Finally doing it right - need some input

[LongThrow]

TL'DR? Scroll down to where the numbers start.

This forum has helped me so much since I joined back in '14, when I was 18-19 And I've went from knowing ABSOLUTELY nothing about how car audio works, to a pretty good intermediate understanding. Don't get me wrong, I'm still a total noob in comparison to you guys who have been doing this most of your lives.

But, on to the topic, I switched from an explorer to an Accord - not my personal choice - but I am in the position where I can start dumping more money in this lovely hobby.

So, to start, I need a much bigger alternator, the 80amp stock alt I have in my accord is barely doing what it should, and I'm afraid it'll go out soon so I currently have my system unhooked, hopefully be able to piece it out or sell as a bundle pretty cheaply to put towards my next install.

1. HO alternator - won't be running more than 1000-1500w at 2 ohms, I don't need to go that big. So what amp size alternator should I get? What website is good for the best deals? Will it fit in my accord with no modifying?

2. Since I have to put my subs in the trunk (can't wall of my accord, or I would LOVE to ******' do this in a small *** car!!) I wanted to make a blow through since I use the backseats, obviously. I don't run rear fill, obvious reasons, so I figured taking the two rear SPEAKERS OUT and leaving the SPEAKER GRILLES in. Would this work for a blow-thru? Should I just take ONE speaker out, leaving only ONE hole, and seal off the other side?

Thanks guy, been a big help. Even those of you who were rude to me, you still helped me.

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[wew lad 5,000+ posts]

you should be able to save some money by having that alternator rewound by a reputable local alternator shop. it really depends on the availability of HO alternators for your car and whether or not the case is too small for the shop to get more power out of it, but if you got it from 80 amps to 150-200 amps it'd be less than $200. replacing your main battery with a higher quality AGM, and adding another AGM will also help substantially.

you'll need more than a speaker hole cut out if you want to vent into the cab, you'll need to directly port the box into the car. I would focus your effort on the enclosure and how its ported into your car considering you'll need the rear seats

 

[LongThrow]

Rewound? How so @mitchell0715

And so having a speaker hole wouldnt do ANYTHING? like at all?

 

[wew lad 5,000+ posts]

they pull the alternator apart and put better tighter wound parts and higher current parts in to make it produce more output. it's usually $1-$2 per amp.

it may help to open up the rear deck more, but its not going to help the way you want it to.

 

[LongThrow]

they pull the alternator apart and put better tighter wound parts and higher current parts in to make it produce more output. it's usually $1-$2 per amp.
it may help to open up the rear deck more, but its not going to help the way you want it to.

When you say open up the rear deck, you mean it'll sound louder - in terms of directional bass? It won't give me any DB gain, but when you say that you mean it'll just make the rear of the car sound louder?

 

[blazian87 10+ year member]

When you say open up the rear deck, you mean it'll sound louder - in terms of directional bass? It won't give me any DB gain, but when you say that you mean it'll just make the rear of the car sound louder?

What year is your accord? If you have an armrest hole in the back, that would be your best bet for a blowthrough. Opening up any hole from rear deck will get you louder regardless but there might be too much pressure going into your grill holes that it'll rattle like crazy. Unless you're willing to just cut a giant hole on top and make it act like a port.

Also, about rewinding your alternator.. It might not be a good idea because the casing might get too hot and cause issues. I got an alternator rewound from 80a to 160a before and I had heating issues within a short period of time. It eventually gave out within a few months and had to get a new H/O alt built for me for it to be able to handle the power properly. I would ask mike@singeralternators.com to see if he is able to help you rewind it with better parts and casing. He's one of the best in the alt business so he should be able to give you some advice on that. But I just wouldn't recommend it because it'll shorten its lifespan and you'll just be left with a broken alt. If you're only planning to run 1000-1500w, then a battery upgrade and big 3 might just work for you. Try to utilize getting the most out of your enclosure so you don't have to dump a lot of money into electrical upgrades.

 

[LongThrow]

What year is your accord? If you have an armrest hole in the back, that would be your best bet for a blowthrough. Opening up any hole from rear deck will get you louder regardless but there might be too much pressure going into your grill holes that it'll rattle like crazy. Unless you're willing to just cut a giant hole on top and make it act like a port.
Also, about rewinding your alternator.. It might not be a good idea because the casing might get too hot and cause issues. I got an alternator rewound from 80a to 160a before and I had heating issues within a short period of time. It eventually gave out within a few months and had to get a new H/O alt built for me for it to be able to handle the power properly. I would ask mike@singeralternators.com to see if he is able to help you rewind it with better parts and casing. He's one of the best in the alt business so he should be able to give you some advice on that. But I just wouldn't recommend it because it'll shorten its lifespan and you'll just be left with a broken alt. If you're only planning to run 1000-1500w, then a battery upgrade and big 3 might just work for you. Try to utilize getting the most out of your enclosure so you don't have to dump a lot of money into electrical upgrades.

