GhostMercury
Member
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- MazdaSpeed 3 08.5
as far as i know a LOC is the only way to add aftermarket subs to the BOSE sounds system.
How do we install subs
- Thread starter GhostMercury
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I know it's different because I don't have the bose system. But I was forced to use a LOC. I first tried to use the high level input on my amp but I simply could not get it loud enough even with the level all the way up. Slapped in a LOC and went to the low level input of the amp and it worked like a charmed. So in my case the LOC gave me more adjustability for sure with the level adjustment on the LOC.
Did you not read the messages I just posted previously? jesus man.
Ahh, ok, I understand what your issue is. In that case your sub may still struggle, I have no idea what our freq. response is on the speakers, but the bose sub only hits as low as 120hz which is about as a bad as you can get for a sub.
Your case makes things a bit more complex, but if you want my suggestion you can either scrap the factory HU and get an aftermarket or get the bose HU from someone who is parting out the car or from a mazda retailer.
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I want to replace my stock Bose speakers and sub. I just installed the auxmod and its significantly louder then the cd player so the stockers distort a bit. I would like to retain the stock sub location. Does anyone make a 9inch sub? Will a different size fit?
Oh I'm straight how it is now. I'll probly always keep the stock headunit, eventually replace the door speakers and the two tweeters, my amp is for a sub and it's working well now with the LOC. I wouldn't and couldn't swap to the Bose head unit because it has a low level signal coming out the back for the door speakers with external amps. Atleast that's how all the previous Bose systems I've seen worked.
As for the original post, to hook up subs to a bose system, couldn't you say splice a rca cable into the rear speaker wires and just go straight to the low input on the amp? Seems to me this would work IF there is a seperate amp for each speaker sitting right beside the speaker meaning you be slpicing into an un-amplified signal(As I've seen with previous bose systems) If however the amp under the seat is providing power for all speakers, than this idea would not work and using a LOC would be the easiest thing I can think of. BTW you can easily tap in to the rear speaker wires underneath the big plastic panel where the front seat belts go. The only possible issue I could think of using this method is, is there a x-over filtering out frequencies to the back speakers and where is it? If there is one, hopefully it's in the speaker or amp if there's an amp right by each speaker.
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- 2007 MS3
Some company that likes to make harness adapters needs to come up with one that will plug into the factory harness under the driver's seat. Are you listening PG?
Dynaudio makes some really really nice 8in woofers (they are really more for mid-bass application than a subwoofer). There are others, but generally you will either have to dish out big bucks if you want a large improvement or you will need to do some altercations. This is something I haven't given much though to, so asking someone else may give you different answers
Their is an amp and its under the driver seat. "repeating myself" Every wire going to the amp is a full frequency signal. He could simply splice into ANY of those wires (other than the output ones, hopefully he will be smart and figure it out
). Its very easy, he doesnt need to spend all that money on a LOC, but it seems he already did. Speakers don't have "built in crossovers" all frequency reduction is done at the initial signal, before or after amplification, inside the head unit. aftermarket speakers that come with crossovers are different in that you are getting a different speaker with a different frequency response, therefore you may need to once more crossover the signal.
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- 2007 MS3
This isn't entirely accurate. The Bose system comes with the crossover capacitor mounted to the tweeter. It is fairly common for factory car stereos to use this approach. They use a mid-bass driver that naturally rolls off at a certain point and then stick a cap on the tweeter to make it come in at the correct frequency. The cap also serves as cheap insurance in case someone mods the system by blocking potentially damaging low frequencies.
My understanding is that the Bose system also does its crossover work in the amp, not the H/U.
Aftermarket H/U's that have subwoofer outs will frequently have built in crossovers, though.
Beat me to the punch Mid Life. That's exactly what that cap is you see on speakers sometimes. A type of X-Over! (cap=highpass filter inductor=lowpass filter)
Yes I'm aware of the amp under the seat, my question was "repeating myself" Is there an amp for every speaker and the one under the seat is only for the sub, or does that amp power all the speakers.
Yes I'm aware of the amp under the seat, my question was "repeating myself" Is there an amp for every speaker and the one under the seat is only for the sub, or does that amp power all the speakers.
I never knew about the capacitor thing!! that is cool, I will have to look into that. I understand our signal is full freq. out of our bose HU. I was talking about your average headunit, it was in-reference to the guy without a bose system.
Well if they had speaker wire going to the amp for all the speakers, which I did state, why would they have a second amplifier at the speakers?
I understand how filters work, I simply did not know we used such simple filters as one single capacitor. The damping factor on a signal capacitor in series with a resistor (resistor being speaker) is pretty much as bad as you get. It wouldn't be difficult to make a slightly more complex circuit and have a much better (controlled) cut-off frequency.
But generally, I am glad someone told me about this!
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- 2007 MS3
The speaker is a coil, not a resistor, so its impedance varies with frequency. A single cap is a commonly used 6db crossover. The gradual crossover is deliberate. Remember that the system designers have to account for all possible seating positions that a driver could take. Short, tall, it moves the ears through a wide range of location. By using a gentler slope, there is more of an overlap between tweeter and midbass driver, so it is harder to localize the speaker. This is fine in factory systems, but audiophiles don't like the inherent muddiness of the sound that results, so they end up replacing the speakers with sets that have a crisper slope and can be aimed for their preferred seating position.
