Subwoofer connections & setting-a few queries

[Shashi Kumar]

Hi everybody,

I have had a DefTech Prosub 80 for some time now. Have been reading too. There are still few doubts about the settings to which I seek answers. Deftech has been kind enough not to respond. Please can you help and answer all questions if possible.
1. The LFE line level input bypasses all crossover circuits. Right ?
2. The left and right line level input is subject to the continously variable low pass filter. Right ?
3. The continously variable low pass filter is active on the speaker level inputs also. Right?
4.If the low pass filter setting(40-150 Hz) is higher than the setting(100 Hz) of the fixed high pass filter of the speaker level input, then the high pass filter prevails. That is, if the low pass setting is 120 Hz, the sub is still going to get only 100 Hz, the setting of the fixed high pass filter.Right?

5. The specs link is given below for reference. Incidentally, this specs says the fixed hi pass setting is 80 Hz, whereas, my manual says 100 Hz. Secondly, I have never understood what the unfiltered option for the low pass filter really means. The low pass filter can be varied only between 40to 150 Hz. How can you have the unfiltered option?

Please forgive my dumbness.
Looking forward to a generous help from fellow enthusiasts

http://www.definitivetech.com/loudspeakers/procinema/procinema_80.html#sub

 

[Davemcc]

I believe your #3 is incorrect. Unless I am mistaken on the DefTech, the speaker level connections bypass the crossover and utilize the fixed point for high/low pass.

 

[Shashi Kumar]

Thanks Dave. That makes 4 automatically null & void. Now, only 5 is the mystery. Any takers please?

Shashi

 

[Davemcc]

Unfiltered sounds like disabling the crossover. You would do this if you are using the receiver's crossover because you don't want to use both crossovers at the same time.

 

[MDS]

1. The LFE line level input bypasses all crossover circuits. Right ?

Correct

2. The left and right line level input is subject to the continously variable low pass filter. Right ?

Correct unless the sub is the type that does not have a special input labeled LFE and instead has a switch to enable/disable the internal xover. If the DefTech has a specific LFE input then it is safe to assume that only that input disables the internal xover and the other line-level inputs use the internal xover.

3. The continously variable low pass filter is active on the speaker level inputs also. Right?

Yes and you cannot disable the internal xover when using speaker level inputs. If you were using speaker level inputs then you'd also be using the speaker level outputs to go to the front speakers and need the sub's internal xover to filter out the lows before sending the rest on to the front speakers.

4.If the low pass filter setting(40-150 Hz) is higher than the setting(100 Hz) of the fixed high pass filter of the speaker level input, then the high pass filter prevails. That is, if the low pass setting is 120 Hz, the sub is still going to get only 100 Hz, the setting of the fixed high pass filter.Right?

No. The low pass filter 'let's the lows pass'; ie it determines what frequencies the sub keeps to play itself. The high pass filter determines which frequencies the speakers connected to the sub's speaker outputs will see.

5. The specs link is given below for reference. Incidentally, this specs says the fixed hi pass setting is 80 Hz, whereas, my manual says 100 Hz. Secondly, I have never understood what the unfiltered option for the low pass filter really means. The low pass filter can be varied only between 40to 150 Hz. How can you have the unfiltered option?

I agree with Dave that unfiltered simply means bypass the internal xover. That would be the default case if you use the LFE input.

Please forgive my dumbness.

These are not dumb questions at all. This stuff can be confusing until you learn how all the options work together.

 

[Davemcc]

This stuff can be confusing until you learn how all the options work together.

No kidding. I searched all over for the answer and still got it wrong.

 

[Shashi Kumar]

Thank you very much ,MDS & Dave - for the effort and for the answers.

Q4 is still not clear. For the part between 100 and 120, the low pass should let the sub keep anything below 120, and the hi pass wont let it keep anything above 100. So what happens to the poor fellas between 100 and 120?

shashi

 

[AVRat]

You actually have those frequencies overlapping, no gap.

 

[Shashi Kumar]

I think I am finally getting the hang of it. Thanks folks.

It appears there are two, more or less independent, paths from the speaker level input terminals. One goes through the hi pass filter to the speaker level output terminal of the sub and from there on to the connected main speakers. The other goes through the low pass filter to the sub amp and there on to the sub driver. This may not be the exact detail, but it must be approximately true.

The frequencies in between 100 and 120 are played both by the sub and the connected main speakers, but attenuated according to the characteristics of the filters in their respective paths. This is what I suppose AVR's figure represents.

Thank you

 

[OttoMatic]

Hi there,

For definitive answers on DT products, I have had excellent luck in contacting them directly through their website. Chet's the man over there, and he will give you direct, accurate answers to all your questions about their products. I'm not saying that the answers provided here are wrong, but for the straight dope, as particularly applied to their products, sometimes it's best to go to the source. I had DT BP2002TLs at one time, and the litany of connections is not necessarily terribly intuitive. Flexible, yes, but not intuitive.

Good luck!

 

[Imureh]

how difficult is it?

I have been thinking about buying a HSU sub and speakers for a while. However after reading this and some other threads it appears to me that the process of setting up the system correctly is quite technical, and for a person like me how has never owned a HT system all this jargon is souding overwhelming. Do the subs etc come with instructions on how to set it up or would you recommend that I get some one who knows about the st up to do it for me? Do you know any stores that would set up the system for me for a fee even though the system may not be purchased from them?

Thanks

 

[avaserfi]

While it may be slightly technical it is nothing that can't be done with a little work and reading. There is no real reason to pay someone to set up your HT just because you are worried. Just do the proper research and it won't be hard, everyone has to start somewhere.

Check out the tips and tricks section on the main page that will help a lot.

 

[ParadigmDawg]

Yep; you can do a basic cal and it will be fine and easy or you can make it really complicated if you so wish.

 

[Shashi Kumar]

Hi ottomatic,

I did email to deftech. I sent a mail through my yahoo account to info@definitivetech.com, but they did not respond. If you click on the link on their web site its the same thing is it not? Link is given below for verification. If there is some other way then please let me know. I suppose there is nothing wrong with confirming what has been arrived at from this very enlightening discussion.

http://www.definitivetech.com/contact/contact.html

 

[Shashi Kumar]

Hi Imureh,

I have owned my system for a year now, though the wharfe's were purchased only a few days back. We have enjoyed many movies and many hours of happy listening to music just by following the instructions on the manuals and with some casual reading on sites like this later.

This thread is an endeavour to understand better and reap advantage. Take your call.

All the very best.

 

[Shashi Kumar]

Confirmation from Deftech

This is just to inform that the above mentioned conclusions have been confirmed by Deftech. Thank you Ottomatic. Just to recap:
1. LFE in has no cross overs.
2.Line level R/L inputs has Low pass cross over.
3.Speaker level input has LP cross over for sub.
4.Speaker level output has HP fixed cross over.