Car is 91, it has the arm rest in the middle I believe called a Ski Pass? Gf won't let me do a dedicated blowthrough liek you said, but said I can take out the rear speakers since we don't run rear fill. I'll just keep the rear speaker out as a half *** blow thru. Should I take them both out, or just one?

 

[audioholic 5,000+ posts]

The general problem with just leaving the rear deck speakers out is, it tends to create an unwanted bandpass effect. Basically, the trunk's airspace becomes an "enclosure", and the emptied speaker holes become ports. This alters the tuning of your actual enclosure's output, often drastically (narrowing the bandwidth and spiking its output).

This effect happens if/when the holes thru the rear deck restrict air flow. This creates pressure in the trunk space, which translates into the bandpass effect I described above. To eliminate (or minimize) this, you would want to open up the holes as large as possible. How necessary this is depends on the vehicle and equipment installed. But if you are putting a high displacement subwoofer setup in the trunk, and relying on two 6x9 holes to vent into the cabin, you can be pretty confident it will be an issue.

 

[LosIsATool 5,000+ posts]

The general problem with just leaving the rear deck speakers out is, it tends to create an unwanted bandpass effect. Basically, the trunk's airspace becomes an "enclosure", and the emptied speaker holes become ports. This alters the tuning of your actual enclosure's output, often drastically (narrowing the bandwidth and spiking its output).
This effect happens if/when the holes thru the rear deck restrict air flow. This creates pressure in the trunk space, which translates into the bandpass effect I described above. To eliminate (or minimize) this, you would want to open up the holes as large as possible. How necessary this is depends on the vehicle and equipment installed. But if you are putting a high displacement subwoofer setup in the trunk, and relying on two 6x9 holes to vent into the cabin, you can be pretty confident it will be an issue.

We missed you

 

[LongThrow]

The general problem with just leaving the rear deck speakers out is, it tends to create an unwanted bandpass effect. Basically, the trunk's airspace becomes an "enclosure", and the emptied speaker holes become ports. This alters the tuning of your actual enclosure's output, often drastically (narrowing the bandwidth and spiking its output).
This effect happens if/when the holes thru the rear deck restrict air flow. This creates pressure in the trunk space, which translates into the bandpass effect I described above. To eliminate (or minimize) this, you would want to open up the holes as large as possible. How necessary this is depends on the vehicle and equipment installed. But if you are putting a high displacement subwoofer setup in the trunk, and relying on two 6x9 holes to vent into the cabin, you can be pretty confident it will be an issue.

Small seaed box, trunk has no deadener/not been sealed, 5-6 inch round openings as rear deck speakers.

 

[audioholic 5,000+ posts]

Small seaed box, trunk has no deadener/not been sealed, 5-6 inch round openings as rear deck speakers.

A small sealed box system can generate the quasi-bandpass effect. Unless its an extremely modest sub system, two 6" holes will restrict air flow into the cabin.

We missed you

Thanks man, its been a while huh. lol

 

[LongThrow]

A small sealed box system can generate the quasi-bandpass effect. Unless its an extremely modest sub system, two 6" holes will restrict air flow into the cabin.


Thanks man, its been a while huh. lol

So in terms of SPL or Sq respectively, should I seal up the rear door speaker mount holes? Or leave them open?

 

[audioholic 5,000+ posts]

So in terms of SPL or Sq respectively, should I seal up the rear door speaker mount holes? Or leave them open?

Are you asking if you should eliminate the rear door speakers? Or is that a typo and we are still talking about the rear deck holes?

 

[LongThrow]

Are you asking if you should eliminate the rear door speakers? Or is that a typo and we are still talking about the rear deck holes?

No, I personally don't run rear fill. We are still talking about the holes. Should I seal off the holes, leave one open, or leave both open?

original question -

So in terms of SPL or Sq respectively, should I seal up the rear deck speaker mount holes? Or leave them open?

 

[adulbrich 5,000+ posts]

No, I personally don't run rear fill. We are still talking about the holes. Should I seal off the holes, leave one open, or leave both open?
original question -

So in terms of SPL or Sq respectively, should I seal up the rear door speaker mount holes? Or leave them open?

Doors or rear deck?

If you really are asking about the rear door speaker holes, it honestly doesn't matter if those are sealed or open.