300 watts RMS enough for a sub?
 

I am looking to add a sub woofer to my FRS OEM system...for now. I plan on going with a single 10in in a sealed box, .75cu of space. I've been shopping around online but before I commit and purchase I was hoping some others could chime in. I'm just looking for bass/lows that I can feel/hear well enough without distorting the music or being insanely loud. I'm hoping 300 watts RMS should be enough and if anyone has thoughts on certain products would be great. Been out the sound game for awhile now. Thanks!!

300wrms is plenty for a single sub to compliment music. After hearing my girlfriends 8" 250wrms slimline unit, I struggle to see why you would need anything else.

Depends on several factors, mainly around driver efficiency and enclosure design. Assuming the latter will be optimal for the particular sub, perceived loudness of a sub can vary by a factor of 400% or more with the same power depending on efficiency.

Back in the old days it was all about high efficiency drivers, low xmax and large/ideal enclosures. I've still got some 15" subs which are 94dB efficient, and are only rated at 300W RMS but will be louder than the modern day equivalent which will have maybe 20mm xmax, only 86dB efficienct and burning up 1kw or so.

Bottom line is.. pick a sub and get an appropriate amp for it. Don't under-power a sub and this will most likely lead you down a bad path of clipping and the impending doom of burnt voice coilsl

How can under powering a sub hurt it? People say this, but it makes no sense.

Because such folk tend to run the amp into distortion/clip.

You cant hurt a sub by underpowering it..... as for 300w being enough, yes it should be as long as the sub is rated for that as well. Also make sure the box for the sub is actually correct for it.

A proper tuned ported box is still gonna get more for your money out of 300w tho. But if you want sealed thats fine as well, just dont choke the sub down.

Get a pwk design and those 300 watts will serve you well!

Sent from my SPH-L710 using Tapatalk 2

I always go for sealed box. They always sound much better then even the best ported boxes. Porting just makes the sub make way more noise, at the cost of quality.

A 300W amp for a 300W sub does not make a good match.

BTW, thanks for completely ignoring me about that MiniDSP.

Speakers (voice coil) don't like low frequency square waves with a high amplitude.

I've got about 1200w RMS and I must admit, it sounds DAM good at low volumes where there's a just a hint of bass. 300w RMS is more than enough for this car.

Unless you're a bass head ...so it probably also depends what you're coming from. It's similar to a turbo - car's slow, you want a turbo, you get it, your car feels super fast, then after a while you want MOAR POWER! I like having the extra power there so I can still hear the bass driving on the highway with the windows down.

www.crutchfield.com They are your friends. The heaven of audio.. Call their hotline or chat with them online for any questions. There customer service is amazing, best service I ever dealed with. I can't wait until they update their products to the BRZ/FRS because I still can't find matching audio products that will be vehicle specific.

Brands I like are JL Audio and Rockford Fosgate I feel their products are high quality and look really nice compared to others.

Thanks for the quick responses! I'm currently looking at the following for the box, sub and amp. Anyone got advice as too if this will be a decent setup. I've looked at the specs and everything seems to fall into place. Thanks again!

Sealed box-
http://www.integrityconcepts.net/frs...rder-sale.html

Sub-
http://www.crutchfield.com/p_107DXI1...11#details-tab

Amp-
http://www.crutchfield.com/p_130GMD9...34#details-tab

depends on the sub but most have rms ratings between 250-400rms.

For someone, that has no idea what to get its a good start.

As for the minidsp, I replied back and said it sold.

You have to tune the box to compliment both the car, and the sub. If you were local, Im sure I could change your opinion of ported lol.

As others have said, it depends on a lot of variables. In my last car I ran about 400wrms to an 8" sub, it was plenty for me. If you like lots of low end though, it will depend greatly on box design, driver, etc.

Good box choice

Sub is meh, but for the price a good deal.

Amp I would suggest this instead, just a better amp for better price. http://www.crutchfield.com/p_109GTO5...l#overview-tab

sorry for triple post... apparently multi quote doesn't want to work

300Wrms going to a single 10" sub in a sealed enclosure is plenty in the FRS/BRZ. It is probably bass overkill if you're not planning on upgrading the other speakers in the car. I'm running about 200-300Wrms from a Rockford Punch to a 10" JL sub/sealed-enclosure and it is way more bass than I need with the gain turned up about half-way. The amp is powered by a bridged-channel on the 4-ch RF amp, with the other two channels powering a set of 6.5" components. I think I recently screwed up some power wiring and either f'd up one of the channels on my amp or blew the Sub (either way it was probably my fault). If I were to do it all over, I would try to find a smaller-sized amp (probably about same amount of power) and with a 8" sub that can go into a corner of the trunk (or spring for the integrity concepts enclosure).

Thanks for the actual input aimed towards my question. I looked at the amp you suggested and I agree, much better. As for the Sub, is there another you would recommend? Thanks

Depending on box fitment(I havent looked too in depth at their box yet) and what power you want to run. I would say one of the 2.

http://www.crutchfield.com/p_5751P2D...10.html?tp=111

http://www.crutchfield.com/p_5751P3D...10.html?tp=111

Also budget is a factor between them.


