Rotary Rasp

iTrader: (2)

This weekend I installed two Infinity Kappa Perfect 10.1 and a Polk Momo 500.1. I still need to make a false floor to cover the amp and I need to make some custom speaker grills or buy some nice ones. I took pictures step by step. Tell me what you think.

Rotary Rasp

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Here you can see how I built the box.

Rotary Rasp

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More about the box. You can also see the line converter I installed.

Rotary Rasp

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The finished boxes and the start of the amp install.

Rotary Rasp

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Test fit of the boxes and amp install. If you look close you can see that the cap, amp, and tire kit are mounted on 1/4" plexi glass.

Rotary Rasp

iTrader: (2)

The finished product! It still needs a little fine tuning but it is almost done. I think I am going to make the sub grills look like rotors. Any ideas on a false floor?

dmp

excellent!! Very slick indeed. I wonder how long before ppl start requesting boxes? :D

Rotary Rasp

iTrader: (2)

FYI- the boxes are 0.61 cubic feet. Infinity recommends 0.6 cubic feet for the Kappa Perfect 10.1

truemagellen

hey RR what is going on with the battery compratment and that switch (I'm assuming sub power...something something)

don't mind me I know LITTLE about car audio

Rotary Rasp

iTrader: (2)

I installed a 40 amp circuit breaker in the battery compratment. I thought it would be better then a fuse because I could reset it for free (rather then replacing fuses)...or just use it as a on/off switch when someone else drives my car.

XeRo

any reason in particular you used 5 ply pine instead of MDF? That's just strange to use plywood...i don't know if i need to go into why here, i don't want to insult your intelligence...i've just been in car stereo for quite some time (13+ years)...

MrWigggles

Grade A plywood is probably the best inexpensive material you can use for box building.

The best strength to weight ratio wood is generally considered to be birch plywood. This is the what is used in the very expensive B&W speakers. It is an excellent choice for a sub enclosure.

Quality plywood is an excellent choice for sub enclosures and from the pictures it appears that Rasp used just that.

-Mr. Wigggles

(Ps. I use MDF myself because it is more workable and cheaper; but that doesn't make it better.)

czr

iTrader: (3)

Looks good... too good... must resist temptation to install aftermarket audio in 8 as I said I would... pain... ahhhh

Rotary Rasp

iTrader: (2)

Yes, I used 6 ply plywood because it is much stronger, however, it is harder to work with. The last box I built I used MDF and i considered it a single use box because once you remove the speakers screws from the wood. Well, you can't really put them back in the same holes... (the wood isn't strong enough). so you have to drill new ones and seal up the old ones. I used 3/4" 6 ply top grade plywood, glue, silicone, and polyfill on this new box. With all the angles the box has...i can say it is real strong.

mr2000x

yo gotta say that does look RUDE, at first i thought the amp was a nitrous bottle, then looked closer and now it looks like a time bomb crossed with a nitrous bottle just kidding but nice fit with the 10's, do they sound any good ?

Rotary Rasp

iTrader: (2)

The subs it hard, hard enough to take the air out of my lungs and make me see things. I am seriously worried about blowing the rear 6x9 speakers because the amount of air the subs push. Is this a potential problem?

XDEEDUBBX

thats a nice install..really clean without sacrifising space..

mr2000x

no i dont think u can blow them just from the air but dont quote me, are they the stock 6x9's?

Rotary Rasp

iTrader: (2)

yes, stock 6x9 bose speakers

mr2000x

i asked a dealer once about changing the stock 6x9's for a pair of alpines, he said they would sound so much better than he stock 6x9's even with the same amp, did u chang the amp for the rest of the system?

Rotary Rasp

iTrader: (2)

No, I havne't touched the bose system. But I want to replace the speakers with Infinity Kappa's. 6x9 in the rear and 6 1/2 in the front. I am worried about destroying the bose amp by hook non-bose speakers to them. If the amps are made to run at 1 or 3 ohms, hooking a 4 ohm speaker may destroy them.

