2013 WRX SQ Build - Feedback/Suggestions Appreciated

[lyons238]

I'm attempting to upgrade my system and make a SQ / SQL'ish car...but I have a few questions about design and product choice...

I will post pictures of my install currently later today...

Current system

Processor:

- Helix DSP Pro

Front stage:

- Pioneer AVX-4000NEX HU

- ID CTX65 (active)

- Sundown SAX 150.4

Sub stage

- Dual 4 fi Q (fully loaded)

- Box = 2.25 net cu ft tuned to 32hz (baltic birch)

- Sundown SCV-2000d

Electrical (ROCK SOLID VOLTAGE!)

- 250a DC Power alt

- Big 3 w/ 0g OFC

- All 0g OFC run to rear batt and sub amp / 4g to 4 channel

- XS Power D3400 batt up front

- XS Power XP950 in trunk

Questions:

1. Does wiring a sub down to 1 ohm diminish SQ, even when you have plenty of clean power?

2. I want to upgrade my front stage, would you recommend Hertz MLK 1650.3, Hertz HSK 65 XL, ID XS65, or?

3. The fi Q is very peaky and won't hit higher notes, would this be a good sub to use in a 6th order BP?

4. Do you have any design help for 6th order BP in a sedan? I want to blow through, but I don't necessarily want to cut my rear deck apart. Also, what would the chamber volumes have to be for the fi Q for instance?

5. Would a 6th order be good for a SQ/SQL build? Since my front stage isn't 3 way I was thinking a 6th order would help me get rid of the huge dip I have from 50-80hz with my current setup. Also upgrading my front stage will help the mids blend into the sub a little better than my current components.

6. If the fi Q will not suit my needs due to being too peaky (unfixible by 6th order), or if wiring down to 1 ohm isn't proper for a SQ build, or if it's just not good in a 6th order - would you recommend any SQ/SQL woofers? I honestly really like W7's (still) but that would cost me 2 grand to do that as I would need a sub and an amp.

7. Should I go for an IDMAXv4 12" subwoofer or something similar for a 60 / 40 - SQ / SQL application? Other options? Also D4 IDMAX for my full 2k amp on tap or D2 and have 1k on tap at a 2 ohm load. How much losses occur from the amplifier to the subwoofer? Say the amp is rated and delivers 2k watts at 1 ohm load, how much is my sub actually seeing? I suppose the answer to this decides whether or not I would go D2 or D4. Also I've heard some people say the IDMAX can take over 1k and some say it barely takes 1k...

Any help is greatly appreciated!

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[LosIsATool 5,000+ posts]

No it does not diminish anything

Get the best you can afford, for the fact of you wont/cant justify upgrades

The Fi will be fine with the DSP cutting the peaks. Ported will be all you will need. The tune will make or break it

 

[lyons238]

No it does not diminish anythingGet the best you can afford, for the fact of you wont/cant justify upgrades

The Fi will be fine with the DSP cutting the peaks. Ported will be all you will need. The tune will make or break it

The damping of a lower impedance load is more of a myth than anything? Or maybe it has more to do with clean power on tap, in which I have plenty...

I already have a ported enclosure. I'm not happy with it, it's peaky and does not hit above 50hz with any weight. I have a gaping hole from 50-80hz. I was thinking a 6th order BP would help that.

I have yet to install my DSP and tune yet though, I will be doing that soon.

However, I will definitely be upgrading my front stage. I really want to upgrade my sub stage as well, whether that be with getting a more SQ oriented sub, building a 6th order BP for that or my existing fi Q. I feel like the fi Q would be excellent in a 6th order, that way it will hit some high notes too but I don't have any experience with it or the volume that would be needed with each side of the BP box.

 

[LosIsATool 5,000+ posts]

It's a gimmick. And with the DSP you will be able to flatten out and curve the responce. Or it may just be a bad box design

 

[lyons238]

It's a gimmick. And with the DSP you will be able to flatten out and curve the responce. Or it may just be a bad box design

yeah but that wont make my subwoofer have a strong 50-60hz response. it will just weaken my low end. my problem is i want the high end to hit with some authority. i know what strong higher end bass feels like and this does not have it. i had a 15" woofer that honestly played the highs much better while hitting the lows.

the box design is pretty standard. 2.25 net cuft tuned to 32hz. it should be a non issue. also i have spoken to many others who have found the same thing with the fi Q. that its pretty peaky and lacks upper end sub bass authority. i want the 45-60hz bass to cut through me, zinging my head, while i want the low end bass in my chest rattling my core. this fi q does the low end no problem, quite impressive for a single 12 in a trunk. but again, the 50-80hz hole i have in my system is killing me.

which is why i will be upgrading my front stage, and changing something in my sub stage.

how would a t-line box compare instead of the 6th order?

also thank you for your help!

