LS1GTO Forums banner

1 - 20 of 23 Posts

·
Registered
Joined
·
980 Posts
Discussion Starter #1
Has anyone found a good replacement for the stock '7 inch' subs yet?

I have added a JL 12" in the trunk but the stock subs still bottom out occasionally and it sound horrible when they do so. I am torn between replacing them or having them limited.

Just curious to see if anyone has gone this far yet.

My next step is to start replacing the stock speakers starting from the front and moving to the rear with MB Quarts.

_DM
 

·
Si vis pacem, paro bellum
Joined
·
761 Posts
I have a local stereo shop here that believes they can fit a 10" in each 7" location. Now if you want to keep the 7" size. i do believe that MB Quart makes a 7" speaker. my friend had 2 of them put in his Grand Cherokee. they were either the premiums or the q-series, don't remember. But they did sound very good. That would be one option since you are considering a full switch to MB Quart with you other speakers.
Mike
 

·
May I quote you on that?
Joined
·
22,046 Posts
The RWE 202 8" sub looks like a good candidate for deck mounting if it fits. The Qts is .66 with a Fs of 34 Hz which is right in the zone for infinite baffle (deck) loading. I question their recommended Vs of .5 cu ft, as it would give you a high Q bass hump with little deep bass. Good for boom-boom, but not so hot if you're looking for deep bass. I would love to see someone drop in a 10' driver without cutting metal.
 

·
Si vis pacem, paro bellum
Joined
·
761 Posts
phobos- I'm not sure which it was that he got. I haven't seen him in a few weeks, but I'll try to get the info from him.

mistermike- yeah, so would I. These guys are pretty impressive though and have a good history. Most of the Memphis Grizzlies team has gotten there vehicles done there and I've helped them with a few very impressive installs.

mike
 

·
MAX-M6/LS1
Joined
·
223 Posts
Theres no way to get enough air space between the rear deck and the gas tank to install some quality subs, I tried that. Most all subs need at least .5 cuft. air space.. They have the cheap factory speakers installed "Free-Air" which cant be done with just any subs, not any that will put out the sound quality and volume. I think I'll pull out those factory &'s and just let the sound from the sub box in the trunk come through those speaker locations like ports.
 

·
May I quote you on that?
Joined
·
22,046 Posts
04 LS1-MAN said:
Theres no way to get enough air space between the rear deck and the gas tank to install some quality subs, I tried that. Most all subs need at least .5 cuft. air space.. They have the cheap factory speakers installed "Free-Air" which cant be done with just any subs, not any that will put out the sound quality and volume. I think I'll pull out those factory &'s and just let the sound from the sub box in the trunk come through those speaker locations like ports.
The tight spacing between the deck and the tank won't really affect the volume of air "seen" by the speakers, as long as there's a couple of inches of clear space around the woofer basket. The total air volume would theoretically be the entire trunk, but actually it behaves somewhat more like a much larger air volume, due to the numerous air leaks, and the rather high compliance of the body panels. Free-air or infinite baffle loading requires a driver with a Qts in the .5-.7 range. If the goal is maximally flat response, then you want the total "enclosed" Q to be .707, yielding a 2nd order Butterworth alignment. Most extremely high power speakers have too much magnet for this, because the high efficiency is going to park your Qes at a very low number. However, there are 2 ways to overcome this, provided you are willing to trade off efficiency. Put a small amount of resistance in the circuit to raise the Qes, or mass-load the cone to raise the Qms and lower the Fs. Snell did the mass loading trick in the original type A, and got absurdly deep bass out of a 10" driver in a reasonably sized enclosure. Bear in mind, the typical rock or hip hop listener is not looking for deep bass at all, but rather a powerful, high-Q, booming, jukebox bass, so the above excercise in Thiele-Small analysis may not apply.
 

·
MAX-M6/LS1
Joined
·
223 Posts
So your saying use the trunk as the enclosure and not build a box at all.
 

·
May I quote you on that?
Joined
·
22,046 Posts
04 LS1-MAN said:
So your saying use the trunk as the enclosure and not build a box at all.
If you want deep bass at moderate power levels. Your limitations are how much woofer will fit in the deck, plenty if you're willing to cut. If you stay with an 8 in or so woofer, your maximum output will be limited by how much the cones can travel without:
a. producing unacceptable distortion levels
b. physically bottoming out.
Dropping the frequency by half quadruples the required excursion at a given SPL, so depth and power handling are definitely a tradeoff, particularly with a small diameter woofer.
For more punch, and very high output in the 50-100 Hz range, then stick a large woofer in a box, remove the deck subs, and apply plenty of power.
 

