How to Achieve Awesome Mid Bass.

anyway.. components ratings are as low as 30hz and in real life testing when using a test tone CD, it can only perform 125hz and above... so who's trustable and which speakers models?   looking at 6.5" inch speakers.

Who’s trustable is a great point. The most common reason that you will encounter frequency plots that show a 6.5” speaker with strong response at 30hz is that that response shows the typical in car response. And that’s valid, even with an Fs of 65hz. But you must be aware of what you are looking at. With mid bass speakers we are not concerned with its ability to play down to 30hz, we are concerned however with making sure that Fs is below the frequency that we are attempting to accurately reproduce. If the speaker can play down to 30hz but the Fs is at 65hz and the Qts is at .5 (for example) the speaker will not be able to quickly respond to any music in the 30-80hz range. Speakers are the least accurate at or near the resonant frequency (Fs). As Qts gets higher this inaccurate range broadens. This is why low Qts speakers are generally superior. The reality is that most manufactures will either miss print specifications or print specifications from prototypes (not the speaker you buy). And some manufacturers will just flat out lie. It seems though that this is more of a subwoofer problem. Consumers don’t look at the specifications of high frequency speakers, so manufactures don’t even waste their time printing the lies. Also it seems that mid bass speakers don’t suffer the fate of constant reengineering that subs often do. Ever find your self wondering if you sub is a V1 orV2? Or 6 or 9? With a laptop and a multi meter it’s quick and simple to test Fs and Qts your self. This is what I do. If it looks like the printed specifications are pretty close to my results then I assume that the rest (less critical) are also accurate. I have entertained the idea of posting a how to on this subject, but I think it might be a little out of range for most viewers of this site. Let me know if any of you are interested. I just would hate to put a lot of my time into something like that and not have anyone read it.

Great topic and info, I'm trying to figure out speaker placement possibilities in my '92 Accord Sedan. Any suggestions would be greatly appreciated as well as any speaker recommendations,Education, like life is a continuous journey.....

Two way or three way? What is the crossover frequency? If you are using a two way component set with a crossover frequency around 2.5khz (check your speakers documentation) then locating the tweeters in the bottom of the “A” pillars is a good option. If you are using a two way that has a higher crossover frequency (3.5khz or higher) the benefits of placing the tweeters up high is out weighed by the disadvantages of diffusing the human vocal range. In this case you are much better off keeping all drivers in close proximity to each other (tweeters in the kick panels or lower portion of the doors). 92 Accords have great line of sight to both kick panels and an excellent left to right distance ratio. In the event that you have a three way set up with a dome mid then I suggest locating both the mid and the tweeter in the “A” pillar. If you have a cone type midrange then I suggest locating it high and forward in the door (close to the tweeter in the “A” pillar) or in the kick panel with the tweeter also located in the kick. As crossover frequency rises it becomes more critical to physically place drivers in close proximity to each other. Even digital time alignment becomes a less effective tool as frequency rises. Also always consider the dispersion characteristics of your particular speakers. Mount your mid basses in the doors and play with temporary tweeter positions. Pay attention to how your tweeters sound when slightly off axis. Is the sound degraded to an unacceptable level when slightly off axis? Or not? I can provide you with some absolute information on this if you provide me with some additional information. Ultimately though you will have to experiment with some elements. As far as speaker recommendations, the Focal poly glass V2 165 is one of the best car audio two way component sets ever produced specifically for car audio for under $1,000 (they are sold for around $450 at most stores). The tweeters perform well even when aimed 20 degrees off axis and the poly glass mid is one of the best midbass-mid ranges that I have ever encountered.

Thanks, speakermakers, that was very informative. I am looking at a couple different two ways and one or two three ways.  I've thought about possibly doing a dual component set up in the front but I was wondering if that would be overkill or just too tacky to pull off.  That way I can use the kicks and seal off the door panel for a 6 1/2 woofer and still do a tweeter in the "A" pillar to bring my highs up like you suggested (the component set I'm leaning towards has a 2.6kHz crossover frequency).  I don't really have passengers in the back so, I'm thinking how to get some pretty decent midrange there also with little to no freqeuncy  gap between the speakers and subs.  When I'm not beating down the block, I still want a full sound when I'm not playing the subs. Any ideas on that one??Education, like life is a continuous journey.....

Some things to keep in mind. You want to achieve around 2.5khz and up at the “A” pillars as a minimum. Even at this frequency you must still manually manipulate both the amplitude and the phase (incrementally) in order to avoid a very disappointing defused human vocal range (this also covers many popular instruments). Because of this I strongly recommend not even attempting this unless you either have multi-channel/electronic crossover capabilities (ditching the passive crossovers) or you are willing to take a gamble with the odds of success stacked against you. One example of how to do this. In one of my own rides I have 1” tweets in the “A” pillars and 6.5” mids in the doors. I power the mids off an amp but I use the amplifier built into my Eclipse 8455 (CD player) to power the tweeters. This is plenty of power for my tweeters (speaker power requirements decrease exponentially as frequency rises). My Eclipse head unit also has electronic crossovers and digital time alignment built in to it and that makes this an ideal (and economical) arrangement. If you want to use the passive crossovers that come with component sets then I urge you to go with a three way set that contains a dome type midrange. This way you can locate the dome mid in the pillar with the tweet and achieve fairly low frequencies up high on the dash. Of coarse this is also a great way to go with active crossovers as well. Point is that Tweets alone in the “A” pillars is great but requires some finesse. Be prepared. What not to do. Don’t put a 6.5” in a small kick panel with an identical 6.5” in the door. This is begging for phase issues and consequently poor mid bass. Even if they do not share the same pass bands. Don’t use more than 1 pair of tweeters in the front of your setup. This will guarantee harsh comb filtering and no chance of decent sound quality. As far as three way speaker sets with a dome mid go, I recommend the Hertz High-energy three way ($500) or if you have the dough the Zapco comp three way component set ($2,100).

Wow, that's why its good to get a second opinion so , scrap that idea. I was actually considering getting the Eclipse CD5000 myself but I may opt for a Nav. unit and use an outboard processor. The Nav. unit I'm considering is the AVN 6610 but last I checked it didn't offer time alignment.  Since I was thinking in that direction I was trying to see if anyone actually makes an outboard processor that has time alignment capablity. Other than that I'm just weighing my options right now.Education, like life is a continuous journey.....

Last I knew Eclipse offered a nav with great DSP features in their line up, but I am not up to date on this years product. Audio control has great digital processors with time alignment that use RCA in puts and out outs, and Zapco makes a killer piece that can use digital input as well as RCA or balanced inputs. The cool thing about getting a dedicated out board processor is that you are free to pick and choose your headunit and amplifiers. Be aware though that many (most all) video/navigation units have inferior digital to analogue converters and weak pre-amps. This can ruin your best efforts. If you can find a head unit with digital out and you get the Zapco processor you will be able to achieve one of the best possible signal paths, and precision control over every speaker in your system. All adjustments are performed by software on your PC. This gives you a great visual tool. You can actually see in real time what modifications you have made to the signal. This makes things easy to understand. In the time alignment (lower right hand corner) the software even calculates distance for your adjustments, making it a snap! But that’s just one of many great possible options.

Ok, after your last reply I check out AudioControl to see what they offered that would be useful in my application.  I'm thinking that if I go with the DQXS processor.  How do you feel about 6.5" subs?? I've been looking at them and wondering what the possibilites are with those.Education, like life is a continuous journey.....

umm i bet this is a stupid question but how do you add a delay to the left side?