AMGala

iTrader: (4)

I have a question about Ohms. I know some basics of audio but I have a question about source output vs. speaker input and ohms. I have a 2003 TL with the stock Bose system, and I have bought a Kicker RMB8 replacement sub that is rated at 175W RMS, 350W peak, at 4 ohms. I am planning to eventually get a small amp to give the sub some more power, but I was wondering what would happen if I simply swapped subs for now. I think the OEM headunit puts out 100W at 0.5 ohms for the subwoofer. Would it even be worth it for me to just swap out the sub right now? Or should I just wait until I get the amp?

I also bought 4 Polk DB651S slim mount speakers for all 4 doors. They are rated at 55W RMS, 165W peak, at 4 ohms. Again, I think the OEM headunit puts out 100W at 0.5 ohms divided among the four channels. So, I guess I have the same question about these speakers as well. Also, I was reading the A/V FAQ which talked about speaker clipping and the causes and results. This was much debated even in that thread. Should I worry about clipping with the OEM headunit powering the speakers and sub?

Thanks for any help!

AMGala

iTrader: (4)

Here's the full specs of the speakers:

Driver Complement
Mid/Woofer 1 - 6-1/2" Diameter (16.51cm)
Polymer/Mica Composite cone with rubber surround
Tweeter 1 - 3/4" Diameter (1.91cm)
Silk/Polymer composite dome
Electrical
Overall Frequency Response 50Hz-22kHz
Nominal Impedance 4 ohms
Power Handling (continuous) 55 w
Power Handling (peak) 165 w
Efficiency 92 dB
Install Dimensions
Full-range Mounting Depth
Top Mount 2" (5.08cm)
Bottom Mount 2-5/16" (5.87cm)
Grille
Height 1-1/8" (2.86cm)
Cut-out
Driver Cut-out Diameter 5" (12.70cm)

Here's the full specs of the sub:

AMGala

iTrader: (4)

Anybody?

Costco

Its probably not going to sound too good if you run it off of the stock head unit. It runs at 0.5 ohms? Thats weird. Personally I would just get an aftermarket head unit and 4-channel amp to get the most out of the speakers. I'm pretty sure it would clip, especially when coming from 0.5 ohms to 4 ohms

AMGala

iTrader: (4)

OK, I thought I read somewhere it was 0.5 ohms, but now I can't find anything about it, so maybe it's not 0.5 ohms?

feuss2

iTrader: (1)

Have you looked at any of the speakers? They probably say right on them. I recall other threads saying the speakers were 2ohms...

ice2fire11

without getting into ohms law and all that mess

.... as long as you try to stay at or above the recommended ohm load you ll will not damage your amps = sub amp or built in radio amp (factory or aftermarket)

i highly doubt that anything in this car is running at .5 ohms, especially since their is no external amp for the door speakers. i could be wrong, as soon as i picked my tl up, everything was taken out so i dont know what the resistance is on the speakers or the sub is to be honest.

im guessing your not happy with your sound now..... wouldnt blame you. bose sucks.

i usually recommend that you go about it in steps. i would throw an aftermarket amp and sub if your looking for more low end sound. and to be honest free air mounting a larger more powerful sub/amp in the factory location will prolly sound a bit better but at the same time your losing a loooot of potential that amp/sub has. and not to mention possible rattling. throw a small box in the trunk or have one guilt outta glass.

any moderately good speaker will give much more sound and responce and clarity that you are looking for. for some unknown reason they decided to throw shity speakers in these cars. you will most likely gain a tweeter witch will help big time. and if not satisfied with that throw an amp on your door speaker and then dinamat.

throwing an aftermarket deck in there would help for overall control and settings of the equipment and technically better sound but at the same time aftermarket decks in these cars are ugly unless you throw a double din in. imo

hope this helps. let me know if you need more help or have any more questions.

AMGala

iTrader: (4)

Thanks for your advice. I don't really need a high-end system, just something that sounds a bit better. And I often need to use ALL of my trunk space so I don't want a box. I will probably eventually change out the headunit also, but I have been piecing it together slowly. I figured, as long as I have the sub and speakers sitting around here, I might as well put them in.

m733l

iTrader: (1)

i believe it is 2 ohms from the bose system. so if you are sure that the sub output on the bose is 100watts @ 2ohms then if the amp is stable at 4ohms your speaker will see 50 watts. most likely the amp is not stable at 4ohms which means you will not be able to crank it up.

ice2fire11

if the amp is 2 ohm stable - it can withstand a 4 ohm load as well. but like ^^^ said, it will sound half as loud.... not meaning you cant crank it up but you will HAVE to or you wont hear anything. the resistance in a circuit is rated in ohms = if you have a alot of resistance you wont have alot of current. if you have little resistance you will have more current.(easiest way to explain it)


and like i said free air mounting an aftermarket sub with a higher impedance will be a huge waste of time unless you throw another amp on it.

feuss2

iTrader: (1)

If you're going to express dissatisfaction with your audio (or any other) system, it should be directed at the car company. Considering the fact that the OEM's just build what Honda/Acura specifies it is really ignorant to say that a particular OEM sucks! BOSE happens to make some OEM sound systems that sound fantastic in other cars.

