thomann t.racks DSP 4x4 Mini Review

[Tzibi]

You seem to be correct. If I am not mistaking you can also program delays individually on every output so you can time align the subwoofers.

Yes you can but it has around 10-20ms step in time delay. Not the most accurate but it will do the job pretty fine.

 

[usersky]

Sorry to say, this amplified unit sems to pass all volume fullrange to the loudspeakers the first second its turned on, potentialy destroying the tweeter in an active setup. At least acording to one user at Thomann.

Otherwise it would had been really neat.

Saw that. It was in firnware v1. 02 I believe. Hopefully they fixed the issue, now it is at v1.04. Allow me a week to get the unit and I will report back about this. It doesn't seem so bad to me, since the volume control should be done before the unit, for the tweeters to be abused you need to have the volume at max and loud signal in the first second. Not very likely but a thing to check and account for in such an application.

Edit: the issue is the same for the variant without power amps, same dsp module, same firmware, all the same.

 

[Tangband]

Saw that. It was in firnware v1. 02 I believe. Hopefully they fixed the issue, now it ia at v1.04. Allow me a week to get the unit and I will report the status. It doesnt seem so bad to me, since the volume control should be done before the unit, for the tweeters to be abused you need to have the volume at max and loud signal in the first second. Not very like but a thing one should check and account for in such an application.

I also wonder what class D chip its using. Is it a tpa 3118 or 3116 then the sound will probably be very good.

 

[Tzibi]

From the link I referred to in my previous post in this thread. See pages 25-26 (many pictures so you do not need to know Swedish to understand how it works).

Translates this (which fits with the speaker subwoofers in that listening room / living room):

Measurement up to 1 kHz is sufficient and will be over.

As for the software control, you only need to change Gain, Out1 and Delay.

I expect a system delay of about 2 ms, so you can set Delay to 4 ms (4 + 2 = 6, which corresponds to about 2 meters of runway difference to the speakers), you can enter which values you want even if the steps are rough. Note that the delay is only used to obtain a better integration around the crossover frequency. The system is already shared via the analog filter, so the LP filter in DSP 4x4 does not need to be used.

Under Out1 you set parametric filters, you only need to make changes in the PEQ part.

Finally, make sure to set Gain / Input / InA so that you can certainly not override the device, i.e. the inverse to the maximum eq level (eg -9 dB if the maximum Gain for PEQ is 9 dB).

Press Store on the bar at the bottom when you are done.

faktiskt.io • Visa tråd - Soffsub

Yes you can but it has around 10-20ms step in time delay. Not the most accurate but it will do the job pretty fine.

Disclaimer: last time i did time alignment on this DSP is like a year ago so im not 100% about the delay step. I just remember that i wanted to enter a specific value (ex. 25ms) and it would allow another close value (ex. 32ms) I could check in a few days and let you know for sure.

 

[DanielT]

Disclaimer: last time i did time alignment on this DSP is like a year ago so im not 100% about the delay step. I just remember that i wanted to enter a specific value (ex. 25ms) and it would allow another close value (ex. 32ms) I could check in a few days and let you know for sure.

Thanks , if you feel like researching it. That would be interesting to know.

 

[DrZingo]

Thanks , if you feel like researching it. That would be interesting to know.

In the meantime, a user on the Thomann site has written this:

The granularity of the sliders is unusable with a minimum of 4,688ms (at least for my purposes). 4.688ms corresponds to 1.61m at 344m/s speed of sound, much too much for a precise runtime alignment between woofer and tweeter. I then came up with the fact that you can also type in numerical values for the delay. But you have to find out for yourself which granularity is possible. The field has 3 decimal places (whereby the point must be used as the decimal point, you can't use a comma), so it should theoretically be possible to make entries with an accuracy of 1/1000ms. In fact, the smallest possible value that is accepted is 0.021ms, anything below that is reset to 0.000ms. The next larger accepted values are then 0.042, 0.062, 0.083 etc.
In 0.021ms, sound travels about 7mm, which means that a reasonably accurate runtime compensation between drivers that are not quite the same distance away is already possible.

 

[Tzibi]

In the meantime, a user on the Thomann site has written this:

The granularity of the sliders is unusable with a minimum of 4,688ms (at least for my purposes). 4.688ms corresponds to 1.61m at 344m/s speed of sound, much too much for a precise runtime alignment between woofer and tweeter. I then came up with the fact that you can also type in numerical values for the delay. But you have to find out for yourself which granularity is possible. The field has 3 decimal places (whereby the point must be used as the decimal point, you can't use a comma), so it should theoretically be possible to make entries with an accuracy of 1/1000ms. In fact, the smallest possible value that is accepted is 0.021ms, anything below that is reset to 0.000ms. The next larger accepted values are then 0.042, 0.062, 0.083 etc.
In 0.021ms, sound travels about 7mm, which means that a reasonably accurate runtime compensation between drivers that are not quite the same distance away is already possible.

That sounds legit.

 

[fordiebianco]

Dear All,

I have to profess my ignorance here: I thought DSPs are only of value if you can use them together with room correction software (such as Audyssey or Dirac). What use would a DSP have without responding to the listening room? Is it really just a glorified multi-frequency equalizer?

