TOPIC:

I have owned several miniDSP products in the past (4x10hd and SHD Studio) and now I find myself needing a simple 2 way Active Crossover, preferably with Dirac.

My system consists of a preamp with both XLR and RCA outputs. I use the preamp XLR output to the stereo amp to a pair of passively crossed over speakers. I use the preamp's RCA outputs to run a pair of subs with plate amps that have the typical gain, crossover frequency, phase controls. Thus the speakers run full range and the subs use the mftrs (REL) proprietary crossover topology which they will not disclose other than "it isn't the normal 6/12/18 or 24 dB slopes". My room is 28'x16.5'x8' and is a dedicated 2 channel room. One important point is that I am a vinyl junkie.

My goal with the Flex is room correction below 100hz which will likely require the use of PEQs to tame the peaks. A friend and REW user, confirmed I have peaks at 45 and 80hz.

I have a few questions:

1) Will I have issues with the Subs turning the plate amp crossover control to max (120hz) and then using the Flex to control a crossover point below that? I cannot bypass the internal crossover other than to turn it to max.

2) I currently have 2 subs but have been reading about 3 or 4 subs being easier and producing smoother bass in a typical room (Dr Earl Geddes & Dr Floyd Toole). Thus, I may add 2 more subs if I can't seem to tame the room adequately with 2.

2) It appears the website's microphone purchase alone come with a small tripod, but the ordering process for the Flex doesn't specify that the microphone comes with a tripod and gives the separate option to order a tripod. I don't need 2 tripods.

3) I don't think I'd ever need the greater capability of the Flex 8, but would be tempted to get it, if for nothing else than for future expansion but the graphic on the Flex 8 page doesn't show an analog source input.

4) Lastly, maybe question 3 & 4 are one and the same but I imagine the Flex sits in the equipment chain after the preamp and before the amps. And if so, then why wouldn't the Flex 8 accommodate an analog source? Is there something larger here I'm missing about the difference in the Flex and Flex 8???

Thanks for taking the time to help me through this purchase decision.

Paul

1) That shouldn't be a problem.
2a) I've not played with multiple subs so can't advise on that.
2b) The UMIK-1 and UMIK-2 come with a tripod - I assume the separate tripod is for people that have other mics.
3) The Flex 8 doesn't have any analogue inputs. I use mine with all digital sources, so I have dispensed with a preamp and use the Flex as a preamp, but you could of course insert an A to D conversion stage between your pre and the Flex-8. If you don't plan to go fully active (bypass your passive speaker crossovers an d add extra amps) then it may be that the extra channels of the Flex are superfluous. I needed the 8 outputs to run a 3-way active system.
4) Yes, in your system that is where the Flex would sit, and no, you're not missing anything. They left the analogue inputs off the Flex 8 because they ran out of real estate on the back panel, apparently - something had to give. If you run a digital-only front end (see my answer 3 above) that isn't a problem, but if you run a combination of analogue and digital sources then you would need to insert an A->D stage between your pre and the Flex. If you also have digital sources you could feed those directly into the Flex - there's no point in feeding them via the (analogue) pre and then going through an A->D conversion.

I hope that helps...

Thank you Tony. Your responses are great and very much appreciated!

Prior to your comments, I was assuming that because of the analog turntable, I'd need to use my existing preamp, rather than the Flex, but you've got me to thinking, why would I want to convert the digital signal back and forth between digital and analog and back again if I don't have to. Hummmm????

I have a MC cartridge, so I'm thinking that running the analog input directly into the Flex wouldn't work. For that, wouldn't I need the phono preamp (built into my preamp)?

Thanks
Paul

Yes, you would definitely need a phono pre for the output from your MC cartridge, but any digital sources could go straight into the Flex's digital inputs.

I'll just add that honestly the little provided tripod is of very limited use, and realistically you'd need to buy something like the following anyway:

www.amazon.co.uk/gp/product/B00NW7MT5C/r..._title?ie=UTF8&psc=1

This is the one I currently use which is OK but not perfect.

So, being kinda new to analog when using miniDSP products, I guess I really never stopped to think that an analog input from a phono pre to the Flex (or any other miniDSP product with an analog input/output) uses a ADC to get it in a digital format to manage the desired changes and then uses a DAC to create an analog output at the rear of the miniDSP device? Do I have that right?

Champster wrote:

So, being kinda new to analog when using miniDSP products, I guess I really never stopped to think that an analog input from a phono pre to the Flex (or any other miniDSP product with an analog input/output) uses a ADC to get it in a digital format to manage the desired changes and then uses a DAC to create an analog output at the rear of the miniDSP device? Do I have that right?

Correct.

Alrighty then... Thank you guys!

Now I need to think about the pros and cons to having the pure analog signal converted like that and how it would affect the sound...

Champster wrote:

Alrighty then... Thank you guys!

Now I need to think about the pros and cons to having the pure analog signal converted like that and how it would affect the sound...

For a while, before I bought the Flex 8 I was running my 3-way with a DDRC-24 which split the HF signal off direct to the tweeter amp, and the rest was fed into a miniDSP 2X4 Balanced (not the HD) to split the mids and bass signals. That involved an unwanted analogue to digital step between the DDRC-24 and the 2X4, but TBH I didn't notice any untoward effects. Later my audio nervosa got the better of me and I substituted an analogue 2-way active crossover for the 2X4 Balanced, but I can't honestly say that it made a detectable difference.