·
MAX-M6/LS1
Joined
·
223 Posts
mistermike said:
If you want deep bass at moderate power levels. Your limitations are how much woofer will fit in the deck, plenty if you're willing to cut. If you stay with an 8 in or so woofer, your maximum output will be limited by how much the cones can travel without:
a. producing unacceptable distortion levels
b. physically bottoming out.
Dropping the frequency by half quadruples the required excursion at a given SPL, so depth and power handling are definitely a tradeoff, particularly with a small diameter woofer.
For more punch, and very high output in the 50-100 Hz range, then stick a large woofer in a box, remove the deck subs, and apply plenty of power.
I LIKE THE LAST STATEMENT, "APPLY PLENTY OF POWER", SOUNDS LIKE MY KIND OF SETUP.
 

·
MAX-M6/LS1
Joined
·
223 Posts
I'm planning on pulling out those little sevens and letting the sound get into the cab through those openings. Mount a sub in a fiberglass box mounted on the drivers side of the trunk, connect a amp and run a gain control into the cab to control the sub volume.
 

·
May I quote you on that?
Joined
·
22,046 Posts
I'm not sure if you want to use fiberglass. It's not very rigid. When I build speakers, I use 40 pound or better Corpine. If you're looking for maximum strength to weight ratio, make panels out of 1"styrofoam with 1/4" tempered masonite laminated to both sides. Fitting the panels together into a box is something I haven't tackled yet, but a test board I made out of the styrofoam sandwich was remarkably strong, and light as a feather.
 

·
Registered
Joined
·
163 Posts
Build the "interior" box out of the masonite with butt-joint edges, then cut the styrofoam with mitered edges and laminate to the "inner" box. Then laminate an Outer box to the styrofoam..... should work. Just be sure glue all joints of masonite and predrill/countersink all screws. If you can find an adequate 1.5" router bit, that would probably be the best way to cut the holes. If you want to make it real trick and finish great, then lay glass over the outer box, sand and paint.
 

·
MAX-M6/LS1
Joined
·
223 Posts
Okay, I think I'll try the sandwich trick and then fiberglass the whole thing. Thanks for the input. I'll let you know how it turns out. If anyone is looking for an adjustable line level adapter i found a great one at www.davidnavone.com I bought the N-774v. I think its just what I need to feed the amp I'm installing.
 

·
May I quote you on that?
Joined
·
22,046 Posts
Goatee's suggestion for the corners sounds like the right approach. Be very meticulous there, because the vibration puts the corner joints under a lot of stress. If the fit isn't perfect, you'll get air leaks, buzzes, and eventual structural failure. I would make the actual board the speaker is mounted to out of 2 layers of 3/4" corepine to match the thickness of the other panels. In calculating the internal volume, adhere to the Thiele-small specs for the particular woofer you are using. The volume of air displaced by the backside of the woofer is difficult to measure, if it's not explicitly stated in the specs. It's often better to reverse polarity and mount the woofer magnet side out, and use some sugar poured into the cone to figure the added volume. Using internal dimensions in the ratio of .8x1x1.25 will disperse standing waves ideally. If you're using a small sealed box (acoustic suspension) seek out the woofer with a low Qes which will usually be one with a large, efficient magnet structure. This will give an overdamped (bass rolls off at a higher than desired frequency) alignment, but the response can be corrected with the proper (parametric) equalization, provided there is sufficient excess power available, and the woofer can handle it. Remember, woofer power ratings are meaningless if the amp, even a small one, is overdriven. Sealed boxes are much more forgiving of parameter variations, and small miscalculations, than are vented or bandpass designs.
 

·
Registered
Joined
·
163 Posts
Another thought woud was to build a "frame" out of 1x1 and secure the "inner" box to the frame. That way, you would be able to run adhesive/sealant on the frame prior to running screws down into it to eliminate air leaks and also reinforce all the edges and corners. It would be a major pain in the a$$ to calculate the volume loss and make all the joints perfect, but it may be a better way to go......
 

·
May I quote you on that?
Joined
·
22,046 Posts
goatee said:
Another thought woud was to build a "frame" out of 1x1 and secure the "inner" box to the frame. That way, you would be able to run adhesive/sealant on the frame prior to running screws down into it to eliminate air leaks and also reinforce all the edges and corners. It would be a major pain in the a$$ to calculate the volume loss and make all the joints perfect, but it may be a better way to go......
Excellent idea. I considered some type of corner or edge reinforcement like extruded aluminum angle brackets, but the 1x1 with a channel for the panels sounds like the best idea yet. Probably a lot less grief than mitering tempered masonite, coz that stuff cuts like s**t with a saw. A router makes a nicer edge.
 

·
Mod Hungry... Empty Wallet
Joined
·
2,137 Posts

·
Mod Hungry... Empty Wallet
Joined
·
2,137 Posts
Jodi said:
I'm waiting on a reply as to when they will actually be hitting the shelves.
Jodi... where have you looked? This product says it is a "Select Dealer Product." Select Dealer Products are exclusive products only sold by our Select Dealers. These dealers carry a full-line of Blaupunkt product.

When you use the search feature of the blaupunkt site, increase the milage until you find a dealer with the
pic.

Had you checked with a select dealer already, and is there more to this than meets my search?
 
1 - 20 of 23 Posts
Top