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looking for an audio wizz advice!

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looking for an audio wizz advice!

Postby Gost_Dog » Tue Mar 28, 2017 3:34 pm

Hey guys,

heres the deal,

I want to run a full front components kit.
and at the back, replace the current 6.5" speaker with some woofers.


So this is my questions:


REFF for question 1 and 2.
https://pdf.crutchfieldonline.com/ImageBank/v20050505150000/Manuals/108/108R5761A.PDF

1: I think my amp is a 611a (I will validate this weekend but I have 4 sets of screw for my speakers) but it seems like it would be rated 456W RMS @ 4ohm X1.
If I connect 2 subs to it, 4ohm each. will that translate to 228W rms @ 4ohm X2 ?

2: if the amp is a 7521a, rated: 97W rms @4ohm x2
and I want to use 2ohm dual coil speakers, how can this rating be converted to 2ohm?

REFF for question 3 and 4:
https://www.skaraudio.com/products/evl-65?variant=18454532865

3: since the OEM size of the rear speaker, could this potentially work?! I think since its a woofer it might hit the cover grill but I think the holes and diameter would work...looking for other inputs.

4: for the woofers, the manufacture gives specs about box's... Does that mean using it in free-air would not be recommended?

REFF for question 5-6: MRP-F300
https://pdf.crutchfieldonline.com/ImageBank/v20080226112900/Manuals/500/500MRPF300.PDF

5: If I want to bridge this amp there is only specs at 4ohm. What would be the specs at 2ohm if this is the bridged 4ohm one: 150W @ 4ohm.

6: Would the specs talk about peak to peak or rms power?


Final question.
Keeping in mind that I only have those 2 amps to build a setup, and theres no way I put a box with subs at the back. I did not get front components or rear woofer yet. Would you get 2ohm's or 4ohm's with my hardware and why?

Thanks in advance!!!!
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Re: looking for an audio wizz advice!

Postby Foogar » Tue Mar 28, 2017 4:06 pm

#1 Depending on how the subs are wired together the amp would see either a 2ohm or 8ohm load, 2ohms in parallel and 8 when wired serial. The 611a will put out 657W RMS at 2ohms giving you about 327W per sub if wired that way.

#2 If you wire the coils in series the amp will see each speaker as a 4ohm load

#4 I wouldn't

#5 The amp may not be able to handle a bridged load at 2ohm but in theory you would see close to 300W, that's perfect world scenario in a lab and all of that

#6 It depends on the brand and price point they're trying to hit.

For the final it really depends on your goals, what do you want to get out of the system? Without being able to drop a box in the back there's not much I can say really, but a 10in doesn't take up much room in a box.
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Re: looking for an audio wizz advice!

Postby Gost_Dog » Tue Mar 28, 2017 7:40 pm

Foogar wrote:#1 Depending on how the subs are wired together the amp would see either a 2ohm or 8ohm load, 2ohms in parallel and 8 when wired serial. The 611a will put out 657W RMS at 2ohms giving you about 327W per sub if wired that way.
Well in this case, my amp clearly have 2 sets of + and - (2chan?!)
so unless im wrong, it would be 4ohm per channel right? Now my question was more since the spec of the amp specify for 1 chan... how to I transfer that into 2 chan? is it as simple as deviding by 2?


#2 If you wire the coils in series the amp will see each speaker as a 4ohm load
Well I guess this is were im lost, if you check my reff from the woofer company. they have a dual coil 2ohm and a dual coil 4ohm... are they in series? are they in parallel? is it total ohm or by coils?! im all lost in there.

#4 I wouldn't
Would it be because of less produced bass? rattle? or others?

#5 The amp may not be able to handle a bridged load at 2ohm but in theory you would see close to 300W, that's perfect world scenario in a lab and all of that
as per a spec website it would accept 2ohm... not sure if it would be bridged or not or if it even makes a difference. What would be the calculation or estimation done to get to that W ?

#6 It depends on the brand and price point they're trying to hit.
Not sure I get your point here. My original question maybe was misunderstood. I was wondering in the manual (my reff document) Alpine says Watt and does not specify peak or rms. Was wondering which one would make more sense.

