I am really hoping someone out there can help me out because i am going crazy.I just installed a pair of pioneer tst-110 tweeters to my stock bose deck.I wired them to where i read in another forum to the c1/c2 wire harness that goes to the bose deck. So the left to the brown and yellow wires and the right to the light blue and drk blue wires of the c2 wire harness. That puts me in parallel with the rear speakers.But when i turned the deck back on all was well, until i turned the volume up past half way, then they got REALLY distorted? I have no clue what could be wrong. Hopefully one of you can point me in the right direction.

 

Pioneer TS-T110 7/8" Component Hard Dome Tweeter
7/8" PPTA Hard-Dome Tweeter with Strontium Magnet and Magnetic Fluid Built-in Crossover (-6dB/oct. HPF)
Surface or Flush Mounting Capabilities 120 Watts Max. Music Power (40 Watts Nominal) (with Included Crossover)
Sensitivity (Efficiency): 90dB (1W/1m)
Frequency Response: 2,500 - 30,000Hz
4 ohm Rated
Dimensions: 1-7/8" x 7/8" Mounting Depth: 3/4"

Cheapest Ive found this was $23, so that makes it at least $10 cost.

Not only are you asking too much from it, you're also wiring it incorrectly to a strange impedience load.

So, crappy speaker + wrong impedience = lousey sound.


Sorry.


snoopdan

 

so if you don't mind me asking, what is the right set-up? Atleast, what impedance am i looking for, and what is the correct wiring?

 

No no, all questions are good questions

Im assuming you have a c4, siince you didnt specifiy otherwise. What year is it? The bose amplifiers only put output at 1 ohms, so a 4 ohm speaker would have to work almost 4 times harder to produce the same amount of sound that a 1 ohm speaker would. Im just keeping this simple, there is a bit more to this and all. If you are just hell bent on adding tweeters (which isnt a bad thing at all) you would have to put a small 2 channel amplifier somewhere in the vechile, and then tap off signal from either the speakers, or from behind the head unit (still keeping this simple at this point). The amplifier you would have to use would need to accept line level inputs, or if the amplifier you choose doesnt, you can buy what is called a 'line level converter' (google it if need explantion of this device). This device basically converts head unit amplfied output to a signal that can be piped into the RCA inputs of an amplifier.

Again, there is nothing wrong with what you are asking. Some people will tell you to just dump the bose alltogether and get an aftermarket head unit that will run aftermarket speakers properly. You dont have to do that if you dont want. Some people like the stock stuff - nothing wrong with that.


Help any??

snoopdan

 

Yea, i guess i forgot to specify my car is a C5, 2002, even though that probably doesn't make a big difference. But, yes, your info is a help, unfortunatley, it is also a reality check on what i am going to have to do to rectify my situation. So it is looking like an amp addition is the only way to go at the moment.well i appreciate all the help.

 

I wonder what the sensistivity is on the C5 speakers??? My guess is they might be quite low, say 87db?? If so, the Pioneer 90 db sensivity tweeter will more than likely give up before the Bose speakers will. Also, Pioneer seems to supply a weak crossover. 2500Hz is plenty low for a tweeter and 6 db isn't much of a cut-off. SnoopDan's advice is the best solution for your problem since it will give you the most control over the tweeters, especially if the amp has a built in crossover. One other thing you could try is to add an additional in line crossover. Bass Blockers are cheap, I would recommend a 3500 Hz point. That will make your cut-off point higher and your slope will be also higher (both good things) Good luck

 

Hold on a sec here... the bose amps will drive a 1 ohm load or a 4 ohm load... they don't work any "harder" driving the 4 ohm load.

The difference in the amp design has to do with voltage swing and current capability.

POWER = V^2 / R
so given an output power of 10W
a 1 ohm speaker needs 3.16Vrms
a 4 ohm speaker needs 6.32Vrms

While the power sensitivity of the 1 and 4 ohm speakers may be identical, their voltage sensitivity is not. By adding a 4 ohm tweeter to a 1 ohm system, at a given voltage, the output of the tweeter will be too low relative to the output of the 1 ohm speaker unless the tweeter is drastically more voltage sensitive.

What you're likely hearing is the Bose amplifier clipping or running up to it's maximum voltage limit. As suggested, you need an amplifier with higher voltage swing capability... in other words an amplifier designed for a 4 ohm load.

FYI, Bose chose a 1 ohm system for one reason only: LOW COST. By using 1 ohm speakers, the voltage swing required at the speaker is substantially less. No switching power supply is required to boost the battery voltage. This drastically reduces the cost of the system. The result is a bridged amplifier that can swing the output voltage between ground and the battery voltage.

 

Ok, but you pick and chose what I said. I stated first off "to keep this simple, there is a bit more to this and all". I wasnt trying to write a disseration on how it worked, since the only perosn id be pleasing by doing so would be myself. There is no question that the bose amps will not perform well with his pioneer tweeters, which was the point. I try not to get over technical in explanations, since no one really bothers to understand it anyways. They just want a basic understanding of what works and what doesnt, and how to make it work. Sorry for being a bit layman. The tweeter still isnt effecient anyways, as the capacitor in the circuit is still matched at a cutoff fequency realitive to the drivers particular load. Changing the load level on the amplifier, by adding a tweeter at a mismatched impedience will simply not make an efficent nor well sounding match.