Could someone explain this to a DSP-simpleton please?

 

[usersky]

Dear All,

I have to profess my ignorance here: I thought DSPs are only of value if you can use them together with room correction software (such as Audyssey or Dirac). What use would a DSP have without responding to the listening room? Is it really just a glorified multi-frequency equalizer?

Could someone explain this to a DSP-simpleton please?

You can measure and compute PEQ filters with REW software (free and very good) and set the filters into DSP. The same for time aligning. If Dirac does some more magic I don't know but peq and timig is probably enogh for very good room correction results.

 

[DSJR]

That sounds legit.

In the meantime, a user on the Thomann site has written this:

The granularity of the sliders is unusable with a minimum of 4,688ms (at least for my purposes). 4.688ms corresponds to 1.61m at 344m/s speed of sound, much too much for a precise runtime alignment between woofer and tweeter. I then came up with the fact that you can also type in numerical values for the delay. But you have to find out for yourself which granularity is possible. The field has 3 decimal places (whereby the point must be used as the decimal point, you can't use a comma), so it should theoretically be possible to make entries with an accuracy of 1/1000ms. In fact, the smallest possible value that is accepted is 0.021ms, anything below that is reset to 0.000ms. The next larger accepted values are then 0.042, 0.062, 0.083 etc.
In 0.021ms, sound travels about 7mm, which means that a reasonably accurate runtime compensation between drivers that are not quite the same distance away is already possible.

Isn't all that a bit anal once you sit 2.5 to 3m away from the speakers?

 

[fordiebianco]

You can measure and compute PEQ filters with REW software (free and very good) and set the filters into DSP. The same for time aligning. If Dirac does some more magic I don't know but peq and timig is probably enogh for very good room correction results.

Many thanks for the response. This sounds like a language I don't speak. Could you please signpost me to a guide on how to understand the concepts (and acronyms).

Ta!

 

[Nango]

Assuming a retailer like Thomas is not the mfr would have been nice to know who the real mfr is.

 

[DrZingo]

Many thanks for the response. This sounds like a language I don't speak. Could you please signpost me to a guide on how to understand the concepts (and acronyms).

The help file seems fairly user-friendly and might be a good place to start?

REW help

REW is free software for measuring and analysing room, loudspeaker and device responses

www.roomeqwizard.com

 

[gfx_1]

I have to profess my ignorance here: I thought DSPs are only of value if you can use them together with room correction software (such as Audyssey or Dirac). What use would a DSP have without responding to the listening room? Is it really just a glorified multi-frequency equalizer?

You can use them with an amplifier as active crossover see picture above in this thread. In DIY speakers you can add a filter for the tweeter and woofer and not having to use passive components like coils, capacitors and resistors.
Also for pro (live stage) audio when there are separate boxes for high mid and low. Feed everthing with it's own amplifier.

 

[heraldo_jones]

Now bring Dirac to this please!

Is a very old product, so don't expect more than what it is. Good thing is that the software has been improved through the time. IMO is good for integrate a sub (or a pair of subs).

 

[PeteL]

Assuming a retailer like Thomas is not the mfr would have been nice to know who the real mfr is.

You are probably correct, but that’s what the OEm market is. Part of what Thomann purchase is licensing and they become the manufacturer. Rarely they would disclose who made them because the whole market would crumble. Your brand is yours. You’d be surprise how many products by Bose, Sony or others that are completely outsourced. These OEM companies are nothing without the Brands, Even if you where told who made this, nobody have heard of them, that’s he Idea. Only some rare time they would disclose if it has marketing value, like NAD using Purifi modules for exemple but that’s exception.

 

[usersky]

You are probably correct, but that’s what the OEm market is. Part of what Thomann purchase is licensing and they become the manufacturer. Rarely they would disclose who made them because the whole market would crumble. Your brand is yours. You’d be surprise how many products by Bose, Sony or others that are completely outsourced. These OEM companies are nothing without the Brands, Even if you where told who made this, nobody have heard of them, that’s he Idea. Only some rare time they would disclose if it has marketing value, like NAD using Purifi modules for exemple but that’s exception.

Have one of you seen elsewehere something so similar that it may actually be/use the same DSP module? I have the feeling that this exclusive to Thomann so the manufacturer will be of little relevance.

 

[PeteL]

Have one of you seen elsewehere something so similar that it may actually be/use the same DSP module? I have the feeling that this exclusive to Thomann so the manufacturer will be of little relevance.

Notthat I’m aware of no.

 

[Tzibi]

Have one of you seen elsewehere something so similar that it may actually be/use the same DSP module? I have the feeling that this exclusive to Thomann so the manufacturer will be of little relevance.

When I bought it, 3 years ago there was nothing close to a balanced 4x4 at this price range.

 

[Jim Shaw]

Looks like a good buy for me. I kind of wish it had at least a couple of presets so I could have different EQs for old recordings and new ones. But for $100 (and it works), it is attractive.

Can anyone explain if/how it can be used directly with REW and a calibrated mic to sort out two subs as well? Or is it the 'finger-typing connection' method?