make sense to bump the sensitivity up a touch for the 4 that are in series?

[MLA]

Cool. I'm there. I switched the 4 main cabin speakers to series, which now means the Amp is seeing 5.4 ohms from those 4. The two bow speakers are just wired directly to the amp.... 2.7 ohms. All things being equal, the bow speakers should now be louder, right? Would it make sense to bump the sensitivity up a touch for the 4 that are in series?

And you can easily dial back the bow chnl gains to reduce their dominance.

[David Analog]

I totally agree with MLA on avoiding a 1.35 impedance which actually is lower at some frequencies as that is just the nominal impedance. It could pass thermal but it's better for sound quality to run it higher.

Whenever the output impedance load is high you will need a little more rotation on the input gain with the inverse being true at a lower impedance load.

[yooper]

And you can easily dial back the bow chnl gains to reduce their dominance.

Except the fact that both gains are all the way down.... so the only way to equalize them would be to bump the 4 speakers up, rather than the bow speakers down.

Which brings me to another question.... should the gains be all the way down? Or should I lower the gains on the ZLD so that I can turn up the amp gains a little?

[MLA]

Except the fact that both gains are all the way down.... so the only way to equalize them would be to bump the 4 speakers up, rather than the bow speakers down.

Which brings me to another question.... should the gains be all the way down? Or should I lower the gains on the ZLD so that I can turn up the amp gains a little?

There is absolutely nothing wrong with having the amp gains bottomed. Now, wide open is another story. The lower the gains, the lower the noise floor. I would not lower the EQ's gains, simply to raise the amps' gains, this is counter productive. Raising the gain on the chls driving the 2 pair, in order to balance thier output to the bow pair is fine, providing you are not exceeding the pre-clip level, over driving the speakers, or getting to a point that gain hiss is introduced. Once balanced, then use the EQ's volume to do the rest. If the balance you seek can not be achieved without the main cabin gain being to high, then a simple RCA line level controller can be put in after the EQ, prior to the amp, with a dedicated set of RCA cable to the bow chnls. This would allow for further control.

[yooper]

Here's what it looks like now:

http://img.tapatalk.com/d/14/06/02/ysazeqej.jpg

http://img.tapatalk.com/d/14/06/02/e6yhapas.jpg

[uniwarking]

Yooper, what size wire is running to from your buss back to the Perko switch and battery? I'm running a Jav and 800.4 and I'm using 1/0 to a distribution block and then 4AWG to the amps. Those two amps can draw some current so you may want to look at that. Maybe I'm not seeing a separate ground wire in the pic but that looks like 8AWG running back to the battery.

[yooper]

Yooper, what size wire is running to from your buss back to the Perko switch and battery? I'm running a Jav and 800.4 and I'm using 1/0 to a distribution block and then 4AWG to the amps. Those two amps can draw some current so you may want to look at that. Maybe I'm not seeing a separate ground wire in the pic but that looks like 8AWG running back to the battery.

I think you are exactly right.... I haven't changed that part at all. It has whatever came from Moomba.

[MLA]

The cable to the B+ BUS looks like 2ga. Depending on the length to the battery/switch and what other loads are drawing off that BU, 2ga could be about right. But, no way is 8ga for that ground side BUS. I would suggest 4ga to the amps and what ever is ample for for the load of those 2 amps and other loads also wired to that ground post.

[uniwarking]

Actually, stock is 6 AWG to the bus and then 8 AWG to the stock kicker amps. I still have my old stuff in the garage. The + looks bigger than it is because it's got color matched corrugated wire sheathing on it.

You'll really want to up that wire size to 4AWG to the amps per the spec, and 1/0 running from the battery to a distribution block. Brian @ Exile can set you up with the right stuff. They've got some solid Tspec kits that will have everything you need, including properly sized fuses.

Here is how mine ended up, it looked just like yours before:

20059

[yooper]

The cable to the B+ BUS looks like 2ga. Depending on the length to the battery/switch and what other loads are drawing off that BU, 2ga could be about right. But, no way is 8ga for that ground side BUS. I would suggest 4ga to the amps and what ever is ample for for the load of those 2 amps and other loads also wired to that ground post.

The cable on the B+ has a wire loom over it, so it's a little smaller than it appears. I do have 4ga to the amps. Looks like I'll have to upgrade the power and ground to the buss.

[yooper]

Ok. Power and ground cables have been upgraded to 1/0. I think I'm finally done for a little while!