So what am I saying? He still do what I suggested. Buy a little amp if he wants to keep the tweeters, and interface it to the bose system. YAY. Sorry, I was just tying to keep it simple. Everytime I post something with too much information, I feel like no one reads it anyways, and just skips to the chase. And I totally understand anyone who would want to do that....there isnt simply enough time in ones life to read all the applicable material on this site to be 100 percent effective. It already takes me 3 hours to go thru the sections on this particular forum, and im on about 8 others. I figure if someone is REALLY that interested in the specifics, they can buy the Speaker Cookbook


snoopdan

 

First off it takes a far better power supply to drive 1ohm than 4ohms . Earlier amps would overheat and shut down if you ran 2 sets of 4ohm spks paralell at 2ohms nevermind 1ohm . I had some US Amps high current amps @12.5 watt rms $359 retail but w/ a power supply that could go down to 1/4 ohm , what I'm saying is 12.5 watts x 2 @
$359 who in their right mind but this technology is far more costly than a standard 4 ohm system . Lets get off the tech stuff now .

As far as your tweeter problem , Pioneer has never been known for their speakers , but Bose has never been known for high frequency reproduction either (no highs , no lows , gotta be the work of Anwar Bose) . Try putting a capacitor inline on the tweeters pos lead to block the low freq's from reaching the tweeter (it can't reproduce them) . That should smooth out your sound as long nothing else is wrong w/ the system . HOPE THIS HELPS

BTW I have over 20 years experience in mobile electronics ,now I work in high end homes.

 

Uhm, ok. Your suggestion would be great, if the tweeters he has didnt already come with a cap. Maybe they dont supply those sort of things in high end homes


snoopdan

 

Hey , fellas, no beef here. we are all friends . But seriously, i do like to learn and take the time to understand what i am dealing with, so when you get in to the real technical realm of things, i am folllowing. But at the moment, i am looking for the easiest fix possible. If that means changing the speakers, adding an amp, try adding a better cap to eliminate the lows, then i will do what ever. unfortunatley i relied to much on other forum strings that said what i did would work when in reality i should have just asked you guys in the first place.So, much appreciation to all of you.

 

Unfotunately the caps they ship are easily overpowered and allow the low HZ to bleed through and cause distortion , the down side to a higher volt rating cap is that it will eat a bunch of power and could make the tweet volume very low . Tough crossroad . Maybe try to swap out the whole speaker (the older ones are in a tuned box , haven't been in my C5 yet ) w/ a matching size coaxial spk.

 

The caps they ship with are crap . BTW MECP First Class Installer since '92 . But as I'm sure you know everybody does things a little different . In these cases there are more than one to skin a cat or cap !

 

When I read forums, I like to learn things. If I have a chance to share some of my knowledge, I will do that. It's not about proving anyone wrong. I'm a design team manager in the consumer audio industry with blank sheet automotive amp and speaker design experience. I do my best to ensure myths are not spread. I posted here because I read something that was technically not accurate.

I think it's great that people can find answers to their questions in these forums. It's dangerous when some answers contain additional information that is not accurate and can be misleading.

 

That is I recommended the use of the bass blockers. Snoopdans small amp with crossover will do the same plus it will give you control on the level and that is probably the best option. Downside...added cost.

 

Those amps are what, 25 watts at 1 ohm? So probably 6 watts at 4 ohm. So he'd clip the living crap out of the amps trying to get volume out of them, yes?

 

Kale's reply X 1,000,000

snoopdan

 

Those amps are what, 25 watts at 1 ohm? So probably 6 watts at 4 ohm. So he'd clip the living crap out of the amps trying to get volume out of them, yes?


Ok, i understand that the amps would be overloaded and clip, but wouldn't that show up in all the speakers( allbeing tweeters and rears)?i have the tweeters run in parallel with the rear speakers and i only get distortion through the tweeters.

 

thorazineDream.....you connected the speakers to the head unit's rear output? So you are most likely clipping the head unit. Where are the tweeters located? If in the front of the car connect the tweeter to the 3.5" in the front door in parallel. That should work fine and be on the amp side not the head unit side. The impedance should be ok for the amp also. It would not hurt to add a bandpass xover to the 3.5 and a highpass to the tweeter but not neccessary.

 

Distortion by definition is any deviation from the original signal. Harmonic distortion (the HD in a THD spec) refers to deviations that are harmonic in nature. Every signal can be made up by adding various amplitudes of different frequencies (look up Fourier series for more info). The harmonic components of distortion are other frequencies in the distorted signal that are multiples of the original signal. When an amplifier clips, mostly odd ( 3rd,5th,7th,etc) order harmonics are generated. If the fundamental or original signal frequency is 1KHz, the third harmonic is 3Khz, the fifth is 5KHz and so on.

As the amplifier approaches clipping, the distortion is audible from the tweeters first because the high frequencies are “riding on” the low frequencies and is it the high frequencies that “hit” the voltage limit of the amp first.

In a heavy amp clipping scenario where even the low frequencies are clipped, the woofer output does contain higher frequency components but your ear isn’t as sensitive to these frequencies ( look up Fletcher Munson curves for more info). Furthermore, the inductance of the woofer voice coil can be sufficiently large so as to act as a 1st order low pass crossover and reduce the amplitude of the harmonic distortion components.