| jrtiger |
In another thread I installed some infinity kappa speaker into the front doors a few days ago. Here is the link:
http://www.acuramdx.org/forums/show...&threadid=21733
In this thread I would like to share my install of an Infinity Reference 1042w 10-inch woofer. I had planned to pad the Bose subwoofer with an inline attenuator because it was too much sound level for me and it just walked across the other speakers and it was boomy and rattled on some frequencies. I sometimes got ear fatigue real quick with this setup.
So I took the Bose sub woofer out and when I saw it I decided I wanted to replace it real bad. Rather than order something from the Internet and so I could return it quickly, I when down to Circuit City and purchased the 1042w. It goes for around $70-$100 on the web and at local stores. Here is a brief list of its specifications. 10-inch woofer, dual 4-ohm voice coils, sensitivity 91 dB, power handling 250 Wrms… yea sure. Frequency response 25 – 400 Hz, 2 or 8-ohm, voice coil 2-inches. Mounting depth 4-9/16 inches with a cutout of 9-1/8 inches. If you measure from the speaker mounting wall in the SUV to its interior outer wall on the left side it is 5-inches and then tapers in to a little over 4-inches on the right side. The Infinity fits just fine with dynamat and polyfill and 5/8-inch spacer.
Here is a shot of the two speakers from the front. Bose left, Infinity right. |
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| jrtiger |
| A shot from the back. |
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| jrtiger |
| I measured the DC resistance of the Infinity speaker and it was 3.6 ohms per voice coil. This is not the impedance but at these low frequencies of operation it is probably pretty close. Then I got my first surprise when I measured the Bose and it was 1.0 ohms. Don’t have to have much voltage swing to develop power across a 1-ohm speaker, not a bad design. I removed the Bose sub woofer and connected a 2.2-ohm low inductance power resistor to the output the Bose’s sub woofer amplifier. I know a few people have asked: “Is it full frequency or lowpass?” I am not sure about other model years but the 2004 and most likely the 2005 touring are bandpass filtered. I think probably earlier models may also have filters. I did read that some thought they where full frequency because they could hear midrange signals coming from the woofer. I think I can explain why that is happening. Using a test-tone CD and having all tone controls set flat here is a frequency response plot of the Bose Sub woofer amplifier. You can see from the plot that it is a 2-pole band pass filter centered around 60 Hz. As the frequency increase above the center frequency it attenuates by about 30 dB and then has a bit of shelving and then a secondary peak at 6,000 Hz. Most sub woofer in this range may roll off by 40 dB from their peak to say… 300 Hz so that secondary peak is out to lunch. However at reasonable gain levels you can indeed hear vocals coming from the sub woofer. Given this information and the response curve of the Bose or Infinity sub woofer you really do not need an inline low pass filter. It would not be a good idea to use an 80, 100, or 120 Hz filter because of the compound effect of both filters and this only causes undesirable interaction in the critical passband area. If you really need to add a filter it looks like from this graph and a few to follow that the sweet spot is around 200-250 Hz. This would eliminate the shelving and with a simple 2-pole Butterworth lowpass filter you could send the roll off into the noise floor. But as always whatever floats your boat… I mean SUV. |
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| jrtiger |
| Here are frequency plots of the Infinity and Bose sub woofers. I only tested them in my modified enclosure which means the added polyfill and dynamat. Please note that these plots are limited over one decade from 20 Hz to 200 Hz. The Bose with the 1-ohm resistance is noticeable louder than the Infinity at the same level settings. The speakers have a similar response curve and also follow the amplifiers bandpass filter. The Infinity tracks the amplifier better and has less deviation through the frequency range. There is noticeable peaking around 50 Hz and in fact I found that most mechanical vibrations of both speakers takes place in the 40 to 50 Hz range. The extra padding in the enclosure and the Butyl seal got rid of all noticeable vibration for the Infinity setup. That made me very happy no more rattles at lease on reasonable power levels. Even though the two speakers look somewhat similar on their frequency responses there are a lot of differences! The Bose is definitely louder as mentioned before and it takes two to three clicks on the head unit’s volume control to get equal levels from the Infinity. So if you want boomy, muddy, and loud bass the Bose wins. I think in almost every other area the winner is the Infinity and probably the Polk which I haven’t heard but seen good reviews on this site. I am more than happy to give up some intensity because the low end sounds so much tighter and clearer with the Infinity. Using a glide-tone I didn’t perceive any peaking or resonance with the Infinity, not so with