I am installing my shiny new 20GB unit into my 2001 Maxima SE in the coming weeks. I need some advice from all you pros. I have a set of MB Quart QM 218.61Q seperates for up front. For rear fill I have a set of MB Quart 6x9. I need some subwoofers and amp advice.

I listen to mostly freestyle dance music and electronica. Lots of tight repetitive bass. What would be some subwoofer solutions for my particular set-up and type of music I listen to. I know I want two subwoofers, leaning towards 10's rather than 12's.

In addition, I need to get an amp. I have an older MTX Thunder amp 50x4, but I want to upgrade this also.

One last thing, I have a tuner with my riocar, but I also own an Alpine 7940 CD Tuner Head Unit, with the ERAG320 Equalizer. Will the EQ in the riocar be as good as the Alpine? Should I save the tuner and put in my Alpine equipment?

Thanks to all in advance, this community has been a great place to learn all sorts of new things.

eddie

www.jlaudio.com Simple. So simple.

Bruno

One last thing, I have a tuner with my riocar, but I also own an Alpine 7940 CD Tuner Head Unit, with the ERAG320 Equalizer. Will the EQ in the riocar be as good as the Alpine?

I know nothing about the equalizer on the Alpine, but here are some questions you need to ask yourself:

- Does it have more than ten bands? The Rio Car can have up to have ten bands of correction available.

- Does it allow you to EQ the front and rear speaker separately? Or the left and right speakers separately? The Rio Car allows this.

- Is each of the bands fully parametric? The Rio Car's equalizer is.

- Does it allow you to store 16 separate named equalizer presets? The Rio Car does.

How's the Alpine looking now?


Should I save the tuner and put in my Alpine equipment?

That depends on the car and you. Only if the car has a full double-DIN opening in the dash should you even begin to consider installing the Alpine. If it does, then you need to ask yourself if playing the occasional CD is important to you.

Personally, I bought the empeg because I specifically wanted to be rid of CDs in my car completely. And everyone who has both a Rio Car player and a CD installed always says that the CD just gathers dust. If you choose to leave the Alpine out of the equation, you will not miss it.

Another thing to consider is how gaudy does the Alpine look? You will come to like the smooth lines and clean simplicity of the Rio Car in your dash, and the Alpine unit will look garish and busy next to it.

Let us know what you choose.

JL's look sweet! But there are so may different models...Ugh.

thanks Tony, I appreciate the advice.

eddie

JL has been amazingly good at email in the past. Give them a shout.

Bruno

I want two subwoofers, leaning towards 10's rather than 12's.

This is just personal opinion, YMMV, but I agree with you in this.

With the exception of some astonishingly expensive 12's in a very serious competition car (Est. $60,000 in the stereo system) all of the 12's I have listened to seem dark and boomy, virtually atonal, just thump thump thump.

A good set of 10's on the other hand can actually be melodious, contributing to the warmth and ambience of the system if you are courageous enough to cross them over at a high enough frequency. Again, this is just my opinion and people who know a lot more about stereo than I do will disagree with this, but I have found that running such a high frequency through the subs that they almost certainly are distorting adds a warmth and presence to the sound that I really like -- and quite a few IASCA judges have agreed. I'm guessing that in my car at least (it's a Taurus station wagon) with the subwoofer nearly eight feet behind the listening position, the distortion may be just getting lost in the rest of the sound. Not a purist attitude, I know, but I'm happy with the end result.

Finally, a pair of 10's is a lot easier to fit into the car than a pair of 12's.

tanstaafl.

Great advice...I am defintely looking at getting 10's. I think that for the tight bass I'm in search of, 2 - 10's in a sealed enclosure will give me the best sound. Again, I apprecite the helpful advice.

eddie

2 - 10's in a sealed enclosure will give me the best sound

Will you put both 10's into a common enclosure, or separate them with a sealed bulkhead so they are in separate enclosures (even if it is all one box)?

There are several things to consider about this. If you are going to run the two subs in stereo (that is, one left channel, one right channel) you must separate them, otherwise you will get phase cancellation because they will be playing different signals in the same enclosure.

If you are going to run them bridged mono, then you have a choice. Run them in a common enclosure (this is called acoustic coupling) and you lose efficiency (that is, the maximum decibels you can produce) but you gain lower frequencies because the lowest frequency the speaker can produce is determined not by the size of the speakers, but by the total combined cone area within the enclosure.

There is another school of thought that says it doesn't matter because you are already getting acoustic coupling whether the two speakers are sealed individually or combined in a single enclosure, because they are playing into a sealed enclosure, that is, the cabin of the car.

When I build my ShoWagon stereo, I plan on building the sub box with a divider between the subs that has a port in it that I can open or close and I'll just determine empirically which way I like the best.

tanstaafl.

The reason a lot of car audio 12s sound bad is that their magnet is too weak for that size of cone (manufacturers often save money by using the same magnet/vc assembly for a arange of drivers eg 8", 10", 12" and sometimes 15" all with the same magnet. Generally, the larger sizes of cone will be too massive for the magnet, giving a high Qts, which results in the bad sound.

If you can find a car 12" with a decently low Qts (eg .2 to .35) then you probably won't get the sound quality problems you mention. Actual cone size isn't the issue - its the bad mechanical impedence match between a weak magnet/vc and a large cone.

Cheers, John

With a mono input signal, a panel that divides the cab in half will make no difference (by symmetry, the net force on such a panel would be zero).

Using 2 drivers requires twice the cabinet volume, and will give you twice the efficiency as a single one. The shape of the frequency response shouldn't be affected.

Cheers, John