• These commercial threads are for private transactions. diyAudio.com provides these forums for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members, use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

Another project, all digital DDX amplifier

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
In my opinion, the cross talk is very weak and you can even ignore it.
for the sake of information, Troels Gravesen, well recognized in the speaker building community, has done some research on coils placement in crossovers. See this page including bottom comments. He indeed does not recomend this placement.

There is potentially cross talk, but neglictable. The proof is the great sound produced by this amp :)
 
Moderator
Joined 2002
Paid Member
@Uriah - I'm pretty confident this kit is nowhere near Sunfire or REL level and quality of performance (no disrespect to the kit manufacturer!!!) :)

And at the $8000 for two REL subs plus speaker budget, I could arguably find a few combinations that would perform as well as the combination itself. Unless, of course, the room is extremely large and it cannot be pressurised properly without subwoofers!

Sorry once again for the OT posting!
 
Though you're some way along the development, I would put in another vote for a stereo setup instead of a 2.1. Most subwoofers already have a high level crossover which can be used with a stereo setup if required, and (IMHO) the use of a subwoofer in a stereo setup is in itself a compromise, being the domain of PC sound (rather than High fidelity reproduction) systems.

While most subwoofers have an internal low-pass crossover, only a few (more expensive) models also have high-passed outputs that can be connected to a set of main speakers. Most budget subwoofers lack these outputs, since their manufacturers assume you'll be using a DSP or a shelf amplifier to handle the crossover. So the 2.1 functionality is indeed important, particularly for the DIY crowd.
 
While most subwoofers have an internal low-pass crossover, only a few (more expensive) models also have high-passed outputs that can be connected to a set of main speakers. Most budget subwoofers lack these outputs, since their manufacturers assume you'll be using a DSP or a shelf amplifier to handle the crossover. So the 2.1 functionality is indeed important, particularly for the DIY crowd.

Quote, mine only has low pass crossover. So if only one kind of crossover can be set in the kit, i'd like it to be high pass.
There are only 2 kinds of crossovered subwoofers in the market: full crossover (both high pass and low pass), and only low pass.
The subwoofer is needed for many reason, but in my opinion the very first one is to reduce the HUGE distortion of the usual 5 or 6'' woofers of speakers. No high pass can still give all the other advantages, but doesn't have one of the most important features of subwoofers.
 
Though you're some way along the development, I would put in another vote for a stereo setup instead of a 2.1. Most subwoofers already have a high level crossover which can be used with a stereo setup if required, and (IMHO) the use of a subwoofer in a stereo setup is in itself a compromise, being the domain of PC sound (rather than High fidelity reproduction) systems.

And a 5.1, for the HT crowd :) I wonder how you'll get Dolby and DTS decoding into it....

On another note, when are the T3 boards without the power supplies expected to release? As of now the shop only has the single power supply and protection board as a bundle with the T3, but I may be using my own linear supplies - I already have too many transformers and capacitors :) Apologies for going off topic. I do want to explore Class T, after Class D was a wipeout for me :(

Hi, for 5.1 next product, will be Dolby and DTS, and I already do some work.
Please contact Nick for T3, I think your requirement will be fulfilled.
 
for the sake of information, Troels Gravesen, well recognized in the speaker building community, has done some research on coils placement in crossovers. See this page including bottom comments. He indeed does not recomend this placement.

There is potentially cross talk, but neglictable. The proof is the great sound produced by this amp :)

I don't think we can make everything perfect, so some thing may be ignored when it only have very small effect.
For coils, big one (like mH in your link) and without core (like air coils) will have bad cross talk to each other. Large changing flux in the air lead to current on conductor near by... and so on. So if you take a look again at what will happen on our system, you can see that it just has very small effect and can be ignored. Similar placement can be found on some official reference board (RB-TK2050 for example).
 
Moderator
Joined 2002
Paid Member
Excellent, I'll surely be in for an all-digital 5.1 amplifier whenever you're ready to release. Will you be integrating the subwoofer amp on the board itself? Most HT sets have active subs running off a bass management setup (crossover/level/phase) within the amplifier itself, though for complete DIY systems I guess thing could swing any way you wanted (as long as the sub channel has enough power - 200W should cater to a very wide variety of users.

I will get in touch with Nick, thanks for the tip :)
 
remote

At last we make a remote and here it is.
 

Attachments

  • remote.JPG
    remote.JPG
    30.2 KB · Views: 1,276
Nice hifimediy, but be careful you don't clutter the display with too much info. When do you really need to see the Xover frequency? Only when setting it.
In my oppinion it should not be displayed when you are not in "settings" to keep a clean display with only the relevant info.

On another note, is it possible to change the LCD to VFD without much hassle or is a major rework needed (not that you should include VFD in your kit as it is too expensive, but is it possible to swap the LCD for a VFD myself?)
 
Nice hifimediy, but be careful you don't clutter the display with too much info. When do you really need to see the Xover frequency? Only when setting it.
In my oppinion it should not be displayed when you are not in "settings" to keep a clean display with only the relevant info.

On another note, is it possible to change the LCD to VFD without much hassle or is a major rework needed (not that you should include VFD in your kit as it is too expensive, but is it possible to swap the LCD for a VFD myself?)

They need different driver in program, so may be not easy to use both LCD an VFD.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.