the Bose. I think the Infinity has much better damping and you just don’t get all those extra overtones that were not there in the music to begin with. I think this mod for me was a bigger improvement than the door speakers although they do work as a team. I did crank up the volume and found as an added benefit with the Infinity sub woofer my front seats are now both heated and have a therapeutic vibrator built in at no additional charge. The Bose can do something similar but I could not listen to it for any length of time and both me and my dog were not happy, oh wait I don’t have a dog. I think the only thing that bothers me is why I didn’t do this sooner. Total cost was around $110 for the speaker, $5 for the MDF, $5 for mounting hardware, $4 for polyfill, $20 for dynamat, Misc $6 = $150.00. Again as I mentioned in the other thread an external amplifier would also be a great improvement but I didn’t want to get that involved. I really appreciate all the information I got on this topic from other members and I hope I was able to add some additional information for the group. Again thanks! What follows are the install pictures. |
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| jrtiger |
| This picture shows the template for the mounting spacer/bracket I made from heavy construction paper. It really helped in reducing errors in fabricating the bracket. I decided to use 5/8-inch MDF. |
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| jrtiger |
| I removed the oem batting from inside the enclosure by slowly pulling it off. There was some damping material on the back of the enclosure but I cover it and the surrounding area with dynamat extreme. I think this stuff is over priced because it looks like butyl-rubber and tin foil… oh well. I also applied dynamat to the outer mounting area for the speaker. |
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| jrtiger |
| Here is another shot showing the speaker and wiring connections and you can see I covered the dynamat and then stuffed in about 1/2 lb. of polyfill. I pushed the polyfill down into the area towards the bumper. The speaker’s spacer/bracket is also installed and I sanded it and painted it gray. You can not see it but I used butyl-rubber tape to seal the spacer to the dynamat. More on this later. |
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| jrtiger |
| There are two sets of 5-way binding posts on the Infinity 1042w since it has a dual voice coil. I wired the two 4-ohm voice coils in parallel for an effective 2-ohm load to the sub woofer amplifier. |
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| jrtiger |
| This is a close-up of the speaker’s wiring and shows male spade lugs used to connect to the oem wiring. I got this good idea from another member’s posting on the site. I added heat shrink tubing to seal and insulate the connections. |
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| jrtiger |
| To prevent rattling of the speaker wire, I wrapped and taped the wires and connectors in foam. |
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| jrtiger |
| This is an important step and was done on the backside of the spacer and on the speaker’s rim. I used butyl-rubber tape which is a pliable, tacky adhesive and sealing tape. I have used it in the past and really like if over other methods. I can come back several years later and still pull it off with a bit of work. But it really seals and isolates the vibrations from the speaker to the bracket and from the bracket to the SUV’s body. It got rid of the last rattle and vibration problems for me. The butyl-rubber stays flexible from -40 degrees to +180 degrees F and you can cut it with scissors. It is also inexpensive. If fact when I went to get some today at a local glass store they just gave me six feet for free. Did I mention I like this stuff? |
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| jrtiger |
| This shot shows that the butyl-rubber has sealed the two surfaces when the speaker was tightened down to the spacer. |
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| jrtiger |
| Here is the picture of the final install. I used four beveled head #10-32 x 1.25 inch screws to mount the bracket using the oem clips. I also use eight pan head #8 x 1.25 inch sheet metal screws to fasten the speaker to the bracket. On a couple of these screws I was able to drill into the SUV’s speaker mounting metal to make a stronger and tighter installation. Note: Gray color matches interior quarts color… very important! |
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| eurohazard |
| Another good write up....thanks! |
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| hammermdx |
quote:
Originally posted by eurohazard
Another good write up....thanks!
Ditto, great job! |
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| phins2rt |
jrtiger,
It looks great!!! :29: |
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| jrtiger |
| Thanks everyone. Now that I have done some more subjective listening I am very happy with this modification. I am now scratching up my hands on installing a BlitzSafe and OmniFi hard drive music system. |
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| abm |
Thanks for the great post!