For the final it really depends on your goals, what do you want to get out of the system? Without being able to drop a box in the back there's not much I can say really, but a 10in doesn't take up much room in a box.

Well the first goal here was to have a good audio system without a sub. Using my 4chan Alpine amp, I wanted to change front and rear speaker. Then I started to wonder if that could lead to a bass deficient system. Then I started questioning because of the overall car physical specs, are the rear speaker that important?! And then I said to myself, why not put woofers at the back. But I didn't want to sacrifice trunk space so box and woofers were out of the picture. But then I realized that rear speaker were not really necessary (I think) and 6.5" woofers existed... So I figured, why not use my Infinity mono amp... stick 2 6.5" subs into the rear speakers instead? This is all where this came from... I hope that helps or maybe you could provide some insights.





thanks for your prompt reply!!!!

Ive added additional questioning in red above.
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Re: looking for an audio wizz advice!

Postby Foogar » Wed Mar 29, 2017 2:56 am

Gost_Dog wrote:
Foogar wrote:#1 Depending on how the subs are wired together the amp would see either a 2ohm or 8ohm load, 2ohms in parallel and 8 when wired serial. The 611a will put out 657W RMS at 2ohms giving you about 327W per sub if wired that way.
Well in this case, my amp clearly have 2 sets of + and - (2chan?!)
so unless im wrong, it would be 4ohm per channel right? Now my question was more since the spec of the amp specify for 1 chan... how to I transfer that into 2 chan? is it as simple as deviding by 2?

Sorry, I had to leave for work and rushed a bit. The 611a has a single channel but I didn't see it had 2 connectors. Look at page 10 of the 611a pdf, in the middle on top they cover the wiring for 2 subs and below that you'll see how to wire the DVC subs for #2

#2 If you wire the coils in series the amp will see each speaker as a 4ohm load
Well I guess this is were im lost, if you check my reff from the woofer company. they have a dual coil 2ohm and a dual coil 4ohm... are they in series? are they in parallel? is it total ohm or by coils?! im all lost in there.
Until they're wired up they're completely separate, it's about flexibility allowing you to make the most out of what subs you have room for and what load your amp can handle.

#4 I wouldn't
Would it be because of less produced bass? rattle? or others?
Actually it might not be too bad but I would keep the power lower until you know how the sub handles it.

#5 The amp may not be able to handle a bridged load at 2ohm but in theory you would see close to 300W, that's perfect world scenario in a lab and all of that
as per a spec website it would accept 2ohm... not sure if it would be bridged or not or if it even makes a difference. What would be the calculation or estimation done to get to that W ?
In the specs it lists that you can run at 2ohms in 4 channel mode, them not mentioning a spec for 2ohms in 2 channel mode says the amp more than likely can't do it.

#6 It depends on the brand and price point they're trying to hit.
Not sure I get your point here. My original question maybe was misunderstood. I was wondering in the manual (my reff document) Alpine says Watt and does not specify peak or rms. Was wondering which one would make more sense.
You're right, I didn't see what you were asking, on the specs page it says they are RMS.

For the final it really depends on your goals, what do you want to get out of the system? Without being able to drop a box in the back there's not much I can say really, but a 10in doesn't take up much room in a box.

Well the first goal here was to have a good audio system without a sub. Using my 4chan Alpine amp, I wanted to change front and rear speaker. Then I started to wonder if that could lead to a bass deficient system. Then I started questioning because of the overall car physical specs, are the rear speaker that important?! And then I said to myself, why not put woofers at the back. But I didn't want to sacrifice trunk space so box and woofers were out of the picture. But then I realized that rear speaker were not really necessary (I think) and 6.5" woofers existed... So I figured, why not use my Infinity mono amp... stick 2 6.5" subs into the rear speakers instead? This is all where this came from... I hope that helps or maybe you could provide some insights.

Now I understand a bit more and again, I read too quickly earlier. Personally if these were my only choices I'd go with the 2ohm DVC subs. I'd wire them for 4ohms each and run everything from the 4 channel amp and see how that works before wiring in the other amp.
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Re: looking for an audio wizz advice!

Postby Gost_Dog » Wed Mar 29, 2017 8:07 am

Thank you for your inputs.



If anyone else got some advices or anything.

Id be glad to hear them.
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