Ok, either will work well in that box. I would say if the p3 is in your budget go with it. Yes, its 500w but if its "too much" sub after tuning it, you can still just turn it down. I just believe its better to have more headroom than needed.

if you are dead set on a 10" sub i would recommend this: https://www.woofersetc.com/p-5806-id...subwoofer.aspx

if you wanted to run an 8" (all the car needs IMO) at 300 watts i would recommend one of 2 subs:
first most expensive but definitely the best 8" i've ever heard: https://www.woofersetc.com/p-4314-21...subwoofer.aspx
or: https://www.woofersetc.com/p-8129-mm...subwoofer.aspx a really decent sub for SQ.

all 3 subs would work well with the JBL amp (you'll have headroom with both 8s) that has been brought up. all 3 of these subs like sealed enclosures .7cu/ft for the 10" and .35ish cu/ft for both of the 8s.

i really could not pick a better amp for the money but, i also would consider: https://www.woofersetc.com/p-7247-ks...amplifier.aspx arc makes great stuff that will be very clean. 310w/rms @ 4 ohms

Now with the sub(s) and amp you suggested would I get some of the "boom" factor. I'm not expecting anything crazy. Just trying to dial in what I want and if I need more power or not. I do plan on upgrading the rest of the speakers and HU in the future.

That depends how you set it up, it has the potential to have good impact with out sounding all woofy tho yes. That will come down to tuning tho. It will sound pretty good on everything else stock tho, just not amazing.

Upgrade your head down the road and tune the whole system will yield better results obviously. Each part of the system plays their role to have it sound awesome. It will be a great starting point in this car and somthing you wont need to change later.

If you are thinking of doing more later tho you can always get the JBL 5 ch instead and have the other channels either waiting or go ahead and use them. then you have one amp for the whole system.

Not necessarily recommending this, but sound dampening the doors, trunk lid, spare tire, & rear license plate area will improve the sound quality you'll get from the sub and door speakers as well. In my opinion, the two 3.5" rear speakers are not worth messing with too much as most of your higher frequencies will come from your 6.5" speakers in the doors and potentially some new tweeters in the dash. The 4-channel amp in 2/1-bridge mode works pretty well IMO (leaving the two rear speakers powered by the head unit).

It's not under powering it that causes the problem, it's driving an amp too far that hurts the sub. With a more powerful amp, as the desire for more volume increases you turn up the volume, the input wave form to the amp gets larger, the output wave form gets larger, and the wave shape stays the same. This is what you want.

But with an "under powered" amp. as the input goes up the output quickly gets to a point where the peaks are as high as the rail voltages and can't go any higher. From that point on as the input amplitude gets higher the output amplitude stays the same, but the wave forms square off. These new corners in the wave happen much too fast for the driver to respond to, so the volume doesn't get any/much higher. BUT, the squared off waveform actually transmits MUCH more power. This power has to be dissipated by the voice coil as heat. This heat can cause the voice coil to overheat, warp, or just expand to the point that it hits the side walls of the magnet. When that happens, you have a blown speaker on your hands. Not because it was under powered, but because it was over powered due to improper use of the amplifier.

The problems is that it's hard to hear when this starts to happen, and even harder to resist the urge to turn the volume up just a little more. I know when I'm setting up a system for someone else that isn't going to touch their own gains, I try to set it so that the sub amp can't get to this point and then level match the other drivers to that. The problem is, that invariably leaves more room to go, but it's safe.

Now, should you spend more money and get the bigger amp? Well, something will always be the weak link in the system and the sub will almost always be the one being punished for that weak link. If you over power the sub with nice smooth wave forms, the voice coil will still fail, BUT you'll be able to reach higher volumes before that happens. Also, many class D amps are more efficient when not run near their limits. Meaning a more powerful amp, say a 1000 watt amp, being used to output 300 watts will be using less power then another amp that's at it's limit to output that same 300 watts. This will put less strain on the cars charging system. My recommendation is to run the larger amp and under use it vice running a smaller amp and possibly over using it.

YMMV

http://www.sounddeadenershowdown.com/


Before anyone sets out to install sound deadening, I HIGHLY recommend taking a look around this site. You can save yourself a ton of time and cash with the info they have.

Totally agree, that site does an excellent job explaining the difference between CLD, CCF, and MLV.

Correct, deadening should be the first thing done in anycar. For 100$ you can pick up 50sf of rattletrap 80mil. Its more than enough to do the key parts of the FR-S. Its a good overall product as well, it doesnt stink, sticks well and no issues hanging upside down in southern summer heat.

That is a good site, but a lot of it is overkill for most vehicles. On average you really just need the 50% surface area of CLD, and some CCF in the doors.

I've got this in my STI, and it'll probably get moved over to the BRZ. It's more than enough for average listeners. I'm into heavy bass and will probably need to get another amp and a 12" to cover the full range of frequencies. Best part of that amp is it's tiny and doesn't get really hot so you can mount it just about anywhere. It'd probably be perfect in the spare tire compartment.

http://amzn.com/B0068XYNH4
http://amzn.com/B004T163PW

Yeah, I only picked up 25 ft^2 of GTMAT Ultra (80 mil) and still have some left over. I did about 50% on the outer skin and 50% of the inner skin in the doors, 50% on the trunk lid, and maybe 30% around the spare tire area. Not quite sure where to put the rest of my GTMAT.... Behind the doors on the car skin next to the rear seats, more underneath the spare, around the wheel well, ?

I just don't want to put much more on the trunk lid cause I'm afraid it'd be too heavy to automatically open at some point. I don't really want to go into the roofline to get any in there. I just want to put it somewhere where it'd make the biggest difference.

Sent from my Nexus 7 using Tapatalk 2

I run 750 to 2 10's and have unlimited (well, never got high enough to damage my eardrums) volume. So you should be fine around there.

Also check Crutchfield.com those guys have TONS of great support.

Rear deck

Interesting, I haven't thought about the rear deck much but I guess it makes sense due to its close proximity with my sub. I should have more then enough for that, what would be the next few areas before doubling up in areas I've done already? (btw, I don't feel I NEED to use it all up especially sense it would save a few more lbs off the car - but want to apply it where it would make a difference).

I would actually put it up top in the headliner, it will make it so much quieter and actually make the temperatures lower. Other then that the rear seat sections will help alot.

Sent from my SPH-L900 using Tapatalk 2