Upgrade Questions

[Budah93 7]

I have a 98 blazer with aftermarket electrical system. I currently have 2 SA-15s running off of a hifonics hifi1500d. I'm wondering if i would notice any difference in sound if I added another sa-15 and ran a hifonics hifi 1000d on it? I want my system to be louder but not stupid loud haha any input on upgrading amps or anything like that will be accepted!

[Aaron Clinton 2,372]

Just to understand correctly, you want to add a 3rd sub woofer with a different amplifier to the existing install?

[ssh 924]

Just to understand correctly, you want to add a 3rd sub woofer with a different amplifier to the existing install?

If so, bad idea.

Depending on the coil configuration on the drivers, you would be better off wiring all three together on the existing amplifier.

Before purchasing another driver, how do you feel about your current enclosure? Did you build it, or a shop? Do you know the specs as far as volume and tuning? Reason I ask is the enclosure plays a HUGE part in the end result.

[pro-rabbit 64]

What kind of enclosure do you have those SA15s in?

If you want more output I would get a little better amplifier and work on the enclosure to ensure you have what is working best for your application.

[Notorious97200 339]

Get 2 more SA's and another amp like your current one !

3 is not a good number

[pro-rabbit 64]

Get 2 more SA's and another amp like your current one !

3 is not a good number

He does not have the room for 4 with out folding down the seat....well three won't even fit lol.

[Budah93 7]

lt was custom built in a shop 7 cubes. and my amp is 1 ohm stable can't run 3 subs down to 1 ohm. Reason for getting a different amp is i don't want to put 1500 rms on 1 sub hence why i want to drop down to the hifi1000. and lastly i will be able to fit all 3 w/o folding down the seats

[Budah93 7]

btw my subs are dual 4 ohm coils so they will be ran at 1 ohm on the hifi1500 and then i will buy a 3rd sa15 d2 and run it at 1 ohm on the hifi1000d

[swift 501]

You could do that if the 3rd is in its own enclosure but it would be completely stupid. No other way to say it.

[Budah93 7]

i'm having a box built for 3 15s wiring 2 of them to one amp and the other to its own amp. how is that completely stupid?

[pro-rabbit 64]

There is very limited room in the back of those trucks. We use one as a demo truck. If you run 3 behind the back seat you will have to go pretty high to get the correct net volume which will cause loading issues.

As for your idea, it will not operate correctly at all. You should do some reading on what are some better options then what you are attempting. Personally I would get another D4 15 and run all three subs to a 2.66 load and snag a second amp and master/slave them. That would net a better overall result over what you are trying now.

While our insight is not being used here(you are doing to do it anyway), please tell me that the 3rd 15 is in its own enclosure in no way sharing space/port area with the other subs? If it is, you will find yourself with worse results then doing it the "correct" way if there is such a way as correct for this situation.

Edited June 29, 2012 by pro-rabbit

[Budah93 7]

The box is 10.5 cubes there for the right size and I talked to sundown and they said go for it

[An-i-no 86]

The box is 10.5 cubes there for the right size and I talked to sundown and they said go for it

So two of the 15's will see ~750wrms and the other will see ~1000?

The one with more power will move more and cause funny shit to happen.

[Budah93 7]

i can get an amp that does 750 rms i just throwing an amp out there for a refference

[ricksi30 923]

Plain and simple, it is a BAD idea. You wanted opinions and you don't like them so you argue?

[swift 501]

i'm having a box built for 3 15s wiring 2 of them to one amp and the other to its own amp. how is that completely stupid?

Dont even run 3 15's if thats your plan. You will never get the gains matched up perfectly and will possibly end up tearing your shit up and it will be super ghetto. Hell you could be louder too by adding a couple sets of home tower speakers in your back seat but why would you do that?

I would suggest a different enclosure and a high quality amp to power them. Two 15 SA's setup right on good power should be very loud. What is the current box tuned to and what kind of port area do you have now?

