Jump to content

Bridge Mode for KG-4s?


Recommended Posts

I have two pairs of Kg-4s that I'm considering powering with two Harman Kardon Citation 19 Power Amps.  The Citation 19's can be operated in bridge mode so that both channels operate as one.  HK warns against operating in bridge mode for speaker loads at 4 ohms since it may cause the amplifier's current limiting circuits to operate and distort the signal.  The KG-4 is rated at 6 Ohms.  If I operate both amps in bridge mode (one for each channel), but with two speakers per amplifier, will this potentially cause a high-current situation?  The manual says each amplifier will deliver 3.7 Amps to a 16 Ohm load, and 6.3 Amps to a 8 Ohm load in bridge mode.  If yes, should/ can I add fuses between amplifiers and speakers?  Thanks!

Link to comment
Share on other sites

Hmmmm, if I recall correctly 2 6 ohm speakers connected in parallel on 1 channel would give 3ohms...that could be an issue with that amp.

goto 5:30 for the part relating to you situation..but the whole vide is informative

Edited by RadBlue
added link,and timestamp
Link to comment
Share on other sites

Acually I'm pretty sure you would fry something if you tried it that way. You may want to try a Y splitter for each channel off the pre-amp so you could use 2 left channels and 2 right.

Or..get a pair of pro-amps that can do 2ohm, many of them can

Edited by RadBlue
Link to comment
Share on other sites

Thank you everyone for your replies.  Circuit Analysis course was 35 years ago for me, and very little of it was applicable for me back in the day.  Hey, now it makes sense.  I had no idea you could even connect speakers in series.  Looks like I will need to buy more speaker wires since I will require 3 runs per channel (but only using one half of each run - ugh).  I can only assume that all wires should match, so I will need to buy another pair of same wire I am using.  Thanks again!

Link to comment
Share on other sites

Since you have 4 speakers and 4 amp channels, your best option is to power one speaker with one amp channel.  Wiring speakers in series increases the apparent output impedance of the power amp and lowers its damping factor by a large amount.  You will get sloppier bass that way.  Bridging a power amp doubles it's power output into a given load, but no more.  Then, dividing that power into 2 speakers takes you back to one amp/one channel in terms of power, but with higher distortion levels and the chance of overheating the amp(s), depending on amp design and speaker impedance.  KG4s are very efficient and likely need only 2 or 3 watts for loud listening indoors. 

 

These adapters are an clean, easy way to parallel 2 amps on one preamp. 

https://www.amazon.com/dp/B01H9QW6FY/ref=sxbs_sxwds-stvpv2_1?pf_rd_m=ATVPDKIKX0DER&pf_rd_p=3524794302&pd_rd_wg=1eywu&pf_rd_r=EQE2AC1HM0M8RAJD4X5G&pf_rd_s=desktop-sx-bottom-slot&pf_rd_t=301&pd_rd_i=B01H9QW6FY&pd_rd_w=gsjqq&pf_rd_i=rca+Y+adapter&pd_rd_r=8f2f0e24-160c-491e-8f8f-54461736c45d&ie=UTF8&qid=1522858614&sr=1

 

 

RCA Y.jpg

 

Paralleling 2 power amps on one preamp channel drops the impedance of the load in half, just like parallel speakers, but line level impedances are so high (~47k ohms) and preamps are so tolerant of a very wide range of load impedance, it will not cause a problem. 

Link to comment
Share on other sites

John, thank you for your reply.  If I understand you correctly, I would simply install the Adapter on the input of one Amplifier, and then interconnect each Adaptor with the same channel on the other Amplifier?  This certainly would be a cleaner set-up, especially for a 2-channel home audio system.  Other than high line level impedance, will there be any "degradation" by splitting the signal out of the Pre-Amplifier?

Link to comment
Share on other sites

Wow. I just learned that my Pre-Amp, an HK Citation 17s, has two sets of Power Amplifier outputs.  The manual even says that two Power Amplifiers may be used at the same time as long as the input impedance of the Amplifiers exceeds 2200 Ohms.   I guess I way-over complicated this.  I did learn allot though, so thanks again!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...