Lowering the crossover point.

**bowtie427ss** · August 13th, 2012, 07:08 AM

It's the unwritten audio law of compromise Cradeldorf. It exists in some form in every step of the audio chain.

Everything we know in our tangible world is confined by basic laws of general physics. Speakers are no exception. In fact, speakers are in some ways a "bridge between worlds" where the laws of electricity meet the laws of kinetics.

**VolvoHeretic** · August 13th, 2012, 10:48 AM

Get a 418 guitar speaker run full range and use it as your center channel. Don't you have a left over OB?

**Cal Weldon** · August 13th, 2012, 11:40 AM

Hi cradeldorf,

I know just what you are thinking. I had the same thoughts come back and bite me. Aditya has done a nice job helping to explain the pressurizing thing.

I had made a little boombox with some small Jordan speakers along with vented woofer all in the same box. I didn't worry about the Jordans because there was a vent so how could the woofer cause excess cone movement in the Jordans when there was a great big port in there to relieve the pressure.

Well, long story short, bye bye Jordans, hello new project.

I am now wiser.

**aditya** · August 13th, 2012, 01:33 PM

Originally Posted by cradeldorf

Not an error....well apparently it's an error but not in the drawing. I meant to ask somebody about whether the cap should be before or after the attenuator. Thanks for the heads up.

Hi....thanks for the nice words.

I will suggest you to try out the xover again with the proper connections, but I suggest to use a 10mfd in place of 6.3mfd for the HF. The 1.5 mH coil can remain the same.
Pls try it out and see the outcome.

**aditya** · August 13th, 2012, 01:50 PM

Originally Posted by cradeldorf

I guess my argument isn't that I think the HF needs to be down to 1000 but that the LF doesn't have the ability to stay at 98-100db efficiency up to 1600. sounds like it's down to about 70-80db by the time it gets there and is leaving a huge gap in the loudness between about 1000 and 1600. Also going by 515 specs just because they have the same cone and voice coil I think isn't a very good decision either since about half the cone is robbed by a giant 6 inch felt dust cap behind the horn which coincidentally is also blocking the sound path as opposed to a normal 515 which has a much less restricted cone and 3 inch dust cap. It would be nice to have the ability to measure the actual response of the LF side of these things to get a grasp on how they are performing.

Yes you are quite right here about the differences between the standard 515 and the one in the 604. Yes, in the case of the 604, it will have a drooping o/p post 1K Hz compared to a standard 515. All the points that you have mentioned will have their influence. But I don't have any actual 'db' figures with me. But i think the combination that the 604 has with the Hf horn, it should be able to match it up. I have listened to them for nearly 2 years, and I am yet to find a substitute to be sounding so good and so full !

**zelgall** · August 13th, 2012, 06:12 PM

Also, I've read that the horn on a 604 doesn't provide loading below 1600Hz. That could be an issue for longevity of the diaphragm / voice coil.

**bowtie427ss** · August 13th, 2012, 07:37 PM

Originally Posted by cradeldorf

Your welcome buddy, I think I made Bowtie cringe a while back when I told him I'm running 30 ft runs of menards speaker wire to them.

I will try it your way and report back.

I filed a report with the Speaker Wire Police.

If your speaker wire runs don't add enough impedance to impart a negative impact, and can deliver the voltage and current your speakers need to satisfy you, then it passes my litmus test, even if it's household romex or the coily cord from your landline.

**donaldpatten** · August 13th, 2012, 08:21 PM

I got some clear zip speaker wire, at Menards , that only had half the number of strands. So my # 16 awg was in fact # 19.
It was under the Phillips brand.

Don

**aditya** · August 13th, 2012, 11:50 PM

Originally Posted by cradeldorf

I like Hiraga's ideas about the 604.

The 604 was designed keeping studio-monitoring (point source) in view. Any attempt to highlight the lows specifically will create imbalances. Also it can sound boxy pretty easily. So any enclosure careful of this will perform well. OB is definitely a good choice here. Or a BR with an almost IB-ish approach will also do well.