4 replies to this topic

[Blitz]

Hi guys

well im planning to build some small ported box's for a set of 6.5 inch (80watts rms) low mid bass drivers.

now im only wanting this to play down to around 50-60 hz from around 100hz. (not wanting a bandpass box)

what do i need to look out for ? e.g low group delay.

Fs = 43 Hz
Qms = 9.758
Vas = 15.1 l
Qes = 0.471
Re = 3.79 ohms
Qts = 0.449

so far ive come up with a 10 litre box tuned to 59hz with 2 40mm ports

keeping in mind this is not for sub duties and id want tight punch bass in a very small box. am i going about this the right way or should i just stick with a sealed box ?

also having my subs (when i eventually get some after perfecting my frontstage ) will this just sound bad having splits in the doors playing down to 100 hz then a 6.5 inch driver playing 100 hz - 60hz (prolly located infront of seat under the legs) then the subs > 60hz ?

and are 6.5 inch drivers going to be worth it or should i find some 8 inch ones ? (small box size is essential!)

thanks

[Maz]

This could work at bringing the sound stage further forward. However what i would concentrate on would be sound deadening your doors and sealing them real well. Make a good baffle for your current driver and angle it a bit.

That should allow you to cross over the splits a fair bit lower, a good 10-20hz lower and they'll still play loud.

If you can get a steeper crossover slope on your fronts thats always good at increasing there power handling when it comes to midbass. That should bring the bass more upfront

If you want a bit more punch rather than upfront, then maybe up the bass on the headunit and turn the gains down on the subs. That way there is more 100hz bass coming upfront if you want more punch.

Also try changing the phasing of your subs. They might not be in phase around the crossover frequency. There should be a clear difference between one and the other. If there is little difference then the phasing of your subs are 90degrees out of phase instead of 180degrees.

By placing a 400uF 100 volt capacitor on each fron speaker it moves the speaker 90degres out of phase at around 80hz. This will then make one of the phasing louder than the other. Also that will make the crossover slope steaper allowing more bass to be pushed into the speakers before they start to distort.

[Blitz]

thanks maz

i will be sound deadening the doors but i want to try and achieve soemthing really punchy and bring the soundstage forward thats why i was thinking the best way to achieve this would be using a box not in the doors and having something that plays low.

with my current headunit i have the option of 24db-6db slopes and also setting the fronts/rears/subs to HP/BP/LP (Splits/front midbass driver/subs)

not having any subs or a car to do the install into im just planning it at this stage. but it will all happen very soon (within the week if all goes well )

[Bassaholic]

I'd try it sealed first.. If it isn't quite what your after then I'd tune it to around 50hz - maybe higher if your willing to tweak the port length..

[shiny_car]

a sealed enclosure should also optimise the power handling of the drivers which may or may not be important depending on how loud you need to get them to keep up with the remainder of your speakers/sub.

i'd go with bassA's suggestion of trying sealed first. results should be more predicatble.

good luck