Did I buy the right miniDSP?

[TLS Guy]

Im going to have 2 JL audio 12W7AE's and I also have the mini statements for fronts powered by an Acurus amp. I am not running a 2.1 system though I have a 7.1 system... So should I just use the subsonic filter on the miniDSP on the subs and cross over the subs at 80hz LP on the AVR or should I set the LP on the miniDSP instead at 80hz?

With ports that long a 60 Hz crossover to the subs would be better.

 

[DS-21]

Or you can do your own bass management and use chip amps to drive the speakers.

Or any other types of amps. When it comes out, I'll be using the 8x8 in-a-box for LCR mains with a separate amp, and probably keep my current 2x4 in-a-box running Advanced 4-way for subs.

I just think the 2.1 plugin is limited compared to using the bass management in the AVR (which one can do with external amps as well), because it doesn't provide for separate levels/delays/EQ for multiple subs. The Advanced 4-way just is a lot more functional.

Also, one is seldom going to use it to EQ the mains above the modal region, I wouldn't think, so going 2.1 wastes a lot of DSP horsepower. Maybe if the miniDSP had five outputs (allowing active crossovers for biamped mains and sub) that would be different. But it doesn't.

 

[Inertia]

TLSGuy: so are you saying I should use the miniDSP to cross over the subs at 60hz HP and the fronts at 60hz LP? I said I was using the kappa perfect build for these JL's is the port too long at 55"...

DS-21: You are saying to use my AVR to cross over the fronts at 80hz because thats all the lower my AVR will go... And use the mini DSP for my dual subs?

 

[TLS Guy]

TLSGuy: so are you saying I should use the miniDSP to cross over the subs at 60hz HP and the fronts at 60hz LP? I said I was using the kappa perfect build for these JL's is the port too long at 55"...

DS-21: You are saying to use my AVR to cross over the fronts at 80hz because thats all the lower my AVR will go... And use the mini DSP for my dual subs?

The port resonance is 120 Hz, ideally you should be 24 db down at port resonance, so 60 Hz crossover fourth order gets you there. However at 80 Hz you are going to be about 18 db and probably will be just about OK.

If you mains won't tolerate a 60 Hz crossover, go ahead and set it at 80 Hz.

 

[Inertia]

Well the miniDSP will let me set the subs and fronts at 80hz with a LR48. And on top of that I could also set the AVR at 80hz right?

 

[Inertia]

Could someone explain to me what port resonance is?

 

[TLS Guy]

Could someone explain to me what port resonance is?

The port is an open ended flu organ pipe. Pipes open at both ends resonate with a wavelength twice the length of the pipe. There are even second order harmonics at fundamental time2, 4, 6 8, etc in decreasing amplitude in proportion to order.

Resonance Tube

 

[monsterman]

You might look into a change of amps. There are more high power chip amps on the way. It is certainly a good time to be in DIY audio.

Can you expand on this 'high power chip amps on way" topic to me in a PM.
Sorry to almost thread jack.

 

[TLS Guy]

Well the miniDSP will let me set the subs and fronts at 80hz with a LR48. And on top of that I could also set the AVR at 80hz right?

Don't stack the crossovers, let the receiver cross your speakers to Sub and use the mini DSP as the high pass filter, set between 20 and 25 Hz and for any Eq you may require. Do not try and extend the bass of a ported enclosure with Eq, it does not work and is damaging.

 

[Inertia]

I was thinking HPF at 22hz sounded good. And would this work to set the eq's on the subs: Digital Sound Level Meter - RadioShack.com

 

[TLS Guy]

I was thinking HPF at 22hz sounded good. And would this work to set the eq's on the subs: Digital Sound Level Meter - RadioShack.com

I guess you are good to go.

 

[Inertia]

So that SPL meter will work?

 

[lsiberian]

Can you expand on this 'high power chip amps on way" topic to me in a PM.
Sorry to almost thread jack.

T3S 2 x 300W@4ohm sta517b stereo amplifier MUNDORF MCAP input cap | Hifimediy

Is the highest I'm aware of. 300 watts per channel in a Class D is very strong equal to a Bash 300 amp.

 

[TLS Guy]

So that SPL meter will work?

Will it measure sol. yes. Will it be a good guide to set Eq no. Mini DSP is designed to work with REW.

 

[Inertia]

So why did you say I am good to go if that SPL meter wont work well?
What is an REW?

 

[TLS Guy]

So why did you say I am good to go if that SPL meter wont work well?
What is an REW?

An spl meter is what it says it is.

This is REW.

 

[Inertia]

Well I specifically asked for something that would work to set the EQ's on my miniDSP. Thanks for the link to REW! So I download REW and use an SPL meter to work with REW?

 

[TLS Guy]

Well I specifically asked for something that would work to set the EQ's on my miniDSP. Thanks for the link to REW! So I download REW and use an SPL meter to work with REW?

Sorry, I missed that. It is a long complex thread. However they do go into REW and mini DSP on the mini DSP site. So I can be forgiven for assuming you knew about it.

REW is complicated, and you need to put time in studying it. Yes your spl meter I think will connect to the mic input of a computer, if not it will not work.

This would be much better. An spl. meter is still a good thing to have in your tool kit though.

I don't want you to take this the wrong way, but I'm going to give you some friendly advice.

You need to spend more time in research and study.

If you had been one of my students or residents, we would have had a visit in my office after rounds.

 

[DS-21]

DS-21: You are saying to use my AVR to cross over the fronts at 80hz because thats all the lower my AVR will go... And use the mini DSP for my dual subs?

I would. But honestly that's one reason why I only use subs that are good to at least 200Hz. Gives you a lot more flexibility.

T3S 2 x 300W@4ohm sta517b stereo amplifier MUNDORF MCAP input cap | Hifimediy

Is the highest I'm aware of. 300 watts per channel in a Class D is very strong equal to a Bash 300 amp.

Interesting, though one does need a PS and such. Power-wise it's about the same as this IRS2092-based board. Though I don't trust that any of the various amp kit boards are rated accurately.

 

[agarwalro]

To use REW one needs both, an SPL meter and a measurement mic. The meter is used in conjunction with a mic to calibrate the SPL reading as seen by the software/soundcard. Without performing this step, the measurements is void (for absolute level and usable only for relative level measurement).