 

[350zspl 10+ year member]

maybe you need a new box tuned to 40

it may be what you are overlooking and the easiest , fastest , cheapest fix , keeping everything else the same equipment wise

i see in your list of all your stuff you did not even mention your box

 

[lyons238]

maybe you need a new box tuned to 40
it may be what you are overlooking and the easiest , fastest , cheapest fix , keeping everything else the same equipment wise

i see in your list of all your stuff you did not even mention your box

yeah i did in the sub stage section...

"- Box = 2.25 net cu ft tuned to 32hz (baltic birch)"

also, i doubt i would like a box tuned to 40hz. i had a 15" tuned to 36hz and that was perfect because it hit lows and highs decent.

40hz on a 12" fi q would totally kill my low end. i dont want to lose any low end, i just want more high end, either with a box design that allows for a larger frequency response, or getting a sub that plays a larger freq response.

the fi Q is more of a one trick pony. this has been discussed by many and i failed to consider it until i realized it myself. dont get me wrong. im sure with some changes i could improve the response, but frankly i dont think it has what im looking for, at least in a single ported box, maybe a t line or a 6th order could transform the response, but as is no.

 

[LosIsATool 5,000+ posts]

Just try it first. And a lot of what you are missing will be helped by the new better mids.

 

[350zspl 10+ year member]

try a box tune of 38

 

[lyons238]

try a box tune of 38

Just try it first. And a lot of what you are missing will be helped by the new better mids.

not keen on building another ported enclosure with a higher tuning. im familiar with what will happen. right now my low end is beautiful. i wouldn't want to lose any low end extension, especially for this particular sub tuning to 38hz just wouldn't be ideal.

as far as components go. would ID's XS series suit my needs as much as say Hertz HSK 65 XL's? I think that's the model anyway, it could be something else. But they are a step down from the MLK 1650.3's but are apparently close.

 

[350zspl 10+ year member]

i have had boxes tuned to 37 that played down to 30 fine

and by giving a bit up on tuning you will gain some mid back

but don't , change your mids to 3 way

 

[LosIsATool 5,000+ posts]

not keen on building another ported enclosure with a higher tuning. im familiar with what will happen. right now my low end is beautiful. i wouldn't want to lose any low end extension, especially for this particular sub tuning to 38hz just wouldn't be ideal.
as far as components go. would ID's XS series suit my needs as much as say Hertz HSK 65 XL's? I think that's the model anyway, it could be something else. But they are a step down from the MLK 1650.3's but are apparently close.

I like my XLs. Had them for years. But the Mille is better. That will bring in the gap. They will play to 63 with the slope starting at 80. Also it will help bring the bass up front.

 

[lyons238]

i have had boxes tuned to 37 that played down to 30 fine
and by giving a bit up on tuning you will gain some mid back

but don't , change your mids to 3 way

I get what you mean but I feel like tuning that high it would be even more peaky and then lack the low end.

I'm in the camp of building a different type of box or changing woofers all together, I'd prefer a larger response range, not to move my response...beating a dead horse at this point.

Also 3 way is tough, that would require more amps, and custom kick panels. possibility but that is more of a long term project.

 

[LosIsATool 5,000+ posts]

Just giving you something to think about. 50hz from a sub will pi$$ you off during tuning. That frequancy will show every rattle in the car and kill up front bass.

Don't look for it, it will come

 

[lyons238]

Just giving you something to think about. 50hz from a sub will pi$$ you off during tuning. That frequancy will show every rattle in the car and kill up front bass. Don't look for it, it will come

I shall see once I receive my Scopemeter (DMM + Oscilloscope) and install my Helix DSP Pro using a UMIK-1 mic + RTA.

However, I can't make my sub play higher without making some bigger changes so im going to have to figure out what i want to do.

I'm really leaning towards trying an IDMAX v4 12" and either running it in my existing box as the specs matchup, or making some type of a T line or a 6th order or maybe even a 4th order. But I have read mixed reviews for BP on a SQ/SQL application, I don't have any personal experience though.