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

Well I just bought it. be prepared for questions

Here in the Good 'Ole USA, a Gunsmith is a place that works on your gun.

I don't know WHAT the hell is going on down under....!

There's another straight line for someone....

That just cracked me up It is indeed a store, more for electronics

Full appreciation of a finely tuned instrument.

All this talk of down under has me yearning to go back for another extended visit.

Road Trip!

I wish. I have to win a lottery first, which means I have to actually buy a ticket...

Oh, that reminds me. I was going to have a "Win a Date With CV" contest at work, and the beauty of it is that the girls don't even have to enter to win.

But you can still set it up with a very thorough application?

Apply liberally?

Hey! No Political Talk here!

Is that a clever way of saying "no lying here!" or something?

No... If we talk Politics, an Instant Fight will break out!

It's okay. If we all pray to the one true god, violence will be avoided.

Yes, let's pray to Ian-Tom, the Binity of Audio.

One day (when I win Lotto) We might get to the States.

I nominate CV for hijack of the month.

Graeme. Maybe you can find someone to swap a house with for a month (preferably equiped with M80s and an ep800).

Maybe one day.

I was only half kidding in my last post. There are people who do this as a way to go someplace they could otherwise not afford to.

My trip to Australia was probably a once in a lifetime event, something I had always dreamed about. I am glad I had the chance.

Graeme, hope you get your chance to travel to North America.

I hate to hijack this thread, but I'm receiving my second sub today , an EP500 to go along with my EP350. I don't have a SPL meter, but I do have EZset/EQ I can use on my HK 247.

My question is, how would I use that in a two sub calibration? Do I need to have both subs on and set to about 9 o'clock on both of the dials? Or does one need to be set a little more "hot" then the other before hitting the calibrate button?

I think it will be a little difficult to get them both dialed in using an autosetup method. I calibrate each of my subs seperately with the other shut off with my Radio Shack meter, then turn them all on.

If both subs were the same then I think the autocalibration would be close, as the 2 subs are different, it may have a hard time setting them. I would be shopping around for an SPL meter, they are not expensive and an indispensible tool for an HT enthusiast.

Also, if the subs are near each other it would be better, but if you have them across the room from each other, I don't think it will calibrate well.

Thanks for the advice, I'll go to ratshack and pick up a meter. Both of the subs will be located on my front wall about 10 ft from each other. Thank you for the help guys!

Besides, an spl meter is a critical tool in the audiophile world. You can't be a jedi withouth the light sabre!

Your falling granny avatar kills me every time I see it. Is that what the jedi call collateral dammage?

Lol!! Thanks! There's another one I've seen where Obi-Wan is force pushing some goats. It's pretty hilarious!

Sure, it's good to get the SPL meter, but even with different subs well-separated it's possible to auto-calibrate with one sub at a time working, then afterwards reduce each sub by 3dB on the receiver sub trim setting so that the overall balance will be the same with both working.

Ok, I did some rearranging in my basement on my subs (EP350 and EP500). I first put them two on the front wall under my projection screen.

I don't have a radio shack spl meter yet because the one here in my town don't have one. So I'm going to have to wait a little bit before I get one.

Anyways, it sounded to my ear good, but not spectacular, after doing numerous eq'ing with my HK ez setup. So I watched the video that Ian provided and decided to set both of my subs on adjacent side walls in my basement, like what Ian suggested. I did the automatic setup from my receiver to get the right db levels from all of my speakers then I manually set my crossover points to what sounds good to me. (80hz on center, surround and back surround. 60hz on my mains)It sounds 10 times better now.

Now onto my question. My EP500 was doing fine for a couple of weeks in it's new position. Then lately( it started last friday ), at certain frequencies, there will be a slight vibration coming from it. I put my ear up to the sub, but I can't tell if it's coming from the driver, or within the cabinet. I don't have any kids or any animals, so I don't think anything got into the port. Any help would be appreciated! Thank you!

Ascension - first things first, you need to update your signature now that the 500 is in.

On the vibration, sometimes wires come loose inside near the driver. If they hang close to the woofer, they can vibrate when the woofer moves and cause sounds like you are hearing.

If it's bothering you enough that you feel like removing the woofer, it's fairly easy to check to see where the wires are hanging.

Jason

I will do that! Thanks for the tip Jason, I appreciate it! Plus the signature is now updated. LOL!!

Great, it looks much better this way. I can't wait to update mine!

Um, more like...

<- mryson........us ->

Thanks Fred, maybe looking at it that way will help. Noreen told me last week that the parts "might" come in this week... fingers crossed.

I hope I hope I hope.

I bet you can't wait! I can't wait to hear your impressions on that bad boy!