New forum member - mid bass question

[Bret]

I've been in to car audio a long time and I've been pretty happy with a system  I had once, but usually not satisfied. I've only ever used coaxial speakers and am now, maybe, planning on getting in to a 3 way system. My car is a 96 Volvo 960 wagon. I'm contemplating picking up a '92 Cadillac Eldorado, but I've never had a car with a trunk for subs and I'm not sure if I'd be happy with that. I always had wagons, hatchbacks and a '71 landcruiser.

For the most part I've only used Image Dynamics 15" subs. My first system using a first gen. ID 15 I had it crossed over quite low, and was pretty happy with it. My second set I had a pair of later version ID 15's crossed over much higher and thought it sounded terrible except for the very low notes. I've read countless times, in various forums, that 15" subs can play higher bass notes just as well as smaller subs, if you get a quality sub. Not my experience. I had the 15's in a sealed, factory recommended size enclosure. Now I have a pair of Rockford Fosgate 10" punch subs ported with the stock Volvo premium sound system in front. I don't know what the enclosure is tuned to, I just picked up a cheap ported enclosure and switched from sealed a few weeks ago. Having never tried a ported enclosure before, I just wanted to find out if I could even stand it. I'm much happier with the ported enclosure than sealed, to my surprise. With the 15's I had many of the bass notes were hard to differentiate from each other. The 10's play clearly but some of the mid bass notes are ridiculously loud and make my car buzz and rattle, while the low notes are audible but not played with authority. I miss how the 15's, even though less defined, played all the notes closer to the same volume.

So my thinking is either to build a ported enclosure for the 10's and tune it lower, or go back to a 15" sub crossed over on the low side and install a 3 way system in front that uses a good mid bass driver. I'm leaning toward the second option. I don't really know if the 10's would ever play low notes loudly, even in a ported enclosure tuned low. I don't have experience in this. I have sought help from local shops for close to 30 years and have always had them tell me 15's are just no good. I don't agree. I think 15's have their strengths and weaknesses just like everything else, but I'm not an expert, despite having been at this a long time.

So finally getting to my main question. Have any of you used a 5.25" mid bass speaker in a 3 way system? Are they anywhere close to what an 8" can do? I've never even heard a 3 way system in a car before so I don't want to start spending tons of money without some advice. I am willing to make custom door panels and cut up the doors to fit 8" speakers if you all think it would be worth the trouble. The stock door speakers are 5.25".

I guess I have another question. Is a 2-channel amp using passive crossovers too limiting in a 3 way system? I want to try and keep things simple, but I can assume I would probably want to have some control over the volume of each component. I already have a dedicated sub amp.

I listen to a lot of traditional and dancehall reggae, metal with a lot of double bass, rap, techno, and country blues. Most of the trouble I have is with rap and electronic reggae where there are a wide range of bass notes in one song. My current system plays each note at a completely different volume and it drives me crazy.

Thank you for reading all this and thanks in advance for your feedback.

-Bret

 

[Joshdashef]

I'm in no way a professional and this is all my 2 cents.

In saying that I think there's a couple things that could improve your current setup to suit your preferences.

Firstly you say your subs play certain frequencies really loud but then it falls off with lower notes. This is because the ported box is tuned too high, likely 40s, where most people prefer 30s. Another thing to check is your subsonic filter on your amplifier to make sure it isn't robbing your low end from you. 

Another issue you said you were having was some aspects of the system were louder than others and vice versa. If you have a good headunit or a dsp you can apply an eq to balance your sound environment with some pink noise and a rta/mic with a spectrum analyzer I think. Or your headunit may have an auto eq function that could help but not sure if it would produce a quality result.

You said for the most part you have used coaxial speakers so your considering a 3 way setup instead. In my opinion you could go for a 2 way setup instead (components) and there is less to go wrong. Where as the 3 ways require specific conditions to play optimal, a 2 way component setup is fairly straight forward and hard to make sound bad.

Hope this helps you with your rig man,

Cheers

[Bret]

Thanks for your reply, Joshdashef. I figured my box was probably tuned to 40hz or thereabouts. I wish I knew if building a box tuned to 30hz would make me happy, or if it is just asking these little subs to do something they were not designed to do. I'm not going to risk my time and money to find out, I'm just going to go back to a 15". My subsonic filter is turned down to 17hz.

I hear what you are saying about going with a 2 way setup. I'm a little concerned that since I'll be asking the midrange speaker to play down to something like 50hz, with heavy bass music, that it might not be able to do that and play the upper frequencies very accurately at the same time. What is your opinion on this?

As far as the eq, my alpine head unit doesn't have the best. I wish I had a later model with the tunit phone app. I did reduce the levels a bit where the sub was hitting hard and it helped. My amp has a bass boost but I have been advised to avoid this feature.

Thanks for your feedback I appreciate it.

Bret

[Joshdashef]

Yeah box building is a lot of work just to find out whether the box was the issue or the subs were. The 15 sounds great for what your trying to do, it'll play the lows while the midbass will pickup after that. 

If your wanting that low of mid bass then yeah going three way is a better idea, because most two ways can only reach around 80 Hz. If your wanting that low of range for your midbass then your going to need a dedicated driver like an 8 inch shallow sub in the kicks/door paired with a 5.25/6.5" midrange and a tweeter or similar speaker. Plenty doable but with that many crossovers to set I'd recommend getting either a DSP or a tool like SMDs CC-1 to help you finely tune once you set it up. 

Bass boost on amps should never have to be used if the amp itself is properly tuned. I'm pretty sure it introduces some form of distortion into the signal. 

Yeah man, welcome to the forum. If you have questions someone on here usually has answers/opinions on it.