POWERED TOWERS, and a taste of what is to come (1 Viewer)

[Bob_A]

***A TASTE OF WHAT IS TO COME***
I am going to test out my powered towers tonight. First I will turn down the volume of one of the built-in powered woofers (while keeping the other built-in woofer's volume at my normal position of 1 o'clock on the dial) and play my favorite music. Second, I will turn the volume back up to 1 o'clock (so that each built-in woofer is set at the same volume again).
Let me know if there are any major problems or concerns with this test.
Others owners of powered towers should also try this out.
Def Tech's internal crossover is set at 80Hz. My DSP-A1's crossover is fixed at 90Hz. I use no external sub. My speakers each have two 1 inch tweeters, four 6.5 inch midrange drivers, and one 15 inch woofer. I have wired my woofers via "full range low level in" on the speaker, to the "pre out" and "main in" on the receiver. I am not sure if the receiver has overrided the internal crossover of the speaker. If anyone has information about this, I would much appreciate any info you can give me.
It has been said that all frequencies below about 80 or 90 Hz are nondirectional. So if I turn down one of the woofers, in theory it should not make a huge difference correct? Maybe there will even be an improvement because there is only one woofer playing, which means no cancellation? But on the other hand, will the smoothness and coherence of sound still be evident?
Later tonight, we shall see...we shall see

 

[David Giles]

Better yet, wear a blindfold, let someone else do the adjustments for you, and see whether you can detect "directional" bass. Then when you're satisfied with the blind test, use an SPL meter to check to see if the output actually improves due to reduced cancellation. Should be interesting.

David

 

[Tom Vodhanel]

>>>It has been said that all frequencies below about 80 or 90 Hz are nondirectional.

 

[Andy Watts]

It has been said that all frequencies below about 80 or 90 Hz are nondirectional.

 

[Bob_A]

This will not be a scientific test. This will be a subjective test using only music program material which is very familiar to me. I am mainly concerned about the overall presentation, not really about directionality.

 

[John H]

I am mainly concerned about the overall presentation...

I would consider that by shutting off the woofer in one of your mains you will be significantly decreasing bass output. Wouldn't you want to compensate by raising the gain on the active unit?
I calibrate my powered subwoofer sections with Avia cycling high and low tones.
When I play a dedicated subwoofer test tone through just both main speakers (no external subwoofers) and disconnect one I loose 6dB overall output.
John

 

[Bob_A]

I'll try increasing the volume of the other unit and see how it goes.

 

[RichardH]

Ummm, don't know if you've addressed this correctly, but are you feeding the powered woofers a mono bass signal? Because if you're feeding each powered woofer a different signal, then more than likely you'll prefer the stereo bass over just the right channel's bass.

 

[Bob_A]

I am pretty sure it is a mono signal and that both channels get the same signal.

I'll post my impressions in a couple of hours.

 

[Brian Bunge]

I am pretty sure it is a mono signal and that both channels get the same signal.

Bob,

From your explanation above it sounds like you are using your main L/R output to the towers and then running their outputs back to the main ins on the receiver. Is this the case? If so, it doesn't sound like each tower's bass section is receiving a mono signal, but rather the independent L and R signals. This could make a big difference in the sound, IMHO.

Why not spend the $50 to get a SPL meter and a disc with test tones so you can actually take measurements with one internal woofer off, then with both on and compare the differences. This will be much more conclusive than a subjective test.

Brian

 

[Bob_A]

Yes, I think that would help.

Posted from the other thread:

To simplify a little, let's say we have two nOrh bookshelf-type speakers, along with two nOrh subs (which can be used as stands for the nOrh loudspeakers). Use your favorite music program material. Set the speakers to "small", and cross them at 80Hz or 90Hz (internal to speaker or external from receiver, I do not know what would be better). First listen to music using a sub for each main channel (meaning one sub as a stand for the left speaker, and the other sub as a stand for the right speaker). Then listen to music using two subs for one channel (meaning both subs are together and are either used underneath the left speaker or underneath the right speaker. Heck, you could even compare them with both of the subwoofers placed next to each other in the same corner. Does this seem plausible?