Hey Guys, I hope everyone had a great holiday! Santa was very good to me this year, so I am installing the following into my '68 GS Convertible: A. Secret Audio 2 AM/FM Receiver B. Infinity 7540a 4-Channel amp which will power a set of Infinity 3-way 6 1/2 components installed in the aftermarket kick panels and a pair of 5 1/4 components under the dash (the PO has 5 1/4's custom installed on each corner already) C. Infinity 7520a 2 channel pushing a pair of Infinity 6 X 9 components in boxes on the floor (I don't want to cut the interior if I don't have to). D. Infinity Basslink X powered 10" Sub in the trunk. I will have it all professionally installed, but I want to make sure I know what I am talking about when I go over the installation with my shop. I will have an unobtrusive box/platform built for the amps in the trunk as well as a place to anchor the Basslink. Also, I am expecting to use high quality and properly guaged wires and RCA Jacks throughout the installation. Here are my questions: 1. How do you link 3 amplifiers together? Looking over the equipment I just don't understand how they are made to work in concert with one another. I understand crossovers and filters, but not how to run all at the same time. I also understand how to effectively ground the multiple amps. 2. On the Infinity component systems, how close to the actual speakers do the crossover boxes have to be mounted? Do they need to be cooled? What are the ramifications to mounting them in the trunk with the amps? 3. Any good sites or books that really go into how to build a custom system? I have tried Crutchfield, which gave a lot of good info, but not enough to clearly grasp how it is done. 4. I am considering using a capacitor to make sure the car can handle the extra drain. Good idea? I should say that I am interested in crisp, clear sound and not in slammin' base. Also, I am doubling up on the front speakers in the event that I have more than two people in the car, and I will take out the 6 X 9's and store them in the trunk. Let me know what you all think. Thanks, Gersh
well... I'm not even gonna' try to explain this as there are some really good stereo-tech people on here. (I'm just a semi-tech) HOWEVER.... I would really like your opinon of the Basslink once it's installed. I upgraded my stereo last year to the point where I can enjoy it, BUT I really have an itch for a bit more "thump" but don't want the db. or current drain of a monster amp and a pair of 10's. good luck
Personally... If it was my system, I'd ditch those inline crossovers for one base electronic crossover. You can adjust the frequencies that each set of speakers recieves to taylor the sound to your vehicle (every car is different in the way they "reflect" the sound). That will also let you run everything off of one set of RCA cables comming off the radio. Plus... To me the electronic crossovers actually block better & have better clarity. I switched from inline to electronic in my old car (used to do Sound Comps. in my teen years)... and I couldn't believe the difference. I'll never have anything else. Even in the basic system I have today. But if you stick with the in-line's, I've heard its better to place them as close to the speaker as possible..... But don't really think it'll make a difference in your case. I'd do what's best to keep the wireing clean. Do the secret audio units even have RCA terminals??? With two amps.. It is a must that you upgrade your charging system... Unless you've already put on a higher output ALT. I rember days in my old Comp vehicle... driving at night watching the headlights dim to actually shut off with the beat of the music.... was actually kind of cool. But that didn't last long before I fixed it...lol. A "cap" isn't necessary if your only running one sub off a mild amp. But are allways a "good idea"... just in case the amp needs alittle extra power at times. Infinity speakers are very nice... I've heard some really nice souding systems from them. Good Luck..... It's all fun till your ears start to bleed
Thanks Jeff Jeff, Thanks for the advice. The Secret Audio 2 has 2 sets of RCA outputs as well as a CD Changer Controller/Input (unfortunately it only works with the changer that they sell). I like your idea about using an electric crossover. Makes much more sense to me. However, if I choose to stay with the stock crossovers, how do the amps work together. Are they hooked up to each other? Or do I need another component like the electronic crossover which ties them all together? Thanks again for the input. Gersh
try to keep the inline crossovers within 3 foot of wire from the speaker. if you get too much wire between the crossovers and the speakers, there could be some varience in the overall speaker/wire resistance that might cause a slight shift on the crossover frequency. ...but understand ... this would most likely be a rare instance... but here is another point. if you mount the inline crossovers in the trink, then you will have to run TWICE as many speaker wires to the front ..... so keeping the crossovers near the would have several benifits and mounting them in the trunk will have no sonic advantages. i have seen lots of people omit their inline crossovers for elaborate electronic ones. at first it sounds like a good idea, but there needs to be one major consideration when doing so. if there is no crossover between the amp and speaker, every ampifier turn on or turn off "thump" that will ever happen will go straight to the tweeter which has a limited excursion. some thumps are in the 2-5 hz range that most woofers wont even make a sound from... the woofer can usually handle it with ease because of its longer excursion, but tweeters will soon surrender to it. are all of your front speakers infinitys?
this guy has alot of good info. http://www.installdr.com/ there is a book called "how to design and install high performance car audio" and one called "auto audio". both are good and lack BS. BTW ..if your installer is lacking ideas on how to hook it up ...pack it all back up and find another installer :laugh:
Basically... Amps don't really work "together".... you have one for the subs, mids/high (combo), or for the Mids & highs separatly (like I used). As for the "thump".. Yuk is right you will hear a thump, but that will happen even with the inline's... As long as the amp pushing the speakers doesn't meet or exceed the power handling capabilities of the speakers... you'll be fine. Mi tweeters lasted 2yrs with comps & daily use... still would shatter wine glasses. Most amps are built with a "soft" power on circuit now... so it minimizes (or with my amp... there was none) the "thump"... my sub amp had this technology and that was 8 yrs ago. The electronic crossover will have one set of RCA inputs from your radio... then will have at least 3 seat of RCA outputs to run different frequencies to those specific amps. So there is more RCA wire to route, but not that bad since you're planning to run the speaker wire from the trunk anyway. The only "Inline" I use is the one for my dome Tweets.... the little caps that install in that specific wire. Extra protection for them, plus they don't matter since I usually have the High's cut off at 4K anyway (My inlines are at 2K) basically the only thing the amps share is the power...lol. after that, there on their own. Now if you stick with the Inline's, you'll have to run some kind of RCA splitter so you can deliver input signal to both amps at the same time, unless your amps have a RCA out as well. Starting to miss my big stereo. :ball: 137db of pure pleasure, or annoyance for others...lol. p
...the thump would happen, but the inline would protect the tweeter. the inlines will keep dangerous lows from reaching the tweeters....most in lines are at least a roll off of 12db/oct.... so lets say that an inline has a tweet xover of 3500hz ...... lets say you have an amp that puts out a thump @55hz ...(maybe it will only do it one time caused by something like trying to start the car with the radio/amps on) ... the flux in voltage can make the amp kick create a thump... i would rather have a 55hz sound sent to the tweets that is more than 60db quieter than one that would have no inline protection at all. dont those infinity amps have crossovers built in?
Ok... I got ya now. Was having trouble making the connection...lol. Crossovers at the amp... it could have, Although.... I'd imagine he'd said something about it by now if they did have it. o No:
