Silly mistake

squidlydeadly · 02:49 AM

Hi,

I've built my first 2-way project (original thread here) and I like how they sound so far although they are a bit bass shy.

Anyhow, as an impulse buy I ended up buying a Yaqin Vk-2100 hybrid amplifier off ebay to drive them and noticed right after the unit had shipped that it only handled 8 ohm loads. After contacting the seller he mentionned that it does not like 4 ohms loads and runs really hot and could get damaged.

I've been googling all day to find a solution to this and see if there was any way to change the impedance load of my towers (my first reflex was to simply add a resistance in series) only to realize that things weren't that simple.

So here's the question: Is there an easy solution to this, besides selling the amp and buying one that handles 4 ohms loads? Could I use an l-pad for he fr125s to help with the bass shyness and "adjust" the impedance load at the same time (at least increase it a little to make it easier on the amp)?

Thanks in advance!
E.

infinia · 1st August 2010, 05:46 AM

How do you arrive at 4 ohms?
I think you are OK if your crossover network isn't competely wonked.. Dont you have an EQ for bass?

squidlydeadly · 07:22 AM

Hi,

Unless I'm mistaken (and I can very well be since I'm new at this) the fr125s has an Re of 7 ohms and the impedance curve is fairly flat over the crossover point, same for the sdx7 at 6.4 ohms and both are connected in parallel that would be around 3.something ohms.

As far as my crossover being wonked that's also a possibility

however I went with a first order XO to try and not mess it up to much.

The amp as a loudness comp but no EQ.

Funny story: I took me a while to figure out why no sound was coming out of the sdx7... I didn't know you had to strip the red coating of the inductor wires

Live a learn I say :-)
E.

infinia · 1st August 2010, 08:17 AM

Yea that the whole purpose of crossovers, they are not really in parallel.

planet10 · 1st August 2010, 08:34 AM

The speaker will be a comfortable 8 ohms.

Because of the XO the SDX7 has a very high impedance above the XO point.

Because of the XO the FR125 has a very high impedance below the XO point.

A very high impedance in parallel with 8 ohms is 8 ohms.

dave

squidlydeadly · 1st August 2010, 03:03 PM

Wow ok.

Didn't think I was missing the boat that much....it makes sense though...I think

...back to reading!

Thanks guys. At least my "problem" is solved!

E.

1st August 2010, 02:47 AM	#1
squidlydeadly diyAudio Member Join Date: Oct 2006	Silly mistake Hi, I've built my first 2-way project (original thread here) and I like how they sound so far although they are a bit bass shy. Anyhow, as an impulse buy I ended up buying a Yaqin Vk-2100 hybrid amplifier off ebay to drive them and noticed right after the unit had shipped that it only handled 8 ohm loads. After contacting the seller he mentionned that it does not like 4 ohms loads and runs really hot and could get damaged. I've been googling all day to find a solution to this and see if there was any way to change the impedance load of my towers (my first reflex was to simply add a resistance in series) only to realize that things weren't that simple. So here's the question: Is there an easy solution to this, besides selling the amp and buying one that handles 4 ohms loads? Could I use an l-pad for he fr125s to help with the bass shyness and "adjust" the impedance load at the same time (at least increase it a little to make it easier on the amp)? Thanks in advance! E. Last edited by squidlydeadly; 1st August 2010 at 02:49 AM.

1st August 2010, 05:46 AM	#2
infinia diyAudio Member Join Date: May 2005 Location: Californication	How do you arrive at 4 ohms? I think you are OK if your crossover network isn't competely wonked.. Dont you have an EQ for bass? __________________ like four million tons of hydrogen exploding on the sun like the whisper of the termites building castles in the dust

1st August 2010, 07:17 AM	#3
squidlydeadly diyAudio Member Join Date: Oct 2006	Hi, Unless I'm mistaken (and I can very well be since I'm new at this) the fr125s has an Re of 7 ohms and the impedance curve is fairly flat over the crossover point, same for the sdx7 at 6.4 ohms and both are connected in parallel that would be around 3.something ohms. As far as my crossover being wonked that's also a possibility however I went with a first order XO to try and not mess it up to much. The amp as a loudness comp but no EQ. Funny story: I took me a while to figure out why no sound was coming out of the sdx7... I didn't know you had to strip the red coating of the inductor wires Live a learn I say :-) E. Last edited by squidlydeadly; 1st August 2010 at 07:22 AM.

1st August 2010, 08:17 AM	#4
infinia diyAudio Member Join Date: May 2005 Location: Californication	Yea that the whole purpose of crossovers, they are not really in parallel. __________________ like four million tons of hydrogen exploding on the sun like the whisper of the termites building castles in the dust

1st August 2010, 08:34 AM	#5
planet10 frugal-phile(tm) diyAudio Moderator Join Date: Oct 2001 Location: Victoria, BC, NA, Sol III Blog Entries: 4	The speaker will be a comfortable 8 ohms. Because of the XO the SDX7 has a very high impedance above the XO point. Because of the XO the FR125 has a very high impedance below the XO point. A very high impedance in parallel with 8 ohms is 8 ohms. dave __________________ community sites t-linespeakers.org, frugal-horn.com ........ commercial site planet10-HiFi p10-hifi forum here at diyA


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1st August 2010, 03:03 PM	#6
squidlydeadly diyAudio Member Join Date: Oct 2006	Wow ok. Didn't think I was missing the boat that much....it makes sense though...I think ...back to reading! Thanks guys. At least my "problem" is solved! E.

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