XeRo

You're correct in void free birch ply, and I wasn't stating MDF is better...but comparatively speaking between PINE ply and MDF it IS better...you have more weight, yes, with MDF but you have a more dense box...pine ply is very prone to shattering amonst ply's especially when used as a sub enclosure. Now void free birch if you wanna pay the pretty price for a sheet is by my standards and tastes the best suited and sounds exquisite (sp?) as an enclosure...I have done custom enclosures using birch in several BMW and Mercedes cars, with inset pieces of zebra wood and other exotic woods, stained and high gloss poly to make for 'pimped' out rides and they always sounded better than any MDF box...that's all beside the point, I was just wondering if he might have been led astray on using PINE...that's all..

no biggy..

SlashMatrix

Nice choice. Go with the infinity kappa perfect series components if you are willing to dish out the cash. They are awesome. I'm not sure if they have 6x9s though but it would be something to look into. My brother had kappa perfects all around in his montero sport and 2 12" IKP subs. All i had to say was wow. Almost as loud as my diamon TDX :D But very nice install. You could even mount a PS2 between the subs if they don't hit hard enough to make it skip every 5 seconds. probably will though

Rotary Rasp

iTrader: (2)

I get a huge discount on Infinity products, so i'm installing only their best stuff. But I still need to know if hooking 4 ohm speakers to the Bose amp will hurt them. How many ohms are the Bose speakers, how many watts RMS?

MrWigggles

The rear deck Bose speakers are 2 ohms. 4 ohms should be no problem at all but will play about 3 dB lower in output than the Bose that are already there.

Keep that in mind. Good luck.

-Mr. Wigggles

Rotary Rasp

iTrader: (2)

What is the efficiency of the Bose 6x9's? The Infinity's are 90 dB, so IF the Boses speakers were 87dB, wouldn't that mean they would ultimately equal out to the same out put?

Rotary Rasp

iTrader: (2)

I have another question. As of now I am using a Hi/Lo line converter after the bose amp. Should I replace it with this Soundgate (http://www.logjamelectronics.com/sounlocbosli.html) bose converter since it takes the differental signal before it is amped. Will I notice any difference with subs or is this made for mid range/ tweeters?

MrWigggles

Rotary,

That looks like the best thing to use. Transformers in most line output converters usually create some distortion usually in the sub bass region. How bad is the distortion? That is a tough question. Very few companies spec distortion. Rane makes a quality unit http://www.rane.com/pdf/lt22dat.pdf and you can be sure that it is top notch given their pro audio lineage.

Active converters are rare but are the best way to go and the smartest way to do things. I was actually thinking about making my own if I couldn't find a good aftermarket version. (They are not that difficult to design and are found internally on virtually any amplifier that has speaker level inputs.) The Soundgate unit sounds promissing and I will likely go that route. If it doesn't work well, then I will make my own. One thing I would like to do is create a turn-on lead in the process. If the BOSE is a differential system then there should be a DC offset voltage whenever the system is turned on. That voltage can be amplified to create a 12 volt trigger.

Good luck.

-Mr. Wigggles

Ps. I don't know what the effieciency of the Bose speakers are. My guess is that you will be fine using 4 ohm speakers, but it depends on how much output you are looking at getting from the system.

Rotary Rasp

iTrader: (2)

Thank you Mr. Wiggles. I noticed something on my amp today. I seems that it has the capability of using the low level (RCA) inputs as high level inputs. Look at the switch to the left of the RCA inputs. Would using this better then the line converter I am using now? Is it active? -Thanx

MrWigggles

Rasp,

Yes and no.

Wether you tap into the signals before they reach the Bose amp (line level differential) or after the Bose amp (speaker level differential) the signal is going to be differential. You can not plug either signal directly into your amp in a conventional way.

However, you might be able to hook up the signals in an unconventional way. When you make the RCA cable to go from the Bose amp to the Polk, connect the "L+" and "R+" wires to the center conductors of the RCAs as usual, but DO NOT connect the "L-" and "R-" signals from the Bose to anything. Instead connect normal ground to the shields of the RCA's.

This will work but it may either be noisey or exhibit power on/off thumps when you turn your system on/off.

It is free if you want to try it and give it a shot.

-Mr. Wigggles

Rotary Rasp

iTrader: (2)

wait, are you saying that the high level lines going to the speakers are differential? I didn't know this was possible. Will this cause problems? i know that other people have been burning up their head unit by tapping in before the bose amp. am i going to have this problem? Also what does my line converter have that allows me to tap into the speakers, that my polk amp wouldn't have?