It looks like you are running this from the stock amplifier. This is much simplier and cheaper than building a box.
When you mentioned you drilled into the sheetmetal, I assume that was an interior wall?
Looking forward to your blitzsafe install!
Thanks!:D |
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| Paclark01 |
Your instructions for the subwoofer install were great. Would it be possible to purchase a fabricated sub pacer like yours? I would be willing to pay for it, since I do not have the tools to make one of my own, and I do not have that steady of a hand either when it comes to fabrication.
What do you think? |
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| jrtiger |
Abm,
Yes I am using the stock amplifier and for me it really has sufficient power levels. I read or was told somewhere that for the 2004 touring amplifiers are digital. Not sure which amplifier class and I haven’t measured the power output. I am a bit afraid of doing that because I am not sure how fail safe the amplifiers are and I don’t want to find out.
You are also right that I only drilled into the interior metal speaker mounting plate. Not all of the eight screws caught the metal but I decided to get extra long screws for those holes so that I just added a little extra mounting strength… really didn’t need to because the spacer is really tightly fastened to the mount with the four oem screws. I am so happy that there are no rattles or resonant bumps in this installation!
Have the blitzsafe and omnifi installed and working and I have taken lots of pictures. I will post the pictures when I finish the mounting faceplate for the omnifi controller. I got a lot of good ideas from mdxx3 he did a spectacular job! There are also several other threads on this but I think I have a few extra ideas to share.
Paclark01,
I have had a few private emails about acquiring the spacer. I threw the template that I made away because I really didn’t think I would ever need it again. To make another template I would have to break the butyl-rubber seals… which I don’t want to do. Otherwise I would have made one at least for one other member for free. It takes less than 30 minutes to cut, drill, sand, and paint. There are several other threads that show varying types of spacers that members have made for the MDX. A few have suggested that some car audio shops make spacers for installations and you might check there. Might be expensive having them make you one because of labor but for me the screws, paint and MDF was less than $10.00. Maybe a local community college woodshop student could make you one for part of a summer class project. Sorry I don’t have any other ideas at this time. |
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| Paclark01 |
| No problem. I will take some of the info you provided from these posts... My father in law is pretty handy with tools so I hope he can replicate your excellent work. Thanks for the insight. |
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| perk |
A couple of weeks ago I installed the same Infinity Reference 1042w 10-inch woofer. It works great as long as volume is about 3/4, but when I crank the volume all the way up I notice something alarming. Here is what happens.
Say for example, I'm listening to a normal song with bass and treble. When I have the volume turned above 3/4, everything works fine until the song reaches a point where bass is predominate for some period of time. At the point where bass is predominate in the song, the treble output of the stereo all but dissappears. As soon as the bass segment is over, the treble comes right back. I don't mean that the bass washes over the treble, I mean that the bass removes the stereo's output of treble while the bass is pumping.
It seems to me that the sub is taking away too much power from the Bose amps, so that when bass is required, it sends the limited power available to the sub and has to remove most of the power that would have otherwise been going to treble also. I have the sub wired in parallel so it should be 2 ohms and shouldn't be doing what I'm seeing.