[Budah93 7]

i'm not trying to argue. i'm trying to understand your logic. The shop will be doing all the installs and they have machines so everything will be matched up perfect. and second why would jacob at sundown say that i would have no problem as long as it's install correctly

[Budah93 7]

If i stick with 2 what amp would you recommend i use?

[///M5 2,833]

The "shop" probably does not. If you don'tnknow why then a one amp solution is definitely best

[Budah93 7]

They are the best shop around. They have dmm and all the stuff to make sure that the gains and everything are matched up correctly. No one has given me an actual answer to why it would be a bad idea they are just saying that gains can't matched up. I can get them matched up so what actually makes it a bad idea besides peoples own personal philosophy

[shizzzon 461]

They are the best shop around because they can prey on those who appear to not have experience and get their money regardless of what the customer wants even though it's not wise.

Many shops do this.. The shops who educate people and reject customer's money will lose potential profit..

If the shop is big.. they'll do anything you ask them too.

And same box, different box.. doesn't matter. The end result will still be flawed.

You want to know what kind of effect it will have? Do this-

Balance your headunit all the way to the left, then fade forward about 6/15.

Why do you mainly hear the front speaker if not ONLY the front speaker?

Uneven power distribution results in speaker(s) receiving more power than other(s).

The speaker with the most power will have the potential to audibly overpower anything else in the install.

This is the same reasoning why you shouldn't mix dual 4 ohm and dual 2ohm, etc.. together.

You want to save money and still get loud?

Get larger enclosure built for the 2 15s and keep amp.

or

Recone to D2s and get 2 APSM-1300s and sell that Hifonics amp.

or

Get 2 SSA D2 15" Gcons on 2 APSM-1300s.

OR.. just use a single sub, high power application.

[Budah93 7]

They do reject people quite often. I can get a D4 and run it at 2 ohm. They will all 3 be getting the same amount of power so your analogy makes no sense at all. Everything will be lined up so that neither sub is getting more than the other ones

[pro-rabbit 64]

Do they have a clamp meter, oscope, and dmm? All of these would be needed to adjust the gains correctly. Also, even if adjusted correctly the length of speaker wire and rca cable can and will affect a time delay which can/will cause issues with loading and if it is off enough phasing can become an issue. If you run the 3rd in a seperate enclosure you would be a tad better off but still a waste of funds.

The shop should be nice enough to explain why this is a bad idea in full detail as would Jacob if you ask him to post in here. The shop should also inform you that there are far better ways to improve on your current setup rather then just cramming more into a small area that never actual fixes anything.

I would like to see pics of what you current have for a setup.

[shizzzon 461]

They do reject people quite often. I can get a D4 and run it at 2 ohm. They will all 3 be getting the same amount of power so your analogy makes no sense at all. Everything will be lined up so that neither sub is getting more than the other ones

I forgot that since you have all the answers.. you are just trolling here.. damn me..

Edited July 1, 2012 by shizzzon

[Impious 1,476]

While I agree it's a stupid idea, yes you could technically make it "work" by properly matching the gains and xover settings. It would simply make much more logical sense and be a much simpler install to use a single amp. Not to mention you are relying on the shops ability to perform these settings, which may or may not be within their capabilities. Being "the best in the area" doesn't mean a whole lot. They can be "the best in the area" and still not be the sharpest knives in the drawer...it's all relative to what else is in your area.

Also, you asked earlier about how much louder.....ideally, assuming you maintained the same alignment, I believe you'd be looking at a difference of ~3.5db. So an audible difference, but not dramatically louder.

Do they have a clamp meter, oscope, and dmm?

A DMM and common sense should be enough to get them set close enough not to matter.

Also, even if adjusted correctly the length of speaker wire and rca cable can and will affect a time delay which can/will cause issues with loading and if it is off enough phasing can become an issue.

No way in hell there is not going to be enough of a difference to matter. That one's kind of out there.