MrWigggles

99% of all speaker level signal from factory radios/amplifiers are differential. This is called a BTL radio and is able to get peak to peak voltages onto the speaker of about 28.8 volts without having to use a transformer. This is why the max rms power you can get out of a radio is almost always 25 watts (i.e. (14.4 volts peak X .707)^2 / 4 ohms = 25 watts rms)

The reason as I see it why people are burning out there headunits is because they are shorting the R- and L- signals together and attaching them to ground. In a balanced system there is voltage on both the positive and negative signals. Shorting them together is the same thing as hooking the output of one cd player into the output of another CD player. You are creating a collision and it is a bad practice. If the equipment isn't fool proof you can short something out real easilly.

In your case you shouldn't have a problem. You are terminating the signals into a high impedance load the preamp inputs of your amp.

-Mr. Wigggles

Rotary Rasp

iTrader: (2)

If differential signals are so clear, why doesn't the aftermarket audio stuff use it?

MrWigggles

Differential leads itself very well to unshielded wires. The noise cancels out. Most factory wiring harnesses use unshielded wires so differential is the way to go.

Shielded wire (i.e. good ol' coax) don't really need to be differential so headunits don't use them. You can easilly get 90dB+ signal to noise with moderate voltage RCA so why bother with the expense of differential?

When you need to go long distance and get 100dB+ differential is the key (i.e. XLR connectors), but for most listening enviroments that is completely uneccessary.

-Mr. Wigggles

Rotary Rasp

iTrader: (2)

Ok, so I have decided to buy the LOCB.2 (http://www.logjamelectronics.com/sounlocbosli.html) because it will give me a flat signal before the bose amp has a chance to equalize it. If anyone has it installed already let us know how it works.

irfan

I built a double box for my subs, but i had to make them face forward (i'll get a pic).. but I love your setup there. I have the exact same speakers but I didnts think they would fit like that. Ive only had this box for 3 weeks but I really want to do your idea now. Would you mind sharing plans and dimensions? I always build with 3/4" MDF so if you ised 3/4" ply then it should work well. I know what you mean about not being able to screw in speakers in the same holes.. and with infinitys tiny lip you cant really get room for tnuts either. I'm going to turn mine and face them backwards and give em a test, if they sound great think id want to try your method. im using a 600W jbl amp

care to share plans?

thanks. my email is 'khan(dot)95-at-osu(dot)edu' --
replace (dot) with a ".", -at- wih @

hopefully spiders wont pick up on that address

irfan

Rotary Rasp

iTrader: (2)

Ok lets see if I can remember off the top of my head. (i'm at work)

The external dimensions are as follows:
Bottom 13 x 12 (13 deep, 12 wide)
Top 9 x 12 (9 deep, 12 wide)
Sides 13 - 9 (60 degree slope on one side) x 12
Front 12 x 12 with a 45 degree cut in one side (Cut measured 3 inches down from top and 3 inches over from top)
Back 12 x 15 (sloped, so its longer)

Total internal volume is aprox .61 cubic feet

I have much better pictures at home, i'll post them later. I have a feeling this is only going to confuse you more.

P.S. My polk amp was tested at 595 watts rms by polk, you got at least 600 with you there. You're going to rattle your muffler baffles like me! I just placed a order for 70 square feet of rattle trap sound deadening (dynamat knock off), I plan on doing the entire car.

irfan

thank you very much... regarding the outboard side, do you still haev the dimensions/angles for the notch you have in the top corner? i see that there are 2 piece involced, a vertical wall and an angled piece, if you have those numbers that would be very helpful.

Rotary Rasp

iTrader: (2)

Today I replaced my line output converter with the Soundgate LOCB.2. I installed it right behind the stereo because this unit it also a line driver. I must say, the results were impressive. The bass is even throughout the entire volume range. Before the bass would be too loud at low volumes. Also it is a much cleaner sound with less distortion and more bass.

MrWigggles

That's good to hear Rasp.

I will be placing mine at the back next to the Bose Amp. I think the noise will still be small.

It is going to be a month before I finish installing my system - the line converter was one thing that was still up in the air.

Thanks,

-Mr. Wigggles