Yes, I don't like the muddier sound. And I know what a speaker is, but for circuit consideration (atleast that I have done) they are looked at as resistors. Atleast thats all I have done, I am sorry I don't claim to understand the creation and such of speakers but I don't think I am wrong in saying that capacitor as a x-over is a pretty simple and cheap way to do it, when a much better crossover can be made using multiple circuit elements. if you wanted to know, back when I worked with Cable Tech. (we made wiring harness and circuit boards), we bought a roll of capacitors for practically nothing. each capacitor was a few pennies (I realize we used small ones, which were slightly cheaper). It wouldn't be difficult to make a decent crossover with it.
Considering this is a car, I understand where you are coming from, I notice my sub sounds different depending on were I position my head and were I sit in my car, This is not the case in a room with good acoustics, which were more of my experience is based on. But I will say that I enjoyed this alot, I learned a few new things i didnt know!! I hope the thread creator understands it will be able to get his s*** worked out.
X-over circuits are usually really really simple circuits in general. They're all just caps, inductors and resistors connected a certain way to acheive whatever filter. It's really neat stuff if you research it. Just trying to say 1 cap isn't necessarily the cheap way to do it, it's just all that's needed. I have a couple schematics attached. The first one is real simple. The second one is a lil more complex and includes a notch filter (Passes just a certain range). Neat stuff.
Edit: A thought just came to me from my old electronics courses. The teacher always pushed the idea of K.I.S.S (Keep it simple stupid) Hehe, no pun intended.
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LOL!! you know who used to tell me that? my intro to computer logic teacher, who just happens to be 1 of the 12 who made the first computer. His name is Bill bradly.
You are right in KISS idea, but if you notice "They're all just caps, inductors and resistors connected a certain way to acheive whatever filter" was stated here. You have just named the majority of the parts in a filter, 1 cap. is involved in our filter and just as crisis stated in his previous message, a Cap. is usually used as 6db crossover. So a single capacitor will reduce the signal by 6db. If we look back some, 3db is the half power frequency. so its doing a "decent job."
Unfortunately, as a psych major I learned that our ears have, exactly a +/-15 db range were we wont notice things. So if my tweeter is getting a signal at 5khz and its only supposted to play as low as 6khz and the cap. is reducing the signal by 6db, I will still hear that 5khz signal from the tweeter. that 5khz signal will usually be a much of scratching and s***, which could also dam. the tweeter.
Its just an example.
GhostMercury
Member
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- MazdaSpeed 3 08.5
OK guys this got really confusing. I have installed subs before and have a general idea on how everything works, but I'm still not sure about what the best way to install them would be. I had a LOC installed because in other threads people said it was the only way to do it. But anyone want to simplify what the best way would be
ihadacivicsi
Member
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- Speed 3 (True Red)
There are 2 types of levels you are dealing with, speaker level and line level. The stock HU outputs speaker level. Some amps will ONLY take a line level input. If this is the case, then you must use a LOC to convert the speaker level to line level before connecting the amp.
HU speaker level out -> LOC -> line in of amp
However, some amps will take speaker level or line level input. If you have such an amp you don't need a LOC as you can connect the speaker level output from the HU. Basically, the amp has a built-in LOC.
To make it easy on yourself, I suggest you look for an amp that will take speaker level in. I know Kicker makes some.
HU speaker level out -> LOC -> line in of amp
However, some amps will take speaker level or line level input. If you have such an amp you don't need a LOC as you can connect the speaker level output from the HU. Basically, the amp has a built-in LOC.
To make it easy on yourself, I suggest you look for an amp that will take speaker level in. I know Kicker makes some.
JESUS!!!
He has a BOSE headunit, which OUTPUTS in LINE LEVEL (low level, as in not amplified). he does NOT need a LOC at all. He needs a wire cutter and wire stripper and some wire and either butt connectors with pliers or soder. I am sorry if my message is short, but I am a little inebriated at the moment.
Dont buy anotehr LOC. Just go push your driver seat all the way up. then go to the back seat and check out all the wire going under the black cover. Now check Crisis' wiring diagram and choose a color that states as an INPUT, cut the damn wire and soder that to another wire which on the other end will become an RCA to plug into a LOW LEVEL input for the amp for your sub. This will be a full freq. signal with no crossovers or cutoffs or any of that s*** you normally have to deal with.
He has a BOSE headunit, which OUTPUTS in LINE LEVEL (low level, as in not amplified). he does NOT need a LOC at all. He needs a wire cutter and wire stripper and some wire and either butt connectors with pliers or soder. I am sorry if my message is short, but I am a little inebriated at the moment.
Dont buy anotehr LOC. Just go push your driver seat all the way up. then go to the back seat and check out all the wire going under the black cover. Now check Crisis' wiring diagram and choose a color that states as an INPUT, cut the damn wire and soder that to another wire which on the other end will become an RCA to plug into a LOW LEVEL input for the amp for your sub. This will be a full freq. signal with no crossovers or cutoffs or any of that s*** you normally have to deal with.
