KG 4.5's boomy with new receiver, but fine before?

[Jkaput]

Hi folks,
I recently replaced my Nakamichi AV-2 with a Sansui 2000x and am surprised at the results. For a long time I wanted to jump into the classic silver face stereo scene, but nothing came up that was a good deal. The Sansui was in great shape cosmetically and almost dust free inside. I did need to clean the pots, but after that its running well. But after all the fanfare this unit receives, for some reason, to me it doesn't sound as good as the Nak.

Here's how I have it setup. I have a Adcom GFS-6 speaker selector with two Klipsch KG 4.5's and a pair of Cambridge Audio S30's in the main room. In separate locations and on separate switches on the selector I have a small Jamo SAT-300 and a pair of ADS AW-4's.

I am new to this stuff, but am enthusiastic to get started. In my humble opinion, the AV-2 sounded great - it pushed the Klipsch's just enough and the bass produced sounded rich and full. Highs were good, mids as well. It was a stellar sound. Now, I always wanted to try to go more vintage and had great experience with a Sansui in college. What I ended up with makes the Klipsch's sound very boomy, even if I select only them. I guess I would describe the sound as thin, especially if I try to pare down the bass. The Cambridge's sound fine.

I really don't know how to proceed, and honestly, I'm pretty bummed that this is the outcome after all these years of looking. Does anyone have any thoughts on what to do about this? I would really appreciate the advice.

Thank you so much in advance.

 

[isotopesope]

That Sansui has a really low damping factor of 24, which would contribute to the booming bass. I can’t find the damping factor spec for your Nak... are you using the loudness switch on the Sansui? That could be making it worse... I wonder due to the age of the Sansui if it’s in need of service and a recap.

I also noticed the Sansui only has 39 watts, versus the Nak’s 70. You might be straining the Sansui further getting your speakers to the same SPL with the lower wattage?

 

[uteman1011]

I've tried Pioneer, HK, Yamaha, Kenwood and Onkyo on my Heresy I, KG 3, KG 2.5 and Cornwall II's. Each Amp has it's on personality on each speaker pair. I loved the HK and Kenwood's on the KG 2.5 and KG 3 but not the Heresy. The Pioneer SX-737 really woke the Heresy and sounded fantastic, but didn't work well on the KG 3. The Pioneer didn't do nearly as well on the Cornwall's in comparison to the HK870 Amp with HK825 Pre.
Point is; there is some trial and error with the vintage systems to find the right sound.

 

[Jkaput]

Thanks for the replies. I have heard from others about caps considering the age of the unit. I'll look into it. There are a bunch in there!

I had read on AK that the 4.5s were a good match for the 2000x, so I was stoked to check them out together. They do sound good playing some stuff. For instance, Paul Butterfield sounded great. Other records too. But bluetooth from spotify...not so much.

 

[isotopesope]

Thanks for the replies. I have heard from others about caps considering the age of the unit. I'll look into it. There are a bunch in there!

I had read on AK that the 4.5s were a good match for the 2000x, so I was stoked to check them out together. They do sound good playing some stuff. For instance, Paul Butterfield sounded great. Other records too. But bluetooth from spotify...not so much.

Do you have a local tech that could go through the Sansui?

The Bluetooth performance could also be due to the onboard DAC on the BT receiver.

I too appreciate the silver face receivers. I have a H/K 730t that sounded great with Klipsch, though I now use McIntosh separates in my main 2 channel system. Perhaps you should consider running a more powerful separate amp and use the Sansui as a preamp. You should probably have more power to run two sets of speakers effectively.

 

[Jkaput]

Thanks Isotopescope - Can you explain what you mean by 'onboard DAC on the BT receiver' (BTW, it was great through the Nak)

Any thoughts on an affordable amp?

 

[isotopesope]

If your BT receiver sounded good on the Nak, it makes me suspect of the Sansui’s health...

If you’re using the RCA outs on the BT device to a stereo receiver, the sound output is coming from the BT’s on board Digital to Analog Converter... but again, if it sounded good on the Nak, something in the Sansui could be out of spec.

If your BT receiver has a digital out, then you could bypass its internal DAC to an separate external one.

In terms of a separate amp, you may want to weigh your budget against what your existing Sansui may cost to get it back to health vs perhaps investing in a more powerful receiver in better health... but anything vintage is likely to need work, unless you find a refurbished or at least fully tested unit.

 

[Guido57]

My experience: I've recently acquired a set of 4.5s. I recapped them and installed Crites diaphragms on the tweeters. On first listen after this work I found the bass to be muddy and boomy. Switching to a lower power but higher damping amp eliminated much of this. I might have liked them at this point but they still did not have the resolution and tight bass of my reference speakers. Putting some very loosely packed fiberglass provided some more improvement but not to the level of the reference. They will be an ongoing project, at least for the immediate future.
Note: the caps and Crites diaphragms made a significant improvement in the upper mid range and treble.

 

[Jkaput]

Thanks for the info! Im a little confused as to what to order there part number wise. Can you give me the exact names? I wrote to them but haven't gotten anything back.

My experience: I've recently acquired a set of 4.5s. I recapped them and installed Crites diaphragms on the tweeters. On first listen after this work I found the bass to be muddy and boomy. Switching to a lower power but higher damping amp eliminated much of this. I might have liked them at this point but they still did not have the resolution and tight bass of my reference speakers. Putting some very loosely packed fiberglass provided some more improvement but not to the level of the reference. They will be an ongoing project, at least for the immediate future.
Note: the caps and Crites diaphragms made a significant improvement in the upper mid range and treble.

 

[Guido57]

Crites recommends and sell SonicCaps. Somewhere on his site he explains his reasons. As I had other parts to buy for other projects I got Jantzen and Solen caps for mine. Maybe not fully up to the level of the SonicCaps but not shabby either. Cheaper too. There are two crossover versions for the 4.5 and Crites recommends staying with the version you have. The difference is in the tweeter circuit. Older version has 2.5 and 3uF caps, newer I believe is a 2 and 8uF. You need to remove the woofer to see what you have. Note the 33uF cap is a bypass for the woofer and should be replaced also. If you email Crites through their website and tell them what you want they'll most likely email back a link that will directly lead to a purchase for the parts, at least that is how my transaction went. If you decide to go with the SonicCaps you just need to order the rebuild kit and the titanium diaphragms and not worry about ordering the caps individually. Note the kit also includes new poly-switchs that are the tweeter protection. As far as I can tell they don't really use part numbers. If you have enough cash to pay for the workmanship, don't know how to solder and don't want to learn you can also order completely new crossovers from them, (you get better inductors too).
https://critesspeakers.com/

 

[Guido57]

Update on my pair of KG 4.5s. Putting 3" of rockwool on the bottom, along with the loosely packed (3" fiberglass) and higher damping amp brought them close enough to the level of my reference that the difference is more of a preference issue. Note: amp used has a damping factor of 150.