Axiom Home Page Forums General Discussion Technical Questions Using Two Subs

Hello everyone

As some of you know I am waiting for the Aussie dollar to go back up so I can get the EP500.

But the wait is killing me. The I had a brain fart, why don't I drag out my old sub and hook that up with my current one?
I have a Sony SA-W90, it's only 70w but I figure if I connect that as well as my little Sound Dynamics it should give me a little better bass?

I plan to get a RCA splitter and run that from the Yamaha 661 out to both subs, using coax.

Is there anything I need to be aware of?

Thanks

You will have to do a little calibrating to get the levels right, and play around with positioning. Are you placing them across from each other, or along the same wall? When calibrating the SPL on them with the other speakers, do them one at a time, then turn them both on...

I don't have an SPL meter. I was going to use the auto setup on the 661.
I may have to look at getting one though.

Ok I see that Dick Smith have SPL meters, Annalog is $50 and the Digital is $100.

Which one is ok? And how do I use it?

I assume Dick Smith is a store?

I got mine at Radio Shack, probably don't have them in your neck of the woods.

I like the analog ones, but digital is ok as well. The main purpose of them is to get all your speakers at the same Sound Presure Level in dB's by running test tones or your receivers pink noise in the setup menus. The auto setup in receivers does a pretty good job, but not sure it would work well to calibrate multiple subs.

I usually just go into the receivers setup menu and kick off the manual test tones and adjust all the speakers and subs to about 75-78dB's. With multiple subs, do them one at a time, then turn them both on...

Here is a good article on how to use a meter.

http://www.audiophilia.com/hardware/spl.htm

Graeme, the analog meter at Dick Smith's is the analog RadioShack meter. In the past I used both the analog and digital RS meters that colleagues had and found the digital meter to clearly be more useful, so I bought one. Numbers are easier to read than a moving needle and additional measurement modes, particularly a max/min measurement, are available. The digital RS meter apparently isn't sold directly in Australia and the one available at Dick Smith's advertises a measurement range of 300-6000Hz. If correct this would make it less suitable for audio purposes, although that range is appropriate for measuring hearing damage possibility in the workplace. This unit for AU$99.95 would appear to be more suitable, judging solely from the written description(I have no knowledge of it).

An SPL meter is nice to have for seeing what sound levels that you're actually working with, but for simply calibrating speaker levels the built-in meter in the Yamaha and many other receivers does a fine job, so you might try that first, even as to the two sub calibration.

Thanks for the info, I am wondering if it would be worth the money to have a professional come in and do it.

The reason I say this is because I have been trying to do a little research on the net and have been reading about things such as calibration DVD's as well as the SPL meter. I figured that if I was going to outlay a couple of hundred on this stuff then why not just pay to have it done properly.

I would assume it would cost me around $200 - $300 for a professional.

From what I've heard/read it may make sense to calibrate the video that way but not necessarily the audio--because video calibration DVDs may be surpassed by professionals with video calibration equipment which may not require additional tweaking to suit your taste whereas you may have to tweak the audio on multiple occasions to address changes in your HT room and to suit your own taste across time/program content in which case you're better off doing the audio setup yourself because you'll have to learn how to tweak things eventually anyway. Someone else may be able to explain better but I think it goes something like that . . .

That is pretty much the way I see it as well. Learning how to set up the audio portion of an HT is relatively easy and once you get the hang of it, you can adjust it for any reason required, sometimes to the point of driving yourself insane with tweaking this and that looking for the last tidbit of extra sound possible.

The video portion can even be done by yourself to a certain extent, as there are a couple of sites on the web that have professional calibration settings listed for flat panel tv's.
Tweak TV is one of them

Well I will have to look at getting a DPL and then I have to figure out how to use the thing.

Thanks for your replies