SI in a car with focal 165k2's

I was thinking of getting two Sonic Impacts, and having each drive it's own side of the 165k2's. The set consists of a 3/4" tweeter and a 6.5" midbass, left and right.

On the datasheet for my speakers, it claims they have a 92db/m sensitivity at 2.8 V/1m. I currently have a soundstream rubicon 502 (125w x 2) powering the components, and I listen to music loudly every once in a while. I am planning on powering the SI's off of my carputer power supply. Do you guys think the SI's will be loud enough in a car environment?

Here is the specs of the 165k2s
 

BWRX

diyAudio Moderator Emeritus
2005-01-17 5:29 am
Pennsylvania
moderate listening level with fairly efficient speakers at HOME! unless your car is not moving or has a LOT of sound deadening material, you have to overcome a rather loud noise floor which means your speakers require more power. 9W/ch at 8ohms can get high sensitivity speakers to more than adequate volume levels in small/medium size rooms. then again, it depends on what you consider an adequate volume level.
 
Well, I purchased one from parts express...I'll be able to tell you guys how it sounds after my finals are over (wed.) or when I get the amp in the mail. Thanks for the opinions, and I am hoping that it will get loud enough. I've been doing a lot of searching and I haven't seen anyone thats hooked them up in a car.... maybe there is a reason behind that. With the sensitivity, what is the difference between them measuring at 2.8v/1m instead of at 1w/1m? Are they doing this so the speakers look more sensitive then they really are?
 

BWRX

diyAudio Moderator Emeritus
2005-01-17 5:29 am
Pennsylvania
nickmig said:
With the sensitivity, what is the difference between them measuring at 2.8v/1m instead of at 1w/1m? Are they doing this so the speakers look more sensitive then they really are?

If you have an 8 ohm speaker, the sensitivity at 2.83V/1m and 1W/1m would be equal. If you have a 4 ohm speaker, the sensitivity at 2V/1m and 1W/1m would be equal. If the speaker is 4 ohms and the sensitivity is quoted at 2.83V/1m then it would be the same as the sensitivity at 2W/1m. Since your speakers are 4 ohm nominal, the 92dB @ 2.83V/1m is a misleading figure. It would be less than 92dB @ 1W/1m, actually more like 89dB @ 1W/1m.
 
The SI will still put 10-15 watts into a 4 ohm driver. You might want to tweak the output caps for a 4 ohm load. You may also wish to biamp the component set if it supports it -- 1 SI for the left and 1 for the right. Unless it's a series x-over, you can probably find a way to biamp the set.

I also think with mods, the SI would probably be on par with the rubicon in terms of SQ..
 
I agree. I would do the standard mods to the SI. Actually, if you don't plan on having it play below 60 hz or so, you can leave the stock input cap in there anyhow. You should probably pull the volume control out of the signal chain.

I think in an active setup, or maybe a biamped one, this would probably provide a decent amount of volume. It probably won't be as loud as your rubicon, but it will still probably be satisfactory.
 

MEXXX

Member
2004-10-04 11:31 pm
I've used a stock SI in a car to power a 6.5" component set with passive crossovers. It was powered from the cars 12v system which was about 14v when the car was running.

I was extremely surprised at how much output I actually got from the setup. I'm sure if you used 2 SI's and bi-amped you would get even better results.
 

BWRX

diyAudio Moderator Emeritus
2005-01-17 5:29 am
Pennsylvania
was this while you were driving the car or while it was standing still? i have a 65Wx2 continuous amp for the components in the front of my car, but it takes quite a bit of volume to reach good listenting levels while driving on the highway. even more so with the windows down. if your car is quiet it might be worth trying out.
 
I got my amp, and put batteries in it, and the light flashes on and off sporatically. I tried plugging in a power adapter, but it might have been too big. 4 of the batteries were brand new (alkaline), 2 just got out of the charger(nimh), and I pulled 2 from my digital camera(nimh). Will the SI still turn on if 2 of the batteries aren't at full voltage?