Yamaha 8" speaker replacement

[shufflebeat]

I have a couple of old Yamaha msr100 powered speakers, one of which has developed a nasty growl. A new replacement driver looks uneconomic and could take months for parts, a recone may or may not be possible.

There is a version of the Stagepas (300) which uses what looks like a similar 8" low driver.

Anybody got any insight as to whether parts are interchangeable or whether there's another 8" that'll do the job?

[Wonks]

They share the same HF driver, but the woofers look different.

Yamaha AAX4222R for the MSR100

Yamaha AAX6165R for the Stagepas 300

MSR100 driver here, but as you say, it's expensive, about £109 with VAT.

https://www.proaudioservice.co.uk/produ ... -aax4222r/

The performance of the enclosure will be heavily reliant o the T/S parameters of the driver, and without knowing those, I wouldn't really like to speculate what may be suitable.

Probably cheaper to look for some used Alto TS308s or TS310s, which you can get for around £200-250 a pair if you look around and get lucky. They are often well overpriced (often more than available new) .

[shufflebeat]

Thanks for that. I've been in touch with PAS and got the same numbers but parts aren't immediately available, est. 3 months delivery time.

At the minute I'd be prepared to compromise sound character on both soeakers for something useful that won't pull itself to pieces.

It may be unrealistic but otherwise I have one elegant doorstop.

Alto has already had some of my money and won't be getting any more.

[Wonks]

Have you tried turning the speaker round by 180°?
Sometimes gravity will cause the cone to sag downwards, and the voice coil can then start to catch. Rotating the driver can sometimes offset this.

Otherwise, do you know what the speaker ohmage is? I’d assume 8 but you never know. Can’t see any obvious values printed on the chassis in the pictures.

[Wonks]

The other consideration is the space available within the speaker enclosure. There’s this £45 Celestion 8” driver, https://www.lean-business.co.uk/eshop/c ... 9qgt52msq5 but its magnet looks a lot wider (but flatter) than that of the Yamaha’s. Depth can also be an issue as the amp PCBs can often be mounted directly behind the speaker.

[shufflebeat]

Thanks W, I know it's irrational but I have a soft spot for the name Celestion.

At first glance I think there's enough space to accommodate that but will get the divining rod out and check.

Should I expect to see any kind of false reading on the meter if the coil is damaged but intact?

[Wonks]

It’s obviously working, so you should measure the normal DCR reading. if there was a short between two adjoining coil windings, then you’d hardly see any difference in the readings. A short to ground would probably cause any short circuit protection in the amp to kick in and the speaker not work at all.

An open circuit is the most likely other sort of reading, but as the speaker makes a sound, that’s very unlikely.

[shufflebeat]

Speaker is reading 5.7 ohms, not a number I was expecting but it's consistent pre/post a good jiggling shake so I'm thinking there's no temporary situation going on.

I'm reading this as an 8ohm speaker unless advised otherwise as it seems relatively safe to err on the higher side if I must. The original was advertised as a "custom" driver but I'm not sure if that extends to a custom impedance.

Another thought comes to me. As the original is a foam surround with apparently quite a long travel is it worth considering something similar rather than a paper surround which I would think has a much stiffer response and shorter travel.

As you might guess I'm way out of my comfort zone here.

[Wonks]

That's about normal for an 8 ohm speaker. Its impedance varies with frequency and any audio frequency signal will see a higher value than the DC reading.

'Custom' drivers are often only marginally different to standard range drivers, often only 'custom' because it's got a different sticker on the back or the assembler's own part number on it. I wouldn't worry too much about it.

No idea about the foam. Without knowing the T/S parameters of the original driver and comparing them with the Celestion's, then you'd be guessing as to what the differences may be. The overall efficiency of the MSR100 should have been 92dB for 1W input (based on 112dB for 100W). The Celestion is quoted at 94dB for 1W, so it may in fact have more travel than the original speaker, as its got to shift more air to be that bit louder. The speaker diameter is the same so the overall movement of the Celestion must be greater.

You'll end up with the speakers sounding a bit different anyway and 92dB vs 94dB isn't enough of a difference to worry about.

[Murray B]

As a MSR100 fanboy (despite their limitations) , I am wondering if it's worth you buying another second hand MSR100 - there are a couple on eBay for the same price as a new driver. Your problem speaker could then act as a future pars donor?

If you decide to get some new speakers instead I might be interested in taking the old ones off your hands. They make very nice monitors - just wish they had an XLR through / link to save me using splitters.

[shufflebeat]

Food for thought.

I shalll peruse my options, cheers Guys.

@Wonks, thanks for the guidance. Very helpful.

[iamtvi]

I realize this thread is old, but I'm in the same boat as you were. I have two working MSR100 speakers that need new woofers. I don't mind using aftermarket ones, as long as the specs are similar. I'm trying to avoid spending $120 on Yamaha's direct replacement offering (AAX4222R).

https://encompass.com/item/8309442/YAMAHA/AAX4222R/
https://www.fullcompass.com/prod/079449 ... for-msr100

Thanks, in advance!

[iamtvi]

So far, my search goes on. I have learned some information which might help someone else in the future.

I don't have a clear alternative for the AAX4222R (the MSR100 woofer replacement speaker from Yamaha) yet, but I'm still looking.

If your cone is not actually ripped, or your voice coil is not blown, one thing that's possible if you have a lot of time is to replace the edge with a repair kit. It's basically, carefully removing the old edge, and gluing new edging and gasket in place.

If you still want to replace the entire speaker (easy and inexpensive provide we can find the right one) you'll need to find a speaker that has a measurement of 200mm diagonal center on the holes (7-7/8 inches).

This is where I'm having the biggest challenge. None of the inexpensive speakers you can get on Amazon or parts-express seem to have those mounting dimensions, and I'm not willing to drill new holes (just yet).

[iamtvi]

OK I can confirm that the Skar FSX8-8 speakers are a precise fit for the MSR100. The mounting holes lined up perfectly.

After several hours of playing programmed music through them, I’ve had no problems. They also make a four ohm version of this so make sure you get the right one.

https://www.skaraudio.com/products/fsx8 ... ge-speaker

I can’t discern any difference between these and the OEM speakers. If anything, they sound a little better. Be patient and give them at least an hour break-in period. The cones are fairly stiff right out of the box which isn’t a bad thing, but it may not produce quite as much air movement right away.

[Drew Stephenson]

Sounds like you've got a result. Thanks for confirming.

[iamtvi]

I almost forgot to mention the best part: I bought these speakers for ~$21 each on Amazon. I got free overnight shipping from Amazon Prime, so it was great to get them the next morning.

I checked today, and the price went up to $25.99, so maybe they decided they were under-pricing them, but still, $26 for a decent replacement for Yamaha's $125 price is a bargain.

Skar's website still lists them for 20.79, with no tax and free shipping, so that's definitely the place to buy them now.

https://www.skaraudio.com/products/fsx8 ... DyEALw_wcB

[shufflebeat]

Hi iamtvi,

The original post was mine and I spotted yours the other day. Sorry for the delay in responding, end of January is always a bad time to get sidetracked into potential rabbit holes.

Great to hear your progress. My own quest hit a bit of a dead end except for a trip to a speaker specialist in town which I never got round to making as I've only needed one of the speakers.

Once some dust has settled here I'll explore your suggestion, might save myself a trip after all.

Big thanks for posting back.

[charliestevens]

Hey guys, I know this is an older thread but did anyone find an equivalent of the AAX6165R? This thread is the one of the only results that pops up online when you Google the model! Thanks in advance