I removed some very cheap looking speakers from my TSX that were manufactured by Panasonic. They sell some really excellent products under their own name. There are always going to be different products for different price points that need some differentiation. Similarly, Acura will differentiate between the TSX, TL, RL in terms of features, power, audio systems, etc...

feuss2

iTrader: (1)

It is rare to have a problem with an amp as a result of replacing a speaker with a higher impedance than what was removed. Putting a 4Ω speaker in place of a 2Ω speaker should be fine as far as the amp is concerned, however, the output power of the amp will drop proportionately to the impedance change. If you start with 100W @ 2Ω, then you will see approximately 50W @ 4Ω, 25W @ 8Ω, etc...

This does not mean that the 4Ω speaker will be half as loud as the 2Ω speaker you removed! All other things being equal, the difference would be ~3dB.

Compare the sensitivity ratings of both. Typically, this number represents the sound level the speaker will produce with 1W of power. As a general rule, each time you double the power, it will increase the sound level 3dB. For example:

1W, 89dB
2W, 92dB
4W, 95dB
8W, 98dB
16W, 101dB
32W, 104dB
64W, 107dB *not possible to do based on assumptions above!

If the sensitivity of the BOSE Speaker is 92dB, replacing it with the KICKER will result in a ~6dB drop in sound level.

This particular KICKER speaker is not terribly efficient, nor can it take alot of power.

You would have to find a speaker with the same impedance and a higher sensitivity to make an improvement with just a speaker swap. You could consider something like this:



Infinity REF1220SE. It's a 2Ω 12" speaker with 94dB sensativity and a great review! Without knowing the spec on the OEM speaker, you won't know for sure that this will increase sound level. It is very likely to improve sound quality and frequency response over what you have now, and would require a minimal sacrafice in trunk space. This would be the easiest thing to install (because you can use the existing amp). Next up would be something like the Infinity BassLink or similar...

ice2fire11

GO SCREW!

you just repeated what I said but you thought youd be fancy and use more technical terms, the common person will not understand nor care about your babble - as why i said that it would "sound" half as loud (much easier to understand)

honda uses a few different "brand" speakers. bose, pioneer, and your panosonic's

and yes bose does suck in each and everyway in car audio. home audio they live up to a little bit of thier credit but is extremely over priced.

its funny how i constantly pull bose products out of cars all day everyday due to the sound quality or a parts of thier stupid designs. (ex. common ground)

i will agree with you that the infiniti is a great combo if you are looking for space and sound quality. but you are very limited to what you get with them.

and i also recomended that if he did use the factory location and a new sub. Another amp would most likely be needed. go google so more.

feuss2

iTrader: (1)

The title of this forum is actually “Question about Ohms”! So why would you start of your post with “without going into ohms law and all that mess”.... The OP wants to know about ohms law...

...and what mess are you referring to? It is a simple equation that explains everything perfectly!

As for “sound” half as loud, that is not the case. The relationship between power input to a speaker and perception of loudness is logarithmic, NOT linear. That's why the mention of dB's in the previous discussion. Fact is that “an increase of 10db SPL is perceived to be approximately twice as loud”

Here is a source of that info:

http://trace.wisc.edu/docs/2004-About-dB/

From the same source:

“a gain of 10dB would represent a ratio of ten to one for power - so 10 dB be 10 times the power ”

Without knowing the SPL of the two speakers you're comparing, saying (or even "approximating") that one of twice the impedance will be half as loud as the first is a claim with absolutely no factual basis. This could lead people to the wrong conclusion.

My previous post was an effort to provide information to the OP, who was clearly hear for both an answer to the original question and to learn something.

The product I suggested was a loaded enclosure with great frequency response and efficiency. This could be used with the stock amp to achieve a gain in sound quality and possibly volume, with a minimal sacrifice of [very valued] trunk space. Of course an amp could be added but without the dB discussion it would not be obvious that getting a speaker with and SPL of 3dB higher will have the same effect as doubling the output power. This also explains why not to use the Kicker speaker for this application. It's SPL rating is only 89dB and it's power handling will be exceeded before decent results are achieved....

Limitations on the Infinity? Please explain....

ice2fire11

does this make you feel better.....

im not going to continue to argue with you. the question has been answered long ago. if you choose to keep trying to prove your point that no one really gives 2 shits about, have fun.

hope that didnt offend you so you dont have to send me anymore sissy pm's about your feelings being hurt. i believe i told you what you needed to know in my response to your little pm.



have a good day "google boy" take your "intelligence" and cut and paste somewhere else. i will not respond to your useless comments or pm's anymore and waste my time.

AMgala i hope your question has been answered if not i sure google boy can help you. if you would like a more reasonable answer to you audio/electrical systems in your car feel free to pm me.