Anyone have any ideas on this? |
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| jrtiger |
Hi perk,
I don’t think I have that problem. I have been sick for a couple of days so I will try and go out to the SUV and see if I can duplicate your problem. I don’t have a wiring diagram so someone on the site can correct me if I am wrong with my following comments. I think that the subwoofer has a separate amplifier near the speaker and I would assume that because it is rated at around 100 watts that it should have its own power wires. I don’t know if there are independent midrange and tweeter amplifiers, (active) or that they are using the same amplifier with passive crossovers. The power requirements to the tweeter should be very low and I would expect you would have midrange problems before tweeter problems. Oh wait isn’t the midrange/tweeter system around 25 watts per channel? I measured the dc resistance of the Bose subwoofer and it was around 1 ohm and therefore even not accounting for the actual impedance of the two subwoofers the Infinity should be demanding less current when you reach voltage clipping compared to the Bose. Thats why even at the same speaker sensitive the Bose is noticeably louder than the Infinity. Ok I just went out and put on some music that in one place has a lot of high frequencies with a very heavy bass line. I cranked it up all the way and it was uncomfortable… see the sacrifices I am making, I am even sick… read looking for sympathy. I then tried it at maybe ¾ level and I hear no change in the treble high frequencies when the bass comes on. Is this the only mod to the sound system you have made? |
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| stlb5.5 |
| so how does it sound? how much airspace would you say is back there? What would a maximum mounting depth be? |
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| perk |
quote:
Originally posted by jrtiger
Hi perk,
I don’t think I have that problem. I have been sick for a couple of days so I will try and go out to the SUV and see if I can duplicate your problem. I don’t have a wiring diagram so someone on the site can correct me if I am wrong with my following comments. I think that the subwoofer has a separate amplifier near the speaker and I would assume that because it is rated at around 100 watts that it should have its own power wires. I don’t know if there are independent midrange and tweeter amplifiers, (active) or that they are using the same amplifier with passive crossovers. The power requirements to the tweeter should be very low and I would expect you would have midrange problems before tweeter problems. Oh wait isn’t the midrange/tweeter system around 25 watts per channel? I measured the dc resistance of the Bose subwoofer and it was around 1 ohm and therefore even not accounting for the actual impedance of the two subwoofers the Infinity should be demanding less current when you reach voltage clipping compared to the Bose. Thats why even at the same speaker sensitive the Bose is noticeably louder than the Infinity. Ok I just went out and put on some music that in one place has a lot of high frequencies with a very heavy bass line. I cranked it up all the way and it was uncomfortable… see the sacrifices I am making, I am even sick… read looking for sympathy. I then tried it at maybe ¾ level and I hear no change in the treble high frequencies when the base comes on. Is this the only mod to the sound system you have made?
Oh well, there must be something wrong with my wiring. I hooked the sub up in parallel by connecting positive speaker wire to red inputs on both ends of subwoofer and negative to black on both ends, i.e., reds hooked together and blacks hooked together on sub.
Remember the problem only arises at about 3/4 volume or louder. I dont notice a thing at lower volumes.
I also replaced all four of the remaining speakers with infinity 6012i reference speakers that are often mentioned on this website. Those speakers are coaxial and have much higher treble output, but nothing should be causing the sympton I describe unless the bass is somehow drawing high-range output away from remainder of system. No other mods. |
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| jrtiger |
| Yup you have the wiring correct and that does put both voice coils in parallel for a resulting 2 ohm resistance. In fact excluding a short, wiring in series or parallel at least to my knowledge should not cause any stress on the amplifier. We are basically putting a lighter load on the subwoofer amplifier than the original Bose speaker was at its 1 ohm resistance. I did turn the amplifier up as loud as it would go with no problems except being way too loud and some distortion. You indicated after a while at that level you noticed the problem and maybe I am not leaving it at the high volume long enough. I only did the test for maybe 30 or 40 seconds. Here is a wild thought! Since you have the entire system turned up loud enough to give the subwoofer enough power for your preferences that is also increasing the level on the midrange/woofers and tweeters. The amplifier may have overload detection and sees these high levels going to a fragile tweeter for an extended period of time and therefore reduces or removes power to the tweeter for protection. When you reduce the level the signal is restored to the tweeter. Obviously if we had a parametric or graphic equalizer we could compensate and with some headroom loss overcome this possible problem. The other possible fix as I mentioned in this thread is to add a subwoofer amplifier with level controls. |
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| Rick_James |
Guys, How can I tell if my X has the Bose system?
It does not say bose, but I know that it has a 6 disk changer on the head unit.
My X is an 2001 w/ navi
BTW... I am wanting to replace my SUB, is it a 10"?? Also if it is a BOSE did you need a modulator to use a different kind of sub in its replacement??
Thanks |
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| Sooner in FL |
quote:
Originally posted by Rick_James
Guys, How can I tell if my X has the Bose system?
It does not say bose, but I know that it has a 6 disk changer on the head unit.
Thanks
Silly Rabbit...all you have to do is to look at your speaker grills and if it has BOSE on it, then you have BOSE speakers.
You can also take the speakers out and look behind it at the magnetic. If it says BOSE, you have BOSE speakers.
Sorry, I could not resist being a smart A$$.
Anyway, the BOSE speakers in the X are weak and Bose to me are just a real great marketing plan that has the vast majority of consumer believing that they rock. Bose does a lot of "cutting" or "removing" certain frequencies. It's not as pure. The best thing you can do is replace all speakers with real nonfactory car speakers. Heck, even Pioneer or even Jensen speakers are better than the factory Acura stock Bose speakers. |
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| Rick_James |
quote:
Originally posted by Sooner in FL
Silly Rabbit...all you have to do is to look at your speaker grills and if it has BOSE on it, then you have BOSE speakers..
Ok.. it does not say bose on the speaker grills or the HU.
See on my TL is says bose on my HU.
Either way the MDX HU sounds like ca-ca. Thanks |
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| Warzau |
| I just got a 1040 W Infiniti Sub. I wanted to do the MDF but then thought back to when I installed the Infinities in the doors. Why not use poly. But where can I get a sheet of it. Im thinking of heading down to the local linens and things hell even ace to pick up a cutting board to fabricate something like the OP did. |
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| Rick_James |
quote:
Originally posted by Rick_James
Ok.. it does not say bose on the speaker grills or the HU.
See on my TL is says bose on my HU.
Either way the MDX HU sounds like ca-ca. Thanks
Opps my BAD. It is BOSE. |
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| Sooner in FL |
quote:
Originally posted by Rick_James
Opps my BAD. It is BOSE.
And it still sound like ca-ca :noshiz: |
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| jrtiger |
Warzau,
I think the 1040 W Infinity Reference speaker may not be a good match for the MDX. I noted that you have the 2002. I am not sure what the amplifier’s output impedance is but in the digital subwoofer amplifier of the 2004 the Bose speaker is a low 1-ohm voice coil. You might want to check the resistance/impedance of your current woofer and see if it is closer to the resistance of your 1040 W which is specified as a single 4-ohm voice coil. I installed the 1042 W which is the same animal except it has dual 4-ohm voice coils that I wired in parallel to get the resistance down to better match for the amplifier. As I stated a couple of time earlier in this threat the Infinity definitely puts out lower bass levels at the same volume level as the Bose albeit at much better sound quality. If you are planning on adding a different power amplifier to match a 4-ohm speaker then never mind and best of luck with your install. |
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| Warzau |
quote:
Originally posted by jrtiger
Warzau,
I think the 1040 W Infinity Reference speaker may not be a good match for the MDX. I noted that you have the 2002. I am not sure what the amplifier’s output impedance is but in the digital subwoofer amplifier of the 2004 the Bose speaker is a low 1-ohm voice coil. You might want to check the resistance/impedance of your current woofer and see if it is closer to the resistance of your 1040 W which is specified as a single 4-ohm voice coil. I installed the 1042 W which is the same animal except it has dual 4-ohm voice coils that I wired in parallel to get the resistance down to better match for the amplifier. As I stated a couple of time earlier in this threat the Infinity definitely puts out lower bass levels at the same volume level as the Bose albeit at much better sound quality. If you are planning on adding a different power amplifier to match a 4-ohm speaker then never mind and best of luck with your install.
I just realized I got the wrong one the second I took it out of the box, only ONE set of binding post,back in the box it went and just am going to CC to pick up the correct one 1042 I guess in my excitement and trying to avoid my wife seeing me purchasing the sub I got the wrong one. Oh well at least Crutchfield has free return shipping. THANKS!! for the heads up. |
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| Rick_James |
quote:
Originally posted by Sooner in FL
And it still sound like ca-ca :noshiz:
Yep, your right about that!! ;) |
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| mdx99 |
| FYI, Circuit City had that infinity 1042W 10" sub for sale, buy one get one free for $99. I got the Polk installed last year. May be some of you want to get the infinity sub. |
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| wal92tt |
| Dumb question but are you able to install the factory sub grill cover back on without it touching the sub? You did not show any pics with it on which is why I ask. |
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| jrtiger |
| Yes the grill fits fine with no problems. |
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